Audio Asylum Thread Printer
Get a view of an entire thread on one page
|For Sale Ads|
Does anyone have operating points or, even better, a schematic for the George Wright Mono 8 300B SET?
I'm currently developing a 300B SET inspired by his WPA 3.5 circuit, which is the same as the Mono 8 but for a 2A3. Mine would use the Magnequest TFA-204 (3K, 60mA), so I'll probably run the 300B at the 350Vak/60mA op point. But I'm curious as to how George set up the 300B for the larger FS-030 and more specifically the 6SN7 input stage.
I imagine the input stage is not much different from the WPA 3.5 but it would be good to know.
Be aware that George often changed bits of the circuit, and rarely if ever documented those changes. So there is no such thing as "THE circuit," there is only "a typical circuit."
Thanks, Paul. Oh yes, I'm well aware of George's idiosyncrasies. Right now I'm modeling a circuit in LTSpice and PSUD2, based on a WPA 3.5 schematic that was reverse-engineered by an owner at diyaudio (which is here by the way: http://www.diyaudio.com/forums/tubes-valves/227426-wright-audio-wpa-3-5-humpot-schematics-2.html#post3405178). Of course, there's no way to corroborate its accuracy, but it does work well in the sim so far.
At the moment I'm trying to get a sense of how he thought. There are various threads that indicate George's op points were usually "by the book," so I'm trying to gather more evidence. Ultimately the design will depend upon on how things come together physically and how they measure (and sound). And of course if a Mono 8 owner happens to post a schematic that varies from the WPA 3.5 one, then that would help me think it through.
I'm kind of on a search for lost sound here, learning as I go. It won't be a GW clone, but if it sounds similar I'll be very happy.
The sound I'm looking for was from a pair of one-offs, not a production model, that he sold to a friend of mine more than 15 years ago.
Post a Message!
This post is made possible by the generous support of people like you and our sponsors: