Advice please; Passive pre.

[Haselsh1]

I need a passive preamp to power my Samson Servo 600 power amp. Two or more inputs, one volume control, one input selector and any number of line outs. Must be no more than 400 notes. Do not need a remote on any of it, I'll just shift my arse.

[Lee Henley]

Why not get a Tisbury, very very good for the money

[Audio Advent]

Whilst I've never heard one, the one for sale on this very forum looks interesting at least: http://theartofsound.net/forum/showthread.php?44059-Remote-control-passive-preamp-with-HT-bypass asking £350.

Or for about the same price new, you could buy the Khozmo stereo passive with remote control ~ $499 / £350 + shipping : http://www.khozmo.com/stereo_selector.html

[Haselsh1]

Loving the look of the Tisbury but prefer the look of the Khozmo however that one would incur extra import costs would it not...? It still wouldn't be expensive though as I don't want remote operation.

[struth]

A tvc might be possible on your budget. Ive found them to be superb pres.

[Arkless Electronics]

+1 for the Khozmo.

[Ali Tait]

If you can solder, get some of Dave Slagle's autoformers. Probably one of the best audio bargains out there. Took mine to the last NEBO where it was well liked.

[Macca]

At NEBO, although it was hard to tell because of the valve power amp being used, I thought Ali's was the best of the transformer passives. None of them gave anything away to the NVA P90SA which is a lot cheaper than most of them (possibly not Ali's) although at £600 it is outside your budget.

The Tisbury is good for beer money but you can - and should - get something better.

[Ali Tait]

Have had a P90SA in the past, I'd say the Slagle is better.

[walpurgis]

A tvc might be possible on your budget. Ive found them to be superb pres.

I use one. It's the best sound I've had from my system. I've used all sorts of passive and active pre-amps, but none came close to the TVC. Still got my VTL valve jobbie 'cos I like it and it has a great phono stage, but the TVC beats it hands down.

[walpurgis]

If you can solder, get some of Dave Slagle's autoformers. Probably one of the best audio bargains out there. Took mine to the last NEBO where it was well liked.

How did you source your Slagle autoformers Ali? I've looked on his site and there's no sales bit. He just discusses the product.

[Ali Tait]

Here you go-

http://www.intactaudio.com/atten.html

[Audio Advent]

Loving the look of the Tisbury but prefer the look of the Khozmo however that one would incur extra import costs would it not...? It still wouldn't be expensive though as I don't want remote operation.

Khozmo is from Poland so all within the EU.

Are you SURE you don't want a remote? Other than cost, why not? Can't do any harm - you can still get up and turn a knob if you want but having to get up because some loud passage or there's a sudden need to turn it down completely disturbs the listening in my view.

That coming from someone who wishes their pre was remote controlled, more for differences in loudness from internet sources than anything else and turning down those add breaks too!

[Haselsh1]

Soldering...! Are you joking...? Mine would look like melted butter.

OK, I understand where a remote might come in useful but I just don't want one to be honest. It is just another bloody power socket and psu.

Have actually thought about a Glasshouse TVC but that is well over five hundred quid I think and therefore more than I think I would value it at.

Really do love the look of that Khozmo. The name reminds me of Les Dawson.

[walpurgis]

Have actually thought about a Glasshouse TVC but that is well over five hundred quid I think and therefore more than I think I would value it at.

My Ming Da MC-9 TVC pre-amp cost me in the same region when I had it sent from China and I'd definitely pay the same again if need be. It's a beautiful sounding unit. Ming Da are high quality products. Not to be confused with some of the rubbish from the far east.

[wee tee cee]

Another vote for the TVC....Grant let me take stewardship of a promethius it is staying put in my set up-by far and away the best sounding pre i have tried.

[Macca]

Have had a P90SA in the past, I'd say the Slagle is better.

There was certainly a difference in presentation between them, I couldn't detect a difference in quality terms, though.

[Ali Tait]

As ever, always system dependent.

[pgarrish]

Id suggest you borrow a passive before you buy as not all power amps get on well with them - your Samson might want more driving than a vanilla passive. A TVC would provide more drive and they do sound good.

Regarding soldering - I'm as cackhanded as anyone and I bodged together my own passive with a DACT stepped attenuator which works really well. Start with an Alps blue pot for 30 quid or so and go from there. Nothing to really cock up and you will get a lot of satisfaction.

[Haselsh1]

Id suggest you borrow a passive before you buy as not all power amps get on well with them - your Samson might want more driving than a vanilla passive. A TVC would provide more drive and they do sound good.

I have heard lots of negativity about passives and was never impressed with the Creek jobbie but my Samson is currently being directly driven from the Bushmaster via its own L/R gain pots. This causes no problems whatsoever but I shall soon be buying a decent phono stage and really wanted a couple of switchable inputs.

[guy]

well worth a go:

http://www.ebay.co.uk/itm/NVA-P20-Passive-Pre-amplifier-/272074844462?hash=item3f58eca92e:g:rt0AAOSwzgRW1fI 7

meets your requirements, excellent price (£100), and send it back if you decide it isn't what you are looking for.

[Marco]

I think all the recommendations so far are bang on the money. Of particular note for me is the Slagle TVC of Ali's, which I heard at NEBO, as it offers truly stupendous SPPV! :)

However, one very significant thing I've learned from my own (now extensive) experimenting with passives, during the process of modifying the Goldpoint, is that in order to get it absolutely right and maximise performance, passives *must* be properly matched to the partnering system!

And the two key areas here are:

1) Ensuring that the source component has sufficient output (2V minimum), in order to properly 'drive' the passive preamp in question.
2) Ensuring that the power amp is sensitive enough to partner the passive, in order that the overall gain structure is optimised.

On top of that, interconnect cables (unless of the balanced variety) should be kept as short as possible, preferably no longer than 0.5m, and this applies especially to the cables going from the passive to the power amp. Also, it is inadvisable to use inefficient speakers in a system featuring a passive preamp.

In terms of 2), above, the ONLY way to ensure that's the case is to listen to the passive preamp in question, in conjunction with your existing power amp, as mismatches can happen very easily; sometimes bad ones, but more commonly those which are sub-optimal - and when you hear a truly *optimal* match, you'll certainly not want to settle for anything less! ;)

Marco.

[Haselsh1]

I really do appreciate all of the comments so far. I have been pointed in a certain direction by a member of AOS so will definitely wait to see what develops but I think in the interim period I will continue to drive the power amp directly from the CD player. I am currently suffering no definable loss of the frequency extremes using the direct output of the Bushmaster but, if all else fails, I may still go the Croft Micro 25R route with Series 7 monoblocks. That way I save on an expensive phono stage. It all depends on what happens in or around July.

[CornishPasty]

A friend has Papworth valve monos and to me the system always sounded a bit anaemic so I lent him my Django TVC. Using the 6db setting the system came alive giving a very powerful and dynamic sound. After some persuasion I succumbed and let him buy it from me. I don't regret selling it but sometimes I really do miss that magical sound.
To anyone thinking of buying a TVC I'd recommend getting one that has a 6bd lift facility. You may not need it but if your amp(s) need that bit of an extra shove it's a nice thing to have.

[Macca]

Or get a power amp that doesn't have an issue with a passive.

In principle you don't want any gain stage or a traffo in the pre-amp since it will colour the sound/ add distortion.

I've used my stepped attenuator passive with 10 different power amps to date and there was only 1 which it was not wholly compatible with (the Nikko at the last NEBO).

[awkwardbydesign]

While looking at TVCs and AVCs to use as a volume control for a preamp I'm building, I came across Thomas Mayer's view. http://vinylsavor.blogspot.co.uk/search/label/passive%20linestages
I use a TVC myself, an earlier version of this - http://www.promitheusaudio.com/tvc.htm and I had never thought of the inductive load presented to the source component. Which may account for some of the variability of their performance.
BTW, the current version is $530 posted. About £370. If you can get hold of Nic!

[Arkless Electronics]

Or get a power amp that doesn't have an issue with a passive.

In principle you don't want any gain stage or a traffo in the pre-amp since it will colour the sound/ add distortion.

I've used my stepped attenuator passive with 10 different power amps to date and there was only 1 which it was not wholly compatible with (the Nikko at the last NEBO).

+1 I would never use a TVC myself. 10K switched attenuator would be my weapon of choice (not that I have one... I'll make something when I get a round tuit).

[Yomanze]

Or get a power amp that doesn't have an issue with a passive.

In principle you don't want any gain stage or a traffo in the pre-amp since it will colour the sound/ add distortion.

...those power amps that don't have an issue with a passive tend to have buffer stages in the power amp themselves i.e. doing pretty much the same thing as an active pre does and are 'load rejecting' - of course this all requires extra components. It doesn't really make a difference whether you have an active pre driving a low impedance into a non-buffered amp or dealing with higher impedance with a passive by moving the buffer stage into the amp...

As with anything in HiFi it's all about matching.

[Arkless Electronics]

There is no matching issue.

[walpurgis]

+1 I would never use a TVC myself. 10K switched attenuator would be my weapon of choice (not that I have one... I'll make something when I get a round tuit).

Does that mean you'd never try one Jez? You might have a surprise. :)

[Macca]

He had a listen to several at the last NEBO

[Ali Tait]

The Slagle AVC's avoid a lot of the issues of TVC's, plus the lams can be restacked to change the inductance, which could be useful.

[Arkless Electronics]

Does that mean you'd never try one Jez? You might have a surprise. :)

They address a non existent problem. Lets say you have a 10K pot or switched attenuator, the worst case output resistance of this will be 2.5K at half volume. This is a pretty low output resistance and should drive 90% + of power amps no problem as nearly all power amps have an input impedance of >20K. Lets allow a typical 100pF for 1M of cable capacitance and a further 100pF for the power amp input. This will give a worst case -3dB point of 318KHz. Well more than adequate!
90% + of sources driving the passive will have an output impedance of 1K or less and will drive the 10K of the pot/attenuator plus parallel load of power amp (max loading at full volume) with no issues whatsoever. The only likely problem in driving it would be with some (a minority) valve sources without a cathode follower at the output and some older equipment (< 1975 in general) with highish output impedance. For such cases a pot/attenuator of 50K or 100K can be used but this gives a far less ideal output resistance of 12.5K and 25K respectively and needs to be used with short output interconnects and an eye on the input impedance of the power amp. Many are 100K so still OK. Ideally though use 10K pot/attenuator with a normal low impedance source.

