Passive Attenuator anyone?
Steven Stone got me thinking about preamps. Again. The reason is pretty straightforward — it’s really hard to do right something that’s not supposed to do anything at all. Let me untangle this a bit, tell you where I’m coming from and what my concern is.
First, what does a preamp do, exactly? In short, it’s a volume control and a source selector. That’s it. That’s all we want. It’s not supposed to add anything to the audio stream and it’s also — and perhaps more importantly — not supposed to take anything away, either.
Apparently this is much easier to say than it is to do.
I’m not at all privy as to why this is, but the short of it is that the parts have to be quite good to keep them from “veiling” the source signal. And most preamps don’t really do a good job of this — that is, most actually do veil, obscure, cloud, and otherwise rob the source signal of life, detail, and, well, everything. That’s the story, anyway.
I was chatting with Bill Baker about all this at Capital Audiofest, in between drooling on and attempting to steal one of his impressive Purity Audio Design preamps. Yeah, I want one of those bad boys. The reason I’m so interested in his work is, to all reports, the Reference and Statement preamps are some of the most neutral you can buy — and don’t actually rob the signal blind when passing it along. Music to my ears! Sadly, this level of performance comes at a rather dear price point. Hmm.
Given that you have a single system, and that system plays at a high level, perhaps a Purity Audio preamp is your ticket to audio heaven. If you’re building several systems, at several price points, perhaps another solution might be on offer?
Steven Stone recommends passives. I asked him about the frequency attenuation issue — he cites impedance mismatches as the culprit there. Which is one of the things a powered/active pre should sort out for you — but in a passive, well, there’s not a lot in there to separate your source from your amp. Like, nothing. So, finding the right fit is important. But do that, and, well, Bob’s your Uncle — right?
We’ll see — I want to bring in a few passive preamps and see what’s what.
I found Luminous Audio at Capital Audiofest, and Tim Stinson was telling me about his marvelous $400 “Walker Audio” mod for his Axiom II passive. I was very curious, naturally, and in a move of sheer awesomeness, he’s sending me one to play with. Score!
First Watt also has a passive, the $1,000 B-1. Given how enthralling the J-2 I have here on loan is, I’m betting that the match is pretty much perfect.
Another I’ve heard about is the Lightspeed Attenuator. This little doojabber is a bit different from the rest, it uses diodes or something … clearly, I need to do some more research. But I’m told this little guy is amazing. $525 Aussie Bucks and it’d be on the way.
And then there’s the AVC from Intact Audio — which is neat, because the autoformer mechanism is designed by Dave Slagle, and that AVC was used in the Bent Audio Tap-X and is currently being used by Bill Baker at Purity Audio. Not sure if Dave is actually still making these for sale, but even if he is, the last price he had up there for a “fully assembled unit” is something north of $1,200. But look at that aesthetic. It’s awesome! Like the Terminator, after it got fucked up a little. Yeah!
Anyway, that’s where I’m at. What am I missing? Any thoughts on what I need to keep in mind? Any others I need to try?