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Refurbished, serviced, rebuilt ... what's in a word? My "puzzler ... [is] sore" (Dr. Seuss).

Rosewind

Rosewind

Lost in Translation
As some of you may have noticed, I have been looking for a classic power amp to go with my still forthcoming ESL 57s. I have looked at quite many sales ads and have come to wonder what exactly the difference is between ...

- a refurbished unit
- a (fully) serviced unit
- a rebuilt unit

As the title suggests, just like the Grinch, my "puzzler" is sore from second-guessing the sales ads.
 
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I suspect the terms are pretty much interchangeable. With ESLs I’d want to know which if any panels had been replaced and with what. Be aware that One Thing Audio rebuilt ESLs have a different treble panel and apparently a rather different treble sound to the originals, i.e. the last thing you would want is one side done and one not!
 
It does indeed. One man's "rebuilt" is another's "serviced". Unless you go to great lengths and meet a service engineer who will tell you, you won't know what exactly has been done. Have all serviceable parts been changed, or just the ones that looked iffy? Have they been like for like exchanged? Have more modern and better components been used? This may be better, or not, for you. Have any modifications been carried out? If so is this what you want?
 
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Ah. My ESL 57s are not standard because of the upgraded side panels (bass panels) from One Thing Audio. As I understand it, One Thing Audio will first try to repair the original bass panels, but if they cannot do this, they offer their own bass panels as a replacement (yet they call it an "upgrade" = supposedly meant to sound better than the originals?).

Some people think that this makes them sound un-original = too bright. Others disagree and say that they sound like Quad ESL 57s would have sounded when new. I will never know who is right.

Anyway, I may get a heavily rebuilt Quad II Classic integrated (converted to power amp only) to drive them with. That will be 2 x upgraded Quad then.
 
Rosewind said:
Thanks Tony. Did not know that abut the ESL 57s.
So the same thing goes for amps?
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Yes, very much so! I’d not profess to have any real electronics knowledge yet even I can tell a lot of the vintage Leaks and Quads that pass through eBay have been taken a long way from their designer’s intent, some are just horrible botches, others use modern components that will sound very different from the period-correct carbon resistors and paper-in-oil caps. I love this kit as what it is, it sounds so ‘right’ when properly serviced why the hell would you want different? The last thing I’d want is some self-professed “expert” thinking they can do better than Harold Leak or Peter Walker so I’d not go near such examples unless they were very easy to rip out and start again in a proper period-correct true restoration sense.
 
Tony L said:
Yes, very much so! I’d not profess to have any real electronics knowledge yet even I can tell a lot of the vintage Leaks and Quads that pass through eBay have been taken a long way from their designer’s intent, some are just horrible botches, others use modern components that will sound very different from the period-correct carbon resistors and paper-in-oil caps. I love this kit as what it is, it sounds so ‘right’ when properly serviced why the hell would you want different? The last thing I’d want is some self-professed “expert” thinking they can do better than Harold Leak or Peter Walker so I’d not go near such examples unless they were very easy to rip out and start again in a proper period-correct true restoration sense.
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Well you would not want from me then as I can do vastly better than Harold leak or Peter Walker and do so in my refurbs. The LAST thing I do is attempt any sort of "period correctness" and I aim to improve old equipment to considerably better then new spec and sound quality.
I would always remove paper in oil caps and carbon resistors (the worst available IMO) and replace them with modern metal film and polypropylene.
So basically I proudly do everything you say you want to avoid in a refurb... With great results!
 
Indeed. I’d not want you to paint a moustache on the Mona Lisa, add a bit more red to a Rothko or whatever either! If I buy something designed by Harold Leak, Peter Walker, Paul Klipsch, Jim Rogers or whoever that is what I want to listen to, if it wasn’t I’d buy something else!

Your view regarding carbon resistors and PIO caps is in direct conflict with the collectors of these amps and would IME reduce the value quite dramatically. If you want to “improve” things I’d stick to modern Chinese tube amps where there is a lot of scope and nothing of value to damage.
 
Carbon resistors are indeed bloody awful. Never encountered paper in oil caps, thankfully.

You get a lot of the "original is best" arguments in the classic car world, with a similar level of (lack of) agreement. I suspect that there are even people who stick with original grade and vastly inferior period lubricants. Good for them, I hope that the limited use that most classic cars will ensure that the period correct but avoidable engine wear thus caused won't come back and bite them.
"Ah yes, I have the original 1955 Mk 1 Stinkley Special, absolutely original to the last bolt, including the original Mk1 brake design that was discontinued for the Mk2 following the 1956 Cheshire Bus Stop Disaster. Original is best, you just have to keep cars within their design limitations."
 
Much has been learned since 1960 and just as importantly there has been leaps and bounds in component technology. Be assured that the likes of Leak and Walker would not have used those parts if they had something better available!