Everything is pretty ideal and close to perfection.

Now take a TVC.... we have reactance plus stray reactances which can cause resonances and non constant impedance and we also have a small amount of distortion from core hysteresis etc. It is technically inferior to a plain passive and far more likely to have colourations, which may be of a pleasant nature and hence the preference for them that some have. All colouration is bad in my book.

For greater impedance transformations and driving really long cables and/or low impedance power amp inputs then a source/emitter/cathode follower after a 50K pot can be used. No longer entirely passive of course but still unity gain and about as purist/minimum parts/no global feedback etc as it gets ;) There are simple DIY projects for these on the interweb thingy. I could of course also build them fairly cheaply for folks if they've already got the pot/switched attenuator :eyebrows: I'll get my coat.....

[Macca]

Jez, why is it that a Tisbury passive sounded 'thin' in my system whereas the NVA I use now doesn't? Power amp is the same and no-one else who has tried the Tisbury had this issue (or they are just used to having no bass ;) )

[Arkless Electronics]

Jez, why is it that a Tisbury passive sounded 'thin' in my system whereas the NVA I use now doesn't? Power amp is the same and no-one else who has tried the Tisbury had this issue (or they are just used to having no bass ;) )

If they are the same resistance and have no other added parts then there is no reason to suppose that they will sound any different beyond minute changes in the sound of different resistors used. A non TVC passive is flat all the way to DC and cannot cause any bass roll off at it's output. The only way you would get any bass roll off is if the source feeding the passive has a capacitor coupled output and uses a low value capacitor which would then cause a bass roll off in conjunction with the input resistance of the passive. This is very unlikely. Some valve sources can have a sufficiently small output capacitor for the bass to be rolled off by a 10K passive but not many..... The Tisbury is apparently 10K but no spec is given for the NVA. Even if the output cap were as low as 1uF then into a 10K passive this would put the low frequency -3dB point at 16Hz.

[lurcher]

-3dB point at 16Hz
-2dB point at 20Hz
-1dB point at 30Hz
-0.5dB point at 43Hz

Not sure that would not be noticed if the system has good bass extension.

[walpurgis]

Yes. I know what you're saying Jez. You've expressed yourself on this before. You still didn't say whether you'd try a TVC, just to give it the benefit of the doubt maybe? :D

[Arkless Electronics]

-3dB point at 16Hz
-2dB point at 20Hz
-1dB point at 30Hz
-0.5dB point at 43Hz

Not sure that would not be noticed if the system has good bass extension.

I nearly added the same comment Nick but thought a 1uF coupling cap fairly unlikely and combination of that and a system with such bass extension for it to be noticed even more unlikely..... with most speakers you ain't going to notice 1dB down at 30Hz never mind think it sounds "obviously bass light".
Even with valve amps the coupling cap is likely to be at least 3.3uF and probably a 4.7 or 10uF (or more) even if a film cap. By 10uF -3dB is 1.6Hz so hardly an issue!

[Arkless Electronics]

Yes. I know what you're saying Jez. You've expressed yourself on this before. You still didn't say whether you'd try a TVC, just to give it the benefit of the doubt maybe? :D

No I wouldn't try one. Any perceived improvement, if present at all, can only be a "pleasant sounding colouration" and I don't want that thank you :)

At NEBO I thought the differences between passives tiny, if noticeable at all, and the only real difference I noticed was a slight extra "zing" and "bite" at the top end from a TVC one, which was almost certainly a mild treble lift caused by the TVC and so a colouration... euphonic or not.

[Macca]

destined to remain a mystery then, but thanks for your answers.

I think the TVC with the zing was Ali's - I think the power amp smothered most subtle differences though.

[struth]

sure, we dont want pleasant ;)

[Arkless Electronics]

sure, we dont want pleasant ;)

For me no I don't.... Not if it's not present on the recording ;)

[Macca]

Me too Jez but we are a small minority in hi-fi circles these days. On the forums, anyway. I don't like the sound to stray into 'hard' though, so maybe I'm just as bad ;) No real way to be sure if that's 'right' or not.

[Arkless Electronics]

Me too Jez but we are a small minority in hi-fi circles these days. On the forums, anyway. I don't like the sound to stray into 'hard' though, so maybe I'm just as bad ;) No real way to be sure if that's 'right' or not.

Indeed yes. Stuff with a certain "rose tinted" coloured sound does seem to be by far the most popular and some peoples perverse (to me) choice of equipment seems designed to actually be as coloured and characterful as possible :eek: Each to their own at the end of the day of course but some choices make me think "way don't you just add a DSP effects processor and graphic equaliser and be done with it!!? You could even ditch the £5k speakers for somat cheap and get the same sound with a quick play about".... I digress.

[Yomanze]

There is no matching issue.

Ah, then my active pre must add better dynamics, add a more 3D soundstage, and add more bass slam... :D

[Audio Advent]

I think all the recommendations so far are bang on the money. Of particular note for me is the Slagle TVC of Ali's, which I heard at NEBO, as it offers truly stupendous SPPV! :)

However, one very significant thing I've learned from my own (now extensive) experimenting with passives, during the process of modifying the Goldpoint, is that in order to get it absolutely right and maximise performance, passives *must* be properly matched to the partnering system!

And the two key areas here are:

1) Ensuring that the source component has sufficient output (2V minimum), in order to properly 'drive' the passive preamp in question.
2) Ensuring that the power amp is sensitive enough to partner the passive, in order that the overall gain structure is optimised.

On top of that, interconnect cables (unless of the balanced variety) should be kept as short as possible, preferably no longer than 0.5m, and this applies especially to the cables going from the passive to the power amp. Also, it is inadvisable to use inefficient speakers in a system featuring a passive preamp.

In terms of 2), above, the ONLY way to ensure that's the case is to listen to the passive preamp in question, in conjunction with your existing power amp, as mismatches can happen very easily; sometimes bad ones, but more commonly those which are sub-optimal - and when you hear a truly *optimal* match, you'll certainly not want to settle for anything less! ;)

Marco.

I agree with that Marco - it's down to the drive your source components can give. A competently designed, quality output stage of a source should be equal to an output stage of any preamp, but is just lacking a volume control. Problem only comes from making sure each source has a suitably strong output stage so one needs to choose their source equpiment much more carefully.

Or of course have add-on buffer stages to help boost the drive of any weaker components before the passive.

Matching with your power amp is a good reason to go down the route of passives like the Khozmo where you can specify what you need.

[StanleyB]

Impedance matching is not just for maximizing signal transfer, but it can also be useful for minimizing signal reflections. I am personally not keen on passive preamps, especially since they really need to be tailored to the power amp that is is going to be used with. But funnily enough, I have recently been playing about with some old impedance bridging designs of mine again. ( I had a 10 year long agreement with my previous employer that I wouldn't use anything that I had worked on for them in anything I designed or built for myself or an other company. That period came to an end last year) . in a nutshell, that method involves having a far lower source impedance compared to the load impedance. There is some info on that technique at https://en.wikipedia.org/wiki/Impedance_bridging

[Macca]

Here's list of all the power amps I have used my passive pre with, with absolutely zero issues:

XTZ A100
Firebottle AIR
Firebotle Dulci
Firebottle OTL
Linn LK100
Harmon Kardon 930
NVA A30
NVA A80
NVA A40 monoblocks
Sony 55ES

Possibly a couple of others I can't remember.

The only one it was not compatible with was a NIKKO (again at NEBO)

[StanleyB]

Here's list of all the power amps I have used my passive pre with, with absolutely zero issues:


That is good to know. It would be interesting to know as well if a preamp using impedance bridging would make any difference, positive or negative, with any of those amps, if you still got them. If you are up for it and willing to give it a try with an open mind, let me know.

[Macca]

I still have the XTZ, the A30, the Dulci, the Linn and the HK 930, so yes, happy to help out with any experementation

[StanleyB]

Thanks. I shall be in touch in the not too distant future.

[Macca]

Okey dokey.

[Arkless Electronics]

Impedance matching is not just for maximizing signal transfer, but it can also be useful for minimizing signal reflections. I am personally not keen on passive preamps, especially since they really need to be tailored to the power amp that is is going to be used with. But funnily enough, I have recently been playing about with some old impedance bridging designs of mine again. ( I had a 10 year long agreement with my previous employer that I wouldn't use anything that I had worked on for them in anything I designed or built for myself or an other company. That period came to an end last year) . in a nutshell, that method involves having a far lower source impedance compared to the load impedance. There is some info on that technique at https://en.wikipedia.org/wiki/Impedance_bridging

Absolute rubbish!

[StanleyB]

Absolute rubbish!
I am not surprised, but still shocked that you are prepared to dismiss what I wrote in such strong words. Mind you, it is not the first time that people have been keen to dismiss my work as rubbish without having heard the results of my findings. But a long list of customers over the years have had the last laugh after being pleasantly surprised by my ability to back up my claims with a 100% money back guarantee if my claim did not match or exceed its criteria. They say the proof of the pudding is in the eating. Well I just spent some money making that pudding as a proof of concept. And so far each and everyone who has had the time to try it out is mightily impressed.

[Lee Henley]

I know these are more expensive than what you were looking for but the past week Ive been having a play with one of the Takman REX resistor based preamps from Hattor audio, its the balanced version and is dual mono fully remote controlled and I have to say to date as a passive preamp its the best Ive had in the system. Over the past year or so Ive had a couple of Music Firsts, copper and silver and reference models, and also a Lightspeed LDR which is excellent. Im my opinion and in my system then Hattor is on another level, so much so Im about to order one all being well today.

Here is a link to the web site, Hattor is the high end version of the Khozmo

http://www.hattor.com/

Lee

[Haselsh1]

Lots of thanks everybody for the contents of this thread but in all honesty it is looking as though I will not be able to use a passive. My power amplifier requires 1.24V input for full output which is of course OK for a compact disc player but I also want to use a phono stage by Graham Slee and they do not output anywhere near this kind of level.

