KT77 in Diezel amps ?

[Peter Diezel]

They start working at 25 mA each tube. This is a
setting for distortion, because it´s tight and stiff.

With 40 mA each tube You get a nice clean and
harmonic tone.

Some techs state that the KT77 works best
with plate voltage over 500 volts but I cannot
agree. We have 340 volts in the Schmidt and
it sounds excellent.

 

[flownomis]

a range of 25 to 70 mA ???????

sounds interesting

 

[Peter Diezel]

The post with the 65 to 70 mA was for a pair

Btw, the class A power amps are running their tubes
with a bias current of 90 to 95 % of plate dissapation.
So 100 mA for a single EL34 is no problem.

Best,

Peter

 

[wolfeman28]

I used to run KT-77s in my XXX... Alwyas thought they were perfect for me, little bit of EL-34 and 6L6 all in one. I'll have to try them in my Herbert next tube change.

 

[BigR]

Were you able to tell much difference between the Ruby's and the JJ's at lower volume levels? Not talking bedroom levels, but not gig level, either. I have 2 matched quads of JJ E34Ls, and cant decide whether to try em in the Herbert, the XTC, or just save em until I need em. The Herbert is so damned easy to bias, though, its almost a no-brainer to just try em out, but I'd like to get opinions first if possible.

Oh yes. Now don’t get me wrong here, the Ruby’s are very good and reliable power tubes, but the JJ power tubes (although did have some reliability issues in the past) are just great all around dynamic and consistent power tubes. You’ll notice that I emphasize JJ’s power tubes, because the JJ preamp tubes are not my cup of tea, to any extent for my style of playing. Also, I’m not letting go of my sextet of JJKT77s for future enjoyment. I wouldn’t however, recommend that one mix the JJKT77s or the JJE34Ls with any other tubes of that variant or otherwise in Herbert, for that matter.

So to answer your question, for me yes, at any volume I hear the difference. What’s very nice about the JJ power tubes in Herbert is the openness it produces (and I can’t speak to any of the other Diezel amps at this time.) And the player immediately gains a much more touch-sensitive (even though you have it to varying degrees in Herbert regardless of power tube choice) response in the dynamic of the amp and this becomes much more significant and noticeable to the player who is privy to this type of extension of vibrancy and feel.

David

Thanks. I had a quad of JJ E34L's in my Marshall JVM for a while, and really liked them when compared to the stock =C= EL34's, and was hoping there'd also be a noticible difference across the entire volume range in the Herbert. Looks like my question (to myself) as to when to try the JJ's was answered by the Herbert not long after I posted my original question to you-my 1 & 6 fuse blew (and I mean BLEW, as in the glass disentegrated) not long after I posted. Nothing visibly wrong with either tube (not that there necessarily would be), but #1 is the one that redplated on me a couple weeks ago, so I figured it'd be safest to replace it. That, and I only had 1 extra fuse , and didn't wanna risk blowing it if the tube is indeed bad
Thanks again for your response. I went ahead and replaced all 6 Ruby's with the JJ's based on your recommendation, instead of just the 1 & 6 pair, and my initial observations are that you were 100% correct. I was able to tell a difference at even VERY low volume-as in 3am baby asleep volume. Looking forward to cranking it up a little bit and recording with it a little bit this evening. I'll don't think I'll ever get to power tube saturation, at least not at the house. 180 watts may very well blow a couple of walls down, not to mention windows
Looks like it's about time to try retubing the XTC with the JJ's as well, as I've never been that impressed with the =C='s that it came with. I have a quad of regular JJ EL34's (vs E34L's) that I may try in there first, as I now only have 2 E34L's left. I really do like the low end response of the E34L's in everything I've tried em in, though. If only the XTC weren't such a pain to rebias

Rich

 

[Capulin Overdrive]

meh, i don't like the JJ KT-77's!


check out the Gold Lion KT-77


and also the Tung-sol EL-34B

 

[nbarts]

I've just retubed my VH4 with JJ E34Ls & again, like with the Herbert, I find channel 2-4 sounding much better compared to Chinese tubes, which keep blowing on me. I do prefer Rudys for cleans in my both Diezels a tiny bit, but not nearly enough to warrant having them in my amps.

 

[steve_k]

From the Tone Quest Report....July 2006

The RUBY EL34 may be about to be unseated by the new JJ KT77. As many of my customers have pointed out,
most tube changes result in subtle but noticeable differences, but the change in tone with the JJ KT77 is huge! They have
quite extended lows and highs with crystal clear 3-D cleans that thicken up with a harder attack. As one
customer put it – “the JJ KT77’s have such defined and pronounced lows and highs that the amp gags for relief.”


