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I've always found that people claim valve amps to be silent tend to never have heard a truly silent solid state setup. I've yet to hear 'totally silent' valve amps there's always residual whisper close to the speakers.
 
I've always found that people claim valve amps to be silent tend to never have heard a truly silent solid state setup. I've yet to hear 'totally silent' valve amps there's always residual whisper close to the speakers.

The Prima Luna is as quiet as a typical solid state amp (e.g. Quad, it's a lot quieter than any Naim or Densen I've owned). Also worth noting that a) I have hugely efficient speakers (95db), b) live in an area with next to no ambient noise as the quiet road outside is about 25 foot below my house, and c) my speakers can properly reproduce 50Hz and well below (unlike many), i.e. if there's some noise from my system I'll hear it! The Leak is certainly noisier than the Prima Luna, but as I say that's quiet by solid state terms, let alone tube. I'd say the Leak was about what one would expect from a little tube amp, most hiss and hum a little IME, especially in the context I describe here. It's not an issue, though getting the deck back on form definitely is. CD sounds bloody amazing so it's not the Leak's fault, I now need to swap some stuff out upstream of it.

As an experiment I'll possibly try a Quad 34 later, though mine is a really early one and is so high gain as to be virtually unusable in any modern context, I bet I can't get beyond the first click on the volume knob into the Leak...
 
I must revalve my Stereo 20 when I get back to the UK. Mine was completely Mullarded when I bought it, and sounded absolutely wonderful, but I haven't had it in running condition for about three years. Agreed on the preamp question, I always used mine with a passive pre, there's no need at all for an active gain stage in front of it.
 
What did you use regarding vinyl Ian? I'm getting really weird results with the passive, CD sounds amazing, a definite step up from what I'm used to, but vinyl is dead in the water, just lifeless / gutless - a cheapo Cambridge 640 phono stage beating my 1200 quid Dynavector too. I can't explain that one at all.
 
I was using my 47 Labs Phonocube and an Ortofon Rohmann (low output MC). The Phonocube is very low noise and very high gain (so much so that I had to use it with an attenuator when I was running the full 47 Labs setup into Lancasters - couldn't get beyond the first click on the volume control without it being way too loud). That seemed to work fine with the Stereo 20 into my home made Jordans. Does the Dynavector have any DIP switches you can play with?
 
Does the Dynavector have any DIP switches you can play with?

No, sadly not. It's a weird thing, hard to put into words - it's like all the balls / slam / heft / punch has been removed, i.e. all the things a 301 is good at in other words. This is usually a very punchy and enjoyable front-end. That the Cambridge now beats it certainly indicates the DV is not happy driving the Leak via the passive. I guess this means something has to change; so that's either a new phono stage or a new preamp by my reckoning. If the latter I'd prefer to get one with the phono stage built in to save space / wires etc.
 
How annoying. I used mine with a Creek passive and (briefly) with a borrowed older Rothwell Indus (he still makes these, the old ones can be had quite cheap). They both worked fine, although neither of them had built in phono. Maybe worth trying an active pre with adjustable output sensitivity - Rega used to supply the Cursa 2000 as a passive (which maybe was a special order), or as standard at a range of outputs from 0.25v upwards, adjustable by internal dip switches, and it has a decent phono stage (and a decent gain structure - the volume control is quite smart, it deliberately gives you more range at the lower end). You should be able to find one of those for not too much money secondhand. I heard a Cursa into a Stereo 20 and refurbed ESL57s at one of Terry Bateman's Leak fests a few years back at Roy Gandy's house, and it sounded fantastic.
 
Tony, Have you used the same phono stage and passive into other power amps with no problem? Do you know what value the pot in your passive is?
 
Tony,

Time for Dr. Robert to make a house call.

Joe
 
Tony, Have you used the same phono stage and passive into other power amps with no problem? Do you know what value the pot in your passive is?

The passive is normally in the other room with a Quad 303:

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This is hooked up to a pair of Klipsch Heresys and I use it with the TV (Skybox) and digital audio via a MF V-DAC, both sound great. I also have a TD-124 and the little Cambridge running through it, though again vinyl does not sound special in this system. It wasn't until I took the TD-124 through to the main system (at that time Dynavector, Prima Luna P2) that I realised just how good it is. It really is a superb sounding turntable and somewhat wasted in my second system. So thinking about it I don't think I've ever had vinyl sounding good via the little Audio Synthesis passive. I don't know what type of attenuator it has, but I'd expect a very good one as when it was current it was anything but a cheap item. It sounds lovely on CD!
 