[Audio Advent]

I would have thought 1.24V sensitivity is about average for any power amp isn't it? Graham Slee phono stages have a max output of about 1.26V acording to some of the specs on their website, dependent of course on the output from your cartridge as they have a fixed gain.

Active pre-amps mostly operate in an attenuation mode anyway until you turn the knob up past say 2/3 full volume I read somewhere (I rarely go past half way).

I think, from a not very technical point of view (the stats I find a bit confusing, especially when you factor in +4dBu and -10dBu specs etc for pro gear) the issue is not about passive/active pre at all. It's about relative outputs of your sources and whether one will need attenuating (the CD player) vastly more than the other.

Hopefully someone technically minded will come along to check that!

Probably what is more important is how much of that 1.24V input you actually want to be amplified given the sensitivity of your speakers and the Samson's 34dB voltage gain.

[walpurgis]

TVCs can provide gain. Mine offers a claimed 9.5db and I believe the Promitheus (yes, that is correct spelling) models offer around 5db.

[Audio Advent]

I've a feeling no gain will be needed, personally. It's a guess though. My amps have just a 26dB voltage gain and go plenty loud into 90dB sensitivity speakers from 2V max source and the pre-amp only half way. Don't know the precise attenuation/gain structure of my Pass Labs X2 preamp though... still I'd guess there is only attenuation happening.

[Haselsh1]

OK guys thanks yet again. I was kind of assuming that the phono stage would only output around 250mV which of course may not be enough. I have used a Croft Micro 25 Basic preamp as a line only phono stage and that gave enough signal but required an increase in volume from the Samson. I also used the Croft as a full blown preamp into the Samson but the results were not particularly good. The sound was much more impressive taking things straight into the Samson and controlling from the two front gain pots. I guessed this was due to the Croft being a valve unit. I have no problem changing from CD to vinyl by swapping over input cables every time. It is only a matter of switching off and then on again.

[walpurgis]

Which Graham Slee phono stage will you be using Shaun?

[Haselsh1]

Which Graham Slee phono stage will you be using Shaun?

Geoff, I was seriously thinking about the Era Gold V as in a month or so I would be able to afford one. One thing though, I would not pay almost two hundred quid for a power supply so would use the SMPS that comes with it. My only other option and one that I like, would be an Angle Audio Reference which is around three hundred quid brand new. Bargain...!

[walpurgis]

I had the ERA Gold V and used it with the basic power supply and the PSU1. Can't say I really heard much difference. The ERA Gold V is a really lovely sounding device. Better than the well regarded valve EAR 834P unit that so many like. I had both at the same time. I kept the PSU1 and bought the Slee Reflex M phono stage to use with it. It is slightly more revealing than the ERA Gold V, but certainly no more musical. I loved mine and wish I still had it too (might get another to use alongside the Reflex :)).

[Haselsh1]

I had the ERA Gold V and used it with the basic power supply and the PSU1. Can't say I really heard much difference. The ERA Gold V is a really lovely sounding device. Better than the well regarded valve EAR 834P unit that so many like. I had both at the same time. I kept the PSU1 and bought the Slee Reflex M phono stage to use with it. It is slightly more revealing than the ERA Gold V, but certainly no more musical. I loved mine and wish I still had it too (might get another to use alongside the Reflex :)).

That is really good to know cozz there is no bloody way I am paying 185 quid for a bloody psu. That is a good portion of the cost of the phono stage and for me, it is just not justified. I am though looking forward to being vinyl again. It has been a quite a few weeks since I had that capability.

I may be completely wrong but I just think that with reference to the Slee psu, these bloody makers rely on our inbuilt insecurities to sell us any old tosh at quite a high price in most cases.

[walpurgis]

I may be completely wrong but I just think that with reference to the Slee psu, these bloody makers rely on our inbuilt insecurities to sell us any old tosh at quite a high price in most cases.

You are wrong about Graham Slee products. The company seem very honest about everything they make. No doubt there will be advantages from using the PSU1. It's just that I found the basic psu effective enough for my purposes. Their product pricing is good. The ERA Gold V offers outstanding sound quality for the money.

[Haselsh1]

Geoff, that is really good to hear. I trust your word on this. I think as I use an old Thorens TD160 BC MkII there would be no point in spending more on a phono stage as I think it would be wasted. My only concern is that I get enough volume from the phono using what is essentially a 'passive' setup. Using the Croft as a phono only stage I did get enough gain but I do not know whether that would be true of the Graham Slee. I think for a given input, the Croft has a much higher output.

[walpurgis]

Shaun. Did you know that if you visit the Graham Slee site and join the forum, you can then borrow Graham Slee products for home evaluation?

That may help you make a decision. At least then you'd know whether you'd be happy with the phono stage.

[pgarrish]

I use a nad pp1 on a rega bias cart and it's quite quiet. Via a passive into my hh power amp I usually have to dial the power amp up a notch to get enough volume from the TT. Using a rotel pre rc850 I can boost the signal enough to leave the power amp alone. I suspect your Samson will go plenty loud enough is a passive - unless you need it flat out with a direct feed you are reducing the signal anyway

[Haselsh1]

I easily have enough output from the Bushmaster to power the Samson all the way if required but I was a little bit concerned that a phono stage might not have enough guts to push the Samson to a decent enough volume. I know that the Croft had enough output but the Graham Slee stages are quoted as outputting a lot less. This may result in nowhere near enough volume from the power amp.

[Haselsh1]

Just as an addition, two years ago, I bought a Fidelity Audio Pre-120 active preamp to use with my then Rotel RB850 monoblock power amps. As I recall it cost around £300 but sadly the difference in sound quality over the Rotel RC850 was slight and it only had one pair of inputs so it was hurriedly moved on. If I buy a passive preamp now, I do not want it to detract from what I currently have which is mainly the cavernous 3D stereo imaging. I also do not want it to flatten out the dynamics of the amplifier as my previous experience of passives is for that to happen.

[Marco]

I also do not want it to flatten out the dynamics of the amplifier as my previous experience of passives is for that to happen.

Hi Shaun,

No need to worry, as that simply won't happen *if* the match is right. However, there is no real way of knowing that other than selecting a passive (from the many types available) and assessing what it sounds like in your system. Perhaps someone could loan you one to help you make the right choice? :)

Marco.

[YNWaN]

I know these are more expensive than what you were looking for but the past week Ive been having a play with one of the Takman REX resistor based preamps from Hattor audio, its the balanced version and is dual mono fully remote controlled and I have to say to date as a passive preamp its the best Ive had in the system. Over the past year or so Ive had a couple of Music Firsts, copper and silver and reference models, and also a Lightspeed LDR which is excellent. Im my opinion and in my system then Hattor is on another level, so much so Im about to order one all being well today.

Here is a link to the web site, Hattor is the high end version of the Khozmo

http://www.hattor.com/

Lee

That's interesting - I've not come across the Hattor brand before. Interesting styling, though I'm not sure about the chrome (I realise that's a personal taste thing). If they compare favourably to the Music First designs then the Hator is good value because it's a lot less money. However, as far as I can see, the Music First designs are TVCs and the Hator is not - it's just two very nice resistor ladder volume controls.

[Marco]

I know these are more expensive than what you were looking for but the past week Ive been having a play with one of the Takman REX resistor based preamps from Hattor audio, its the balanced version and is dual mono fully remote controlled and I have to say to date as a passive preamp its the best Ive had in the system. Over the past year or so Ive had a couple of Music Firsts, copper and silver and reference models, and also a Lightspeed LDR which is excellent. Im my opinion and in my system then Hattor is on another level, so much so Im about to order one all being well today.

Here is a link to the web site, Hattor is the high end version of the Khozmo

http://www.hattor.com/


Looks very interesting, Lee. I'm unfamiliar with ladder-type passives, and good ones interest me. How do they compare with shunt types, having a single resistor to ground at each position? Is that how the Hattor works, or if not, how? :)

Marco.

[Arkless Electronics]

Geoff, I was seriously thinking about the Era Gold V as in a month or so I would be able to afford one. One thing though, I would not pay almost two hundred quid for a power supply so would use the SMPS that comes with it. My only other option and one that I like, would be an Angle Audio Reference which is around three hundred quid brand new. Bargain...!

Not considered the Arkless 640P? Considerably better than the Slee and for less money ;)

[tubehunter]

These look interesting, I may try one.

http://www.amb.org/audio/delta1/

[montesquieu]

Just a cautionary dissenting note on passives here. My conclusions are quite the opposite of many here - for me passives are on the whole acceptable and certainly routinely better than a cheap linestage (which includes many valve designs), with the caveat that some sources and power amps don't get on with them - but a good line stage will improve on even the best passive out there.

This is not a question of 'liking' added colourations - the notion that the best preamp is no preamp because it's somehow easier to minimise losses than minimise added colourations is a simple-minded falacy given for example the vanishingly small measurable distortion of the prototype pre I got from Will at Radford Revival a while back - one example out of many low distortion designs.

Rather, it's a question of an active pre doing properly the job a preamp needs to do, which is provide efficient switching and attenuation while at the same time matching impedance (something only an active device can do effectively in my opinion - passives are essentially trusting to luck that the bits around them will be fit for matching) and - crucially - ensuring that the drive and snap doesn't go out of the music in the process.

I say that as past owner of assorted passives from Audio Note (top end kit built up by Hifi Collective), Glasshouse (ditto), Tisbury, and a couple of TVCs including a £5000 retail Mk II model from Music First, into literally dozens of power amps.

I agree that a good passive into a good power amp can sound very good indeed and the clarity is often a refreshing antidote to some of the more coloured or snoozeworthy active preamps out there - but in my view it can ALWAYS be bettered by a top quality active. No iffs, no buts. Cash permitting of course but isn't it always?

[Arkless Electronics]

As a majority seem to think that some sort of matching is required in a passive I'll repeat again that this is not correct. See my earlier post explaining why not.
I also disagree that a passive can be beaten by an active.
"Impedance matching" is another complete fallacy. It applies in this context only at radio frequencies and we are anyway dealing with mainly resistance not impedance... as was also explained earlier....

