Hello all,
I finally finished up my Drip REDD47 today (it's been a busy few years). It fired up just fine, reasonable amount of hum with a mic plugged in with gain maxed. I had reduced this a bit with some additional connections of earths at terminals to the star ground by the transformer (pad, to amp, vu meter, and audio ground by the xlr terminal).
I ordered a phantom power unit as recommended by another board member:
www.digikey.com/catalog/en/partgroup/psa065m-series/15727
This had been installed through early testing, but it didn't seem to be working so I pulled it out while I de-hummed. Got my hum to a good place then popped it back in. Phantom still wasn't working so I kept it connected but removed it from the case so that I could check voltage from the pcb connection itself - I got a reading of 40V.
Anyways, I was looking at something else then out of the corner of my eye saw a spark on this near the power hookup of the phantom board (which was connected to one of the Primary terminals). One of my monitor speakers (which wasn't in any active monitoring circuit, and actually connected to a totally different power circuit!) made a funny wubwubwub sound for a second or so. I looked back down at the REDD and all the lights and tubes were out and no audio was passing anymore. Dead.
The onboard fuse is totally fine. Same with the fuses in the IEC connector. I've tried a couple of different IEC cables, no difference. Other gear on the same power circuit is fine - though this is just my soldering iron and some lights.
I'm getting voltage readings at the AC in terminal (118V on positive, about 1.3 on Neutral) and primary (1.3V on both terminals) but now nothing coming back out of my transformer - the Allied 6K56VG.
Sooooo... Is it possible to fry one of those transformers somehow? I'm wondering if there was a massive power spike in the building that just happened coincidentally while I was working on this - though I've never experienced anything else like this is in the few years I've been in the building. Is there anything else I should check? I've tried switching the 5Y3GT tube but no change, tried switching fuses just incase - nothing.
So - is 1.3V a normal reading on Neutral? And is it possible to blow a transformer like this? It seems pretty heavy duty. I've been unable to find a schematic which would confirm whether or not the fuse on the PCB is pre-transformer or not. Otherwise do you think that the phantom board could somehow have caused a problem? I don't know if a component may have somehow shorted against the case, but it was hanging on the outside and all the metal around it is painted, I'd also guess if something shorted there it would have got to earth...
Please help! It was sounding great and I'd love to use it!
Thanks,
D
I finally finished up my Drip REDD47 today (it's been a busy few years). It fired up just fine, reasonable amount of hum with a mic plugged in with gain maxed. I had reduced this a bit with some additional connections of earths at terminals to the star ground by the transformer (pad, to amp, vu meter, and audio ground by the xlr terminal).
I ordered a phantom power unit as recommended by another board member:
www.digikey.com/catalog/en/partgroup/psa065m-series/15727
This had been installed through early testing, but it didn't seem to be working so I pulled it out while I de-hummed. Got my hum to a good place then popped it back in. Phantom still wasn't working so I kept it connected but removed it from the case so that I could check voltage from the pcb connection itself - I got a reading of 40V.
Anyways, I was looking at something else then out of the corner of my eye saw a spark on this near the power hookup of the phantom board (which was connected to one of the Primary terminals). One of my monitor speakers (which wasn't in any active monitoring circuit, and actually connected to a totally different power circuit!) made a funny wubwubwub sound for a second or so. I looked back down at the REDD and all the lights and tubes were out and no audio was passing anymore. Dead.
The onboard fuse is totally fine. Same with the fuses in the IEC connector. I've tried a couple of different IEC cables, no difference. Other gear on the same power circuit is fine - though this is just my soldering iron and some lights.
I'm getting voltage readings at the AC in terminal (118V on positive, about 1.3 on Neutral) and primary (1.3V on both terminals) but now nothing coming back out of my transformer - the Allied 6K56VG.
Sooooo... Is it possible to fry one of those transformers somehow? I'm wondering if there was a massive power spike in the building that just happened coincidentally while I was working on this - though I've never experienced anything else like this is in the few years I've been in the building. Is there anything else I should check? I've tried switching the 5Y3GT tube but no change, tried switching fuses just incase - nothing.
So - is 1.3V a normal reading on Neutral? And is it possible to blow a transformer like this? It seems pretty heavy duty. I've been unable to find a schematic which would confirm whether or not the fuse on the PCB is pre-transformer or not. Otherwise do you think that the phantom board could somehow have caused a problem? I don't know if a component may have somehow shorted against the case, but it was hanging on the outside and all the metal around it is painted, I'd also guess if something shorted there it would have got to earth...
Please help! It was sounding great and I'd love to use it!
Thanks,
D