Hello group, just joined up. Living in Tennessee. Work in the entertainment business. Love DIY tube projects. Been at it for about two years now. Anyway, just wanted to introduce myself.

Tom

Once RL stops interfering and I can get this project going, the front end design will definitely be single stage: an LTP phase splitter/voltage amp up front driving source follower grid drivers. Since the 814s require just under Vp= 95V, you require a front end that can swing the voltage and do so with reasonable linearity. These are conflicting ( Read more... )

Once I get the Wolverine project completed, I've decided what to do after that one, once RL stops interfering with my plans. As much as I'd like to do one, I can not justify a hollow state OTL regardless of how elegant the Circlotron topology is. Using four or five 6BQ6s per phase to get a lousy ten watts or so makes no sense whatsoever. Make a ( Read more... )

The main problem with this sumbitch is the need to swing the big volts (some 310VP-P) that the 845 requires since it's such a low-u type, while keeping the distortion down. These really are conflicting requirements. It's also nice to have some open loop gain for dropping in a bit of gNFB, which will sound like heresy to all the DHT fanatics out ( Read more... )

anyone got any good schematics for a tube based guitar amp that pushes headphones?

( Read more... )

Does anyone know where I can find ECC85 model that will work with LTSpice?

Аs far as fixed biasing supply goes for the output tubes, does it make sense to regulate it using LM317 etc ( Read more... )

Buyers beware of this seller. Tubes advertised as NOS - and what I got was tubes with visual varying degrees of use, in some cases with heavy black burn marks all over the glass, and others with faint, but still visible discoloration.

What should have been a "red flag" I guess is that for most of them they are not shown outside the box.

I whipped up this amp tester earlier this evening. This device consists of a linear subtractor and voltage amp. The idea is to sample the output signal from the gNFB summing node and subtract it from the input signal. Theoretically, whatever's left is distortion after you null the output by adjusting the input signal level. I ran some tests on the ( Read more... )