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A Rivera Venus 5 Combo Amp came over from our inventory, note stating no Reverb. Simple issue of it's Input connector to the tiny xfmr pins not making good contact, exercised and all back to normal. But, in the process of checking out the amp on my Check-out Bench, I was getting this nasty staticy buzzing when I connected my transformer-isolated burst pink noise source to the input. I use this daily in checking amps out, with AC mains on this bench being sourced directly from the power panel in the room, thru a General Radio W20 20A Variac & Valhalla 2101 Power Analyzer. The GenRad 1382 Noise Generator, Genrad 1396B Tone Burst Generator and Khrone-Hite 3550 Filter are all sourced from the same circuit, though different breaker off the panel.
Also having a microphonic tube in the amp, and the amps' large heat sink preventing access to the preamp tubes, I had to remove the chassis from the combo amp case. Had to set it down on it's front face to extract the chassis rather than risk the weight dropping itself onto the speaker and breaking the power tubes. Got the amp onto the test bench lab jacks, and removed the input tube....TAD 12AX7A. Replaced with a J/J ECC83S, which sounded fine. Gain control also staticy when turned, and their orientation was such that you could spray contact cleaner in without having to get it in off the floor of the PCB.
When I powered back up, this time powering off of the Test Bench 5KVA Topaz isolation-xfmr 30A Variac/Magtrol 4614B Power Analyzer, I wasn't getting that staticy noise. Odd. Powered down, then used the power cord off the Valhalla Analyzer/GR Variac, and.....the staticy noise was back. WHAT THE ???!!**!
Switched back to the test bench AC mains, all normal again. I've no idea what this is about. Never heard this problem before with any other gear. Just to be sure, I plugged in the next amp to be serviced....a Fender Deluxe Reverb, and as far as this odd staticy noise thing goes, it's non-existent with this Deluxe Reverb, all else set up the same.
I've no idea what is inside the Rivera Venus 5. First one of these I've ever seen. Class A Output Stage. No idea what is using the heat sink. I didn't check to see if the heater supply was regulated DC, or anything else. I don't have a problem plugging an instrument into it, so this seems to be just an issue with AC mains-powered gear plugged into the inputs.
Venus5manual.pdf
Also having a microphonic tube in the amp, and the amps' large heat sink preventing access to the preamp tubes, I had to remove the chassis from the combo amp case. Had to set it down on it's front face to extract the chassis rather than risk the weight dropping itself onto the speaker and breaking the power tubes. Got the amp onto the test bench lab jacks, and removed the input tube....TAD 12AX7A. Replaced with a J/J ECC83S, which sounded fine. Gain control also staticy when turned, and their orientation was such that you could spray contact cleaner in without having to get it in off the floor of the PCB.
When I powered back up, this time powering off of the Test Bench 5KVA Topaz isolation-xfmr 30A Variac/Magtrol 4614B Power Analyzer, I wasn't getting that staticy noise. Odd. Powered down, then used the power cord off the Valhalla Analyzer/GR Variac, and.....the staticy noise was back. WHAT THE ???!!**!
Switched back to the test bench AC mains, all normal again. I've no idea what this is about. Never heard this problem before with any other gear. Just to be sure, I plugged in the next amp to be serviced....a Fender Deluxe Reverb, and as far as this odd staticy noise thing goes, it's non-existent with this Deluxe Reverb, all else set up the same.
I've no idea what is inside the Rivera Venus 5. First one of these I've ever seen. Class A Output Stage. No idea what is using the heat sink. I didn't check to see if the heater supply was regulated DC, or anything else. I don't have a problem plugging an instrument into it, so this seems to be just an issue with AC mains-powered gear plugged into the inputs.
Venus5manual.pdf
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