KT77

[eyeball987]

May I ask how hot you biased the KT77s? I hear they sound their best biased at their max, at around 32W a piece, and I'm curious whether to go with these for my rhythm sound, but as yet have not pulled the trigger on them. Love their KT66s though, biased at around their max (30W each).

Interesting. Where do you bias 34's? I have been keeping mine hotter as of late. Not quite as hot as Fig but still up to just a touch over 35ma.

 

[joey_truelove]

May I ask how hot you biased the KT77s? I hear they sound their best biased at their max, at around 32W a piece, and I'm curious whether to go with these for my rhythm sound, but as yet have not pulled the trigger on them. Love their KT66s though, biased at around their max (30W each).

Interesting. Where do you bias 34's? I have been keeping mine hotter as of late. Not quite as hot as Fig but still up to just a touch over 35ma.

EL34s take very little over the spec'ed 25W. 27.5 I believe is absolute max, even for NOS.

Maybe I should have said 'treated as 32W bottles', which would typically be 90%-ish dissipation for a 25W bottle. The KT77 after all was designed to put out that kind of power but didn't hold up at certain plate voltages. 35mA seems a bit cold for that, may I say, but of course depends largely on the operating voltages.

 

[Mattfig]

32ma on the nose...They just open up right there...

 

[eyeball987]

32ma on the nose...They just open up right there...

34's or 77's? I thought you kept you 34's higher than me at 35ma.

 

[Mattfig]

32ma on the nose...They just open up right there...

34's or 77's? I thought you kept you 34's higher than me at 35ma.

77s at 32ma....Although I've started running my 34s a bit cooler too - currently for the EL34 Mullards I run 34ma and EHcCA7s are at 33ma...

 

[Hamner1]

So what, if any, tonal differences do you hear between;KT66, KT77, & KT88?

 

[nym1985]

I was kind of curious about trying a pair of KT66 mixed with a pair of KT77 in my RM100 combo I see people mixing 6L6/6CA7 and EL34 all the time and being happy.

I'm just kind of scared to spend about $175 for the quartet of Gold Lions if I'm not 100% satisfied with them hahaha I just don't have that money to burn right now.

 

[nym1985]

So what, if any, tonal differences do you hear between;KT66, KT77, & KT88?

My understanding is this
KT66 is kinda the british cousin to the 6L6 (I'm familiar with these as they were in a lot of early Marshalls like the 1962 "bluesbreaker" and the new Vintage Modern series in those amps I really liked the tone they offered)
KT77 is kinda a variation of the EL34 (I have used them in vintage Marshall JTM heads)
KT88 is kinda like the KT66 on steroids

But then again it's hard to say as there are different brands/constructions for many of these tubes that also create variances in tone.

 

[stratotelepaul]

What are you guys biasing your KT77's at? I currently have JJ6L6's in my RM100, but want to get a more British sound out and read this post on the 77's. I plan on ordering a quad of JJ 77's to give them a shot!

Thanks for any input!

 

[joey_truelove]

So what, if any, tonal differences do you hear between;KT66, KT77, & KT88?

I'd say they all have share some similarity in definition, in that they're glassy and hifi-ish clean (but not as much as 6CA7s or 6550s) and all of them have a warm midrange, more mids than 6L6s, less than EL34s.

The KT77 is the most forward and peaks roughly where an EL34 would, the KT66 has lower Gm and are warmish and laid back and the KT88s are darker, harder with more gusto.