Preamplifier power supply

Btw, some of the fellow Audiogoners use passive preamps (resistor or transformer based) with NO power supply at all --> do they have poor dynamics and bass response?

This is a terrible mistake. You will not achieve high input impedance and low output impedance with a device like this. In the worst cases the sound will change character audibly with volume as the circuit will act like a filter when it couples with the source and power amp. Remember a preamp is also a "buffer" - it allows the source to see high impedance (making the source have an easy life) while driving the power amp faithfully with whatever it needs - irrespective of small load variations. Buffering and high S/N cannot be achieved without active circuitry. Volume adjustments require around 120 or more decibels of control - it is not a simple task if you want to do it with high channel separation and high S/N and low distortion/transparency.

Shardone, with transformer based passive preamp you will get high input but low output impedance. I think with saying that a passive preamp is a "terrible mistake" some of us would feel offended (btw, myself not included).

Chris

In 'cost no object' pre..of course, have big everything! For $20K you should expect it.
In the real world, folks make choices about what sort of compromises they are willing to make. When I consider a $2K preamp.. I listen to the sound. Not whether it has a "big Gonzo" along with the mandatory two giant spheres.
Plenty of pre's sound really great with modest power supplies. Including many separate power supplies, which inside that box may have a small transformer and small caps!
The size of a pre's 'tranny' is not the final word. Ditto not what 'caps' or the thickness of the chassis and front panel...

I think with saying that a passive preamp is a "terrible mistake" some of us would feel offended (btw, myself not included).

Ooops sorry - good point. However, there is a good reason for OTL designs: transformers are simply not the greatest of devices when it comes to linearity.

Chris, that is a question many have asked. A larger transformer and power supply has helped every pre amp I have ever tried it on from the Japanese mfgrs all the way up to the high end gear from Jeff Rowland, Threshold and Mark Levinson. A nice 600 watt toroidal transformer will cost 80-120 dollars plus an outboard case to hold it, since almost no manufacturers use a power supply of that size.