A closer to perfect (passive!) preamp? (long)

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What would you need for a perfect transformer?
Very good ears, very good eyes, very good hands, very good material and a very good brain - and patience.
Some are better at it, some less. We know that Tim de Paravicini is very good. I feel there's one name to add now: Serge Schmidlin.
A few months ago someone asked about 'Kristall Kaps' and i visited his website:
http://www.audio-consulting.ch
My comment went along the line: Either he is mad or a genius. Expensive he is.
Well, in the meantime i know a few things more (a very nice thing about getting older: Loosing wrong 'knowledge'.)
He has his parts manufactured in very small volumes, if he doesn't do it himself. He uses (maniac-like) absolutely the best parts he can find. And on his search he is willing to walk his boots to look like in the famous Camel-ad. So: it can't be cheap, i guess it is actually rather good value.
Why this intro:
I have his passive preamp (the trial version - not the best sounding one) newly in my system. It is a transformer with variable output, made with silver wire etc. and the uttermost care.
Before, i used the outstanding passive pres from Audio Synthesis - an excellent product of actually very good 'value' too. It was the place i landed on my search for the highest transparency. All actives (*quite* good ones BTW) brought colorations and a loss of transparency compared to these optimized shunt-attenuated & Vishayed passives. They had very good dynamics too, and a very fast and neutral bass.
I found out that by reducing the series resistor, the sound got better (spec. dynamics), and i found that integrating the shunt pot attenuator into the amp improved the sound even more than a separate passive with better attenuation leg. So i had a pretty 'radical' and transparent preamp concept in my Berning DH 270 amp, very satisfying. (why then did i care to try someting else...;-)
Using this passive transformer preamp sonically catapultes my system into another league (yes passive line-leve bi-amping will do this too, but... Schmidlin has there his own, better solutions).
There is a huge increase in dynamics (no it wasn't sloppy because of that passive pre, because this wasn't your normal passive pre...!), there is a big increase in solidity, bass contour, plasticity and aliveness, and amazingly for me a big increase in timbre resolution depth - the quality where absolutely no active before could approach 'my' passives. Highs were better integrated, the sound more coherent and illuminated, vibratingly alive.
I knew that there is a very audible improvement gained from eliminating even the best passive (or active!), i but thought that i must live with that reduction or information loss.
It seems that the transformer pre is sonically a (way) superior concept to any preamp, be it active or resistor passive.
Why? I have only hints:
- First: The transformer (in theory) in the attenuating mode, will never have a higher source impedance than the source proper. If you half the voltage (-6 dB) you get 1/4 of the source impedance - pretty nifty (if you don't trade in other drawbacks)! So source impedance always is (much) lower than on a resistor passive (where it's highest in the (almost) non-attenuated position, the position that sounds best IMO, and more so with lower resistance values: A congruent observation with the transformer passive experience. It sounds like more Nm or momentum.
It seems that musical signals don't like to get 'eaten up'.
- Second: Breaking the ground connection frees the ground connection from buzzing power supply-modulated ground potential currents. A noise source that sabotages radical thin wire concepts.
- Third: It may filter HF in a benign way.
I would not expect your average transformer to sound like the 'Silver Rock' of Serge Schmidlin, because my experience with different transformers is, that they bring:
Various levels of grayness, a powder- or grain-structure, a slightly 'whaffy' bass, bandwidth limitations, HF loss, upper midrange forwardness, a certain unquietness.
I heard *none* of these. In contrary, every parameter where transformers are weak actually sounded better than with no transformer.
But variable tranformers of other makes are at least very much worth a try. Then subtract the weaknesses and imagine...
Don't forget: Every of your favorite preamps will be a combination of a (probably very sub-optimal) *resistive* passive pre with a hopefully more? or less! transparent active line-stage. It's the approach of trying to combine two more or less 'wrongs' for a 'right'.
Easier to learn a Scarabeus to fly.

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Topic - A closer to perfect (passive!) preamp? (long) - Arbelo 18:46:26 06/23/01 (4)

couple of quick questions - paco 03:26:22 06/24/01 (1)

Schmidlins amp concept, special CD recordings - Arbelos 03:52:14 06/24/01 (0)

Re: A closer to perfect (passive!) preamp? (long) - MikeCh 19:30:51 06/23/01 (1)

different sounds & speakers, horns - Arbelo 06:54:34 06/24/01 (0)

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