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Spectral Morn
24-04-2009, 14:08
Hers a question and I am offering no real opinion here just asking the question.

Can the quality/type/design/materials of a FUSE effect the sound quality of audio gear. I recently had a valve go on one of my valve amplifiers, the fuse blew as it was supposed to. Now when I checked the fuses in the amp I found a mixture of ceramic types and glass. Is there a difference between these and can that effect the sound ? The Fuse type is a 250Ma slow blow or time delayed one. Is there a difference in that description too ?

I ask all this in part because I had an experience a while ago were I was lent a hi-fi tuning 13 amp fuse and a 5amp fuse. These use silver filaments,silver plating and a sand filled body. I swapped the Fuses in a few mains cables namely TCI Boa Constrictor, Audience AU24 and Analysis Plus Power Oval2, for the better ones ? I heard a difference, not a big one, but I am sure I heard it none the less.

I rang Andy at TCI and asked him about this and he started to moan about MK changing the quality of their plugs and fuses. "The new tough plugs are not as good as the old", he said. The old ones have silver plated fuse holders and the fuses are silver plated too, at least externally...I don't know about inside. I compared some of the older white ceramic plugs for the newer plastic ones and hes right. He complained to MK about it but was ignored.

What do you guys think about this ? Do you think fuses make a difference ? I don't know so I am asking the question.

Discuss......



Regards D S D L

Ali Tait
24-04-2009, 14:30
Not something I'd bother with myself,as I can get much greater subjective changes by changing something like a coupling cap,or different resistors etc.With your amp having a fuse on each output valve,you're in an ideal position to answer your own question.Perhaps buy or borrow some different types,maybe putting one type in one channel and another in the other channel,and see if any differences are apparent?

Spectral Morn
24-04-2009, 14:40
Hi Ali

I probably will. but was curious to see what members thought...maybe some have tried this and have found some or no difference. When I went down to my local maplins I could only get glass type. The one blown in the amp was a ceramic, though I found( when I looked) that there was a glass one in the left (which was original is anyones guess) channel...so one had blown before (the amp was S/H got via a friend who bought it from a guy in Scotland.. Shetland I think.)



Regards D S D L

Ali Tait
24-04-2009, 15:10
It may be worth contacting the manufacturer to ascertain the correct fuse to use Neil,i.e. fast-blow or slow-blow etc.Just to be sure you replace with the correct ones.I'd be interested in seeing the circuit of these amps.It's interesting that you had an output valve go U/S without damaging any of the amp's components.Incidentally,had you previously changed the 88's,or were they what came with the amp? Had you noticed any increase in hum before this happened?

The Grand Wazoo
24-04-2009, 15:44
I don't see how fuse types/brands/materials can not affect the sound. Everything acting on the system in any way has a bearing on what it does and how it does it.

But...........it's not something I'd get hung up on. I don't imagine the difference would be worth the trouble. I guess if it were me, I'd certainly ensure that they were all the same (and clean), but that's probably as far as I'd go.

However, I once said that I didn't believe a single resistor would make a meaningful difference & proved myself badly wrong when I started playing about with different types in my Bent Audio Mu step-up transformers. But then, we're talking about minute signals, unlike those in a power amp for example.

Bearing in mind you have the need to sort it out, the time to do it (& probably the inclination), a little experimentation can do no harm at all can it?

I'd certainly make sure you know whether fast or slow blow types are required (slow, I'd've thought, but then I know nothing!).

I'd like to know what you find though!

Ali Tait
24-04-2009, 15:55
Slow blow is almost certainly correct,but as you say,best to make sure!

tubehunter
24-04-2009, 15:58
I read somewhere that Glass bodied fuses should never be used to protect high-voltage circuits such as AC mains.
A short circuit causes the fuse to rupture instantly and vaporise, thus depositing a conductive metal film on the inside of the glass which continues to pass a small current, but heats the glass.
If glass is heated sufficiently, it becomes a conductor in its own right, and so the fuse has failed to protect the circuit.
Fuses suitable for high-voltage use have ceramic bodies filled with sand to prevent the creation of a continuous conductive film.

Duncan

Spectral Morn
24-04-2009, 17:07
It may be worth contacting the manufacturer to ascertain the correct fuse to use Neil,i.e. fast-blow or slow-blow etc.Just to be sure you replace with the correct ones.I'd be interested in seeing the circuit of these amps.It's interesting that you had an output valve go U/S without damaging any of the amp's components.Incidentally,had you previously changed the 88's,or were they what came with the amp? Had you noticed any increase in hum before this happened?


Hi Ali

Its slow blow, says on the amp which is what i bought today, except Maplins call it time-delay.

The Ram vavles are what came with it....No increase in hum. I had the amp on since just before lunch and the valve blew just before 5 o'clock. There was a noise (I was in the kitchen)a soft thump. I thought it was maybe a car door outside...it wasn't very loud. I worked away in the kitchen for 15 mins or so music playing with no audible problem. I walked into the living room and still I heard nothing wrong but I noticed one of the valves was glowing bright blue inside at its base...lower half. I put two and two together thought crap a valve has gone and I switched the amp off...still playing away.

When things had cooled down I took the valve out and tested it...shorts okay but emission was bad in fact it didn't register at all. Grid leakage measured fine but the valve wasn't lit up at all....so I assume its stuffed.

The designer of the amplifier Roger A. Modjeski prides himself on his designs being bomb proof, long lasting, easy to service etc. He is a no BS kind of guy. You want to read what he has to say about the audio industry and he has worked in it for years, he even runs night classes in audio design. If I lived in America near him I would go. Heck you can even build your own valve amp in his class.

I had a look under neath the amp with bottom of and nothing smelt bad or looked wrong so I am assuming it is still okay. Know soon enough when I power it back up.

Ill take some photos and post them up ...so you can have a look.

Heres a link to the Ram labs site http://www.ramlabs-musicreference.com/


Regards D S D L

Ali Tait
24-04-2009, 17:29
Sounds good Neil,the amp is probably fine,though if you'd had a dead short in the valve it may have been a different story!

Spectral Morn
24-04-2009, 18:28
Photos of inside of Rm200 Music Reference amplifier.

http://i549.photobucket.com/albums/ii364/davros124/SystemSynergy031.jpg

http://i549.photobucket.com/albums/ii364/davros124/SystemSynergy032.jpg

http://i549.photobucket.com/albums/ii364/davros124/SystemSynergy033-1.jpg

http://i549.photobucket.com/albums/ii364/davros124/SystemSynergy036.jpg

http://i549.photobucket.com/albums/ii364/davros124/SystemSynergy037.jpg

http://i549.photobucket.com/albums/ii364/davros124/SystemSynergy038.jpg

http://i549.photobucket.com/albums/ii364/davros124/SystemSynergy035.jpg

Regards D S D L

Ali Tait
24-04-2009, 19:12
Looks very clean.No sign of any damage. :)

keeper
24-04-2009, 20:01
Thats quite funny, all the discussions on mains leads etc and the power goes through a 13amp fuse. I wonder if a fuse sounds better one way round or another.

On a serious note, what type fuse is best in the mains plug?
ELCB or standard fuse in the mains box........

Spectral Morn
24-04-2009, 20:03
Thanks Ali


I can't move the capacitor board as it looks a bit fiddly to do...but no sign of damage and the two fuses on it look okay. Its a fairly simple design to work around/in by the looks of it. My friend who had it first had a very talented engineer look at it and he said it was the work of a genius. I am not qualified to comment on that...but I respect Rodney Hanna the guy in question. Hes one of those rare repair guys who makes his own kit...loves valves etc. Rodney can work out what a circuit and a design is about in minutes just by looking at it.

Thanks for the input on this ...you have been very helpful as has Mike.


Regards D S D L

Spectral Morn
24-04-2009, 20:09
Thats quite funny, all the discussions on mains leads etc and the power goes through a 13amp fuse. I wonder if a fuse sounds better one way round or another.

On a serious note, what type fuse is best in the mains plug?
ELCB or standard fuse in the mains box........


Good question anyone know ?

Your right about the mains cable thing, the fuse is part of the process...so may have a positive or negative effect. I am not really sure about this...I have only fairly briefly played around with fuses and I did hear the Hi-fi Tuning fuse alter the sound and for the better in my setup. However I must say that the mains cables they make when used didn't sound right in my set up, they made things sound bright.


Regards D S D L

Ali Tait
24-04-2009, 20:24
Welcome Neil,glad to be of help.One thing,good as the amp may be,the components look pretty standard.If you could locate the coupling capacitors,changing these for something like SCR teflons,Audionote coppers,Mundorfs etc. really would transform the sound of the amp.It's not difficult to do,and it really makes a difference!

DSJR
24-04-2009, 20:48
Back in the day, when I really cared about these things, I used to turn fuses round to get the "best" sound from them. I put 13A fuses in amp mains plugs, 5A ones in preamps etc and 2A in many low consumption sources like tuners, Rega turntables etc...

I DID feel however, that decent glass fuses (such as via RS Components) appeared to "sound" better than ceramic types...

By the way, Anti-Surge had springs in as I remember and "Slo-Blow" had a solder blob, both having slightly different time characteristics for blowing IIRC.

I'd be inclined to email the amp manufacturer and ask their advice. It may just be that the amp really doesn't give two hoots what construction of fuse is there, as long as the basic characteristics are adhered to. I'm now deeply suspicious of overly sensitive products that baulk at the slightest change of bit of wire or component. The best work just fine with well rated standard components as long as they're not being stressed (I'm still suspicious of Naim supply rails of 37V with 40V rated caps on them when 63V may just make them last even longer, especially as these things are often left powered 24/7 for years at a time.

Ali Tait
24-04-2009, 20:58
That's because Naim build very mediocre amps with cheap parts! :sofa:

(IMHO)

DSJR
24-04-2009, 21:09
Now I would never DARE to say such things - I did once and was flamed to a crisp for my honesty.. :D

Spectral Morn
24-04-2009, 21:48
Welcome Neil,glad to be of help.One thing,good as the amp may be,the components look pretty standard.If you could locate the coupling capacitors,changing these for something like SCR teflons,Audionote coppers,Mundorfs etc. really would transform the sound of the amp.It's not difficult to do,and it really makes a difference!