[Marco]

As a majority seem to think that some sort of matching is required in a passive I'll repeat again that this is not correct. See my earlier post explaining why not.

Jez, you'll need to get out of the bad habit of expressing what is merely your opinion as fact, as it's both rather tiring and disrespectful to those who disagree, for very good reason.

Extensive experience tells me (and I'm certainly not alone here) that correct matching with the partnering power amp and system is *essential* in order to get the best from a passive, so none of these contrary and absolutist statements from you will change that. Your views on this matter, and on hi-fi in general, are no more 'special' than anyone else's, simply because you're an EE, and the sooner you accept and embrace that fact the better.

Learn to be more humble in future, and accept that you still have things to learn in audio, the same as everyone else, particularly if you wish to remain a member of this forum. I really don't want to fall out with you, and have let much of this type of behaviour slide, but the arrogance and 'I am right because science says so' attitude has gone beyond a joke and really has to stop.

Marco.

[StanleyB]

- but in my view it can ALWAYS be bettered by a top quality active. No iffs, no buts. Cash permitting of course but isn't it always?
That's the most painful part of it all when trying to put together a modest system of low cost. I had a listen to a couple of low cost/low wattage power amps being powered by a quite expensive preamp. Those power amps sounded fantastic. But how many owners of a low cost power amp would ever get the chance to try a good but expensive preamp? What they have to settle for does little or no justice to their amp.

[montesquieu]

As a majority seem to think that some sort of matching is required in a passive I'll repeat again that this is not correct. See my earlier post explaining why not.
I also disagree that a passive can be beaten by an active.
"Impedance matching" is another complete fallacy. It applies in this context only at radio frequencies and we are anyway dealing with mainly resistance not impedance... as was also explained earlier....

Again, disagree. Your post explained nothing, only asserted an opinion that runs contrary to received design wisdom, which is that one of the essential features of a good active preamp is an input buffer of some sort to address possible (indeed, likely) impedance mismatches.

I've heard with my own ears what a (measurably extremely low distortion) preamp brought to the party in a decent system over a relatively expensive passive with one component in particular and it wasn't subtle. Impedance matching is the only possible explanation for the improvement.

If there was no benefit in spending thousands on a preamp in a high quality system, they would have died out decades ago. There is, and they haven't.

BTW I have to say I doubt very much if all this shouting bollocks at people who are simply describing what they have heard in many cases over decades of trying out kit is encourating business in your direction ...

[Macca]

which is that one of the essential features of a good active preamp is an input buffer of some sort to address possible (indeed, likely) impedance mismatches.

.

I have to take issue with this: earlier in the thread I posted a fairly long list of power amps of all topologies, valve and solid sate and hybrid, which I have used a passive with, with absolutely no issues, and the one example that didn't work. And that didn't work because its input sensitivity was too low for the source.

So whilst matching with a passive is not a given I would say it is unlikely - not likely - to be a problem.

I agree that there are some very good active pre-amps, Marco has one. If it were a consumer product it would cost about £20K

Most of us could not afford to spend even a quarter of that on an active pre-amp. A passive pre is the best solution in the sound per pound stakes, and for some of us the best solution period.

[montesquieu]

That's the most painful part of it all when trying to put together a modest system of low cost. I had a listen to a couple of low cost/low wattage power amps being powered by a quite expensive preamp. Those power amps sounded fantastic. But how many owners of a low cost power amp would ever get the chance to try a good but expensive preamp? What they have to settle for does little or no justice to their amp.


This is absolutely my experience Stanley. There are lots of good power amps around and quality can be quite affordable. By contrast, a good preamp is a lifetime quest.


I have to take issue with this: earlier in the thread I posted a fairly long list of power amps of all topologies, valve and solid sate and hybrid, which I have used a passive with, with absolutely no issues, and the one example that didn't work. And that didn't work because its input sensitivity was too low for the source.

So whilst matching with a passive is not a given I would say it is unlikely - not likely - to be a problem.

I agree that there are some very good active pre-amps, Marco has one. If it were a consumer product it would cost about £20K

Most of us could not afford to spend even a quarter of that on an active pre-amp. A passive pre is the best solution in the sound per pound stakes, and for some of us the best solution period.

Actually Martin I had your post in mind when I was writing, my experience is not that a passive doesn't work in the majority of cases (it does, with some exceptions). But adequacy and optimal performance and not the same thing and my experience is that a really top active can boot things into another league (and not by adding distortion!).

For example, I could never afford one myself, but a visiting Kondo M77 was a truly transcendent musical experience - a Holy Grail moment that reconfigured a lot of things in my mind. I've been seeking a bit of what that did ever since.

[Marco]

BTW I have to say I doubt very much if all this shouting bollocks at people who are simply describing what they have heard in many cases over decades of trying out kit is encourating business in your direction ...

Precisely, and it's that which has to stop - and now.

I've met Jez in person, spoken with him on the phone numerous times and interacted with him on forums, and I both like him as a person (usually always up for some banter) and value his (undoubtedly considerable) knowledge of electronics. He also builds excellent kit that outperforms many examples of commercially produced equipment, and at prices vastly lower than that of those. Furthermore, I consider that, overall, he's a valuable asset to AoS - so all that should be taken as a given :)

*However* Jez's achilles heel, as it were (and let's remember that none of us here are perfect), is that he's a little too much a fan of himself and his undoubted abilities, and gets somewhat 'carried away' with the veracity of his opinion on certain matters, whilst as you say, rather rudely dismissing/shouting down the valid opinion of others, who in certain circumstances may actually know more about a particular subject than he does, simply as a result of the practical experience that they've gained, often over a number of years, investigating that specific subject.

As I've said many times, not everything in audio is neatly (and indisputably) proven by what's contained in 'Johnny's book of physics'. In that respect, Jez would do well to take a leaf out of the book of other very experienced and knowledgeable audio designers here, such as Nick (lurcher), Anthony TD, Firebottle, etc, and *crucially* how they impart their knowledge on others, and to the forum in general, by doing so in a much calmer, more respectful and less confrontational/belittling/absolutist way, which never gets anyone's back up, especially those of a non-technical persuasion.

At the end of the day, we're ALL learning in this game, and new and valid discoveries are being made all the time, so we should be using that collective knowledge to help us better understand the subject of audio that we all love, instead of, in a rather blinkered and arrogant way, believing that all that there is to know is already known. As the old saying goes: "The more you learn, the more you realise how little you know..." And that truism applies to audio as much as anything else in life.

Some here may wish to reflect on that.

Marco.

[Marco]

Actually Martin I had your post in mind when I was writing, my experience is not that a passive doesn't work in the majority of cases (it does, with some exceptions). But adequacy and optimal performance and not the same thing and my experience is that a really top active can boot things into another league (and not by adding distortion!).


I also agree (like you extensive experience in this area dictates my position on the matter), but would also add that when a passive is designed to optimally match the existing components in a system, it can equal or get very close to what ANY active device is capable of, which is equally designed to bring out the best of the equipment in that scenario.

What's wrong is any 'black or white' absolutist notion that one is *automatically* superior to the other in all applications, as quite simply that is an erroneous belief, because hi-fi, and most importantly assembling a system that suits the specific sonic proclivities of an individual, doesn't work that way.

Marco.

[Firebottle]

What's wrong is any 'black or white' absolutist notion that one is *automatically* superior to the other in all applications, as quite simply that is an erroneous belief,

As a relative newbie here (others have way more experience of different kit), I have had the pleasure (and privilege) of hearing some amazing sounds from systems put together by other members of the AoS community.

For me one of the enduring insights of the 'hi-fi' industry is that there is such an amazing, and varied, amount of equipment and designs on the world stage.
To say, for instance, that an amplifier just 'amplifies' a signal is such a shallow description of the emotion and 'soul' that can be felt from different designs is a complete disservice to the passion and talent that top flight designers embody in their products.

Synergy may be an overused expression but every last interaction of individual kit has a part to play IMHO in achieving that ultimate sound.

I'm still learning all the time and can only keep an open mind for all the different iterations that make up superb sounding systems.

:D

[Marco]

As a relative newbie here (others have way more experience of different kit), I have had the pleasure (and privilege) of hearing some amazing sounds from systems put together by other members of the AoS community.


Which proves that we aren't all deaf or hapless victims of our 'delusions'... ;)


For me one of the enduring insights of the 'hi-fi' industry is that there is such an amazing, and varied, amount of equipment and designs on the world stage.
To say, for instance, that an amplifier just 'amplifies' a signal is such a shallow description of the emotion and 'soul' that can be felt from different designs is a complete disservice to the passion and talent that top flight designers embody in their products.

Synergy may be an overused expression but every last interaction of individual kit has a part to play IMHO in achieving that ultimate sound.

I'm still learning all the time and can only keep an open mind for all the different iterations that make up superb sounding systems.


Hear, hear, mate! :thumbsup:

Let's have more open-mindedness and inquisitiveness, together with a willingness to learn, and less dogma.

Marco.

[danilo]

Hopefully Not ;)
However .. having been an active Audio Weenie since '67; I've observed that delusion ..Is.. a Mainstay of Our Hobby... arguably the Cornerstone.
Too many examples to list. But we've All seen them.
Without delusion, the Audio hobby would have neither risen so high .. nor fallen so low (these days :eyebrows:)
Occaisionally I do take enough umbrage at what I perceive to be egregious religious beliefs /sheer lunacy.. to Heckle from the cheap seats.
My small attempt to keep some semblance of Honesty alive.
Personally, I found my assumed/claimed to be V good (close to as good as any made anywhere) bespoke Pre which served well for 10+ years, replaced by simple cheap Chinee Stepped attenuators of dubious pedigree, DIY cobble up.
MY Firstwatt was hugely dissappointing with my Pre fitted. Took a few days to suss that out.
Yet it produced THE very best sounds ever hoped for/imagined through my ancient and bought New Tannoy Golds.. once I fed the Amp with the simple stoopid attenuators and some wires.
It, like the Speakers will needs be pried from My cold dead fingers.. to paraphrase a famous nutter

Clearly.. there's still Lotsa room for wide variety of beliefs under the ever shrinking Audio umbrella.

