Neb
Here's some info about the retube as I posted in another thread:
"Some additional info on the Retube (mainly for the other Krank Rev owners or 'stein owners):
Since I hadn't biased an amp before I took it to a tech. With the JJ Tubes in, he measured the Plate Voltage which was quite high at 526Vdc (I had expected around 480 from info I had researched). One method to set the bias current is to use the following equation:
Tube Wattage / Plate Voltage X 70% = bias current.
Therefore:
25/526 X 0.7 = 0.03327 or 33.3 mA
He then used a bias probe which plugs in between the tube and the tube socket on the amp. The particular one he used was a Weber and it had 4 bias probes connected to an LCD display wi8th a rotary switch to select which probe's measurement was being displayed. He looked at the readings on all 4 tubes (which was close since they were a matched quad) and he adjusted the bias pot until the average was around the desired setting. They were as follows:
Tube1 - 32.6
Tube2 - 32.6
Tube3 - 33.6
Tube4 - 33.6
Attached are some photo's of the inside of the REV and of an access hole that was drilled in the bottom to save from removing the chassis from the box next time the bias needs to be adjusted/checked. One of them is quite blurry, but you can actually see the pot inside. The hole is not actually that far off centre of the pot, the camera was on an angle so I could shine a torch in there.
http://sneapforum.CeltiaProductions....0Photo%27s.zip"
The guy that did it for me only does it for a hobby now. He is quite switched on in regards to all things electronic. He told me how when he was in a band in the 60/70's he made his own tape echo's, modded amps, etc... Just a great, polite and knowledgeable guy. Not really sure if he would be interested/have the time to do yours. I could try and find out in the next couple of weeks though.