I know this is well after the initial inquiry. It's now April 2005 and I have a new pair of Audiopax 88 mono amps. The pair was supplied with Sovtek KT88s and RAM 12AT7s. Look, the amps are a little cold, analytical and ragged brand new. The break-in curve is pretty steep though after the first 10 hours or so. A change to Cardas capacitors has made patience on break-in more essential to your satisfaction. I am now well into that steep improvement curve where sound is noticeably better by the hour.
The Russian tubes are clean but bone-dry. I have a stash of circa 1980 NOS British Gold Lion Kt88s which are magnificent in this amp or any other KT88 device, but I am also getting spectacular results and clear improvement over the stock tubes from a matched quad of Tesla Vrosovic KT88s (the maker of the KR KT88 from a few years ago). They are nearly indistiguishable from the Gold Lions. I also have noticed very strong transient clarity and definition from the Ei Type III KT90. With all these tubes, the key is finding the right differential between the timber-lock controls.
For input tubes, the RAM 12AT7s, while not bad, are clearly bested by a set of NOS RCA 12AT7s I am using now.
These amps are sensitive to tube rolling, but frankly nothing sounds bad in them.
Phil
