DECWARE.....ZTPRE anyone have any expeiriance with one ?

I don't have any experience with the Decware linestage, but, I do have a few suggestions on what to consider in your choice of linestage.  From a practicality standpoint, I always turn off tube gear when it is not in use.  But, because solid state gear, particularly amps, take an extremely long time to warm up and sound their best, I would leave such gear on even when it is not in use.  There might be problems with using a tube linestage with a solid state amp that is left on all the time because of the possibility that the tube gear will emit loud noises/pulses when being turned off and on; if one can mute the linestage for turn on and turn off, that might to be a problem, so that is something to look into about your prospective purchase.

I hope that Decware will allow you to audition their linestage with your amp.  While an audition is really important for ANY purchase, it is particularly important when one is trying to match a tube linestage to a solid state amp.  I have found that, even when the match is theoretically fine (i.e., low enough output impedance from the linestage, short interconnection cable), the result can be quite unpredictable (more unpredictable than the other hybrid approach of solid state feeding tube amp).  

Larryi...excellent point about the in home trial. Decware does offer 30 days for trial and 10% restocking fee, so that would be about a $470.00 hit just to try it out. I would assume that they are so confident that you will keep it that they are right up front about the restock fee.I also have a Mcintosh 225 that has no on/off switch...so I am very used to unplugging it each time.I did have the opportunity to try an Audion pre amp with the CA400's and it sounded wonderful.

Excellent comments by Larry, as always.

Also, I took a look at the schematic for the ZTPre, which is included in the manual provided at the Decware site. I see that the output tubes are coupled to the output connectors via capacitors having what to me is a very surprisingly low value of 0.1 uf, the caps being in series with 100K pots (potentiometers) that are provided on the rear panel, apparently to allow the preamp’s overall gain to be adjusted.

A 0.1 uf capacitor has an impedance at 20 Hz of about 79.6K, which will produce a significant deep bass rolloff in conjunction with the 100K impedance of the pot. That is particularly likely to be apparent given the excellent deep bass extension of your speakers. And depending on the setting of the pot and the input impedance of your amp (specified as 75K, although it isn’t clear if that applies to its unbalanced inputs or its balanced inputs or to the bridged mode you are using), the resulting rolloff may be worsened significantly.

In saying this, I am of course assuming that the schematic is accurate. And for that matter I don’t see how the schematic and the claimed frequency response spec of 20 Hz to 20 kHz +/- 0.7 db can be reconciled.

Regards,
-- Al