Tube Amps / Music Electronics
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|previous: Doug Need some help here guys. I'm stump... -- 3/5/2000 3:36 AM|
|3/5/2000 2:59 PM|
|Randy Jamz||Re: Need help with Fender Pro Jr.|
Sometimes when you look TOO hard, you tend to OVERLOOK! This is a simple 4-tube number, shouldn't be difficult at all. Start with your B+ voltages, and work from the output stage back to the input stage. 6BQ5's need 22.5VAC grid-to-grid to achieve 17 watts RMS output. If you have this, and the B+ voltages are OK, then the answer is the output transformer/speaker are suspect. Otherwise, work your way back to the input until you have the right B+ and 22.5VAC grid-to-grid on the output tubes. You may want to check each 6BQ5 grid. About 10VAC is what you want, and with 1/2 power complaints, suspect one 6BQ5 isn't getting the AC drive it needs. Whew! That was long winded. Sorry. Hope this helps, though.
|Gus Sometimes the cap shorts out thats ... -- 3/5/2000 6:04 PM|