You may be right about the parts...Roger strikes me as perhaps not being as caught up about audiophile parts as some. It is very possible, and I think Eco-Fan is another example; that it is possible to create amazing sound with very clever designs and non-audiophile approved parts. However in saying that, yes what you suggest might be worth doing. I don't think I would want to do it myself but I know a man who can.....Rodney.

Which of the items you suggest sound best or how do they sound ?


Regards D S D L

Ali Tait
24-04-2009, 22:25
Well that's not a question I can answer really-one man's meat etc.I personally like SCR teflons (can be had from diyhifisupply but they are not cheap! Some say they are the wasp's nipples though) Audionote coppers (from diy hificollective.cheaper than SCR but still not that cheap) Also from collective that I liked were Mundorf silver in oils-very good but perhaps would be a little too far in an analytical and detailed system.If you don't want to spend that much,a good choice would be copper Obbligatos,also from diyhifisupply.All just IMHO,you really need to try for yourself to see what you prefer.Maybe try some cheaper teflons against say a Paper-in-oil (PIO) cap to see which type of sound you prefer.Speaking very generally,PIO's tend to have a more laid-back,more organic sound,teflons being perhaps a little more upfront.You really need to try for yourself.A good source of cheap PIO's is ebay-look for the Russian ones,quite cheap and quite good actually!

Spectral Morn
24-04-2009, 22:31
Once again thanks for the info.:)


Regards Neil :)

Barry
25-04-2009, 00:55
Good question anyone know ?

Your right about the mains cable thing, the fuse is part of the process...so may have a positive or negative effect. I am not really sure about this...I have only fairly briefly played around with fuses and I did hear the Hi-fi Tuning fuse alter the sound and for the better in my setup. However I must say that the mains cables they make when used didn't sound right in my set up, they made things sound bright.

Regards D S D L


Niel,

My first reaction on seeing this thread was:steam:. However on reflection it would seem to be a harmless pursuit and a logical one to follow, if you are perceptive to the audible changes wrought about by changing mains leads.

The important thing to remember is that fuses are used for protection, not only of the electrical equipment but of YOU. NEVER replace any fuse of a given rating with one of a larger rating and NEVER replace a fast blow type (marked with an 'F') with one that is slow blow (marked with a 'T'). Also replacing fuses within a piece of equipment with those not specified by the manufacturer, could well invalidate the warranty. Apologies if I'm coming across as an overbearing nanny, but the safety of you and your family must come before any audible improvements that might be achieved.

Having got that off my chest, there is some interesting chat on:

http://www.6moons.com/audioreviews/net/net.html
http://forum.audiogon.com/cgi-bin/fr.pl?htech&1163625539
www.pinkfishmedia.net/forum/showthread.php?t=60469&page=3 .

You might like to try:

'Hi Fi Tuning', a fuse which uses silver wire and has gold plated end caps. £25 ea.

or

'Furutech', with rhodium plated caps, silver wire, degaussed and cryo-treated. £40 ea.

'Phonosophie', gold caps, copper on silver wire. £55 ea.

And my 'favorite':

'Isoclean', gold caps, silver wire and claimed to be directional (!)

Barry

doodoos
25-04-2009, 06:52
I have a couple of hifi tuning fuses lying about - I can't decide where to place them for best effect. Cd player mains cord, or preamp, power amp or the distribution block where it enters the wall? Maybe I should start at the source and work backwards. Any suggestions?

Spectral Morn
25-04-2009, 08:10
Niel,

My first reaction on seeing this thread was:steam:. However on reflection it would seem to be a harmless pursuit and a logical one to follow, if you are perceptive to the audible changes wrought about by changing mains leads.

The important thing to remember is that fuses are used for protection, not only of the electrical equipment but of YOU. NEVER replace any fuse of a given rating with one of a larger rating and NEVER replace a fast blow type (marked with an 'F') with one that is slow blow (marked with a 'T'). Also replacing fuses within a piece of equipment with those not specified by the manufacturer, could well invalidate the warranty. Apologies if I'm coming across as an overbearing nanny, but the safety of you and your family must come before any audible improvements that might be achieved.

Having got that off my chest, there is some interesting chat on:

http://www.6moons.com/audioreviews/net/net.html
http://forum.audiogon.com/cgi-bin/fr.pl?htech&1163625539
www.pinkfishmedia.net/forum/showthread.php?t=60469&page=3 .

You might like to try:

'Hi Fi Tuning', a fuse which uses silver wire and has gold plated end caps. £25 ea.

or

'Furutech', with rhodium plated caps, silver wire, degaussed and cryo-treated. £40 ea.

'Phonosophie', gold caps, copper on silver wire. £55 ea.

And my 'favorite':

'Isoclean', gold caps, silver wire and claimed to be directional (!)

Barry

Hi Barry

You are absolutely right......

NEVER USE, OR REPLACE A FUSE WITH THE WRONG RATING, THIS COULD KILL YOU AND DESTROY YOUR GEAR !

I think a few have maybe miss understood an element in an earlier post. Maplins call their slow blow TIME DELAY I wondered if that was the same as SLOW BLOW...thats all? THe RM200 amp says use slow blow which is what I will use.

Dave (DSJR) was referring to the common practice of playing around with fuse ratings in regard to large items drawing more current via the plug and thus through the fuse. Using larger items such as 13 amp or 15 amp it was felt offered better sound quality. I even remember some advocating the use of no fuse in plugs. I do not, nor, does AOS as a forum recommend such activity...it could be dangerous. If in doubt seek professional advice from a qualified electrical engineer.

If you don't, you do so at your own RISK.

Thanks for the links Barry...


Regards D S D L

Spectral Morn
25-04-2009, 08:24
Well that's not a question I can answer really-one man's meat etc.I personally like SCR teflons (can be had from diyhifisupply but they are not cheap! Some say they are the wasp's nipples though) Audionote coppers (from diy hificollective.cheaper than SCR but still not that cheap) Also from collective that I liked were Mundorf silver in oils-very good but perhaps would be a little too far in an analytical and detailed system.If you don't want to spend that much,a good choice would be copper Obbligatos,also from diyhifisupply.All just IMHO,you really need to try for yourself to see what you prefer.Maybe try some cheaper teflons against say a Paper-in-oil (PIO) cap to see which type of sound you prefer.Speaking very generally,PIO's tend to have a more laid-back,more organic sound,teflons being perhaps a little more upfront.You really need to try for yourself.A good source of cheap PIO's is ebay-look for the Russian ones,quite cheap and quite good actually!


Had a look ALI....wow some dear parts on these sites...we shall see.


Regards D S D L

DSJR
25-04-2009, 09:27
I should add that legislation has been tightened up somewhat since those heady days of the eighties when I did unmentionable things in the interests of getting cleaner sows ears out of dirty sows ears. I then discovered that well designed and stable kit working well within its capabilities is fairly if not totally immune to all this foo...

Neil, there is a difference between slow-blow (delay) fuses and anti-surge types, the latter being ok for switch-on surges and the former taking a little longer to blow, if memory serves. Have a look on the RS site for the specs of each 20mm type and see if it makes any sense to you.



I'm deeply suspicious of silver wired fuses with gold end caps etc. Why not just get a cheap pack of new ones and replace them every few years as they sometimes fatigue for no reason - A&R A60 amps of yesteryear were notorious in our area for popping line fuses for no real reason. NOT a good idea to replace with higher rated ones as any protection offered was removed.


P.S. Quick story which I've told elsewhere. back in the mid nineties, Audiolab started getting 8000P's and 8000M's back with blowing mains fuses (the ones on the back). Thorough testing showed nothing whatever to be wrong with the amps (and they were VERY thorough back then). Another manufacturer making mono amps started to fit 5A slow blow fuses on the back, rather than the 3A they'd previously used for similar reasons. A client was in the habit of turning on his system on Friday nights and then switching off on Sunday nights as he never had the time during the week to listen. One night, one of the power amps' rectifiers failed and went short. The fuse didn't blow, the supply caps melted, taking the other caps with them and the thing caught fire, burning the board out of recognition. Fortunately the casework contained the damage, but the amp was a complete write off, as well as the speaker drivers. getting a replacement power amp was a bit of a problem, but the manufacturer coughed up in the end..

I must admit, this experience as the supplying dealer, coupled with the arrogance of certain well known manufacturers who still seem to refuse to stabilise their products better and requiring them still to be left on for "days" before they come on song, makes me despair of parts of the dwindling UK audio industry. My very humble stereo warms up in minutes and apart from the CD player, is stable very quickly indeed, the CD player taking an hour or so for the soundstage to fully develop, as happened with all machines using the old 16 bit Philips architecture I found.

Ali Tait
25-04-2009, 10:03
Yes good advice chaps.Donlt mess with fuses unless you know what you are doing! Neil,yes can be pricey,but how much would you spend on NOS valves? To my ears different cou0pling caps can effect a greater change to the sound than new valves can.

Ali Tait
25-04-2009, 10:06
Neil,try searching ebay for pio caps from Russia.These are cheap and pretty good.I currently have 4 in my 813 amp.

Spectral Morn
25-04-2009, 16:24
Your right Ali about the NOS valve thing, though in my own case I have never done this...to much like antiques and unlike them(antiques) valves being used have a finite life (see my KT88's self destruction). Any NOS I have, I got from my Dad...FREE !

I think another piece of advice is worth mentioning here tooNEVER LEAVE A VALVE POWER/INTEGRATED AMPLIFIER ON UNATTENDED. A VALVE COULD FAIL, AND BLOW YOUR AMP UP.....Neil listen to this....please.:doh:

Solid state gear is less prone to these issues but if its very old and heavily used it might be worth thinking again about leaving it on too. Problem with amplifiers is when they go they can and do take out speakers as well.

Yes I will have a look/and think about the capacitors....


Regards D S D L

Mike Reed
27-04-2009, 14:50
Well, I'd never thought of that advantage of a valve amp. That it would be turned off when not required. Thought this was a DISadvantage!

Of course, one wouldn't normally leave a valve amp on any longer than necessary by dint of its power consumption and, I imagine, heat dissipation in warm summer weather.

Solid state, however can be and often is left on, and in the case of Naim kit, SHOULD be left on 24/7 if received wisdom is followed (with the possible exception of power amps.).

There have been cases I've read of where amps. have gone tits-up and blown speaker units, but I wonder about (a) those occasions involving a valve amp. and (b) what ghastly state of service must the amp (s) have been in.

