Peavey Combo 300 - 260C power amp low power

[Mars Amp Repair]

Hey folks,
Just ran into this interesting symptom. Power just seemed low, but sound quality was ok even with signal into 'Power In' jack. Compression LED coming on prematurely given the power I was getting out of abt 40watts.
So, I decided to pursue the Compression circuit, albeit I never had any issues in any other PV. BTW, there is no compression switch or control on this amp.
Long story shorter, when running the amp into a load to emulate the level that triggered the compression, I notice a small whiff of smoke. I couldn't find anything heating up anywhere on the board by running my fingers over the components, but could smell the distinct odor of resistor burning, so I sniffed until the smell was its strongest, and determined it was coming very close to the Zobel coil.
Turned out the Zobel network coil had a broken lead and the paralleled 22ohm 1watt resistor was passing all the sound. I find it incredible that the amp put out that much power thru the 2.2ohm resistor, but there it was. The resistor ended up changing value to abt 200ohms, so who knows what value it was before it smoked all the way thru.
Weird stuff we run into.
Anyway, just a little ditty to share.
Glen

[Jazz P Bass]

Nice!
I appreciate the posts that you upload on weird issues.

[Mars Amp Repair]

Thanx, Jazz.

[TomCarlos]

Thanks for sharing that Glen. Chances are, this could apply to other Peavey amps with the 260C.

[J M Fahey]

Strictly not "a Zobel" but yes, it helps the amp stand weird loads.

Amp out has a series inductor added just before the output jack, should still not be "best" because at high frequencies it would now see "an inductor" so to tame that they add a low value resistor in parallel.

Which normally dissipates nothing because coil has very low DC resistance, less than 0.1 ohm, all current goes through it, BUT if vibration breaks one leg, then poor resistor takes *all* of the output current.
Not good.

Your patented Nose-A-Tronic worked very well