72 Twin Reverb Bright Switch Replacement

[npunk42]

Hello, I'm new to this forum. I'm glad to find it as I am taking the time to go through my 1972 Silverface Twin Reverb. The first year with the master volume.
I ordered a a new bright switch from Hoffman, and went to replace one on my amp. I notice that the old one has only two tabs connecting it to the amp. One connects via a disk cap, the other a yellow wire. My new switch has six connections on the back. I tried top right, bottom left, then top right, middle left. I thought I had better ask you guys before I messed something up.
I have also re-capped this amp, electrolytic and signal caps, rewired the bias balance to a bias adjust, and removed the master volume pot and wiring, changed a few resistors to blackface spec. Overall the amp sounds more musical, warm, round, less hifi, astringent, cold. The reverb and vibrato work fine, I am hearing a low volume p-p-p-p that wasn't there before. Previously the amp was earsplitting loud. I wouldn't ever dare turn it all the way up! now with the volume all the way up its pretty loud, but quite as loud. Is that an attribute of blackfacing?
Sorry this post got away from me. Any thought or comments are most welcome.

[52 Bill]

The new switch is a d.p.d.t. the original was a s.p.s.t., just use either of the two center connections and the corresponding upper terminal.

The loss of volume and the noise could be related to the bias setting of the power tubes. How are you setting the idle bias?

[npunk42]

Thanks Bill. I used the shunt method to set the idle bias. I raised it from 10 to 66. I put in a new set of SED 6l6GCs. They wrote the number 17 on the label of each tube.
*UPDATE*
Replaced a bad ax7 in the vibrato position, the volume came back and the pulsing went away!