I've read of surges, both meteorlogically or generator induced, blowing stuff up.

I've blown tweeters by overdoing the volume on low-power amps.

I'm sure there are as many other causes of hifi disasters as are caused by keeping a stable s/s amp. at a stable and constant temperature for long periods unattended.

Another point on fuses. It's a pity they're such a safety issue, as they don't half restrict the sonic capabilities of good kit. However, polishing them (or sanding, or whatever) can only improve this aspect; likewise the holder if accessible. I guess using these patent cleaners (De-oxit, e.g.) could work well, though I haven't tried. Contacts are contacts, after all!

DSJR
27-04-2009, 16:29
Mike, you're welcome to disagree with me on this, but mostly BADLY DESIGNED or BODGED equipment, as much Top End stuff is, seems overly sensitive to different fuses, mains leads, being left on 24/7 and interconnects etc IMO.

One thing about your EAR's is that they were designed using "sensible" rather than outrageous good components from the start and also using TV line output valves too. Your preamp design can suffer from feedback caps not "forming" properly, so needing plenty of time to perform at their best apparently. You may hear all sorts of little tweaky things through your 52 (hang on, it's a 552 isn't it, with quad low voltage 12V rails?), but I bet the 509's won't worry overmuch............

Mike Reed
27-04-2009, 19:03
Mike, you're welcome to disagree with me on this, but mostly BADLY DESIGNED or BODGED equipment, as much Top End stuff is, seems overly sensitive to different fuses, mains leads, being left on 24/7 and interconnects etc..IMO......

Well, I've never heard that said of high end kit (what IS high end, btw?). I cannot gainsay you on technical grounds, but just using logic and track record history I would refute this all-encompassing overgeneralisation (at best).

Surely, in order to design/produce kit which outperforms its predecessors, and (arguably) its competition, more attention to detail, component choice and clever design skills are required.

If you make an analogy with fine (expensive?) cars, both these and 'high-end' audio are going to be sensitive to the smallest changes, whether it be tyres or cables, fuel or mains, etc.

Taking track record, Naim have been making reliable, popular goods, and improving on each 'generation', for three decades or so. Not by using exotic materials, but by design philosophy. Why does this brand enjoy one of the foremost cult followings in audio? Surely not just by marketing!

Would you lump Meridian with your 'botched, badly designed' brands? My G08 CDP shows an immediate sonic gain without a fuse, AND with different i/cs. Is this suspect too?

My experience is hardly unique, Dave, and whereas my relatively cloth ears (due to age, sex, drugs and rock & roll), my younger friend's similar set-up shows even more sensitivity to change. Doesn't ALL good kit?

Two points here: Having a fully dedicated, unit discrete and hard-wired
mains system probably does emphasise these
differences. Ring mains probably doesn't.

The 509s were designed to be what they are:
workhorses that don't (by repute) even respond
to tube-rolling.

Ali Tait
27-04-2009, 19:11
Well I would say Naim's record of using 40v caps on 37v rails does not seem good practice to me!

DSJR
27-04-2009, 19:34
Top End gear - audio or cars - is most often bought by people who can buy them, not necessarily because they're "better." Naim has now entered this rarified realm, yet there are modern designs at least as good for a fraction of the cost and I'd put Glenn Croft's products forward as one alternative for your system, as well as Tim's own designs (I know both fairly well, although I know there are many others). OK, Glenn's preamp lacks mega multiple supplies, a fancy pair of boxes and remote control and cachet of the brand-name is not sufficient to command a hefty price tag, but as it's so cheap I'd recommend buying one 'cos it's so cheap and, just possibly, you may grow to love it.. You really don't need all those components for the signal to go through - input buffers, gain stages, filter circuits to stop the ancient modded power-amp circuit going unstable (for chrissakes) and output buffers for line and tape, so much more to get wrong. Mind you, it's a great way to justify £10K plus for your product isn't it - all those old fashioned regulator circuits? Little new or innovative there then.

I can't speak for car designers and manufacturers, where design at the top of the tree trickles down to the popular tin shopping-trolley/kid-carter boxes but the electronics rule-book was written decades ago at this simple audio level and most components are very cheap to buy these days. Tim himself admits that he makes male jewellery and his casework and transformers contribute muchly to the high cost of his products, along with the fact that I suspect the better EAR amps are made to order I suspect.

I remember my times with the 509's on dem. these amps were indestructible, lovely sounding and I wish I'd bought some a few years later instead of the short lived Tube Technology Genesis mono's which cost more to buy at the time, ate output valves and went through a frightening number of changes in the first eighteen months or so of production life..... I'd never have gone down the ATC/AVI route otherwise... It's taken me nearly twenty years to return to some sort of sanity :D

Spectral Morn
27-04-2009, 19:39
Well, I'd never thought of that advantage of a valve amp. That it would be turned off when not required. Thought this was a DISadvantage!

Of course, one wouldn't normally leave a valve amp on any longer than necessary by dint of its power consumption and, I imagine, heat dissipation in warm summer weather.

Solid state, however can be and often is left on, and in the case of Naim kit, SHOULD be left on 24/7 if received wisdom is followed (with the possible exception of power amps.).

There have been cases I've read of where amps. have gone tits-up and blown speaker units, but I wonder about (a) those occasions involving a valve amp. and (b) what ghastly state of service must the amp (s) have been in.

I've read of surges, both meteorlogically or generator induced, blowing stuff up.

I've blown tweeters by overdoing the volume on low-power amps.

I'm sure there are as many other causes of hifi disasters as are caused by keeping a stable s/s amp. at a stable and constant temperature for long periods unattended.

Another point on fuses. It's a pity they're such a safety issue, as they don't half restrict the sonic capabilities of good kit. However, polishing them (or sanding, or whatever) can only improve this aspect; likewise the holder if accessible. I guess using these patent cleaners (De-oxit, e.g.) could work well, though I haven't tried. Contacts are contacts, after all!

Hi Mike

The issue is not as you have described it. It is the valves themselves which are both the weakness and the strength. Valves like light bulbs can fail suddenly without warning or little warning (usually odd sounds crackling, higher hum levels or sudden brightening of the filaments inside.) My point is that it is sensible to keep and eye on things thats all....I did not so put my amp in harms way. A lesser design without fuses for each valve may well now be damaged because of what happened. Most issues with valve amps are down to valve failure (though like other things can go wrong). They do tend to be more robust though, and can be easier to fix unlike many solid state failures; which can leave an amp as a pile of scrap( I am generalizing a bit), if still working.

In twenty odd years of using valve amps this is only the third time a valve has gone. First was an EL34...blew a resistor under the valve base, fixed easily, amp working perfectly. A 6c33c blew...protection fuse went new valve replaced...Bat amp working perfectly. And most recent problem...let you all know after Thursday when I get the replacement valves.

Valve strengths, better/natural sound to my ears (in my systems) than almost all solid state amps I have heard or tried. Interestingly I am about to retry my Chapter Audio Signature pre and its natural partner the Cuplet amplifier. I like these well enough, but there is something too clean in the way they reproduce things. The noise levels are almost non-existent, blackist of black soundstages for instruments to appear out of. Excellent detail etc, but just to clean (only word I can think of. Sounds not bright or analytical, in away like most kit I opt for just to the warmer side of neutral). It lacks the soul, emotion and naturalness of my valve set ups. However just after I got my Atlas cables I used it for awhile and thought that the Chapter kit with Atlas cables went some way to curing my previous feelings, but this set up was only in situ for a short while....I jumped back to valves quickly.

We shall see, going solid state again, even just for a short time, is well, unsettling.


Regards D S D L

DSJR
27-04-2009, 19:43
A P.S.

Differences in interconnect can often be explained by impedance (mis)matching of phono/DIN equipped equipment. Decently designed modern gear is immune to mains problems and good modern power amps are fine with any suitable sensible speaker cables as long as the gauge is sufficient to the job. Many of the expensive wires on the market have very strange characteristics and it's amazing what some woven outer cover can do to change a £1 per metre cable plus a fivers (at trade bulk prices) worth of plugs into a £500 interconnect, of which the dealer takes at least half.......

I wasn't going to change this thread into a rant and for this I very humbly apologise. I have a genuine respect for people like Tim, who can design an award winning product from scratch on the back of a fag packet (he did this for MF many times I understand).

Spectral Morn
27-04-2009, 20:02
A P.S.


I wasn't going to change this thread into a rant and for this I very humbly apologise. I have a genuine respect for people like Tim, who can design an award winning product from scratch on the back of a fag packet (he did this for MF many times I understand).


I saw him do this once at a local Hi-Fi show we ran....amazing guy and I like him and his products.

As to Tube Technology....early adoption of this brand did lead to chops and changes as Zia and his team learn't there way. They did can the power ratings to high so burnt through valves to quickly. Its probably not a good idea to push the power ratings to close to a valves maximum power output IMHO. Concordant did the same with their Quad 2 based valve power amplifiers.....I was told this and did not have direct experience of this. I did like the sound when I heard their designs though, as I did/do Zia's kit (Tube Technology). I had a Unisis for awhile. Tim De Paravachini is a seasoned professional...with many many years of experience a true genius IMHO.


Regards D S D L

Barry
27-04-2009, 21:09
A P.S.

Differences in interconnect can often be explained by impedance (mis)matching of phono/DIN equipped equipment. Decently designed modern gear is immune to mains problems and good modern power amps are fine with any suitable sensible speaker cables as long as the gauge is sufficient to the job. Many of the expensive wires on the market have very strange characteristics and it's amazing what some woven outer cover can do to change a £1 per metre cable plus a fivers (at trade bulk prices) worth of plugs into a £500 interconnect, of which the dealer takes at least half.......

I wasn't going to change this thread into a rant and for this I very humbly apologise. ......

Thank goodness someone is prepared to stand up and be counted, in exposing a lot of modern interconnects for being the 'emperor's new clothes', that they are. Expensive interconnects, including mains cables, are a bit of a bete noir for me. It's not that changing cables cannot make a difference, clearly they can, it is just that they need not be expensive.

The pseudo-science 'claptrap' promulgated in promoting these items and the 'rip-off' prices sometimes charged, are an example of the exploitation of the gullible by the unconscientious. :steam:

Barry

DSJR
28-04-2009, 20:44
Back to fuses... I always liked the RS Components sourced ones. Nice bright connectors and seemingly reliable in storage and use. I'd be inclined to get a stash of these and change them every year or three.....

