On 07/17/2010 04:44 PM, Ben wrote:
Tony Duell wrote:
Hi Jeff,
Interesting article. I am a big fan of the ez80f91. I find the data =
You know you've been (hardware) hacking too long when you read the
subject: line of this message and assume it's going to be about a
biphase
valve rectifier with a 6.3V heater and a B9A (noval) base. Yes, that did
happen to me...
Not me , I am using 6X4's. :)
-tony
Ben.
PS. Any tube experts out there? I need ideas to keep my hum down
on preamp with a 6X4 and 6CG7.
Make sure neither valve has a heater to cathode leakage. Insure the DC
bus is clean
as a common old valve gear problem is dried up electrolytics. Try
grounding the other
side of the filament string or float the heater string (insure neither
side of the heater
winding on the power transformer is grounded. I've also put a 100ohm 2W pot
across the heater winding and grounded the slider to be able to balance
the heater
voltage against ground. If all else fails run the heaters on DC.
Allison