[Stratmangler]

One thing though, I would not pay almost two hundred quid for a power supply so would use the SMPS that comes with it

I suggest joining the Graham Slee forum and having the Era Gold, the Reflex M and both the cheap as chips SMPS and the PSU1 on loan to have a listen to.
I found the PSU1 to be beneficial.
To discount a power supply on cost alone is folly.
The PSU1 has been well considered, and like all GSP Audio gear has cost a small fortune in getting through all the approval testing and achieving appropriate CE certification.

I have a Reflex M (phono stage)and a Solo II (headphone amp), each with their own PSU1, and neither piece of gear or their PSUs is going anywhere any time soon.
http://www.gspaudio.co.uk/power-supplies.htm

I also ran a Gram Amp2 SE for many years (I still have it) - I have one of the early ones (butt ugly, but sings beautifully), and it too benefited from using the PSU1.

[Ali Tait]

Yes indeed, this gets forgotten about. It's a very high cost for a small business. It cost Nick thousands to have his phono stage CE'd. That money needs to come from somewhere.

[Stratmangler]

Yes indeed, this gets forgotten about. It's a very high cost for a small business. It cost Nick thousands to have his phono stage CE'd. That money needs to come from somewhere.

You're up late Ali - that new cart of yours must be hitting the spot (I'm assuming that you've been up all through the night playing records).

[Ali Tait]

LOL, no, up early. It has been difficult to drag myself away from the vinyl though.

[Marco]

What's the new cart, Ali? I missed that :)

Marco.

[Stratmangler]

I fell asleep on the sofa sometime between 9.00pm and 10.00pm, and woke up around 3.00am.
I've been playing music and drinking ale since then.

It's a good job I don't have to be anywhere until around 4.00pm ....... :cool:

[Ali Tait]

What's the new cart, Ali? I missed that :)

Marco.

Can't copy and paste for some reason, search Gullwing Marco, started a thread the other day.

[Ali Tait]

I fell asleep on the sofa sometime between 9.00pm and 10.00pm, and woke up around 3.00am.
I've been playing music and drinking ale since then.

It's a good job I don't have to be anywhere until around 4.00pm ....... :cool:

Aye, a few beers were had on Friday, but that's my lot for the week. Do the falling asleep on the sofa thing quite regularly too.

[Ali Tait]

What's the new cart, Ali? I missed that :)

Marco.

Sorted-

http://theartofsound.net/forum/showthread.php?44301-Gullwing&highlight=Gullwing

[Audio Advent]

Hmm... This "presenting opinion as fact" business.

When I question people's "facts" about things I've experienced differently, like whether cables make a difference etc etc, you get the opposite accusation that you're being disrespectful for calling out their "Fact" as nothing more than their subjective, human opinion with all the possibilities of human error attached.

And also had a back and forth with Marco recently because he was expressing his opinion as a fact that could be proven (where the "proof" was still subjective opinon). We both had the good sense to walk away because it was becoming circular.

We all need to watch our use of words I think but also watch our reactions too - it's not really a problem unless people make it a problem themselves.

[Audio Advent]

I'm more of a "just try it and see!" kind of person. We can get too caught up in the pros and cons and philosophies of something without really understanding the magnitude of those pros and cons, nor whether they are relevent in the real world.

I'd say, just borrow a good quality passive and try it with your current set up to judge subjectively if it makes a difference to the sound (negatively). Loosing the 3D soundstage etc may be nothing more than an imagined scenario that was never going to materialise in the first place.

[Arkless Electronics]

An analogy:

A car forum exists in which enthusiastic amateurs discuss their cars etc and swap tips etc. Although enthusiastic, most of the people on this forum have little or no technical knowledge. You are an automotive engineer with years of experience and you join this forum..... You observe threads in which the fitting of "go faster stripes" is being discussed and the majority of members seem to believe they really can make your car go faster (:eek:)... in another thread people enthusiastically endorse the mixing of cross ply and radial tyres with again a majority of members seeming to believe this is good advice....
As someone with years of professional experience you point out that this is all bollocks, that it's impossible for go faster stripes to actually make your car faster, no matter how many are claiming otherwise, and that it is always a very bad idea to mix radials and crossplys....

You believe that you have done people a favour and done "the right thing" by putting this BS in it's place and explaining the truth....

What a surprise you get when informed that your professional opinion counts for nothing and is not welcome and, in spite of your having worked for the Williams F1 team, that your slagging off of the view that go faster stripes actually work is against the forum policy, so if you see things which are simply WRONG being claimed then shut up and say nowt....

This is the position I feel like I'm in here folks...... Just saying ;)

[Firebottle]

Hey Jez, I can appreciate your engineering background, but I have personally heard differences in presentation with a swap out of interconnects and type of coupling caps.

Everybody's experience differs, the problem comes with everybody's kit differing as well. At the sonic level a lot of us are trying to achieve there are going to be variations with small changes of hardware.

Can we explain it? With current understanding, no. I prefer to keep an open mind.

:)

[Macca]

Jez - it is not what you say, it is how you say it.

You might think it is good enough to say 'I'm a double E and you are talking shite'

But it isn't - you need to explain why they are talking shite, ideally in layman's terms. If you don't want to do that then just don't get involved at all.

[RMutt]

I once applied go faster stripes. I didn't look at my speedo, but I definitely felt like I was going faster.

[Arkless Electronics]

Jez - it is not what you say, it is how you say it.

You might think it is good enough to say 'I'm a double E and you are talking shite'

But it isn't - you need to explain why they are talking shite, ideally in layman's terms. If you don't want to do that then just don't get involved at all.

If you look back through the thread you should find the bit where I DO explain why there is no matching issue...

[Marco]

You observe threads in which the fitting of "go faster stripes" is being discussed and the majority of members seem to believe they really can make your car go faster (:eek:)...


There's your problem right there, and it's your use of language: "seem to believe". You obviously don't 'get' how patronising that is.

Leaving the 'Go Faster' stripes analogy aside, just because you believe that something in audio can't work, doesn't mean that it definitely doesn't, so if others "seem to believe" that it does, and it's based on considerable experience of hearing it, then allow them the courtesy of not being rather rudely shouted down by you telling them, in no uncertain terms (usually with the use of multiple exclamation marks) that it's "bollocks'.

Do you ever see Nick, Anthony or Alan do that? They will offer their *advice*, based on their technical and professional knowledge, but they NEVER rudely dismiss other people's observations, simply because they might think that they're wrong, so my advice would be to take a leaf out of their book, in that respect, to avoid us having 'little chats' like this in future! ;)

A hi-fi forum is all about enthusiasts discussing their observations and relating their experiences in an environment where everyone is treated equally and with mutual respect, and I won't have it here any other way.


As someone with years of professional experience you point out that this is all bollocks, that it's impossible for go faster stripes to actually make your car faster, no matter how many are claiming otherwise, and that it is always a very bad idea to mix radials and crossplys....

You believe that you have done people a favour and done "the right thing" by putting this BS in it's place and explaining the truth....


There you go, you see. You can't help yourself... Quite simply, your "truth" isn't necessarily the same as someone else's, nor is your idea of "BS" automatically actually BS.

It's only "BS" to you because it appears that 'Johnny's book of physics' rejects it. Well, much as you may like to think so, 'Johnny' doesn't know everything, and neither do you. It's not your place to judge or control what people choose to believe, and so you need to get that into your head.

However, the important thing here, Jez, and the bottom line as far as I'm concerned, is that you need to learn to impart your (undoubted knowledge of electronics and considerable experience in the technical side of audio) on others in a gentler, more respectful and less dogmatic manner (as Nick, Anthony and Alan do), otherwise we're going to continue to have problems.

It's not about *what* you know, but your people skills (or lack of them), and how you express yourself to others here of a different mindset.

Marco.

[Arkless Electronics]

I once applied go faster stripes. I didn't look at my speedo, but I definitely felt like I was going faster.

:D Well put. So many do the same in audio.... it's not faster and it can be proved to be not faster but they "feel like it's going faster"..... so apparently it must be true...

[Marco]

Jez - it is not what you say, it is how you say it.

You might think it is good enough to say 'I'm a double E and you are talking shite'

But it isn't - you need to explain why they are talking shite, ideally in layman's terms. If you don't want to do that then just don't get involved at all.

Nail > head. Using language such as "talking shite/bollocks" is simply unacceptable. You can get your point across without being so rude!

Using such provocative/confrontational language is simply liable to get the backs up of those you're attempting to 'educate', so you achieve nothing other than creating ill feeling. Is that what you want?

Unfortunately, Jez, you'd make a terrible teacher, as you do too much preaching and not enough listening.

Marco.

[montesquieu]

If you look back through the thread you should find the bit where I DO explain why there is no matching issue...

In a way that was utterly unconvincing .... to say nothing of the fact that most of us trust our ears (and experience) first before we'll trust what some random, opinionated bloke on an audio forum says. I've heard matching problems, many people here have and you can't wish them away with a superior attitide and a brief non-explanation.

[Marco]

.... to say nothing of the fact that most of us trust our ears (and experience) first before we'll trust what some random, opinionated bloke on an audio forum says.

Precisely - and no matter who he is or how much 'professional knowledge' he has.

I don't give a flying fuck if you're Nelson Pass. If extensive experience grossly contradicts what I'm being told is 'wrong', then I'll stick with what experience tells me, until sufficiently proven (to my satisfaction) otherwise.

Thank goodness I have a mind of my own. At this point, see the contents of my signature... ;)

Marco.

[Arkless Electronics]

Marco, whilst I would be the first to admit that my people skills are shite.... that's about as far as I can agree with you on this. Some things simply are right/wrong, correct/incorrect. There is no room for personal opinion in this. Scientific method is the gold standard here. If 99% of forum members believe bricks have anti gravity properties then weight of numbers and opinion does not make them right. They are still 100% wrong. Black and white. Simple as that. The brick will still fall to earth when dropped no matter how many wrongly believe it won't.

