A visit to Marco's

[Marco]

Hi Alan,

I really enjoyed your system Marco, I didn't say on the day but when we moved to vinyl I got the same feeling that I always do. With any system of reasonable quality vinyl always gives that better 'organic' feel and yours was no exception.

Cheers, I kind of got that feeling from your reaction (and Darren's) as soon as we started spinning vinyl. However, it's nice having access to three different sources, all of which I can enjoy listening to music on with similar standards of sound quality

The brilliant thing is with such a sorted system that you know so well is that you can recognise and pinpoint the variations with different kit and I thank you for that.

Yeah, I know where you're coming from. The system has essentially stayed the same now for about 5 years, with mainly just some tinkering to the 'infrastructure', so yes I know it intimately well (strengths and weaknesses), which thus makes it reasonably easy to identify differences whenever 'alien' components are used.

I guess the spaciousness of the mid range on the copper amp in comparison is down to the copper being class A. Of course the benefit of going down the hybrid route is not requiring the expense of the quality iron needed in an all valve power amp.

Yup, I do agree. The quality of the iron is where the bulk of the cost comes from on a 'conventional' valve amp, so much so that you can virtually tell how good its going to be from just lifting it up! The Copper amp features very large mains and output transformers, hand-wound by an ex-engineer for GEC.

I also think that the 'sonic signature' of valve amplifiers is largely governed by the designer's choice of output tubes, and of course how well or otherwise the circuit employed gets the most out of them. At this point, it may be a good idea to remind folks of which valves your AIR and KIN unit use, and some other technical specs for both items, such as the power output of the amp, etc.

I didn't quite realise your spend on the Rpi so that explains why it was so close behind the others sources...

Yes the cost of the Paul Hynes linear PSU bumps things up a bit, but still to no where near the cost of my CDP/DAC or turntable, so the RPi, even at £400, still represents extraordinary value for money!

Btw, looks like we'll be seeing each other again soon, as I'll also be going to Macca's place on Monday

I'd like to try and get the basics of his system sorted out, so that the wee daftee can start enjoying his music again. It's no fun at all when your system just isn't doing it for you. I've been there before, and it's a royal head-fuck.

Marco.

[lurcher]

Thats just one area where "it will be good enough" can come and bite the combined solution.

One for Jez. In a typical jfet cascode, the triode on top of the jfet has its grid taken to a DC voltage level. Now that point may either be AC 0v, or a whole complex set of noise sources and inductances depending on how hard you want to look. One thing 15 years of phono stages has taught me is that IT ALL MATTERS.

[Marco]

Which post are you replying to there, Nick?

Marco.

[Arkless Electronics]

Thats just one area where "it will be good enough" can come and bite the combined solution.

One for Jez. In a typical jfet cascode, the triode on top of the jfet has its grid taken to a DC voltage level. Now that point may either be AC 0v, or a whole complex set of noise sources and inductances depending on how hard you want to look. One thing 15 years of phono stages has taught me is that IT ALL MATTERS.

It certainly does all matter! I find my 1nVrootHz balanced input low noise amplifier hugely useful in sussing out the lowest noise sources, when fed into a B & K rms mV meter which also feeds a channel on the scope. The 1500MHz spectrum analyser is a boon for tracing the spurious oscillations at 100's of MHz that can occur now and then and not be visible on a scope. All the above applies equally (at least!) in the design of regulated supplies to power it!

I can see what you mean about sometimes more resources will be spent on separate units, which usually cost much more combined and may result in better SQ due to separate power supply regulation .... however, other than this possibility in some cases, I don't think there is any reason why separate head amps/SUT with a MM stage should beat an all in one unit. I can though think of reasons why an all in one could/should beat the separate headamp/SUT into MM stage!

An all valve headamp, or front end in an MC phono stage, can sound fantastic and I have indeed done this. Whether it's any better than a jfet is another matter. I haven's had the chance to compare them and they can both sound incredibly good! The issue with using valves here is price and reliability. Only the VERY BEST valves can be used, several usually need to be used in parallel to get near the low noise of the jfet and lots need to be bought to select only the best (lowest noise) valves. The requirement for low noise is so stringent that one or more of the valves will usually "go off" a bit and start hissing or making rustling noises within a few months.... or days! I certainly haven't tried all the valves suitable for use in a headamp, some very high Gm types are available at huge cost which look very interesting in the role but whether or not they can kkep quiet for long enough is another issue... and the best of these type are truly silly money. Like £200 each Not good to find "nah this ones a bit hissy"!

[Marco]

I can though think of reasons why an all in one could/should beat the separate headamp/SUT into MM stage!

Yup, but as ever in this game, the final arbiter is your ears...

Marco.

