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6EJ7 or 6EH7 triode strapped?

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K

kegger

R.I.P.
Joined 2004
#1
I am wondering if by chance does anyone have any 6EJ7 or 6EH7 triode data sheets?
I'm really curious about the plate resistance and gain on these tubes strapped in triode.

I have several of these tubes and was thinking of triode strapping them as drivers.
Thanks for anything anyone may want to share on these particular tubes.
 
#4
Not yet. I have many ideas on how to use 'em. Geek has a 6EJ7 mu follower design on his site. Also, they would great in Gary Pimm's hybrid CCS. That's just SE amps. For PP amps, just putting them in the tail of a long tailed pair would be good.
 
#5
I'll try something with them pretty soon myself I'm sure. Thanks.
But I was trying to find some 9pin pentodes to try as triodes that would have really low gain with lowish rp.

I wonder what a 12BY7 in triode is like, humm. Still looking at others I have stashes on to fit the bill nicely.
At the moment I'm running 12B4's and was looking to try some other types in there place, (with tweaking yes)
 
#6
If you want low gain, a triode strapped 6AQ5/6005 gives you a mu of ~9.5 with an Rp of about 1.9k (from memory - actual numbers may be somewhat different). The hefty half of many of the vertical oscillator/amplifier dual dissimilar triodes will give you a mu of around 6 with an Rp below 1k.
 
#8
Hey thanks for that, in this ap I need 9pin tubes as I don't want to change out the sockets though.

I may give a 6bq5 a try but I'd like to see lower gain like that of the 6aq5 you mention.

Looking to see if I can find something that ends up somewhere around 2k-4k plate resistance and less then 10mu.
 
#9
kegger said:
I may give a 6bq5 a try but I'd like to see lower gain like that of the 6aq5 you mention.

Looking to see if I can find something that ends up somewhere around 2k-4k plate resistance and less then 10mu.
Click to expand...

6AQ5 is a noval equivalent to 6V6, hence triode strapped parameters should be about µ=10, gm=5mA/V, rp=2k.

Triode strapped plate curves here.

Tom
 
#12
Actually I got off track right from the begining post. Thank you though.

I was looking for a tube with 4k or less plate resistance and less then 10mu for this ap.
(in a 9pin solution)

It seems the EL84/6BQ5 is closer to 20mu like where the 6S4 you mention is at 17mu.
I also like the 6S4 and the 12A4 along with the EL84 wired in triode as some of the 20ish
gain tubes and may try them in a pre in the not to distant future.

It seems at the moment I have 2 options, the 12B4 I was allready using or the latest is an
EL86 wired triode that yeilds less then 8mu and less then 2k plate resistance, sounds nice.

I'm sure there are some disimular triodes where I could just use half or some triode/pentode
tubes to either use the triode or wired pentode in triode or just some other pentodes wired in
triode to have some other choices, so I am still investigating this further.

But so far I like the EL86 wired in triode, they are a little microphonic though that I am taming.
 
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