Hi,
anubisgrau said:
strangely mr. t, apart from recommending transformer based passive preamps, i can't remember if you have had a nice word on an active pre. are they ALL that bad to you? can't be that there is no some small, hidden gem.
My experience is that most active preamplifiers significantly deviate from neutrality. This can be "a good thing" in the same way winnie the pooh says "hunny is good". I just have found overall that I have no use for this.
I equally find that ANY of the active preamplifiers I have encountered significantly subtracts from what goes in. I have been mostly on passive line stages for a decade and halve, prefering to accept some of their limitations over the problems added by conventional line stages.
Among the best active ones I know are the various Conrad Johnson ART (and related versions, but not the lower grade ones like the PV-10) and BAT stuff among commercial gear and the Arthur Loesch Linestage as well as the Kondo M7 Line (unsurprisingly ALL of these share a lot of the principle design and circuit structure, though implementations vary) among what one may call "low volume custom" gear.
In DIY I find best the various "Euridice" variations, these are basically transformer coupled designs, the best "Euridice" we have come up with uses a S&B TVC as volume control and a S&B Line Transformer (TX-102 Silver & TX-101 MKII Silver) with a custom S&B Anode Load choke, silver foil coupling capacitors, battery based biasing and a super-massive power supply with all film capacitors and several custom made "wideband" chokes.
In my OWN system at home this comes in a close second against my Music First Audio passive Pre. In the system of the friend for whom this was developed having the extra gain and drive is essential (due to the use of low gain amplfiiers and passive line level LC Crossovers ahead of the Amplifiers), so in his case there is no "passive option".
As I build most of my stuff myself and happen to have the circuits for most commercial gear on my HDD (plus usually plenty of inside shots) and have designed plenty that match or exceed many a commercial design. If there was a active line stage that was in my system and for my purposes better than what I have I would use it.
The TVC principle is the result of seeking the best way to generate a "wire with adjustable attenuation" or closest equivalent. The various S & B (and copycats - though I must note that Sowter is not as such a copycat, but rather someone who first refused to make a TVC to my specs and then, when noticing demand, dug out my specifications and started making them) TVC based linestages are merely commercial implementations of this principle.
In my view a well matched modern HiFi system needs an active linestage about as much as a Fish needs a Bicycle only a lot less so. I am equally hardly alone with this view, one of the great contrarian minds and writers on audio (contrarian to the common high end BS) Arthur Salvatore wrote:
'Any system that sounds better with the addition of an "Active" Linestage is an unequivocal indication that a mistake has been made in the choice and "the matching" of the components.'
http://www.high-endaudio.com/RC-Linestages.html
Ciao T