[Marco]

An all valve headamp, or front end in an MC phono stage, can sound fantastic and I have indeed done this. Whether it's any better than a jfet is another matter. I haven's had the chance to compare them and they can both sound incredibly good! The issue with using valves here is price and reliability. Only the VERY BEST valves can be used, several usually need to be used in parallel to get near the low noise of the jfet and lots need to be bought to select only the best (lowest noise) valves. The requirement for low noise is so stringent that one or more of the valves will usually "go off" a bit and start hissing or making rustling noises within a few months.... or days! I certainly haven't tried all the valves suitable for use in a headamp, some very high Gm types are available at huge cost which look very interesting in the role but whether or not they can kkep quiet for long enough is another issue... and the best of these type are truly silly money. Like £200 each Not good to find "nah this ones a bit hissy"!

Indeed, although I'm perfectly happy combining valves and SS, for vinyl replay (not being a valve 'fanboy'), with a view to getting 'the best of both worlds'...

That's why the Paul Hynes head amp I have uses FETs, going through the 6SL7 valves of the Croft MM stage, which incidentally are matched and balanced grey-glass, 1940s military-spec RCAs, and not only sound superb, but have provided trouble-free use now for nearly two years - and the Croft gets used for many hours listening every day!

These days, I exclusively only buy matched and balanced vintage NOS valves, from sellers with professional valve testers, who show pictures on their ads of the valves sold being tested, and the subsequent measurements taken.

Yes, that still doesn't give an absolute guarantee that they'll last, but it tends to sort the wheat out from the chaff, as it were, and I've not had many problems, compared with current production crappy Chinese and Russian valves, which tend to do all the things you say within months, sometimes weeks, or even days!

Another veritable example of: 'They don't make 'em like they use to'.......

Marco.

[Arkless Electronics]

Indeed, although I'm perfectly happy combining valves and SS, with vinyl replay (not being a valve 'fanboy'), with a view to 'getting the best of both worlds', which is why the Paul Hynes head amp I have uses FETs, going through the 6SL7 valves of the Croft MM stage, which incidentally are matched and balanced grey-glass, 1940s military-spec RCAs, and not only sound superb, but have provided trouble-free use now for nearly two years - and the Croft gets used for many hours listening every day!

These days, I exclusively only buy matched and balanced vintage NOS valves, from sellers with professional valve testers, who show pictures on their ads of the valves sold being tested, and the subsequent measurements taken.

Yes, that still doesn't give an absolute guarantee that they'll last, but it tends to sort the wheat out from the chaff, as it were, and I've not had many problems, compared with current production crappy Chinese and Russian valves, which tend to do all the things you say within months, sometimes weeks, or even days!

Another veritable example of: 'They don't make 'em like they use to'.......

Marco.

You are rather underestimating just HOW quiet the valves in a headamp need to be compared to those in an MM stage! Rather different characteristics are required in a valve suitable for a head amp also. Your 6SL7's whilst fine valves would probably drown out out all the quiet bits with hiss if used in a head amp

[Marco]

Yeah, I know. I wasn't referring to a head amp (never heard a valve head amp, only SS), but simply the valves used in the MM stage of the Croft

Like I said, I'm no blinkered 'valve fanboy'; I remain open-minded to the sonic possibilities of any good form of technology, and so tend only to use valves where I consider that they have the potential to produce the best results.

That's also why I'm not averse to using a passive preamp as a line stage, and/or listening to vinyl through that, with the Croft, via its tape outputs, which also sounds excellent.

I don't need to have valves everywhere in the replay chain; indeed it can be advantageous not to do so, which is why you'll likely never see me employing them on my digital sources (or using buffers, etc), as to my ears, they nearly always colour the sound to an unacceptable degree.

However, as ever, the resulting efficacy of applying valves, in such a way, will largely be governed by how judicious, and therefore successful, is their implementation within a given circuit.

Marco.

[Firebottle]

........... efficacy of applying valves..........., is their implementation within a given circuit..

Apart from the 'IT ALL MATTERS' being so true the circuit configuration is also crucial. The 'super linear' circuit I use enables the valve to act as an almost perfect amplifier, enabling top notch performance without needing to source rare and costly valves.

I do veer to using non mainstream types that are both plentiful and inexpensive, PCC85 in line level applications and PCC189 for phono amp duties.
Also using hybrid design definitely helps 'with a view to getting 'the best of both worlds'...'

Firebottle KIN details: http://theartofsound.net/forum/showt...hono-amplifier

Firebottle AIR details: http://theartofsound.net/forum/showt...ower-Amplifier

[The Black Adder]

+1 Nick.

I remember you bringing that MC phono stage you designed/made. I was using a SS one before and the difference was simply amazing.