Tube Amp Archive

I have been using a 50W MASS Lite with the separate treble and bass attenuation. It seems to work fairly well if you don't dial it down too much and the separate controls let you fiddle with the sound a bit.
Broz

Hot glue gun works well.
Broz

Dana and Sliberty, Thanks for the kind words. I'm just a DoD science guy, not in the forces, but we were flying aerial recon and imagery missions in support of US and ISAF troops. Most satisfying work I've ever done, and we're hoping to go back this year. The folks working on the ground, outside the...

Finally got my new Express up and running and what an amazing machine. Sounds spectacular ( although way loud), better with el34's, but good with 6v6's. Started this thing early summer wth a home-brew chassie, Moose's trannies and Dana's boards and then had to put her away for 3 months while I spent...

Well. I guess you would have to come up with the positive (not the negative bias supply like my dumb question above) dc for elevation. Could do a voltage divider off B+ I guess.
Broz

Thanks Mark
Broz

Is there any reason not to connect the 6.3 v heater center tap ( I have one of Moose's PT's that has this center tap) to the bias supply? I have read that elevating the heater supply like this can help reduce hum. Thanks,
Broz

A lot of people started with the P1 theory document at AX84.com. The audio classroom series at http://www.audioxpress.com/resource/aud ... /index.htm is also good.
Broz

I may have answered my own question, a 200 ohm (cold) ntc thermistor seems to be at the large end for the devices. This would knock down the peak inrush a bit, but is probably not enough to allow a large increase in capacitance.
Broz

Could an inrush current limiting device like a thermistor be used to allow a larger 1st capacitor with a tube recto?
Broz

Markusv, look at the power supply filtering and decoupling network articles from the audio classroom series at http://www.audioxpress.com/resource/aud ... /index.htm

These are really good.
Broz

I just got a small order of mallory pvc601, 6122 and 622 caps from REM electronics supply in Ohio (www.remelectronics.com). Don't know if these are older Mallory's or newer CD production. The online cataloge calls them Mallory's. Shipping cost was pretty reasonable.
Broz