Got Joe's wiring kits in. Had my father return today with both amps in tow. I made matching modifications to both. Following Joe's wiring path instructions, I re-routed my AC and DC the best I could. Some Consideration given to the two facts that A.) I already had the backplanes in and wires soldered to em, so lengthening them wasn't an option at this time, and B.) My dad, (the customer) did not want to cut to length the original transformer wires (gray) to the light board. So I made a service loop. Right or wrong, that was his decision.
So this solved the hum I got when only speaker wires were hooked up. At least to the point it was only audible if you smashed your ear into the woofer. It was faint at best. The minute I plugged ANYTHING in to the RCA jack though, we got a louder hum. Both amps, regardless if a source was at the other end. Yes my RCA jack are floating and I metered them to chassis. -No continuity. So considering the test bench had an iphone and a crappy pair of RCA's just for testing amp function, we aren't sold this is actually an issue. He said he couldn't hear it at home BEFORE I re-routed the wiring. Only if he walked up to the speaker and put his ear into it. He's not concerned about it. I DO have that meter attenuation switch washer touching the bottom binding post nut and those two ring out to chassis, but since the binding post core is plastic, I can see only the attenuation switch body being an issue, but it's not because it doesn't ground out to anything else. Would a three prong plug solve some of this? Or is it inherent in the amp build? (i.e. new sensitive parts that can pick up things a lot easier)? I'm just pissing in the wind there so take it with a garin of salt. Joe said his Acurus pre, brings in hum when he hooks to it too, so I presume it to be? The old PL wiring didn't do that though, so I'm wondering what is the cause of it? The great news is, the meters no longer bounce on turn on/off and are protected by the DCP, so I AM glad everyone here prompted me to make sure I made that change while I was in there.
Anyway, that's the last I'm touching the amps. They are DONE. He is SATISFIED, and that's probably it for him. Below some shots as received together, and then one of each AFTER I re-routed the signal paths. The Saga is again...........OVER. Enjoy the amplifier porn............
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