PIO's are the worst capacitors available and are removed on sight when I come across them. It is very rare to find an original one which has not failed and NOS ones are now almost all duds.

Many obvious limitations of vintage gear can be got around by using modern parts and techniques and I'm sure the designers would have done the same things if they had access to the technology at the time.
 
It depends what you want - both approaches valid. I must admit I modify the hell out of kit I play with or service, but it is a conscious decision based on my interest in knowing what is possible with better components, knowing full well resale value may be impacted. Worst itch I had was a red led Nait 1 I picked up in Dublin for €50 - it sounded good, and I desperately wanted to update it with more modern bits and values to see what was possible...in the end I resold it unserviced (for €550 to Taiwan :)).

Another recent example was a CD3.5 - but on that, after repairing and listening to it, I did fit mod7 from Martin’s Acoustica site as an almost no brainer.

I mostly buy kit to listen to it, as I didn’t have the funds to do so as a kid, so it is always a decision on listening to it (generally after repairing it) to see what I do next.
 
Arkless Electronics said:
PIO's are the worst capacitors available and are removed on sight when I come across them. It is very rare to find an original one which has not failed and NOS ones are now almost all duds.
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New PIO caps are available and the NOS Russian military K40Y-9 are superb value and are the choice for most Leak and Quad restorations, e.g. that’s what Classique Sounds use and they have about the best reputation for proper Leak/Quad restorations out there. As I understand it they have not had any of these caps fail yet. I used these caps in mine and the amp sounds stunning, just ‘right’ tonally with none of the over-brightness some report from restorations with modern film caps etc. I also bought a spare set and all tested in spec on my little capacitance meter before I boxed them up.

As mentioned above there are different approaches, but I have no interest in your take on a Leak, Quad or whatever, I want it as close as possible to what it was when new. Nothing more, nothing less. I run this stuff because I just love how it sounds! If I wanted something more “modern” I’d run Conrad Johnson, Krell, Mark Levinson, Chord, Naim or whatever.

PS I feel the same about speaker crossovers too! I’ve lost count of how many so called “upgrades” I've heard with Tannoy crossovers, I even wasted fairly substantial money on some, but they all ‘change’ rather than ‘improve’ to my ears, and in the process end up losing the thing I love about the speakers in the first place! This being the reason when it came to rebuilding my 149s I went like-for-like at every point.
 
Each to their own... As I said I would never use a PIO, unless I suppose specifically requested to by a customer and then I would try and persuade against it. They are unreliable and have no technical benefit to add to things. There are good reasons that PIO's are only used in vintage rebuilds these days.. capacitor technology has advanced considerably in the past 60 years!
In my rebuilds I try to release the best the design is capable of when no longer held back by ancient tech components. I'm aiming for "better than original".

We obviously want very different things from our hi fi. You want "original tone" and I want to banish all "tone" as it's a colouration! Most of your favourite items of equipment are ones which, whilst I quite like them and respect their place in history, I find them ultimately rather too "soft", "rounded", coloured, lacking some transparency, "speed", "grip" and detail.... I've no doubt that conversely you would find the stuff I rate most highly to be "over detailed", "spotlit", "in yer face", "etched" etc!!:)
 
Boutique PIO caps are widely used today at the top end of the audio market, so you are somewhat incorrect there. They also have a far longer lifespan than electrolytics, so I’m not really getting your argument here, especially given that your background is from from MF where so much of the early stuff is over-heated, blown, dead and retired unlike the Leaks and Quads I so value, despite being a mere fraction of the age! There are many Japanese audiophiles still running vintage Quads, Leaks etc with their original PIOs (I assume after reconditioning them on a variac or whatever)! I’m too OCD to do that, but I want as close to the original voicing as I can get.

I agree with your second point and it is no secret I detest the searing brightness many ageing audiophiles seem to crave these days. Hi-fi shows usually give me a headache, but I never come back from listening to a live string quartet, Steinway grand or whatever at the RNCM and think my hi-fi is dull or over warm. Walker, Fountain, Leak etc etc knew what they were doing, they achieved what is to my ears a very natural and neutral tonality. Remember this is the stuff from the era where ‘live vs. recorded’ dems were popular. My systems may not suit you on loud rock music, but on classical and jazz, my normal diet these days, they are very even and balanced, and this is even borne out by room plots too!
 
Tony L said:
Boutique PIO caps are widely used today at the top end of the audio market, so you are somewhat incorrect there. They also have a far longer lifespan than electrolytics, so I’m not really getting your argument here, especially given that your background is from from MF where so much of the early stuff is over-heated, blown, dead and retired unlike the Leaks and Quads I so value, despite being a mere fraction of the age! There are many Japanese audiophiles still running vintage Quads, Leaks etc with their original PIOs (I assume after reconditioning them on a variac or whatever)! I’m too OCD to do that, but I want as close to the original voicing as I can get.

