Peavey transistor question

[Valvehead]

Im working on a Max 112 combo (2012) , ive got it working now (cracked solder joints) .

I just want to make sure what I found is correct. One of the transistors had virtually no lettering left on it , as if it got real hot . Its U6 on page 3 .
So there is U6 / U7 , Q6 / Q7 that are bolted to the chassis. They all had the thermal grease / plastic insulator / plastic stepped iso washer on them EXCEPT U6 ----U6 had no iso washer or plastic insulator.
Looking at the scem , is that correct as far as the way its wired? These transistors all have the metal back , not plastic. MAX_112 PowerAmp_2012.pdf

[glebert]

U6 and U7 are +/-15V voltage regulators, not just transistors. The metal tab on the package of the 7815 is connected to pin 2, which goes to ground, so they don't need the iso washer and insulator.

[Valvehead]

Thanks---wanted to be sure !

[glebert]

Thanks---wanted to be sure !

I even took a look at a Max 115 I have in my bone pile to be sure. I really like that series of amp. I would gig them anytime.

[Enzo]

The key is the nomenclature. Q is used to denote a transistor. U is used to denote an integrated circuit.

[Jon Snell]

U6 and U7 are +/-15V voltage regulators, not just transistors. The metal tab on the package of the 7815 is connected to pin 2, which goes to ground, so they don't need the iso washer and insulator.

The 7915 has the input going to the tab, 7815 is common ground but beware of ground loops.