SY said:The EL84 is sooooo easy to drive that I can only ask, "Why?"
Simply because I have too many (100s) of EL84 and want to utilize them as much as I can
Any further guidance please? Thanks!
SY said:50 in parallel per channel. Or just use two and send me the rest.
Miniwatt said:
I am serious !!
pwan said:
I am serious !!
Yeah, I know, I was laughing because of SY's reply "50 in parallel per channel. Or just use two and send me the rest."
BTW interesting question
Yvesm said:A quick check with Tube CAD.
Triode connected, 250V B+, 10K anode load resistor and bypassed 600 ohms in the cathode should produce near 23dB gain.
Just enough to drive another one.
Not so hi anode current (10mA) but still 4,5W absorbed by the heater.
Yves.
Do you mean this?
Attachments
pwan said:
Do you mean this?
Yes, kinda Zen !
With or without cathode bypass on first stage.
Don't expect more than 2Watts output.
Yves.
Yvesm said:
Yes, kinda Zen !
With or without cathode bypass on first stage.
Don't expect more than 2Watts output.
Yves.
I use Foxtext 166e (94bB) so 1.8W triode is plenty enough.
So, will the circuit I attach earlier work?
( sorry, I relatively new to tube design & high volatge, so just wanna be sure first). Thanks
Yes. I would however insert a 47k or so resistor from grid to earth before the first EL84.So, will the circuit I attach earlier work?
Bas Horneman said:
Yes. I would however insert a 47k or so resistor from grid to earth before the first EL84.
Agreed, or use a potentiometer, same value !
Yves.
Note that at these operating conditions, the linearity will be mediocre at best. The rp will be something like 6k, which means that with a 10k load, you can expect a few percent THD (dominated by second). Now, you may like the sound of a lot of added second harmonic (it fattens and sweetens the sound), but it is not in any sense accurate.
By comparison, the distortion of a more suitable driver tube will be well under 0.05%, leaving your output stage as the primary distortion contributor.
By comparison, the distortion of a more suitable driver tube will be well under 0.05%, leaving your output stage as the primary distortion contributor.
Thanks for all your comment. Due to my little knoweldge, not sure if I can grasp them all.
Is my understanding (in the photo) correct?
Also, more questions popped up now:
1) As SY said, should the Rp (in green) be 6K Ohm or 10K Ohm ?
2) To make the voltage at first stage (less ripple) and output stage (more ripple can be) make easier in practice, can I use the B1+ as ~ 315 Volt?
Is my understanding (in the photo) correct?
Also, more questions popped up now:
1) As SY said, should the Rp (in green) be 6K Ohm or 10K Ohm ?
2) To make the voltage at first stage (less ripple) and output stage (more ripple can be) make easier in practice, can I use the B1+ as ~ 315 Volt?
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