Firestorm wrote:Could we see pix of the power supply (under the doghouse)? As Alexo said, if stages are not decoupled adequately, they will talk into each other. I think I would try disconnecting the feedback loop and see what happens. It may be that you need to follow the AB165 feedback scheme. Beginning with AB165 (the first amp that wraps the V3 signal back to V2) and continuing until AA371, all Bassman amps use that type of feedback network. Before and after they used the one you have. I can only assume they were fixing something.
You get the genius of the day award.
I get the retard of the year award.
I am embarrassed and ashamed.....and I apologize to everybody. I cannot believe I did this. I contemplated lying about this, and making up some BS story. But, my Father (RIP) would not be proud of me at all. Not the kind of "man" he tried to make out of me.
Sorry guys......just cannot believe I did this. I know we all make mistakes, but Good Grief...
Thank You
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Ha! Don't give yourself a hard time though man! I usually don't make goofy wiring errors anymore (I've made them all and learned my lessons) but recently learned a new lesson.
I was going through my Rocket build which always sounded kinda lame. Did some reading and found out that with too much B+ the amp won't clean up right. Did my usual BJT/Zener trick and nailed the B+ right where the voltage charts recommend. Biased up to where I was expecting and the amp sounded great, except for an errant buzz that I couldn't eliminate. It wasn't until I went to loosen the output transformer to move it around a hair that I realized that pretty much every piece of hardware other than the pots and main board were barely past hand tightened. I cranked everything down tight and the hum "magically" disappeared.
THEN I went to my Express which has been unusually hummy lately. I haven't really done (or needed to do) any maintenance on this amp since I built it so I figured it was time to roll some new preamp tubes. It was only as I was plugging in the speaker cable (right before I started pulling tubes) that I noticed the speaker jack was really loose.. Once again I tightened this and the hum disappeared..