Spectral Morn
28-04-2009, 21:06
Thanks Dave...


I am off into town tomorrow, I'll go to a guy I know and see what he has...if not RS.



Regards D S D L

Mike Reed
28-04-2009, 22:04
i'VE JUST TAKEN OUT THE FUSES IN MY 509S, mainly out of interest (as they were only serviced by EAR a few weeks ago), but partly to polish the ends, and I found mismatching ones, to my surprise.

One was (according to T de P on the 'phone today) an old type, possibly original to the amp, no longer available. It has a copper 'helix' inside the glass and is the nicest fuse I've seen. Quite a work of art, really!

That was a T (slow-blow) 1.25amp, but t'other was a T2.5 amp; supposedly slow-blow but with a single element (odd) and looking decidedly bog-standard.

T de P's opinion on fancy fuses (and other forms of audio bling) doesn't bear repeating. However, surely the conductivity of the cap material would be important, albeit theoretically.

Off to Maplin Thursday to see what they sell, but I'm not holding my breath.

Spectral Morn
28-04-2009, 22:19
i'VE JUST TAKEN OUT THE FUSES IN MY 509S, mainly out of interest (as they were only serviced by EAR a few weeks ago), but partly to polish the ends, and I found mismatching ones, to my surprise.

One was (according to T de P on the 'phone today) an old type, possibly original to the amp, no longer available. It has a copper 'helix' inside the glass and is the nicest fuse I've seen. Quite a work of art, really!

That was a T (slow-blow) 1.25amp, but t'other was a T2.5 amp; supposedly slow-blow but with a single element (odd) and looking decidedly bog-standard.

T de P's opinion on fancy fuses (and other forms of audio bling) doesn't bear repeating. However, surely the conductivity of the cap material would be important, albeit theoretically.

Off to Maplin Thursday to see what they sell, but I'm not holding my breath.

I can imagine a lot of "colourful metaphors." might have been used.

I would have thought so. Material quality and type would alter the way the fuse conducts (but can that alter the sound?)....obviously fuses have been changed in the amps in the past, as would appear to be the case in my Music Reference RM200 amp; hence the mix of glass and ceramic fuses. I would have to say that I would have placed my self in the very skeptical camp in regard to fuses...but I did hear the hi-fi tunning fuse alter the sound. Angel Sound Audio do what I need at £18 a pop. However it can wait until I have a job, normal will have to do until then.

Maplins did not have much of a choice.....in fact the guy I spoke to in my local branch felt that glass and ceramic are the same....not so as mentioned elsewhere in this thread.

Regards D S D L

DSJR
29-04-2009, 16:42
Am I right in suggesting that valve amps' power supplies aren't going to modulate their mains' current draw like most/many SS amps do? I thought most of the voltages and current draw was pretty constant in valve gear and if that was the case, then the fuses wouldn't matter too much, as long as they were correctly specified for the job - same for IEC mains cables, some being cheap and nasty and others being heavier duty with higher current rating (the Naim one is 38A wired I understand and that one factor alone would possibly give an improvement to some power amps which modulate their power supplies so much).

Spectral Morn
29-04-2009, 23:05
Am I right in suggesting that valve amps' power supplies aren't going to modulate their mains' current draw like most/many SS amps do? I thought most of the voltages and current draw was pretty constant in valve gear and if that was the case, then the fuses wouldn't matter too much, as long as they were correctly specified for the job - same for IEC mains cables, some being cheap and nasty and others being heavier duty with higher current rating (the Naim one is 38A wired I understand and that one factor alone would possibly give an improvement to some power amps which modulate their power supplies so much).


I don't know.....


Regards D S D L

Mike Reed
30-04-2009, 17:55
I don't know.....


Regards D S D L

I don't know either! Waaaaaaaaaaay too technical / esoteric for me, Barry. Privileged info. for the few(s), i.m.o. (sorry 'bout dat!)

alb
30-04-2009, 18:25
Am I right in suggesting that valve amps' power supplies aren't going to modulate their mains' current draw like most/many SS amps do?

I think this is the case with Single Ended amps, but not sure about PP.

Ali Tait
30-04-2009, 18:33
Al is right in my very limited knowledge,though I believe valve amps in general are more immune from/to mains than sand amps.SE amps do draw power to meet the demands of the music though.PP amps not so much,hence I think less need for high-quality power supplies in PP valve amps,or at least I think you get less noticeable changes by substituting components in the PS.

Mike Reed
30-04-2009, 21:08
Can I infer from this that push-pull valve amps (like my 509s) are less susceptible to tweaks, different mains cables, fancy fuses, etc? Wonder if this would extend to mains supplies, too.

I was going to have I.E.C. sockets put in whilst they were being serviced, as they've got captive leads, because I've got a few 'fancy' mains leads to try. I decided, however, that to introduce another 'join' in the system flew in the face of logical thought.

