Topic: Power Help

[hoyt]

I'm very happy with my current playback system, with one major exception, and I don't really know what the problem is, so I thought I'd see if you guys had some ideas to check...

I have a 64 bit XP media PC > Benchmark DAC1 USB > Audio Research D120 > (new transparent speaker cables, wooo!) > Maggie 12's. 

I live in a house built in the early 1920s, with updating wiring in the late 80's (guess, but that looks like the right timeline to me).  There's only 100 amps coming into the house at the main breaker.  If I have my system on, and playing, when the A/C kicks on for the house, I drop the USB connection to the DAC1.  I have to unplug the DAC, close my media app, and reopen it to continue listening.  Once the A/C is running, it's not a problem, and it's not even every time it kicks on, just sometimes.  Sometimes it's even the dishwasher that causes it to drop out.  It never trips a breaker in the panel, but then again, I have 18 breakers in the panel, ranging from 15 - 30 amps each, and only 100 coming in.

My gut feeling is that I need more than 100 amps coming into the house, but I don't really know how to confirm that without paying some electrician 2k to upgrade my panel to 200 amps.  Perhaps a power conditioner on the DAC & Amplifier would help, but again, not really sure what's happening in the background when I lose the USB connection.

Anyone have an idea I could try to help me figure out what's going on?  This is the last piece of my playback system that irks me, since I just got kick ass cables and sent the Maggies on for a small rebuild...

Thanks!

--Ryan

[guysonic]

I also lived in an old farmhouse with just 100 amp service for almost 10 years, and this service should work if not overloaded to blow fuses.  Sometimes when a motor starts (fridge, air conditioning, other stuff) it places a big power surge that can drop power line voltages, especially if wiring has some bad connections.

1) Make sure all your computer/audio that's connected together is being powered by the exact same power strip, and not split to run on different power plugs or even different multiple breakout power strips are running off the same wall socket, best to use only one power strip powering connected computer/audio gear. 

1A) For your sensitive gear that's all connected together, best NOT to run any other equipment on the same breaker panel power circuit, so find out if other stuff other than your computer/audio gear is running off the same fused circuit and make some adjustments by powering your sensitive electronics off some other fused receptacle so to isolate big power surges from affecting the individual breaker box fused line powering your electronics system.  Maybe look for a different receptacle that gives you a dedicated AC power connection and run a heavy duty 12 or at least 14 gauge 3 conductor extension cord from that AC receptacle to your system.

2) Sometimes good practice to run a UPS or at least a line filtering surge protection power strip for this type of gear.  If having a UPS, best type is one that auto regulates to maintain line voltage when line drops too low, and then switches to battery power if line drops too low for auto regulation to work.

3) make sure all the wiring coming out of the breaker box is secured tight, and is not loose to not make best low ohms contact.  Usually a circuit wire that is not screwed down tight will be getting warm at the loose screw-down point when sufficient power is being drawn; there should be NO heat if the wire is tightly secured.  So maybe have someone with electrical safety knowledge use a non-contact thermal meter to scan all AC mains input/output connections to spot poor connections dropping voltages when stuff is turned on, and when running.

4) Might be a good idea to check the AC socket wiring connection that is powering your sensitive gear for wires connecting the AC receptacle being loose, or see if the socket itself is worn too much to be making good connections to stuff plugged in.

[hoyt]

Thanks for the suggestions.  The amp + dac are on a dedicated circuit with nothing else on it that I installed over Thanksgiving last year.  It's 15 amp wire (14-2 with ground), receptacle, and breaker for the 8 watt DAC1, and power hungry ARC.  The PC is on the other side of the room, but I have moved it over in troubleshooting so that it was on the same breaker to no avail.  I'll break out the electrical tools to double check the plug, but I remember when I hooked it up I was hardly loosing anything from the breaker box to the outlet itself (it's only about 20 feet of wire).  The folks at Benchmark told me that the DAC1 operates as low as 90 volts, so it would have to be a large drop to hit that.

I'll try the UPS idea soon too.  Thanks!

--Ryan

[hoyt]

Quick update, I tried the UPS on the audio gear (DAC and Amp) last night and still had issues after a few A/C kick on and offs.  Seemed to be better, but it did drop the DAC after a bit.  The PC was back on its own circuit, I'll try rearranging that plug into the UPS later and see if it helps. 

Thanks!

[guysonic]

Sometimes it's the MAINS connection into the breaker box that's not tight/secured so that anything with a large surge can drop voltage on all the panel circuits at the same time. 

There are a few products meant for coating aluminum MAIN wiring to be consistently low ohms connection, and this same paste works for copper mains or any high amp draw screw-down connections.  Best to have an electrician mess with this, but being familiar with such stuff, I notice one of my mains cables getting warm so cut power, squirted some paste in, and re tightened the Allen bolt into the breaker box and this solved the heating problem.  Used this also on all my 40 to 60 amp 220 circuit connections with same effect.

Also good to know some UPS devices are a bit slow to respond to a fast line drop-out condition, so this may be why it works better, but not all the time.