el 34 vs kt 77

I have a Rogue cronus with kt77 tubes. What difference would there be in the sound substituting el34's for them?
Night and day, in my experience. I bought a used Cronus based on spectacular reviews. When I first tried mine, with the KT77 tubes, I heard bloated, unfocused bass, average mids and just OK the rest.

I decided to try it with EL34's - often spoken of as sweet tubes, and the difference was astounding. Bass tightened, focus sharpened, highs sweet, clear. Everything perfect. I chose Electroharmonix EL34EH for about 8 bucks a piece.

My dealer persuaded me to try Groove Tubes EL 34 as being better and I found them OK, but a bit unfocused and they were 130.

I replaced the small tubes with Telefunken and Amperex Bugle Boy and the difference was better, but not as HUGE as the power tube difference.

Should you have other questions, feel free to contact me.
If you hit the lottery, vintage EL34's are amazing. I just spent the week with NOS Mullards and NOS Groove Tubes. I don't know of anything newer that will keep up. Svetlana WXT's are good but not as smooth.
If you ever get to hear the M-O Valve Company KT 77 just one time you will be hooked for life.
Night and day all right, but the other way around :-)

I was convinced that my Mullard EL34 xf1 and xf2 tubes were the best of the best until I tried the reissue Genalex/Gold Lion KT77s. These are used as driver tubes in my 845 SET monoblocks, so your results may vary. To put it mildly. Dave


Are these KT77 an exact replAcement for any amp which uses EL34S AS OEM OUTPUT TUBES? I have Dodd 120 wpc MK II monos. I currently use Sqvetlana Winged C throughout the output stage, and Tungsols 5671? in the splitter/driver stage.
As far as I know, yes. Dave
Yes the kt77 are a drop in replacement for the El34 in the Dodds
The pins on KT77 tubes that I have used were slightly thinner
then EL34 pins.You may have to pinch the tube socket for a correct fit.
Goldeneraguy, sounds like those were the JJ KT77s instead of the Genalex/Gold Lion tubes. The JJs had a lot of QC problems, including thin pins, before they got their act together. I have some, and they aren't really in the same sonic league as the Genalex, IMO.

Dopogue & Musicfile

Musicfile you even told me that before! Sheesh. Where's my head? Again, thanks. When I get the urge to splurge I'll get me eight of those goobersmoochers.

Where's a good vendor for these things and about how much do they cost now?
I would highly recommend Jim McShane, but I haven't kept abreast of the prices and don't remember what mine cost, sorry. They're not cheap, except in comparison to the better Old Stock types. Dave
Dopogue , They were the real deal.M-O Valve Company KT 77.
I purchased 12 new tubes directly from a very highly respected electronic mfg.This was 12 years ago.I dont think that JJ was making KT 77's back then.
Have you used or seen M-O valve Co. KT 77's.IMO they are the best.Thinner pins and all compared to EL34's
That's a whole different matter. Yes, I'm pretty sure they would slaughter any EL34s out there. But the new ones laid waste to all MY EL34s, so they're certainly worth a shot for anyone using this tube type.