I have an old DIY amp with EL34SE that I wanna change the drivers on,I have seen schemas with 6SL7 driving the 34´s therefore I saw the 6J51P has about the same Mu if I use ut in triode mode.
The 6J9P has about half of that,that might be to low...?
The 6J9P has about half of that,that might be to low...?
All those triode connected pentodes can be used to drive EL34SE ( and all other output tube types as well...).
The anode current of 6SL7 is typically some 1.5 mA with 100k anode resistor and works satisfyingly with one EL34.
6J51P and 6J9P can be used with 10k...22k anode resistor and up 20...30 mA anode current.
One triode connected 6J51P can drive half dozen of parallel EL34's.
The anode current of 6SL7 is typically some 1.5 mA with 100k anode resistor and works satisfyingly with one EL34.
6J51P and 6J9P can be used with 10k...22k anode resistor and up 20...30 mA anode current.
One triode connected 6J51P can drive half dozen of parallel EL34's.
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That depends on operating point.
Voltage swing to drive EL34 can vary from some 15 VRMS to more than 30 VRMS.
No issue using a tube capable of a larger linear plate swing, linearity should be enhanced slightly with lower swing requirements.
I have a couple of 807`s lying around here,thought I´d try them instead of EL34,(they look cool)but I read they only give about 1,6w in triod mode...but 5-8w in tetrode mode.But how does triode mode sound?Is it much different from triodmode?
Maybe it's only me, but I've never found 6L6 family tubes (including the 807) to sound particularly good triode connected. YMMV
Even in pentode mode with regulated screen grid voltage I paralleled them to get acceptable sound quality on 40W only. I.e. about 80W dissipation to get 40W output. With GU-50 tubes I am getting 80W output dissipating 40W on 2 tubes for the same sound quality.
I am trying the 6J49P to drive my EL34amp in triode mode and it does sound better than the 76 I had before.
But the smalest Edcore SE trafos sounded awful,no bass and just awful.
So I connected another SE trafo I had laying around (2,5K)and it does sound best if I connect the 8 ohm speaker to the 4 ohm tap,does it mean that the tube (EL34) sees 5K?
But the smalest Edcore SE trafos sounded awful,no bass and just awful.
So I connected another SE trafo I had laying around (2,5K)and it does sound best if I connect the 8 ohm speaker to the 4 ohm tap,does it mean that the tube (EL34) sees 5K?
Yes, the EL34 sees 5K. Note that the transformer you have on hand probably does not have sufficient inductance for that to remain true at low frequencies so if this is a serious effort you will want to invest in some good bonafide 5K transformers.
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