Home Tubes Asylum

Questions about tubes and gear that glows. FAQ

Re: advice for KT-66's?

I also have triode-wired Williamson amps, which can be pretty abusive to KT66s... but I see the Electrohome uses a 395V plate voltage vs. my amps' 450V, so you won't have quite as much trouble...

I've had 3 quads of the Saratov / Groove Tubes KT66-HP (heavy black bakelite base, not metal) and have owned one quad of the Chinese KT66 tubes. There are advantages for either...

Sonically it is a toss-up when the tubes are new (Chinese tube is brighter, more-open, Russian tube is more refined, darker -- think 2A3 vs. 300B sound).

My set of Chinese tubes handle high power better, with less plate glow, while the Russian tubes need to be run with reduced line voltage to keep 'em from blowing up. This won't concern you as much, and will vary with production run / luck-of-the-draw.

The Chinese tubes look more like a GEC KT66, with a brown base vs. a black base, and no garish Groove Tubes logo. The Russian tubes have much thicker glass... and they don't turn brown with heavy use, like the Chinese tubes. The Russian tubes also seem to last somewhat longer (of course, I don't run them as hard).

A BIG concern is that the Chinese tubes are still in production, the Russian tubes have been recently discontinued.

Frankly, I prefer the Russian tubes, but mostly for the physical construction ... heavier glass, and a base that fits in my socket clamps. My next set will likely be Chinese, and I'm not too broken up over it.

Since your amps have 395V plates (422V with 125VAC), I think you can try either tube and not have huge trouble if you can keep the current around 60mA per tube. If you get the Russian tubes and hate them, send me an email and I'll take 'em off your hands :-)


This post is made possible by the generous support of people like you and our sponsors:
  Parts Connexion  


Follow Ups Full Thread
Follow Ups
  • Re: advice for KT-66's? - jon_s 17:33:26 12/10/06 (0)


You can not post to an archived thread.