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Re: plate load-"brilliant" question

Posted by hifitom on October 29, 2001 at 17:29:48:
Forgot to mention that I'm running a traditional SE OPT amp so the parafeed inductance issue doesn't apply for me, I just tossed it out as a thought.
Ahhh...the 280! Hard to come by in these parts because all of the old radio restorers seem to hoard em. Found 1 at the last Hamfest but it resides in one of my linestages...you are right, it's a great looking tube! I had not even though of that one for this application. I do have some NOS 80s that I'll have to try but do you think I might be pushing the current limits using a single tube for both 2A3s? Series 5AR4s seems kind of excessive in my little budget amp and I'm not sure the voltage drop would be right.
I don't have enough B+ to get direct coupled on this amp. That led me to using a rectifier tube on the cathodes instead of a VR type. The 5Y3 drops 35 volts for 115ma for the pair of 2A3s. Neg leg of the 5vDC supply gets grounded, right...that accounts for the reduced hum on the output?? Sounds very fast! Now I have to play with the driver stage and coupling caps to get a little more low end. It's nice and tight but I would like a touch more of it.
But how about a VR tube from B+ to plate in a cap coupled output or WOT linestage...or in the driver section of an amp?
Tom