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Low Voltage on Circuit

Just tested the Voltage coming out of my wall and it was 112.7 V. This is obviously too low to feed my 120V tube monoblocs and my tubed pre amp. For about a week when I turned on my equipment it would shut off after about 30 seconds of play. I stumbled for a few days trying to isolate the problem but kept running in circles. I then took a trip to get a multimeter and tested the juice from the wall. Please let me know how to fix this, preferably with an inexpensive step up transformer or other solution that can be done DIY for under $100. My associated equipment all on the same circuit is:

Rogue Audio Magnum M120 Monoblocs (120Watts)
DIY pre amp using 2 6SN7 tubes
EAD Ultradisk 2000 CDP

buckingham
zaikesman
3,017 posts
 
...and then, of course, you'd have to add in your other systems (how many of those did you say you have?)...I think I should start-up a small Enron-style company to corner the electricity market on your block... :-)
buckingham OP
333 posts
 
Hey guys,
Voltage went back up to 118V today and it turns out that that wasn't the problem. It seems to be the power amps themselves that are acting up. When I turn them on there is a rushing and popping noise that grows with time. It is worse on the left monobloc. The right monobloc has similar simptoms but milder. I have changed out the small tubes for some NOS to rule them out but haven't tested the large KT88 Driver tubes (4 per monobloc). I sure hope it isn't a cap or something bigger. Any ideas on what to test would be great. Thanks again for your help guys.
zaikesman
3,017 posts
 
Although I was actually a little surprised to begin with that the voltage you reported would cause any problems, the fact that each of two monoblocks is acting up at the same time would tend to eliminate something like a parts failure - unless they both got zapped by a large power-line event that you didn't know about. Other possibility is that the tubes are growing too old together all around.

Conversely, are you absolutely sure that the problems originate in your amps at all? In a tube preamp, a single tube will often handle both channels. If you've got a tube pre and haven't ruled this out already, the symptoms could be worse in one channel than the other if a tube is going bad. If you need to, try running the amps with the preamp off, or better yet, with the amp inputs disconnected to rule out possible jack- or cable-related culprits. (Can you still cancel the order on that voltage regulator?) Gook luck!
buckingham OP
333 posts
 
Zaikesman,
your response came right after I figured out exactly what you hypothesized :) Looks like there is a bad tube in the pre amp. I should of known there was nothing wrong with the Rogue Monos, those things are indestructable. BTW the order for the regulator somehow didn't go through on the website, so that put a smile on my face. Thanks Zaikesman.
zaikesman
3,017 posts
 
Glad it worked out for the better... Tubes - I love 'em, but they can really drive you nuts!
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