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. :)
Err, that's an EZ90, surely? 7 pin B7G base.
-tony
Ben.
PS. Any tube experts out there? I need ideas to keep my hum down
on preamp with a 6X4 and 6CG7.
Have you built it and are getting hum? If so, my first question is 'what
frequency'. Hum from the heaters or stray magnetic fields from the power
transformer will be at mains freqeuncy (60Hz for you, I guess), HT (B+)
hum would be at twice that (due to the full wave rectifier).
One trick in finding hum sources is to power bits (temporarily) off
batteries. The heaters could be run from a 6V battery so suitable
capacity. For the HT (B+), you don't need much current in a preamp. I
think I'd connect a lot of 9V batteries (or those 12V car key batteries)
in series for testing .Once you've found where the hum is coming from,
it;s a lot easier to get rid of it.
-tony