Super Reverb Pre Amp Tube Voltages

[72Blazer]

On my Super Reverb Clone, the Vibrato Channel (channel 2) does not seam quite as loud as the normal channel (channel one).  Another way to describe this is that when channel 2 is turned all the way up, it sounds like the volume channel turned to 7.  Hope this makes sense.  I'm thinking the voltages of V4 are a little low.  Interested in your thoughts.  Vr, J.



V1                   V2                   V3                   V4                  V5                  V6
               
Pin 1:  258v   Pin 1:  285v   Pin 1:  426v   Pin 1:  260v   Pin 1:  423v   Pin 1:  232v
Pin 3:  2v           Pin 3:  1.5v   Pin 3:  10.2v   Pin 3:  2.1v   Pin 3:  2v           Pin 3:  90v
Pin 6:  252v   Pin 6:  291v   Pin 6:  426v   Pin 6:  262v   Pin 6:  3273v   Pin 6:  225v
Pin 8:  1.8v   Pin 8:  1.8v   Pin 8:  10.2v   Pin 8:  2.1v   Pin 8:  15v   Pin 8:  90v

[sluckey]

Voltages look fine. Well, except for V5 pin 6!   

[72Blazer]

oops!

V5 pin 6 is 327v

I thought there might be a problem with second gain stage for channel 2 (V4 voltages).  They are lower than what the schematic shows and especially with todays wall voltage.  Maybe about 30-40 volts too low?

It must be me then-but channel 1 will shake the rafters.  Channel 2 does not.  it gets loud enough, but I'm not getting the normal breakup starting around 4-5 like on channel 1.  This amp has been giving me fits.  Spent alot of time this weekend chasing the water rushing noises in channel 2.  cleaned the board with isopropyl, changed out a few slightly out of spec resistors that in retrospect were not the problem.  I'd think I had the problem resolved then an hour two later the noise would start again.  Turned out to be a 250pF cap in channel 2.  

Thanks for taking a look at the voltages.

[glass54]

Hi 72Blazer,
Well done with the 250pF Cap on Ch 2.
For my curiosity (and maybe others as well), since it was a clone, what type of capacitor was it? (Ceramic, Silver Mica, etc)? I know that Silver Mica's can fail, and can be fussy regarding a touch too much heat from soldering, even with a careful operator.
Thanks and Kind regards
Mirek

[AlNewman]

Silly question, but did you clean all the pots and jacks?

[72Blazer]

Silver Micah / yes on pots and jacks.

[glass54]

Thank you for that. Appreciate your prompt response.
..and no, just the faulty 250pF cap in Ch2.
 
Regards
Mirek