KT66 alternatives

[tpatton]

My Quad II amps standardly use KT66 output tubes, which  tend to be superexpensive.  If my present four aren't all in good shape--I won't know for a while--I'd like to have alternatives to look at.  In particular, I have on hand a quartet of 6L6's, vintage RCA, but no letters/numbers after "6L6", just that bare designation.  I've already been told that they wouldn't hold up to use in my Dynakit Mk IV's, and maybe the same holds for the Quad II's.  But maybe not, since the Quad II's don't try to match the Mk IV's output power. Any advice on this?  Thanks in advance.

[porcupunctis]

To the best of my knowledge, the KT66 is a premium version of the 6L6 line.  Otherwise, they should be inter-swappable.  The 6L6 are extremely common since they are used in many guitar amps.  You might want to find some used ones just to try out before you invest in a set of matched quads. 

[tpatton]

Thanks, Randall.  As I said, I have a quad of vintage 6L6's on hand, which I'll try first.  I've also seen that DiyHiFiSupply (Hong Kong) sells matched pairs of Valve Art 6L6GC's for a mere $22, which must be hard to beat (shipping only $7, I believe.  So if I get my Quad II's working again, and the 6L6's I already have on hand don't see that good, I might go for that.  The 6L6GC is sometimes described as a "more rugged" version of the older 6L6.  Whether the Quad II's can benefit from "more rugged"--who knows?

Any opinions on Valve Art tubes, in general?  Good, just okay, other?

I used to be a sort of math teacher myself, but logic, not straight math.  Still, pretty close.

[coca]

The 6L6 will work in the Quad 2. You can also get reissue KT66 at a not too wild a price.

Bernie.