Adj bias circuit question

[tWreCK]

A few years ago I let a tech recap my DR103 and perform general service etc. In the process he suggested that he should install an adjustable bias circuit and remove what he claimed was an aftermarket slave output/input circuit. I didn't think anything of it at the time but I recently opened it up out of curiosity and I took a pic of the bias circuit. After reading TB's thread involving a reversable adjustable bias circuit I wanted to compare the two. Unfortunately, I noticed the tech had drilled 2 small holes to accomodate the tag strip with the additional components. If i had known I wouldn't have let him do it but he never asked/told me about it so I never gave it any thought. In any case it's done - can anyone explain what exactly it is that he did here? Should I have it removed and put back to stock and install the uninvasive type of bias that Ted explains or just leave it as is? Has he removed any of the original wiring etc or just added the extra components? The 2 holes would still be there but I can live with that. It just bugs me that he never asked me if he could drill holes in the chassis - he should've known better imho since he claims to specialize in vintage amps

DR103.JPG (470.03 KiB) Viewed 1193 times

BTW, what are the values needed for a recap?

[mhuss]

He installed a voltage doubler for the bias, which is not in itself a bad thing for the old amps with wimpy bias windings. The layout seems neat and well thought out. I'm not too crazy about the bare wires flying over the high voltage can cap, though!

The line out is just the extra black jack and two resistors, similar to the ones the factory installed in the latter years.

--mark