Bottlehead Forum

Bottlehead Kits => Mainline => Topic started by: adydula on November 07, 2018, 03:35:09 AM

Title: Biasing 6c45p's
Post by: adydula on November 07, 2018, 03:35:09 AM

I checked the bias this am and the voltage has drifted up to 150 from 145...not a big deal...but am wondering as the tubes age will this voltage go up or down?
Is this an indicator of the tubes lifespan?

The mainline is still the amp in my inventory that makes me always grin and smile!!

Alex

Title: Re: Biasing 6c45p's
Post by: Paul Birkeland on November 07, 2018, 07:03:16 AM

The voltage will drift up very slowly as the tube ages.  The voltage may also move around a bit just based on how long the tube has been running before you check it. 

-PB

Title: Re: Biasing 6c45p's
Post by: Tom-s on November 07, 2018, 10:52:41 AM

Similar to this. How does the "age" of the ECC82 affect the bias? Or does it?

Title: Re: Biasing 6c45p's
Post by: Paul Birkeland on November 07, 2018, 12:49:32 PM

The 12AU7 assists the TL431 in regulating the high voltage rails. The performance of the 12AU7 doesn't influence the bias of the 6C45.