Interesting that the very expensive Canadian company Tenor ( £ 50,000 plus ) have switched to FET in the output stage while using an OTL valve driver stage in their new top model.
Senior Member
Posts: 329
Interesting that the very expensive Canadian company Tenor ( £ 50,000 plus ) have switched to FET in the output stage while using an OTL valve driver stage in their new top model.
Hans
MBL 1531 -> Allnic L-4000 -> Audiolab 8000S used as power amp only -> Quad 2805. Cables: Transparent Ultra
Trade: Coherent Systems
Location: Gerrards Cross
Posts: 3,164
I'm Tony.
I usually find these discussions most interesting though tend to keep well out of the way.
However on this occasion:-
Personally I have time for both forms of amplification, I have been privileged to have listened to some truly great equipment, both valve and solid state.
Last year I was in a position to spend an afternoon with some truly world class valves and horns. It was the first time I have heard horns produce realism, bass, and dynamics without recourse to any of the usual failings at all.
All powered by 4 watts of SET. A superb musical entertainment fest.
The amps and horns were bespoke built at no expense or technical issue. Cost around 800,000 Euro's excluding the room!
Conversely the Grande Utopia III's with a couple of quality solid state units gave me the same transcendental sensations though in different areas, yet awe factor was just incredible.
The above is all very well and good, however the price constraints mean all but a very few very lucky soles can obtain this.
In the real world, most days I hear both good and bad examples of each breed, and I take this on board and use it when matching systems to customers needs.
Some of the most musically involving systems we have heard seem to lie between 5K and 9K and are carefully selected and matched and have a 'just right' gel factor.
They have a listen too for hours quality that just makes you smile when you listen.
The very bottom line on this debate boils down to a very simple word 'Implementation' nothing more or less.
I have heard 'very average' £30K valve amps, and some great £1k lash up's, which easily out stripped the hugely more expensive 'named' brand.
To be fair, I have also witnessed great one man band self proclaiming 'take on all comers' £10K monster, get creamed by a chap who works for a hospital radio, who knocked up box sat on a piece 3 inch chopping block!
The same goes for solid state too, the are some truly dire examples out there, as there are some quite exemplary examples too.
Though one observation that has always stood out for me is the pre-amplifier, one of the big keys to systems sounds.
Coherent Systems
Real high end sound with musicality not hifi
I so agree with you and have had similar experiences: Infinity Betas run from Audio Research valves, for instance, Horning Agathon Ultimates from SETs and JM Lab Grande Utopias from solid state amps. All fantastic, all different.Originally Posted by Mr. C
I'm sorry I never bought those Focal Altos as an upgrade from my Mezzos from you, but went in another direction and fell in love with Usher. Doesn't make me any less fond of Focal, though.
Agreed too. I found audio Nirvana here in the Pass Labs X1 and believe Nelson Pass has a lot to say about preamp circuits. I have borrowed Krell and BAT preamps in the past and they have not come close.
Audio Engineer; Moderator
Location: South Wales
Posts: 9,148
I'm NotTakingLifeTooSeriouslyTheseDays.
a good preamplifier is a must,
if the begining or intermediate stage is not up to scratch then it wont matter whats in the chain after it, all the dynamics and detail that were present in the original recording will be skewed, or at worst lost all together.
anthony,TD...
Senior Member
Posts: 329
If you are after purity of (unamplified) vocals, is there anything better than a good passive preamp with a valve power amp ?
Hans
MBL 1531 -> Allnic L-4000 -> Audiolab 8000S used as power amp only -> Quad 2805. Cables: Transparent Ultra
Gone, but not forgotten
Location: Central England
Posts: 2,932
Passive preamps are great with purity of vocals and yet very poor with dynamics, according to my experience. An active valve pre is far superior overall.
I have played with passive 'preamps' in the past and also made my own with Alps and Noble pots. They pass the detail and transparency test but fail on dynamics.
Power amps like to be driven, preferably by balanced XLR connections.
Senior Member
Location: Cheshire, UK
Posts: 2,832
I'm Clive.
In general I agree about the lack of dynamics on typical gear where you have:
- 1m interconnects from passive to power amp
- 0.775V sensitivity power amp
- lowish input impedance power amp, eg 20k
The capability of the source is just as important too.
However take a not unusual valve amp with:
- pot integrated with the power amp (it could instead be external but short cables help)
- 0.2V sensitivity power amp
- 100k input impedance for the power amp
This 2nd scenario will work much better. It's likely this 2nd scenario comprises a 3 stage valve amp so effectively you have the preamp in the power amp. I'm being pedantic here but it's not that passives don't work, it's more to do with the gain structure and impedance matching characteristics of a system.
Last edited by Clive; 31-01-2009 at 15:23.
Senior Member
Location: New Brighton
Posts: 190
I'm Tony.
Hi All,
*** Oops! My post came in after Clive's which goes a long way to helping my understanding! ***
I'm not trying to be controversial, nor am I saying that pre-amps are a bad thing, just trying to get my head around the _why_ of it all.
I mean, if your power amp has enough gain, and your CD player or Phono amp has a good buffer to drive the interconnects, why do we need even _more_ gain, just to stick it through a pot and reduce it again? It seems like we'd be better of with less gain stages, less phase shifts, etc.
Where do the extra dynamics come from by using a pre-amp over a "passive pre". (Ooh I _hate_ that term! It's a pot not an "amplifier"
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