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Quad 33 sound quality.

Discussion in 'classic' started by Martyn Miles, Nov 14, 2019.

  1. Martyn Miles

    Martyn Miles pfm Member

    Prompted by another thread, I thought some discussion on Quad preamps might be interesting.
    I’ve not owned a 33, but I have owned a 34 for a long time.

    My main exposure to the 33 is on a friend’s system.
    He is an amplifier designer and has done much electronic work for Loricaft,
    on power supplies and head amps.
    He’s also a consultant to a few British audio companies.

    I have to say his 33/303 has always sounded excellent with other components used with it.
    He looks upon it as a reference.
    I understand the only work he has done on it is some capacitor replacement and general tidying.

    I’d like to try a 33 with my 303, but I have not been able to source one which is in the condition
    I’m looking for.
    Perhaps one day...
  2. Arkless Electronics

    Arkless Electronics Trade: Amp design and repairs.

    What yet another discussion on Quad pre amps? Is there anything left to say?
    Just in case I'll repeat my own mantra on the subject which is that they are poor. The usual "Quad can do no wrong" suspects will be along shortly to say no they are great:D
  3. camverton

    camverton pfm Member

    I’ve had Quad 33, 44 and 66 pre amps. The only one still working is the 33 although it is far from transparent sounding now. This could be due to natural ageing of some of the components as it is getting on for forty years old. Also I’m not sure that it partners well with modern equipment. Was it a low output? Much as I liked the design, and size of the 33 I really liked the Quad 66 pre and its table top remote with a rotary volume control; that is until it went wrong - twice. IIRC the chap at Quad explained that they had been a bit too quick to start using multi-layer boards and they caused many failures. I eventually gave up on it.

    I paid £299 for the 33, FM3 and 303 as a bundle from Laskys in 1982; I think they were the end of line sale. Looking at the resale values today they have held their prices very well.
  4. calorgas

    calorgas Ratty bumpkin

    I suppose anything can be used as 'a reference', as long as it remains consistent in performance.

    I enjoy my 33 in the context of my 33/303 combo. Would I use it with a different power amp? Probably not.
    I like it, it looks nice and sounds nice, and that makes me happy. I don't sit there are agonise over its shortcomings. I probably ought to find a tidy FM3 to complete the set.
    camverton likes this.
  5. Tony L

    Tony L Administrator

    Its a design classic of its era and Quad sold 120,000 of them. As I said in the other thread if you view it in the context of a full system, e.g. with 303 and ESLs, 15” Tannoys, Ditton 66s or whatever then you’d have to spend somewhere between the price of a good family car and bad house to equal that sound today, so the 33 can’t be *that* bad. Even so it has to my mind become largely obsolete as the input gain is entirely wrong for modern 2V+ sources and hardly anyone wants tone controls or filters. It has just lost its context.

    Quad were always spec-led, and whilst I can’t immediately dig anything up my guess is the 33 will be down in the 0.0x% range for THD etc and with a perfectly respectable noise floor. It was also probably the first audio component with a tone/filter bypass button allowing for a cleaner signal path, and that’s certainly how I always used mine back in the day. I do currently have a very tidy and sympathetically rebuilt example, but I’ve not really used it much as I just don’t have the context. I have two 303s, one used with a high-end Verdier valve preamp, the other in the TV system with an Audio Synthesis stepped attenuator passive. It is unfair to expect the 33 to compare with either, especially with digital sources, so much as I love the aesthetics it stays on a shelf as an ornament.

    Bottom line is no audio component sells 120k and ends up in recording studios and radio stations if it is crap. It simply doesn’t happen! I’m not sure you’d want to use one in anything other than a vinyl, FM and tape retro-system context today though.
    camverton and chartz like this.
  6. chartz

    chartz pfm Member

    I have to agree with Tony on this one.
    A 33 on a good day - fresh caps, clean contacts and pots - can sound very good, in the context of a 303 or a 405 and ESLs, which are very revealing things. They gel as they should by design.
    Some say that a 15 V supply improves it.
    Perhaps not my best preamp (that would be a Technics SU-A4 or a valve Hiraga) but really nice sounding with an equally nice 3D sound picture.

    I’m trying a restored 34 which sounds slightly inferior, especially on LP.
  7. mjkelshaw

    mjkelshaw pfm Member

    Hi Martin,
    Unfortunately most of the 33's which I have seen for sale in recent years have been 'cosmetically challenged'. The internals, of course can be restored, or even 'modernised' - see the 'Amplabs' & 'Quad Revisie' websites.

    I've read that the FM3 is allegedly 'better' than the FM4, mine has certainly been more reliable, whereas my FM4 is now 'back in it's box' yet again, and waiting for attention.

    Mike Kelshaw
  8. chartz

    chartz pfm Member

    My FM3 doesn’t sound better than my FM4. Both have been re-aligned and work faultlessly.
  9. Arkless Electronics

    Arkless Electronics Trade: Amp design and repairs.

    How many Mini's and VW Beetles were sold? How do they compare with today's models? Time, place and context...
    ampedup likes this.
  10. Tony L

    Tony L Administrator

    Irrelevant argument. The Quad 33/303/ESL system was state of the art high-end in its day and even now 50 years later would beat all but the very best modern hi-fi systems.

    As someone who constantly bleats on about specs/measurements and attacks anyone who listens/buys on subjectivist impressions I’d be curious as to what published specification of the 33 you find so awful? As I say above I bet the noise floor is perfectly acceptable and the distortion right down at the 0.0x% level. Quad always sold on specification so it will have been seriously good back then, and as audio is old technology, it will still be pretty good now! The thing that has changed is its context; no one needs to amplify such low level line signals, folk who use vinyl want an MC cart option, few want tone controls etc (and many of us hate DIN leads!). It just no longer makes sense in a modern digital source system.
  11. Arkless Electronics

    Arkless Electronics Trade: Amp design and repairs.

    For maybe the 30th time I will state again that I am a subjectivist through and through! BUT only in those areas where it's even possible for there to be differences. Hence amps, speakers, phono stages etc etc all sound different and measurements tell only part of the story. The ear must be the final arbiter. Now in lunatic fringe areas of hi fi where it's not even possible for any difference to exist beyond one's own imagined placebo effect and expectation bias then of course it's a different matter! Things you would have been laughed at for even suggesting back in 1975 have not suddenly started working, nor should any one be taken any more seriously for suggesting them today, the laws of physics have not changed... Anyhow you tried to get a rise from me for suggesting 33 is poor is so there it is;)

    The 33 and 34 are poor, the 303 is better but way below average by todays standards. ESL57's are still state of the art. 33/303 are however perfectly adequate for a retro system and to enjoy music from... it's when people start claiming they are still really good even by modern standards and you'd have to spend thousands to beat them that I start thinking "whoa now, hold on there!" Hence the highly relevant comparison to the Mini and Beetle... they sold loads, it was good in its day, are icons and still perfectly usable as a practical classic... compared to a modern car though it's slow, noisy, uncomfortable, drinks petrol and probably has bad emissions....

    I would take something like a modern £250 Denon or similar over a 33/303 all day everyday. YMMV:)
    ampedup likes this.
  12. mjkelshaw

    mjkelshaw pfm Member

    With repect, I wasn't claiming that my FM3 'sounded' better than my FM4, both have been serviced, and when working, I prefer the ergonomics of the FM4.
    However, my FM4 purchased 2nd hand, was initially serviced prior to installing it into my veteran system. It has in fact been back a couple of times to the 'works' in Cambridge, but once again has lost it's ability to tune.
    I have therefore, 'swapped in' one of my other tuners, a Meridian 504 which has never had a problem and probably, by now has cost me less to buy than the combined costs of purchase + several service charges + plus delivery charges for the FM4.

    Mike Kelshaw
  13. Zombie

    Zombie pfm Member

    I've owned a 33 twice. First in my youth, later bought one for nostalgia together with a 303. The 33 was "in the face" didn't even restore it, the 303 got a full restore and sounded like a good QII. Shifted both om later. Looks very nice and I assume a "modernisation" would do miracles. Modern gear probably have better regulation.
    Can't see why a proper design with a few transistors, resistors and caps and better regulation would sound worse than a modern amp with solid state switches, lots of ICs and passive components and digital bling-bling. Tube designs after often hailed for being simpler, thus better sounding...so why not a discrete transistor design?
    chartz likes this.
  14. Tony L

    Tony L Administrator

    Depends on your context, but with vintage speakers such as ESLs, Tannoys etc the Quad will kill modern solid state. It sounds way, way closer to say a Quad II, Leak or Radford in this context than some dry and over-damped modern amp, and yes, I have compared all at length. Sure, if I wanted to use Mission 770s or whatever you are using these days I’d pick something very different. Context, always, is everything when it comes to audio. Cost is of little issue to me, the 303 just seems the right tool for the job of driving my similar vintage studio Tannoys, so that’s what I use!
  15. chartz

    chartz pfm Member

    Recent measurements here.
  16. Martyn Miles

    Martyn Miles pfm Member

    As I thought, many opinions and thoughts on the 33.
  17. Zombie

    Zombie pfm Member

    Similar values in the Swedish hifi handbook of yesteryear, 0,03 % IIRC.
  18. Yank

    Yank Bulbous Also Tapered

    The number of acceptable preamps designed before the 1970s is vanishingly small. The number of acceptable transistor preamps designed before the 1970s is non-existent.

    Power amps attained maturity about two decades earlier than preamps, with only a couple of exceptions.
    Arkless Electronics likes this.
  19. Zombie

    Zombie pfm Member

    So what did their creators do wrong?
  20. Yank

    Yank Bulbous Also Tapered

    Noise mostly.

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