100 Watt Twin Reverb Low Volume

[dpm309]

Working on another Fender Twin Reverb 100 Watt with a Master Volume. Changed out V1, 4, 5, and 6 (PI) cleaned pots, jacks, sockets and am not getting enough volume out of it on both channels. Tried a couple of brand new 12AT7s in the phase inverter with no luck. Voltages look good and am getting sufficient plate voltages on all tubes: http://el34world.com/charts/valve/ValveData.php?e=view&f=19894

Checked the preamp cathode resistors and caps, and all of the components associated with the PI and everything checks out. I get a clean decent tone out of it but not the wall shaking volume you would expect from a twin. Don't know how old the power tubes are but they tested out good on my BK tube tester. Is there anything else I should be looking at?

Thanks,
Dan

[PRR]

V1 pin 8, K, can't be 108V. Specially if this is shared (not sure which of many "Twins" this is) with V2 pin 8.

V7-10 pin 5 G1 can not be 455V; nor should pin 8 K be -52V.

Old power tubes can test "OK" at 50mA on a "tester" but be unable to pull the 200mA that a big 6L6 amp sucks.

[dpm309]

Good catch PRR. I was in a hurry when I entered the voltages. 1 pin 8 is 1.8 not 108V and V7-10 pin 5 is -52 and pin 8 is 0. Need to double check next time.
Thanks,

[eleventeen]

V2 pin 6 isn't going to work @ 2.8 volts. That's a plate, oughta be 180-220 volts.


Is there an effects loop in this version where, with nothing inserted into the jacks, the shorting tabs are not making contact?

[dpm309]

Another oversight. V2 pin 6 is 238VDC. There is no effects loop on this amp. Also changed out the LDR and got the vibrato working again. I am thinking that new power tubes are in order since they are quite old. Everything else checks out. Am probably getting about 60 to 70 % power/volume out of it now so hopefully new power tubes will do the trick.
Thanks,
Dan