Hello,help me please
I just finish assembly EL34 PP (Assembly kit) but I have question why 12AX7 tube the heater have't a light?
Compare with 6N3 buffer tube it has.
I connect 6.3V to EL34 and 12AX7. > 4 lines (Current 2A/line)
Thank you
I just finish assembly EL34 PP (Assembly kit) but I have question why 12AX7 tube the heater have't a light?
Compare with 6N3 buffer tube it has.
I connect 6.3V to EL34 and 12AX7. > 4 lines (Current 2A/line)
Thank you
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Hello,help me please
I just finish assembly EL34 PP (Assembly kit) but I have question why 12AX7 tube the heater have't a light?
Compare with 6N3 buffer tube it has.
I connect 6.3V to EL34 and 12AX7. > 4 lines (Current 2A/line)
Thank you
Hi,
If you have a look at this link it's a PDF. The 12AX7 has two heaters if they are wired in series then thats 12V they are 6.3v each.
So at a first guess you have them in series and they should be in parallel for 6.3V.
Link:
http://www.r-type.org/pdfs/12ax7.pdf
If you are not sure then join pins 4 and 5 togeather and put the heater supply across 4-5 and 9
Regards
M. Gregg
Last edited:
Hi,
If you have a look at this link it's a PDF. The 12AX7 has two heaters if they are wired in series then thats 12V they are 6.3v each.
So at a first guess you have them in series and they should be in parallel for 6.3V.
Link:
http://www.r-type.org/pdfs/12ax7.pdf
If you are not sure then join pins 4 and 5 togeather and put the heater supply across 4-5 and 9
Regards
M. Gregg
Hi, Gregg.
Thank you for you quoted, I'm recheck again. I connected joint 4,5 to 6.3V and joint 9 connected to ground.
Hi, Gregg.
Thank you for you quoted, I'm recheck again. I connected joint 4,5 to 6.3V and joint 9 connected to ground.
Why have you connected pin 9 to gnd?
This can cause problems with heater to cathode leakage.
Pin 9 is one side of the heater pins 4-5 are the other.
Don't use pin 9 to hum buck.
Use some 220 ohm resistors from each side of the heater supply to Gnd.
Regards
M. Gregg
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