Hi Fi fundamentally (largely) IS electronics. One cannot really know what one is talking about without some knowledge of electronics....
You accuse me of arrogance and high handedness etc and then, as someone who is self confessed a total layman in the matter, try to tell me that electronic theory is wrong....that everything learned from research, everything my own decades of experience have taught me and the combined knowledge of the entire world of electronic engineering count for nothing when confronted by the subjective opinion of some lay people who like stereos..... you couldn't make it up!

It's amazing that I manage to put a 13 Amp plug on correctly, never mind design and build such good kit, when I'm obviously so lacking in the basic knowledge of my subject that I don't even do A/B comparisons of fuses or fit pointy wooden cones under my oscilloscope.... I used the analogy of the go faster stripes because, as an EE, many of the things I read here from lay people are literally as ridiculous (and wrong) as that.

Human senses, and especially hearing, are notoriously easy to fool and open to the power of suggestion. So much so that there is a whole field of science called psycho acoustics devoted to this. For example I am, as people well know, fully prepared to say that mains cables and fuses definitely do not, can not and never will have any effect on sound and that if you think otherwise you are simply wrong. That's a fact not an opinion. Just a few years ago one would have been quite rightly ridiculed for making such suggestions about mains cables and fuses effecting sound. That many now think they do have an effect is testimony to the powers of marketing and mass suggestion. If something is impossible it remains so no matter how many people erroneously hold a different opinion.

I feel like a doctor who, upon pointing out in a medical forum for lay people that no your illness is not caused by evil spirits and no you can't be cured by healing crystals, is being told "go away with your stupid arrogant medical knowledge 'cos we all believe in evil spirits here". This is all so ridiculous I almost have to pinch myself that yes I really am having this conversation and yes they really are serious......

[Yomanze]

Hey Jez, I can appreciate your engineering background, but I have personally heard differences in presentation with a swap out of interconnects and type of coupling caps.

Everybody's experience differs, the problem comes with everybody's kit differing as well. At the sonic level a lot of us are trying to achieve there are going to be variations with small changes of hardware.

Can we explain it? With current understanding, no. I prefer to keep an open mind.

:)
In fairness there are PhD lifelong practising electronic engineers, with all the measuring gubbins, out there with opposing views to Jez's. [emoji14]

[walpurgis]

If differing versions of similar types of 'things' demonstrably influence the sound differently and there is no way as yet of measuring or explaining the variance, that does not mean no difference exists.

[Yomanze]

If differing versions of similar types of 'things' demonstrably influence the sound differently and there is no way as yet of measuring or explaining the variance, that does not mean no difference exists.
No, but many scientists and engineers hate it when it goes to those realms.

[Marco]

Marco, whilst I would be the first to admit that my people skills are shite.... that's about as far as I can agree with you on this.


So are you going to improve your people skills in future and not be so rude when simply disagreeing with someone else's legitimate opinion? I'm afraid that's mandatory if you're to remain here, as it's a fundamental part of our ethos.

Once we deal with that, I'll go through the rest of your post.

Marco.

[Marco]

If differing versions of similar types of 'things' demonstrably influence the sound differently and there is no way as yet of measuring or explaining the variance, that does not mean no difference exists.

That truism should be plastered onto our banner and lit up with neon lights!!

Marco.

[Marco]

No, but many scientists and engineers hate it when it goes to those realms.

Well, that's too bad. Real scientists, with genuinely inquisitive minds wouldn't. It's about accepting that not all there is to know in our world is already known (and that includes the field of audio), and continually looking to find answers that explain currently genuinely experienced, but as yet, unproven phenomena.

Marco.

[YNWaN]

Just for balance - if you do apply racing stripes to your car, and the look of them makes you feel sporty and aggressive and therefore you drive your car more vigorously and press on the accelerator harder - well that will 'improve' the performance of the car and by some token the stripes have made it go quicker...... But also, they haven't actually made the car any quicker, just the driver...

[walpurgis]

'Go Faster Stripes' will actually make a car very fractionally slower, due to increased drag and weight.

[Arkless Electronics]

'Go Faster Stripes' will actually make a car very fractionally slower, due to increased drag and weight.

Yeah but that's science and common sense.... if you subjectively believe it is faster than apparently you are correct and science is wrong :ner:

[Marco]

I'm afraid that I'm going to have to push you for a 'yes' to post #113, Jez. Avoiding that question is not an option.

:popcorn:

Marco.

[Haselsh1]

Someone stated on here that they are a 'try it and see' kind of person. Well, I am also a try it and see kind of person and I do not follow it up with an opinion, I follow it up with my experience. I also follow it up with the experience of my partner even if we differ. I do not preach opinion, I simply state my experience at the time. What we hear as a couple with similar interests are our experiences not our opinions. To that end and because they are experiences, we believe they are correct for they are what we experienced. I read allsorts of stuff on this forum and sometimes I have to believe what I read because I have no differing experience of what is being discussed.

I am still awaiting a substantial claim for compensation which was expected a year ago and which, when it eventually arrives, I shall be using to elaborate my Hi-Fi system. This claim is being processed by the FSCS and I am now looking forward to July time when I should be in a position to spend around £10k. I see it this way, it is either Hi-Fi or a secondhand Harley Davidson Sportster 1200. If it goes on Hi-Fi then it will go on improving the Thorens TD160/ a fab new mm phono stage and a fab new valve amplifier but of course in ten minutes I may have changed my mind.

:eyebrows:

[lurcher]

No, but many scientists and engineers hate it when it goes to those realms.

Also remember scientists and engineers are very different fish. If you talked to a solid state physicist about the behaviour of electrons in a crystal lattice, or the movement of charge on the surface of an organic insulator, you will get a very different answer than asking a engineer about a insulated wire.

[Arkless Electronics]

I'm afraid that I'm going to have to push you for a 'yes' to post #113, Jez. Avoiding that question is not an option.

:popcorn:

Marco.

Yeah yeah I'll disagree more politely.

[Marco]

Nice one, that's much appreciated! :thumbsup:

Marco.

[Marco]

Also remember scientists and engineers are very different fish. If you talked to a solid state physicist about the behaviour of electrons in a crystal lattice, or the movement of charge on the surface of an organic insulator, you will get a very different answer than asking a engineer about a insulated wire.

Ha - nicely put (if I've understood it correctly)! ;)

Marco.

[StanleyB]

No, but many scientists and engineers hate it when it goes to those realms.
I was watching a program about space propulsion engines on BBC4 a few weeks ago. Part of the program covered the mysterious MDRIVE. It has been covered in controversy and ridicule over the years by scientists. But NASA decided to look at it, and found that it worked under their own test conditions. As one of the NASA top guys put it: "Scientists want to know how something works, before they decide if it works. Engineers want to know if it works, before asking how it works."
And that is very true. If one is waiting for science to explain everything, then remember that it has taken decades to confirm that Einstein was correct with his theory of relativity. And that was only done in the last couple of weeks as it happens.

[kininigin]

If one is waiting for science to explain everything, then remember that it has taken decades to confirm that Einstein was correct with his theory of relativity. And that was only done in the last couple of weeks as it happens.

Does that mean i need to change my signature then? :lol:

[StanleyB]

Does that mean i need to change my signature then? :lol:
Nothing lasts forever :D.

[kininigin]

Nothing lasts forever :D.

Apart from the infinite :D

Edited to Geoff's satisfaction :ner:

[walpurgis]

And infinitely bad spelling. ;)

[lurcher]

Apart from the infinate

See Big Bang and Transfinite maths.

[kininigin]

See Big Bang and Transfinite maths.

Implying nothing can be infinite?

Sorry this thread has gone a bit off topic,started out about passive pre's :lol:

[lurcher]

If one is waiting for science to explain everything, then remember that it has taken decades to confirm that Einstein was correct with his theory of relativity. And that was only done in the last couple of weeks as it happens.

Strictly speaking, Science does not concern itself with "proof". There are such things in Mathematics, which is why its not a science. The detection of gravity waves provides evidence for one of the remaining outstanding predictions of the general theory. Nothing is proved, its just further evidence that the theory is sound. We know that the theory is not correct or at least complete in the sense that are observations that are not explained. It may be part of a larger theory which we don't at this time have, but it certainly has been a amazing product of human intelligence. A purely mathematical theory, that based on a few simple ideas could predict so many physical events, many unknown at the time the theory was first created.

[lurcher]

Implying nothing can be infinite?

Sorry this thread has gone a bit off topic,started out about passive pre's :lol:

No, suggesting that Infinity does not have to exist forever, and there only is one of them.

[walpurgis]

No, suggesting that Infinity does not have to exist forever, and there only is one of them.

There may be an infinite number of infinities. But that's not finite of course. :)

[kininigin]

No, suggesting that Infinity does not have to exist forever, and there only is one of them.

Oh i see and i kind of get that,if i understand it correctly. As in there is no past,present or future,no begining and no end. Everything just is??

[lurcher]

There may be an infinite number of infinities. But that's not finite of course.

It depends on the size of each of the Infinities and if they are distinct or overlap.

[walpurgis]

Everything just is??

Was. May have been. Is all happening at once. Is imagined? Take your pick! :D

[walpurgis]

It depends on the size of each of the Infinities and if they are distinct or overlap.

I found one in a box in my shed. It didn't seem to overlap anywhere. Nice and shiny it was too. ;)

[struth]

the human brain has severe problems imagining infinity; I know mine does, as our physicality is always what we can ultimately touch or see. Similarly we often have difficulties with and idea that is so far from all we believed or want to believe.
Think Ive said b4 i have not heard mains cable differences but have with intercons and speaker wires. same re pre's.. Ive heard actives that are great in a system but not in another, and same goes for passives. I dont need to know why, just that it happens....similarly I dont need to know how infinity works as I cant imagine it, but know it is likey and better minds than me say it is a fact.

[walpurgis]

Is there another infinity on 'the other side' of a singularity? Or would that be the inside of this one? Like a sort of universal Mobius strip or Klein bottle.

