Best preamp is no preamp: always true?

We have the same fancy (or as they say in the car industry, "pants") CD player as TVAD, and also find that we prefer having the preamp in the chain. It allows for better separation of the instruments, a preferable 'gain floor' as a complimentary support to the amps, and it conveys a more meaningful heft and density to the music. If we run direct--and our player does have an outstanding hybrid attenuator--the soundstage collapses, and on anything other than light chamber music, vocals or soft jazz, I'm just not feeling it. We take the preamp out, and it sounds like the music is struggling to get out, losing a sense of ease and realism in the process.

Some people will choose a configuration according to sonic preferences, while others wouldn't think of adding the preamp in the interest of maintaining a purist's approach. As TVAD suggests, you'll have to decide for yourself.

I have never heard a situation, where price was not a limitation, where NO preamp or where a passive preamp was superior to a really good, system-matched linestage. I know the mantra about sufficient output and compatible input and output impedance and short cable run, etc., but even in systems that don't need any gain from source (like mine), a good active linestage simply sounds more dynamic, projects a more realistic image, and pulls the listener into the performance in a way I've not heard passive linestages do. I suspect that the putative superiority of passive units may be a superiority AT A PARTICULAR PRICE POINT, but not absolute superiority.

Now, as far as NO preamp at all, with digital sources, one would have to consider whether the volume control is digital or conventional (variable resistance). I don't know if it really is the case, but a lot of listeners claim that the truncating of low level bits to achieve digital volume reduction is not sonically desirable, so playing the source at maximum volume and attenuating with an outside volume control is superior. If the digital source has an analogue volume control, I suppose the issue is whether that volume pot is better built than that in the linestage it is hooked up to -- if it is inferior, one again might get better results by setting it at maximum and using the linestage volume control to attenuate the signal.

Check out the discussion and review of a passive inductive preamp in the January 2006 issue of Stereophile.

Well, lets see...I can think of a member here at Audiogon with a mega buck system that uses (or at least did use) a passive in his system....I don't think he's hard of hearing, and he's sure not a newbee.

If I recall he had the Placette Audio passive in his system.

Dave

I've tried two passive solutions in my system - a Bent Audio TVC with copper transformers and a built-in resistor attenuator in my Audion Silver Night. I've tried various configurations: I've used the Bent with five different amps, both tube and solid-state, and I've tried the Audion nude, with the Bent and with a couple of actives. This has been done on two different speaker systems, both of them efficient and high-res. The source is a balanced AN DAC, with quite low output impedance and sufficient, though not excessive output voltage.

The conclusions that have remained relatively consistent across most configurations are:

- The Bent was sonically problematic in all my configurations. It's very smooth, but robs enough dynamics and detail to make the sound boring.

- The tube preamps I've tried (Canary and Audion) have better dynamics than the Bent, but equivalent detail and higher noise. They tended to be more fun to listen to, but were more coloured (warmer).

- The resistor attenuator in the Audion sounds quite good nude. Putting the Bent or one of the tube preamps in front of it mucked up the sound in various ways.

- The joker in the deck is the solid state Tom Evans Vibe/Pulse. I tried it with three amps, and it produced better sound than any of the others. It even improved the sound of the Audion amp when driving its internal attenuator. Imprevements were in the areas of bass and treble extension, dynamics, detail, neutrality and transparency. The downside of course is that it is two to four times the price of any of the others. I ascribe the superiority of the Vibe to its higher output current and lower output impedance.

So, a passive can be better than a medium-high quality line stage (the case with the Audion's attenuator), or it may be worse (like the Bent). A very good preamp is likely to exceed the quality of a passive because of its current and impedance advantages.