DSJR
30-04-2009, 21:39
Mike, if Tim is servicing them, I'd leave the mains leads as captive and have him put some chunkier gauge cables in himself if the hole and grip will allow this. I'm sure he'll humour you unless he feels that the cables fitted are way over-specified as they are (I know, you want to play....... ;))

Spectral Morn
30-04-2009, 21:47
Can I infer from this that push-pull valve amps (like my 509s) are less susceptible to tweaks, different mains cables, fancy fuses, etc? Wonder if this would extend to mains supplies, too.

I was going to have I.E.C. sockets put in whilst they were being serviced, as they've got captive leads, because I've got a few 'fancy' mains leads to try. I decided, however, that to introduce another 'join' in the system flew in the face of logical thought.

My findings have been over the years that both Single Ended, Push Pull and Parallel Push Pull do indeed benefit from after market mains cables to varing degrees. Years ago it was Kimber which showed this, now for me its the like of Audience, TCI and Analysis plus and others I have tried. There has never not been a difference but in some case it has been for the worse....such as Nordost and the Hi-Fi Tunning mains cables...Fuses good cables NOT in my set up.

I know Dave and I will and do disagree on mains cables. Best thing Mike is try them and use what you like. If you can't hear it or its not to your liking don't.....simples.


Regards D S D L

DSJR
30-04-2009, 21:56
I don't think I would disagree DL, but I tend to have the opinion currently in a possibly similar vein to your amp designer. Get a great and stable sound from amply specified but standard bits and then tweak from there. I used ferrites a lot as they were cheap and easy to remove. As I've said before, our location seems to have decent and consistent mains and many of the things I heard before no longer apply here.

Spectral Morn
30-04-2009, 22:04
I don't think I would disagree DL, but I tend to have the opinion currently in a possibly similar vein to your amp designer. Get a great and stable sound from amply specified but standard bits and then tweak from there. I used ferrites a lot as they were cheap and easy to remove. As I've said before, our location seems to have decent and consistent mains and many of the things I heard before no longer apply here.

Hi Dave

Sorry I thought you were skeptical about cables...my error. Ferrites are an excellent tweek on most kit but particularly digital, phono stages and anything with a class d output or switch mode power supply.

I like Roger Modjesky approach to design...if you haven't read his web site you might enjoy it..just type Ram labs or Music Reference.

Regards D S D L

Barry
30-04-2009, 23:42
I don't know either! Waaaaaaaaaaay too technical / esoteric for me, Barry. Privileged info. for the few(s), i.m.o. (sorry 'bout dat!)

I don't really want to be drawn into this argument/discussion as I am, in general, sceptical about the improvements brought about by using 'exotic' mains cables. However it would seem to be a harmless pursuit, as long as the basic safety aspects are taken into consideration.

I can well imagine that if you are plagued with a 'dirty' mains supply, then fitting ferrite sleeves around mains cables might be effective, as might be the use of screened/shielded 3-core cable (don't rely on the screen/shield to provide the earth continuity conductor).

As to whether amplifiers, valve or solid state, single ended or push-pull are more or less dependant on, or are suceptible to, mains supply quality and therefore on 'tweeks', probably depends on whether they operate in Class A or not. Class A amplifiers draw a constant current from the power supply, and so from the mains. I would have thought that under these conditions, modulation by the audio signal of the mains current drawn by the amplifier would be negligable.

Furthermore, surely a well designed power supply filters out any mains spikes etc. ? Mains transformers are designed to be efficient at frequencies around 50Hz. They ought to present a high impedance to the high frequency components of a 'spike'. This is usually achieved by the low capacitance and high leakage inductance between the primary and secondary windings. In this respect either bi-limboid transformers (where the two windings are on separate limbs of the magnetic circuit formed by the laminations), or transformers in which the two windings are completely separate but adjacent to one another on a common limb, are better than toroidal transformers. In the latter the two windings are wound one on top of the other, and so have a relatively high inter-winding capacitance and low leakage inductance.

These are only my thoughts - I am not a circuit expert; my field of 'expertise' concerned frequencies some million of times higher than those of audio and did not use conventional circuitry at all.

Again apologies for information/opinion overload.

Regards

Barry

NRG
01-05-2009, 10:38
The power supply is in the signal path and has a large affect on the sound, take a look at the block diagram for an SE amp and you'll see how. PSU quality affects both PP and SE, SE more so...class A may draw constant idle current but faced with a varying reactive 'speaker load and signal the AC current demand is anything but continuous. If SS rectification is used the current spikes placed on the mains supply can be very large and the supply impedance becomes a factor.

The average mains TX don't form a LP filter unfortunately, HF hash and spikes will pass through them due to the capacitive coupling of the windings....and then there's DC offset that can appear on the mains saturating the TX core causing the TX to buzz, Toroidal are prone to this.

anthonyTD
01-05-2009, 11:13
The power supply is in the signal path and has a large affect on the sound, take a look at the block diagram for an SE amp and you'll see how. PSU quality affects both PP and SE, SE more so...class A may draw constant idle current but faced with a varying reactive 'speaker load and signal the AC current demand is anything but continuous. If SS rectification is used the current spikes placed on the mains supply can be very large and the supply impedance becomes a factor.

The average mains TX don't form a LP filter unfortunately, HF hash and spikes will pass through them due to the capacitive coupling of the windings....and then there's DC offset that can appear on the mains saturating the TX core causing the TX to buzz, Toroidal are prone to this.

agreed!!!
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