[walpurgis]

the human brain has severe problems imagining infinity

The concept of things going of forever with no boundary conflicts with human perception of 'how things are'.

[struth]

We, as a race often try to overthink things and suffer as a result. Go with the flow, and try and steer a course is my advice. It something sounds better, then why fight it by saying that aint possible :rolleyes:

[lurcher]

the human brain has severe problems imagining infinity; I know mine does, as our physicality is always what we can ultimately touch or see.

Well, not everyone. I cant see or touch a electron, but I can imagine how they behave and make sense of a set of rules describing how they behave. Likewise mathematicians can train themselves to think in terms of more than three dimensions. Don't underestimate the capabilities of the ape mind that evolution has equipped us with.


We, as a race often try to overthink things and suffer as a result.

But that overthinking has produced many useful things. As a child may ask my generation "Granddad, what did you do without the internet?", answer: "We invented it".

[walpurgis]

As a child may ask my generation "Granddad, what did you do without the internet?", answer: "We invented it".

Yes, but we took maybe a couple of million years getting around to it. :)

[StanleyB]

Yes, but we took maybe a couple of million years getting around to it. :)We had real friends then.

[Audio Advent]

I feel like a doctor who, upon pointing out in a medical forum for lay people that no your illness is not caused by evil spirits and no you can't be cured by healing crystals, is being told "go away with your stupid arrogant medical knowledge 'cos we all believe in evil spirits here". This is all so ridiculous I almost have to pinch myself that yes I really am having this conversation and yes they really are serious......

If you go to certain parts of the web you will encounter pretty much exactly that - go off reading about vaccination conspiracies and then find a doctor's blog providing evidence and proof against every single point made on those consipacy forums and THEN go back to read the reactions and accusations now aimed at the doctor's blog etc etc ... Not far off some hifi forums!

[Audio Advent]

If differing versions of similar types of 'things' demonstrably influence the sound differently and there is no way as yet of measuring or explaining the variance, that does not mean no difference exists.

If one has an open mind (seems to be the most respected type of mind...) then one would also be open minded to the possibility that "demonstrations" of a phenomenon can be nothing but a demonstration of confirmation bias or the placebo effect.

What I seem to find is that people claiming to have an open mind have pretty closed minds to anything which doesn't agree with them. "Open mind" is being misused as a term to mean that they simply don't like to be told what to think, even if that then results in them believing in something that is fundamentally and demonstrably wrong.

A good example of what you said are experiences and claims of psychic powers - centuries of controlled testing has turned up absolutely no evidence of anyone able to perform any kind of psychic power in any way whatsoever and yet always the test subjects continue to claim their powers and others end up believing to have experienced their powers. So what is the conclusion from that, the logical conclusion, the SANE conclusion?

Perhaps it is that science doesn't know everything?

[Audio Advent]

Well, that's too bad. Real scientists, with genuinely inquisitive minds wouldn't.

Marco.

Fortunately many do and have done!

That's when they hit upon how unbelievably powerful the placebo effect is and the power of suggestion. It has led people to look at the inner workings of the mind and study the wierd workings of the senses and brain, which controls which (brain pretty much controls the senses and could be said to even create those senses, NOT the outside world ).

So yes, you're right Marco. When they've been faced with these situations across so many fields of science, they've looked at it all as a whole and completely turned around our millenia-old ideas of the human brain!

Fortunately what they didn't have was a closed mind. They were so open minded that they considered that they themselves could be easily fooled by belief and expectation. Beyond the ego.

If you think about it, that is a massive philosophical evolutionary step for a creature to be able to comprehend that what they "truely" see and hear may not actually be true at all. Animals believe their senses completely 100% of the time - humans are able to think beyond their own initial "experience".

[lurcher]

Yes, but we took maybe a couple of million years getting around to it. :)

Well, that seems fine in my book, find me another 50 races that has done the same, and that will start to form a league table. At the moment who knows if 2*10^6 years to invent the internet is good or bad. You certainly cant argue with the exponential nature of development though, we have done a lot in the last 10000 years or so compared to the previous 1990000, and same for the last 1000 against 1999000 and so on.

[Audio Advent]

We, as a race often try to overthink things and suffer as a result. Go with the flow, and try and steer a course is my advice. It something sounds better, then why fight it by saying that aint possible :rolleyes:

The Scottish?

As a whole, the human species isn't really like that at all. It's a social construct stemming from the likes of Plato (I may be getting my ancient greek philosophers wrong - one of that era was very definately of a more Eastern philosophy) and which was kind of revived and pushed aroudn the world via Victorian Britain and the industrial revolution and the resultant education system based (and still based) on Victorian ideals. Therefore it has become a more Western, grand meme of thought and thinking and passed down via the similar education systems in the west since Victorian days.

It says nothing of the human species and our character - it's a social phenomenon bourne of particular circumstance and is only found in a relatively small part of the world in terms of square miles.

[Marco]

Fortunately what they didn't have was a closed mind. They were so open minded that they considered that they themselves could be easily fooled by belief and expectation. Beyond the ego.


Like I've said many times before, I don't doubt that is sometimes, or even often, the case. However, I don't buy the notion that it *automatically is so* every time something is experienced that can't be confirmed by our current level of scientific learning. The key is in the last word "learning", i.e. we don't know it all yet ;)

That big lump of grey matter, nestled between our ears, is an extremely complex and powerful organ, and whilst in some ways 'easily fooled', is also capable of successfully identifying much more than we often give it credit for, especially by those of a rather dogmatic 'objectivist' persuasion.

Marco.

[Marco]

But that overthinking has produced many useful things. As a child may ask my generation "Granddad, what did you do without the internet?", answer: "We invented it".

I agree, however I also know where Grant's coming from. Said overthinking can also on occasions lead us to distrusting our natural human instincts, which in itself can be a hindrance, for example in relation to what I've just mentioned to Sam.

It's fine acknowledging and making allowances for our fallibilities, but not to the extent that it stifles true learning, because *sometimes* our natural senses and human instincts will get it right where science appears to suggest that they're wrong...

Marco.

[Gazjam]

The Scottish?

As a whole, the human species isn't really like that at all. It's a social construct stemming from the likes of Plato (I may be getting my ancient greek philosophers wrong - one of that era was very definately of a more Eastern philosophy) and which was kind of revived and pushed aroudn the world via Victorian Britain and the industrial revolution and the resultant education system based (and still based) on Victorian ideals. Therefore it has become a more Western, grand meme of thought and thinking and passed down via the similar education systems in the west since Victorian days.

It says nothing of the human species and our character - it's a social phenomenon bourne of particular circumstance and is only found in a relatively small part of the world in terms of square miles.

:lol:

[Marco]

Aye, we urnae a part uv the human species, sure we urnae? We are aw just DAFTEEEEEEESSSSS...... :D

Marco.

[Gazjam]

:D

[Idlewithnodrive]

I also do not want it to flatten out the dynamics of the amplifier as my previous experience of passives is for that to happen.

I'm a bit late to this thread so sorry If I add nothing new.

This is exactly what I found using a variety of passive pre's into my 405-2 power amp. That being said, I have just bought a TQ / Colin Wonfor passive pre, so will see what happens when that arrives and is plumbed in.

I think the problem with the 405-2 and passives is it's relatively low output impedance, which is 20K. Not sure a passive could make a good fist of driving that................................... unless you learned folk know better ? :)

[Clive]

I'm a bit late to this thread so sorry If I add nothing new.

This is exactly what I found using a variety of passive pre's into my 405-2 power amp. That being said, I have just bought a TQ / Colin Wonfor passive pre, so will see what happens when that arrives and is plumbed in.

I think the problem with the 405-2 and passives is it's relatively low output impedance, which is 20K. Not sure a passive could make a good fist of driving that................................... unless you learned folk know better ? :)
It mostly depends on your source. An all solidstate DAC should usually easily drive your 405-2. Likewise a solidstate phonostage. Valve sources become a more complex issue, some need an active preamp.

[Idlewithnodrive]

It mostly depends on your source. An all solidstate DAC should usually easily drive your 405-2. Likewise a solidstate phonostage. Valve sources become a more complex issue, some need an active preamp.

You would have thought so. If only it were that easy :)

[Barry]

I agree, however I also know where Grant's coming from. Said overthinking can also on occasions lead us to distrusting our natural human instincts, which in itself can be a hindrance, for example in relation to what I've just mentioned to Sam.

It's fine acknowledging and making allowances for our fallibilities, but not to the extent that it stifles true learning, because *sometimes* our natural senses and human instincts will get it right where science appears to suggest that they're wrong...

Marco.

"Maybe, all systems - that is , any theoretical, verbal, symbolic, semantic, etc. formulation that attemps to act as an all-encompassing, all-explaining hypothesis of what the universe is about - are the manefestations of paranoia. We should be content with the mysterious, the meaningless, the contradictory, the hostile, and most of all the unexplainably warm and giving ..."

Philip K. Dick (addressing a SF convention in Vancouver in 1972)

[Haselsh1]

It mostly depends on your source. An all solidstate DAC should usually easily drive your 405-2. Likewise a solidstate phonostage. Valve sources become a more complex issue, some need an active preamp.

That is one of the reasons I am currently looking at moving over to an SS phono stage like the ifi iphono. I like the sound of its flexibility when compared to others especially the variable gain. This should be able to drive the power amp directly as does the DAC.

[Audio Advent]

Like I've said many times before, I don't doubt that is sometimes, or even often, the case. However, I don't buy the notion that it *automatically is so* every time something is experienced that can't be confirmed by our current level of scientific learning. The key is in the last word "learning", i.e. we don't know it all yet ;)

That big lump of grey matter, nestled between our ears, is an extremely complex and powerful organ, and whilst in some ways 'easily fooled', is also capable of successfully identifying much more than we often give it credit for, especially by those of a rather dogmatic 'objectivist' persuasion.

Marco.

You know *sometimes* people, scientists have other things to do! So the idea that it should be automatic that they abandon their mainstay research and go off at a tangent is a daft notion.

They're trying to focus on a particular area of science and have teams of people working with them - they are not just bohemian, rich self-funding scientists who day dream and follow their whim..

