USB vs dock for iPod on Peachtree units?

Yeah, I can definitely tell the difference without the tube in my system. My speaker/amp combo is very revealing of components down the line. I can easily hear the difference. The sound is brittle and etched on the highs without the tube, the midrange is a bit leaner. I use the tube section to preamp a pair of speakers in my bedroom, they are driven by the idecco's amplifier. They sound much better with the tube on. I use the DAC direct to tube preamp in the living room because it is superior to the idecco's pre. Tubes flesh out the sound in both instances...

That's good to know. In my Njoe Tjoeb CD player I can swap tubes, and I tried some different types and found one that is perfect for my ears.

Is the tube in the iDecco swapable?

Is the tube circuit self-biasing?

Yes, there are a few tubes that can be swapped. I've yet to try that. There are no biasing pots, so I imagine bias is not an issue...

If you can swap tubes, try it! Two types were included with my Njoe Tjoeb (it was used), and after trying both I searched the forums for people's opinions and found one that was really perfect for me. It doesn't cost a lot, takes seconds to swap, and the resulting sound differences are very interesting.

I'm now discussing iDecco prices with dealers here vs getting one shipped over from USA. Hope to have one here soon.

By the way, I'll be using the iDecco mainly in my computer room, which is like a small office where I'm stuck for too many hours/day. For bookshelves right now I've got Quad 12Ls, Rogers 3/5as, B&W 805Ns, and Yamaha MPS7 monitors around the house. I was thinking of using the Quads at my desk for a while and then later changing to either Adam a7s or Quad 12L actives (the latter not available in Japan).

Any idea how the iDecco preamp would sound with actives like these?

Anybody else care to join in here?

I have not heard the quads, but I hear that they are very revealing. In all honesty, I expect that the iDecco preamp (tube on) will really shine with either set of quads. You will not believe how well this preamp images & how beautifully smooth it sounds. My guess is that it will do something akin to what it does with my speakers...