Someone asked in another thread if I had tried to use my ZOTL as a preamp. I hadn't, but just gave it a brief tryout (My ZOTL has been customized by Berning with RCA outputs). I threw together one of the weirdest two channel systems (sort of) I've seen. I connected the ZOTL to an Acurus 200X3 amp (only used two channels though), so it was driving 200 wpc. I used KEF 101.1 speakers (4" driver and a dome tweeter, but not intimidated by any amount of power. Trust me) I didn't have a source near at hand so I plugged my CT-470 in, and turned everything on. It sounded awful, so I gave it an hour to get warmed up and came back...much better, and established that the CT-470 has no bass whatsoever. Found a Toshiba SD-3109 DVD player lying about, hooked it into the nearest ART DI/O and used that as a source. Better!

I'm not sure I should post too much by way of sonic description, as this was a brief trial, and the ZOTL had the tubes I use for the CD3K in it, which puts it on the dark side of neutral. As the 101.1's also tend to be a bit dark, this was not a really bright sounding system. Still, one the ZOTL's strengths is a certain smoothness and transparency that came right through. The Acurus is solid state and proud of it (and I don't mean that as a compliment). The ZOTL's tranparency and clarity came through anyway. The KEF's are a pinpoint imaging speaker (the strength of a mini-monitor). In theory, imaging is not supposed to be the strong point of tubes, but the ZOTL didn't care. Nice wide image. Not a lot of depth, but everything nicely localized (fairly good for a digital source). Tonal balance dark, but fixable with a different tube set. This setup was able to comfortably handle some serious dynamics. It also produced an amazing amount of bass. In theory, the KEFs start rolling off at 80 Hz...in practice there's usable bass much further down with enough power, and 200 watts is enough power (it's almost enough to get bass out of the AKG-501!).

However, the ZOTL was originally designed as an integrated amp. Could a one watt per channel amplifier successfully drive speakers that were happily soaking up 200 watts? I gave it a try. The sound was superb at low levels. All of the solid state hardness from the Acurus disappeared. The music suddenly took on a new dimension of reality. And at higher levels? Well, let's just say that the ZOTL clips very gracefully and leave it there. In a smaller room, or with more efficient speakers, this would be an incredible speaker amp by itself.

I'm impressed. The trial didn't last long enough to say much more (just a couple of hours), but it gave a hint at what the ZOTL can do in a speaker system...and if, over time, it lives up to the potential I heard, it could be a world-class preamp/integrated.

This needs more exploration. I wonder if I've got any *efficient* speakers around here...maybe in the back of the closet...

Don't forget about using the Zotl for the tweeters in a bi-amped system. Usually most of the power is needed for the lower frequency drivers, and many speakers are set up for biamping.

Kurt, I haven't forgotten that at all. The question is whether its 1 watt is enough for the high end of a pair of B&W Matrix 804's...and I may try and find out. If it works with cheap cable, I can get some good cables later on. My present cable is a dedicated biwire type...no way to split the signal at the amp side without trashing the termination.

1 watt is definitely not enough for the top part of my NHT VT-2s, but I wonder if the RKV might...

Hirsch = Curious Audiophile

I really like your adventurous/inquizitive spirit. I could tell by the way you like to "tweak" with various items

BTW, since we are both proud owners of TDS passive audiophile,
I recently picked picked up another "magic box" for power conditioning called Quantum Symphony Pro (used at Audiogon of course) for $300 that will not be leaving my system. Are you aware of this:

http://www.soundstage.com/synergize/synergize200007.htm

Hmmm...that Quantum Pro looks a bit like an uber-Quietline.

There could be a problem in my system...one of the write-ups reported a negative interaction with Tice TPT treatment, and my main power conditioner is a Tice Elite IV. (going to keep an eye on the audiogon classifieds anyway...wait...must work on impulse control... )

The TDS has taken on a very odd role in my system. I'm finding that it helps out a lot when there is a thin midrange...new cans that haven't burned in, for example. When I first got the CD3K, I couldn't listen to it without the TDS. I wasn't expecting a long burn-in, since the cans were used, but it happened anyway (I don't think they were used much...they look mint). Anyway, as they burned in, and I tweaked the ZOTL's tubes, I started using the TDS less and less, and finally took it out of the system. A similar thing happened when I got the ZOTL, I started using the TDS a lot...then started upgrading my DI/O. As the DI/O got better, I started using the TDS less and less...(This was critical with the ZOTL. Loss of detail caused by the TDS that was almost unnoticeable through my other amps is obvious with the ZOTL). The only way I could listen to the AKG-501 was through the TDS. As time went by, nothing changed. I got rid of the AKG.

So, the TDS has become a trouble-shooting device of sorts. It really does make a positive difference...when something is slightly out of whack somewhere. If I need to use the TDS a lot, there's usually a tweak that will let me stop using it again...at least so far. As soon as I get my preamp situation sorted out, I'm going to move the TDS over to the speaker system...

Sometimes something is so obvious after the fact that you have to bang your head against the wall that you didn't see it sooner.

I kept wondering at what point I stopped using the TDS. The answer is when I got my X-PSU, and the X-Can started acting like a functioning tube amplifier. As I drift further into tubes, the TDS has become less and less useful. Is the TDS the solid state equivalent of a "tube warmth" device, such as the one Musical Fidelity used to put out? Or, to put it another way, I think the changes the TDS made to my system was to make it sound more like a tube system. As I went to a serious tube system, it became less and less relevant.

Darkangel, your profile looks solid state down the line. if you're using the TDS a lot, I'm looking into my crystal ball (well, Sylvania glass ball with gold pins, actually)...I see glass bottles glowing orange in your future....

Hirsch
Yes the TDS does perhaps slightly relax the sound a bit like some tube gear might, but I use it mostly for my main stereo imaging/3D
enhancement effects, as opposed to any type of tone control.
Everytime I try to remove the TDS and compare with/without I always hook it back up. I cannot hear any detail loss in main system, but this would be easier to detect through headphones.

Headphones as discussed many times here, give a poor approximation of the room filling 3D soundstage a good stereo
produces. This is where I notice the TDS providing benefits, if I just used through headphones the TDS effect would be very small
or not noticeable.

The Quantum Symphony Pro is used in conjunction with Quietlines
and in my system provides enhanced detail retrevial for all components, it has on/off switch and does not connect to any equipment so I could easily compare. Don't know how it works
but just sounds better.

I did almost buy a tube preamp (Rogue Audio 99) when I purchased my MF A3cr preamp.

Once I get my preamp situation settled, I'm going to run the TDS on the analog side of my main system and see what happens. This could be sooner rather than later, as I should have a SHA-1 on Wed or so. I've already got the Amperexi to roll the tubes before I even plug it in...