When is the brain being fooled and when it is successfully identifying much more than we often give it credit for? Are you personally able to discern the difference? Think about it for a second and if you COULD differenciate the times you were being fooled ... err.... you wouldn't be being fooled. i.e. to tell would mean infalability.

It is seemingly never considered by those who talk about having "open minds" that they may be being fooled. Why? Because their minds are closed to the idea !

[Marco]

Not at all, Sam. I'm entirely open to the idea, and no doubt, like many others, have 'imagined' plenty of things in hi-fi in my time. What I don't buy is the notion that I'm being fooled every time that 'science says so', simply because I can't prove otherwise.

On that note, in order to prevent another circular argument, it's probably best if we once again agree to disagree :)

Marco.

[Audio Advent]

"Maybe, all systems - that is , any theoretical, verbal, symbolic, semantic, etc. formulation that attemps to act as an all-encompassing, all-explaining hypothesis of what the universe is about - are the manefestations of paranoia. We should be content with the mysterious, the meaningless, the contradictory, the hostile, and most of all the unexplainably warm and giving ..."

Philip K. Dick (addressing a SF convention in Vancouver in 1972)


A Sci-Fi author addressing a Sci-Fi convention! A Sci-Fi author whos work consists of day dreaming and fantasising about things that are beyond the realms of much of reality or even likely possibilities.

Yes, for him and others to write fantastic genre fiction (as he did) , he needs to be able to feel the mystery of possibilities to draw him in, to romaticise about, to give him the inspiration and emotional background a believable bit of fiction needs.

He wasn't talking at a scientific convention - i.e. he was talking in the context of a convention on fiction.

[Audio Advent]

:D

Haha... hope none are offended :)

[Audio Advent]

Not at all, Sam. I'm entirely open to the idea, and no doubt, like many others, have 'imagined' plenty of things in hi-fi in my time. What I don't buy is the notion that I'm being fooled every time that 'science says so', simply because I can't prove otherwise.

On that note, in order to prevent another circular argument, it's probably best if we once again agree to disagree :)

Marco.

Well... NO! I agree with that :)

[Macca]

I think a reasonable position is that our brains are being fooled sometimes, and sometimes we become aware of it and sometimes we don't.

But to use it as a catch-all explanation for everything in audio that is not easily explained is just lazy thinking.

[Marco]

But to use it as a catch-all explanation for everything in audio that is not easily explained is just lazy thinking.

Spot on, and that is *exactly* my position on the matter.

Marco.

[lurcher]

Spot on, and that is *exactly* my position on the matter.

Marco.

Problem is that if we accept that we are sometimes fooled, and sometimes not, and that we dont know if we are being fooled or not, its hard to argue that we have to assume that we are always fooled. :-(

[struth]

You can fool all the people some of the time, and some of the people all the time, but you cannot fool all the people all the time

[StanleyB]

Problem is that if we accept that we are sometimes fooled, and sometimes not, and that we dont know if we are being fooled or not, its hard to argue that we have to assume that we are always fooled. :-(
The fool doth think he is wise, but the wise man knows himself to be a fool.

William Shakespeare, As You Like It, Act v. Sc. 1.

[Marco]

Problem is that if we accept that we are sometimes fooled, and sometimes not, and that we dont know if we are being fooled or not, its hard to argue that we have to assume that we are always fooled. :-(

Yup, which is why I just say 'fuck it' and trust my ears! K.I.S.S rules... ;)

Marco.

[Audio Advent]

The fool doth think he is wise, but the wise man knows himself to be a fool.

William Shakespeare, As You Like It, Act v. Sc. 1.

That's the quote I shall go for.

[walpurgis]

Yup, which is why I just say 'fuck it' and trust my ears! K.I.S.S rules... ;)

Marco.

Yeah. I don't need a lab printout to tell me I'm not hearing what my ears do.

[Audio Advent]

Yup, which is why I just say 'fuck it' and trust my ears! K.I.S.S rules... ;)

Marco.

Me too to an extent. What must go hand in hand with the "fuck it" attitude is accepting there may be knowledgeable reasons why your ears may be wrong, just that "fuck it" means you don't care to find out. And so "fuck it" gives you no authority to say you are right in any way other than that which pleases yourself at that point in time.

I think that was my point way back.

Anyway, straying rather off topic to Shaun's search for a good passive so let's not carry it on.

[walpurgis]

"fuck it"

[Marco]

Me too to an extent. What must go hand in hand with the "fuck it" attitude is accepting there may be knowledgeable reasons why your ears may be wrong, just that "fuck it" means you don't care to find out. And so "fuck it" gives you no authority to say you are right in any way other than that which pleases yourself at that point in time.

Anyway, straying rather off topic to Shaun's search for a good passive so let's not carry it on.

Indeed; you're straying towards over-analysing things again ;)

The point is, at the end of the day, when all is said and done, I trust my ears. That doesn't make me 'right' or 'wrong', but simply happy with the choice I've made. Best just leave it there now :)

Marco.

[Yomanze]

Indeed; you're straying towards over-analysing things again ;)

The point is, at the end of the day, when all is said and done, I trust my ears. That doesn't make me 'right' or 'wrong', but simply happy with the choice I've made. Best just leave it there now :)

Marco.
I fitted a passive in my system once and everything flattened, became greyer. I was also experimenting with bi-amping. I was testing for ages and my girlfriend just said "you know it doesn't sound as good, so just set it back to what it was." At the time the active added back in was a Krell KRC-3 pre with vanishing distortion and 15 Ohms output impedance, so transparent by the specs, but wow did it add flesh and bones to the sound.

In other words I agree, our ears and emotional experience too are the final say, not a blunt statement that passives are always better.

[Marco]

Indeed, or that passives are always worse, and active is always better. It cuts both ways, and I hate absolutism! ;)

In the end, after you've tested/analysed everything you feel that needs testing or analysing, simply trust the God-given senses and instincts you were born with. Some 'sceptics' should try that, as it might make them feel and behave more human, and be happier and less miserable, too... :eyebrows:

Marco.

[Yomanze]

Yes, the trap is to settle and have a niggle about the system, rather than have it right for you... and then the tunes start flowing.

[DSJR]

I sort of have the opposite vibe, where one of my active preamps adds too much 'push' over 1m interconnects (the AVI S2000MP+P was designed for long interconnects and is fine in this role I find), the Croft 4PP dedicated active line stage changes the tone of a straight line source too much for me - but I love it anyway - but the old early 70's IC op-amp based active preamps I use don't seem to have any negative effect at all on the signal fed through them despite a less than modern-ideal wiring loom inside. The only difficult amp I have is the (1.3V) Krell KSA50S and this needs an active pre really (I was interested in the slim profile KRC3 but it's several owners down the line I suspect by now), although it works fine on a CD and high output phono stage source using a passive controller (10k log and 47k log pots).

Thing is, you can try and see if it works. It's meaningful if the power amp has user adjustable gain controls (a passive pre-amp in all but name), as you can feed a source straight in and then substitute either a passive or active controller to see what changes...

[Audio Advent]

Indeed; you're straying towards over-analysing things again ;)

The point is, at the end of the day, when all is said and done, I trust my ears. That doesn't make me 'right' or 'wrong', but simply happy with the choice I've made. Best just leave it there now :)

Marco.

So not "over-analysing", as you just said the same thing :lol:

[Audio Advent]

Here's a good little snippet from the Engineer Bruno Putzey about audiophile choices in potentiometers, although I guess some can apply to stepped attenuators too:


The volume controller: As most experimenters will have noticed, potentiometers leave wildly varying and occasionally unpredictable footprints on the sound. Postmodern etiquette then requires that one congratulates oneself on having heard something that the objectivist clique doubtlessly will never have noticed and will most certainly deny, so the new observation is set aside for wonderment and mysticism and, crucially, exploitation by manufacturers of very expensive parts. I must disappoint the postmodern set here.

The problem is perfectly well known and well-understood if not by too many people.

There are two elements at play. The resistive track is rarely linear. On top of that the non-linearity is dependent on the current density in the track. In logarithmic pots the divider ratio becomes non-linear. Also the wiper contact is a source of distortion. Secondly, very few amplifier circuits have a perfectly linear input impedance. It doesn't even matter whether it's valves, JFETs or bipolar, op amp or otherwise. All have, to a lesser or greater extent, a variable input capacitance. Drive an amplifier circuit with a few kilo-ohms at your peril.

Two exceptions. Virtual-ground circuits have no input capacitance modulation problems because the input signal is zero. Differential circuits have no problem either because the nonlinear charge currents cancel.

So some thoughts as to why different attenuators can react differently from an engineering perspective.

[SLS]

I've had a passive Hattor pre-amp for a month or so now. It's got two of Arek's Khozmo stepped attenuators, remote and loads of inputs and outputs. My inputs are phono, DAC, skybox and disc-spinner.

I must say I am perfectly happy with the thing. Cost me $800 delivered.

[danilo]

Here's a good little snippet from the Engineer Bruno Putzey about audiophile choices in potentiometers, although I guess some can apply to stepped attenuators too:
So some thoughts as to why different attenuators can react differently from an engineering perspective.

Yeah.. OK. So Not all carbon tracks are created equal.
Hardly Newsworthy, that.
So... Buy a Cheap Ass Chinese Stepped switch/attentuator then. If there is variance? substitute resistors until it Measures happily.
Hardly something to lose sleep over ;)

[hifinutt]

using a tisbury passive while my amp away for servicing . pretty good and enjoyable

I think they have bought out a mark 2 at 129 pounds now

https://youtu.be/rpdUOVIYPLI

[Virtual-Symmetry]

I was gonna try one of these passives when i had my Quad '303' but never did.

http://www.ciaudio.com/products/VPC3

[ff1d1l]

Just my two pennoth...knocked out an Alps Blue pot-in-a-box (with flying leads to the power amp) last week. This cost very little, wasn't difficult to assemble and didnt disturb the very low WAF factor of my system. I'd suggest if you are curious about the Passive Pre approach, suck it and see. Unless a shedload of money falls on me from the sky, facilitating my spending ludicrously large amounts, I won't be going back to an active pre.