View Full Version : Bugera V22 Tubes And Speaker Rolling

03-15-2010, 11:51 PM
I finally had time to roll a few tubes and speakers through the V22. First, a big note of interest. V1 is the gain channel preamp tube. V2 is the clean channel tube. Second note of interest: When setting bias with "RCA Method" (from the RCA jack on underside of chassis) you can only measure volts DC (vDC) not milli Amps (mA) as you would with normal biasing. I used the RCA method because: I do not own a Bias Rite, nor could I find plate voltage specs. I do not know how acurate this method is. I set the bias at -17vDC with all output tubes I rolled. Other threads have stated -15vDC to -17vDC safe.
Where I ended up: Speaker- Eminence Red Fang (over Celestion Gold), V1-1962 Mullard 12AX7, V2-New Sensor Mullard 12AX7 reissue, V3 (PI)- '50's Amperex BugleBoy, V4/V5 (output tubes)-JJ EL84's ('cause they sounded close to a great set of early '60's GE's, I don't want to burn the GE's up and JJ's can be found/had for decent $$...YMWV..."your mileage WILL vary...so will mine.....

01-19-2011, 11:23 PM
What is the 3rd pre amp tube for? two are marked "a" and the third is marked "b", what would change if I tried different tubes in "a" or "b'??
What do they affect??
I understand pre amp is small signal and prepares the signal for the power tubes....but why so many Pre amp tubes?????

01-20-2011, 04:00 PM
...they're still 12ax7's a or b ..they're just barely different but not different.
ya know?