Steve

 

[Flavatrocious]

Wicked. Ive been wondering what the EL34/6L6 blend of tube would be. Isn't Rig talk a wonderous place...

Now, everybody say ahh....!!!

 

[Duolos]

ahhhhhhhhh

 

[King Crimson]

They have quite extended lows and highs with crystal clear 3-D cleans that thicken up with a harder attack. As one
customer put it – “the JJ KT77’s have such defined and pronounced lows and highs that the amp gags for relief.”
Steve

I would agree somewhat with this assessment. However, I hear the extended pronounced highs with the JJKT77s as a nice jump in sizzle, which to me translates to presence, not treble by any means. This may be rather nice for some folks, and not for others.

I've already got plenty of presence, so a quad of JJE34Ls with a duet of JJKT77s in my Herbert is what I am running at this time and it sounds ridiculously NICE!

And to make matters even more BITCHIN! I just inherited a new Roland Jazz Chorus 120. This amp literally kills for cleans alone. I have never heard any Fender or CA amp even come close to the cleans in this Roland alone. And to boot, I hooked it up with my Herbert in stereo (Herbert the master DOH! And the Roland Jazz Chorus as the slave) and I use my rack unit for the stereo effects. The freaking room is swirling with lush sparkling chorus and stereo dynamic delays.

What a sleeper...

David

 

[Duolos]

You are just learning about the JC 120?????? A must have amp for all.....IMO of course.

And regarding the tubes, I hear ya. The treble and presence knobs turn both ways if you need to adjust them...





























I couldn't resist that one

 

[boulty]

If I was to get the JJ KT77s for my VH4 what would I be looking at getting on my multimeter? 65mA? Peter seems to say there that 25mA each tube is good for distortion, would this then be 50mA?

Biasing still does confuse me, I know how to do it I just need to know the values to dial in

 

[Peter Diezel]

In the Herbert and Einstein You are measuring a pair.

Please start with 60 mA (pair)

 

[wolfeman28]

meh, i don't like the JJ KT-77's!


check out the Gold Lion KT-77


and also the Tung-sol EL-34B

I was interested in finding another KT-77, but $100 a pair? I'll stick with the JJ's for $35... I'm not putting $300 into my power amp section...

 

[guitarobert]

I tried JJ KT-77s in my VH4 recently. I'll disclaim by saying that the set I received seems to have been bad. I was advised by my usual dealer that JJ KT-77s have been testing poorly lately in his tests so he stopped selling them temporarily. He mentioned the Gold Lion, but I didn't want to pay so much as a first try at a KT-77. So I went with another dealer that is still currently selling the KT-77.

Well the original dealer seems to have been right. I had a bad tube in the set I received. It was popping occasionally. But I was able to play a little bit on them to get an idea of how they sounded.

They had more bass than EL34s (I had SED EL34s in before), but felt a little bit looser to me. Not a tremendous difference from the EL34s ringing out though.

Recently I put a TAD 6L6GCSTR set back in. Wow! My favorite again. Of all tubes I've tried these give the most unique tone. Ringing out they don't have the "growl" of EL34s, but attacks and even releases are much more defined. More compressed, sure, but maybe that's my preference.

So overall for somebody who likes EL34s I think KT77s could be good, but in my personaly experience the quality of JJ KT77s is questionable.

 

[K-Bizzle]

but in my personaly experience the quality of JJ KT77s is questionable.

Thats what I've been hearing and is what has kept me away from buying myself a set.

 

[Capulin Overdrive]

meh, i don't like the JJ KT-77's!


check out the Gold Lion KT-77


and also the Tung-sol EL-34B

I was interested in finding another KT-77, but $100 a pair? I'll stick with the JJ's for $35... I'm not putting $300 into my power amp section...

yea, i'll agree they're too damned high and appears they're trying to get rich on the Gold Lion name. if they kick ass, they kick ass, not like they're going in a bugera.


they're a whole deferent critter than the JJ's, they don't have as much low end and have boatloads of mids.

 

[King Crimson]

...and also the Tung-sol EL-34B

CO - what amp did you install the TS-EL34B into and at what bias setting? I tried them in my Herbert and (although very nice) I didn't find them enough of the a change that I was looking to hear away from the R-EL34BSTR.

 

[King Crimson]

You are just learning about the JC 120?????? A must have amp for all.....IMO of course.

And regarding the tubes, I hear ya. The treble and presence knobs turn both ways if you need to adjust them...

I couldn't resist that one

I've had three of them over the years smarty pants. But I never had one given to me, and I never used one to accompany another amp in a stereo rig, K?

Also, this is a mint early '80s model when Roland gave a cat's meow about good tone.

Your tactfulness is impeccable!