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Vintage threads from the first ten years

plate voltage on 5E3 1st-stage...

10/31/1999 11:46 PM
Fj	plate voltage on 5E3 1st-stage... interestingly, I took voltage readings on a 5E3 that I built a while back. they read as follws : pin 1 = 195vdc pin 6 = 195vdc...now in the 5E3 that I just recently completed, those readings are a lot less than 195vdc...AND... they are not identicle!...the amp w / the 195 vdc reading employs 2 separate input jax going thru 68k resistors & shared cathodes (pins 3 & 8) on that same tube...the amp w / the lower readings has but 1 input jack NOT going thru a 68k resistor to pin 2 of 1st 12ax7, then, 2 is wired over to pin 7 w / a wire...cathodes on that tube are NOT tied together...it has 2 separate cathode caps to ground...any insight on what is happening here?...BTW... the voltage on this amp (2nd one) pin # 1 = 111vdc pin # 6 = 130vdc please help me...Frank...fwiw I favor the the "better-finger-sensitivity-response" on the 195 one...

10/31/1999 11:46 PM

plate voltage on 5E3 1st-stage...

interestingly, I took voltage readings on a 5E3 that I built a while back. they read as follws : pin 1 = 195vdc pin 6 = 195vdc...now in the 5E3 that I just recently completed, those readings are a lot less than 195vdc...AND... they are not identicle!...the amp w / the 195 vdc reading employs 2 separate input jax going thru 68k resistors & shared cathodes (pins 3 & 8) on that same tube...the amp w / the lower readings has but 1 input jack NOT going thru a 68k resistor to pin 2 of 1st 12ax7, then, 2 is wired over to pin 7 w / a wire...cathodes on that tube are NOT tied together...it has 2 separate cathode caps to ground...any insight on what is happening here?...BTW... the voltage on this amp (2nd one) pin # 1 = 111vdc pin # 6 = 130vdc please help me...Frank...fwiw I favor the the "better-finger-sensitivity-response" on the 195 one...