Note that I've not bragged about the sound, etc, just that it's my design. Nothing revolutanary to be done with tube circuits. I kept them simple. was more thinking about Low Ohms coming back on here and commenting about too complicated of a signal path, bypassed cathode resistors and lack of detail due to the parts I chose....you know.Originally Posted by alancohen
I'll look into thos PSvane 300B, and the JJ as well.
Enjoying Altec Speakers since 1972
I have a very poor opinion of Low Ohms...I consider him a dead short...
Your neighbors called. They like your music.
You're cracking me up.
Lo-mu or Low ohms, wherever he goes stirs up controversy. That's his gig. He claims to be open to personal experience but only if it coincides with his.
I think that he has a problem with the obvious.
At last, my OTL 300B kit has arrived.
As far as I know this is the first time an OTL circuit has been designed for the 300B triode. It's a very tricky circuit since with a 300B tube, the cathode IS the filament. Using it in an OTL amp places the filament in direct contact with the speaker, since there is no coupling transformer. The filament is A/C heated which opens up the possibility of filament hum directly to the speaker.
While the hum was very slight, and most would not have bothered, the issue was virtually eliminated by a dedicated filament power supply that converts 60Hz A/C to 25Hz. So there is still a slight hum, but it now resides below the capacity of almost all systems to reproduce it. For all intents and purposes, the amp is now dead quiet. Pretty cool.
So maybe all hasn't been done in tube amps just yet...or maybe now it has
Here's the filament supply parts waiting for my coffee to be ready.
PSU is almost done and I'm working on the left channel amp. Populated the chassis last night and now working on wiring it up..
Yes, that's (4) 300B sockets...and that's just the left side.
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