Tony, put the PL back in for a moment just to make sure the DV isn't broken (this once happened to me; I installed a new power amp and the sound was terrible; took me ages to find out that the problem was caused by the pre which had chosen this precise moment to develop a fault).

How is the input impedance set on the Leak? A resistor to ground on the input? If yes, ask on the Leak board if it can safely be set to a higher value. Shouldn't be too hard to achieve.
 
Tony, put the PL back in for a moment just to make sure the DV isn't broken (this once happened to me; I installed a new power amp and the sound was terrible; took me ages to find out that the problem was caused by the pre which had chosen this precise moment to develop a fault).

I'll do that sometime later.

How is the input impedance set on the Leak? A resistor to ground on the input? If yes, ask on the Leak board if it can safely be set to a higher value. Shouldn't be too hard to achieve.

I have no idea what the input impedance of the Leak is by default, and beyond that it's way over my head. I also don't know the output impedance of the Dynavector, it's not mentioned on it's spec sheet. There are indeed many things that I do not know.
 
A quick google found that that the Stereo 20 has an input impedance of 1 MegOhm. That is definitely high enough, unless yours has been modded (very unlikely).

Must be the PAS-02.

P.S. there's loads on this stuff on pfm!

Edit: what cable are you using between the passive and the Leak?

Some discussion opf stereo 20 and passive attenuation here. I'm sure one of our diy bods will be glad to make up a suitable box.
 
Edit: what cable are you using between the passive and the Leak?

1 meter Klotz AC110 soldered up with Neutrik ProFi plugs, exactly as detailed in Rob's Reference room FAQ here. I've tried a few different leads between phono stage and the passive; more Klotz / Neutrik, Gotham GAK-1, Spectral MI-330. Bizarrely the complex Spectral sounds best. The CD is hooked up to the passive with Gotham.

PS I don't want to mod the Leak at all, I'd far prefer to buy stuff that works with it, e.g. I've no issue at all with buying say a Croft Micro 25 and some MC step-up transformers if it would work properly in this context. Flogging the PL2 and DV P100 would pay for it.
 
It's possible that the passive has a fairly low input impedance and that the DV has an unorthodox (in this day and age) output stage that needs to see a fairly high impedance load. You could try in-line attenuators between the DV and the passive. This should help if the problem is as above.
 
Is it worth trying a cartridge with a higher output than the 103 with the DV-P100? maybe a MM?
 
If you think older quad gear is quiet that pretty much proves my point. I'm talking about better than 95db SNR, naim gear certainly need not apply, though that's usually pre-amp related. The Prima Luna gear I've heard was very quiet for valve gear it impressed me
When I heard it at MAX.
 
There is no reason why modern valve power amps, if designed for modern CD compatible input levels, need be at all noisy. If you are talking in terms of having to put an ear right up to the tweeter of a 100dB/W speaker in order to hear any hiss.... and that still bothers you... then maybe it's a bit OCD! :cool:
 
Would be interested to hear how the Quad 34 fares in this context. I have gone back to 34/306 into my Tannoy Chatsworths (12" Golds). I find the tone controls vital (sorry puritans!) in this room with these speakers and have been idly wondering about using a Stereo 20.

Just as a data point my late 34/306 set is also pretty gain-tastic into the Golds - 4 or 5 on the wick is LOUD from the dac.
 
Done a bit more fiddling. I dragged 'the Quad 34 I have for no apparent reason' down and tried that in place of the PAS-02. Whilst CD didn't sound as good as via the PAS-02 it certainly proved the P100 is working fine. Vinyl was back sounding powerful again, so I'm confident I'm looking at a mismatch with the passive and phono stage here. One interesting thing is there was no increase in hiss, noise etc - I was rather fearing an active pre would bring a load of white noise with it. The volume knob was predictably useless though, even via it's least twitchy Tape input it was still very lound on the third click on CD. It is via the 303 and Heresys too, which is the main reason I don't use it at all.

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Here's the back panel of the Audio Synthesis passive. I suspect this is all academic now; the P100 will join the PL2 in the classifieds room once I've taken some pictures of it and I'll start doing some research into alternatives, probably an active preamp with integrated phono stage. I'll just live with CD in the meantime.
 


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