CAV 45S2 and KT77

[Paolo]

I've searched for information on using KT77 in this CJ control amp, but have not found anything of note. At the moment, I'm running OS Mullard EL34's and the amp sounds great. Speakers are Sonus Faber Guarneri Homage.

I will say that I don't hear a significant difference between the vintage tubes and the new production Mullard EL34. They all sound lovely.

BUT, since one reason I like tube gear is the ability to experiment I ask out of curiosity, has anyone used KT77 in this amp? If so Genalex or JJ?

I realize that the amp has been voiced with EL34 and that Jeff F. says that he knows of no tubes other than what the factory uses, that will make the amp sound better.

Thanks very much.

[admin]

I do believe you can swap EL34's and KT77's. Now will one sound better than the other,... I think that's a big question. CJ uses the tubes that they think sounds the best. Whether that sounds the best to you is another matter. Realistically, I think you would have to tube role and see which ones you like the best.

It's always fun the experiment and try different things. With tube prices where they currently are, not sure if tube rolling is very high on my list at this time.

[Paolo]

Thank you, Admin. Yes, indeed, with tube prices being what they currently are, coupled with my satisfaction with how my amp sounds, tube rolling is not a priority for me. My question about KT77 was prompted by curiosity, not dissatisfaction.

[Paolo]

Update. Curiosity prevailed and I purchased a quad of GL KT77 from Kevin. I can't hear much, if any difference between the 77's and the Mullard new-production the amp comes with. I put the EL34's back and keeping the newer 77's as backup. Unless I hear something dramatic, one way or the other, I prefer to simply listen to the music.

[admin]

That happens. Sometimes rolling tubes has a significant effect, sometimes not. At the end of the day, enjoy the music!

[Paolo]

So, after realizing that the old 6922 tube was bad, I ordered a new gold pin EH from Upscale. I got one of "Kevin's Stash" and after about 48 hours I'm extremely pleased with how much better the amp is sounding. I also put the KT77's back in and the synergy is wonderful. The amp has become more "holographic" and is portraying more detail but no added harshness. I'm still running the pair of original GE 5965 that came with the amp from the factory.

@admin
I am super happy and suspect that the significant improvement is primarily due to the new EH 6922. I'll run the amp with the KT77's for a few weeks and put the EL34's back in as a comparison, merely out of curiosity since the amp is sounding so much better now. YAY!

Best,
P