I agree with your second point and it is no secret I detest the searing brightness many ageing audiophiles seem to crave these days. Hi-fi shows usually give me a headache, but I never come back from listening to a live string quartet, Steinway grand or whatever at the RNCM and think my hi-fi is dull or over warm. Walker, Fountain, Leak etc etc knew what they were doing, they achieved what is to my ears a very natural and neutral tonality. Remember this is the stuff from the era where ‘live vs. recorded’ dems were popular. My systems may not suit you on loud rock music, but on classical and jazz, my normal diet these days, they are very even and balanced, and this is even borne out by room plots too!
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Boutique ones yes but you'll not see any PIO's from mainstream capacitor manufacturers outside of certain specialised applications... paper with other insulations are still used for a few things like some suppression caps. They can have a longer lifetime than electrolytics but usually don't. I often find original electrolytics in old leaks etc to be serviceable, if past their best, but have never seen an original PIO that hadn't failed leaky in decades.
It may be possible to rejuvenate them by heating in a suitable oven for a long period, as it is mainly moisture ingress that causes there failure, but I'm speculating there...
 
This is one reason the Russian military ones are so good - they are very solid and sealed with glass IIRC, being designed for a far wider range of temperature and vibration extremes than you’d ever find in audio. Try some (link), they are cheap as chips, last pretty much forever and the hi-fi and guitar tube amp and guitar geeks all love them, often preferring them to crazy expensive boutique stuff. The overwhelming body of positive opinion and proven reliability is why I went with them, my Leak was a cost-no-object rebuild, I’d have happily stuck top-end boutique stuff in if I thought it was any better/closer to original intent. I expect them to last for the rest of my life, though I have a spare set just in case! I’ll certainly be using them again on the TL12 Plus.
 
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Do you not think that maybe the reason for the popularity of PIO's (and various other parts eg carbon composition resistors) in hi fi and guitar amps is simply that when the equipment was new this is pretty much all that was available, and therefore fitted as standard, and that decades later enthusiasts (non engineers) assumed they were fitted due to having the best sound, "the vintage sound", "THE sound" etc without realising that in fact they were all that was available at the time and that there is no way they would have been used if polypropylene had been available at a reasonable price?
I'm guessing that had polyprop caps been the norm in 1960, and then something even better had come out since, then everyone would be fitting polyprops "for that vintage sound", "just like Hendrix"!:)

A perfectly functioning PIO is certainly not a bad cap, and in military spec form will be much more reliable than a civi version of course, but a poly is better in every electrical characteristic, and in reliability.

The best vintage cap IMHO is the Mullard "dog bone" polycarbonates, which over-lapped with PIO's time wise, and which are so reliable I never so much as test them let alone change them! I have never seen a dud one or spoken to anyone who has known one to fail!
 
Arkless Electronics said:
I'm guessing that had polyprop caps been the norm in 1960, and then something even better had come out since, then everyone would be fitting polyprops "for that vintage sound", "just like Hendrix"!
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I’m sure they would, but Hendrix’s sound would have been brighter and leaner, especially given your logic would no doubt dictate he used a nasty solid state amp, and with that he may never have made it!

Had Quad, Leak or whoever had access to modern components they would no doubt have used them, but, and it is a very significant but, they would have almost certainly changed other aspects of the design to compensate for the different characteristics. Come on, you are a bloody electronics engineer; you know any given component has a combination of values, so some idiot flinging bright yellow film caps and metal film resistors into a Leak is going to *alter the voicing*. This is just basic fact and those serious about Leaks etc are pretty unanimous about avoiding doing this. It is just not a good thing if one wants the legendary performance of the original, and if one doesn’t why the hell own it? At this point the question becomes does one want to listen to the work of Peter Walker, Harold Leak or other true greats, or Jez Arkless or whatever current designer. That is for the punter to decide, but it saddens me to see sought-after kit irreparably botched and damaged as so much going through eBay seems to be.

As I said above I run this stuff because I love it; I love the sound, I love restoring it and I love that what I do adds real value and preserves for the future. If I wanted modern high-end sound I’d just walk into a hi-fi shop and buy it!
 
“ .... That is for the punter to decide, but it saddens me to see sought-after kit irreparably botched and damaged as so much going through eBay seems to be.

Tony’s post nails it.

If you want something different and more modern than the classical Leaks and Quads, there is plenty of choice without molesting and modifying these classical pieces.

ATB from George
 
Has anybody heard a Quad, Leak with all original components that are exactly within specification (under all temperature conditions) to be so sure as to what they originally sound like.
Where can one buy original carbon resistors that are still within spec, non leaking TCC paper in oil caps etc.?
 
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