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OLDER DECWARE GEAR SUPPORT >> CSP, CSP2, CSP2+ >> Heater voltage problem
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Message started by funch on 09/12/13 at 01:16:20

Title: Heater voltage problem
Post by funch on 09/12/13 at 01:16:20

I've been having problems with noise in the right channel tube, and
have checked everything I can think of. The only tubes without noise
are the stock 6N1P's. Finally I decided to check the heater voltage.
It measures at 67VDC. I checked it with the rectifier tube in but
no drive tubes.

Any ideas what could be wrong? Bad tranny maybe?

Title: Re: Heater voltage problem
Post by funch on 09/12/13 at 03:38:14

I just read Rizlaw's post in the CSP3 thread he started about the
output tube positions and that has eased my mind about the noise
I've been getting with 6922 tubes. Now to solve the voltage mystery.

Title: Re: Heater voltage problem
Post by funch on 09/12/13 at 20:09:30

Update. I installed the stock 6N1P's, fired up the amp, and measured
the heater voltage. Now it's at 4.2VDC. I guess those tubes do pull
quite a bit of current to pull the voltage down that much. I'm assuming
that voltage is adequate, albeit quite low.

Title: Re: Heater voltage problem
Post by clowkoy on 09/13/13 at 13:40:10

That's about right. Mine read 4.37 volts. You can't really go below 10% of spec (5.7-6.9). Maybe the harmonics go up at that voltage.

Title: Re: Heater voltage problem
Post by Francesco on 10/06/13 at 19:15:21

Bonjour
I mesured the heater voltage of the 6N1p-EB and is 4.4v
It is normal? these tubes must be heated at 6.3V.
Any body can explain?
Thanks
Francesco