Hmmm, lights dim when you flick on your 8000 watt class A amp (no sliding bias).
Wonder what it could be?
Do your lights dim when your amp powers up?
Mine do. Even though I have a home electrical system that is only 15 years old, a separate 20 amp breaker, 10 gauge line, and the amp plugged directly into a medical grade outlet.
Do you have this issue? If so, do you care about it, and is there any chance that it is affecting the quality of sound?
kn
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- 30 posts total
@kennyc :-) @tomic601 tightening a few screws seems like an easy thing to try, never would have occurred to me. It’s not like the room gets dark, but I notice it more recently. Fwiw, this “turning on” from standby to 100W at idle, but perhaps the capacitors don’t remain charged on standby - so part of the initial draw. My “amp” is actually an old Arcam AVR400. I have never considered it particularly powerful by multi-channel receiver standards, but does have a respectable transformer, and lots and lots of circuit boards. Here are the power specs:
Power Consumption
kn |
You are talking high current draw on start up. My suspicion is that your amp may be aged, old caps, etc. and that is contributing to the draw when you fire it up, resulting in light flicker. Dedicated lines don't necessarily insulate from that- they eliminate the noise of additional appliances on the same circuit, but current demands are not changed by the existence of dedicated lines. I defer to someone with technical chops to explain why-- |
It is quite normal for some amps to draw very hard on turn on because the power supply caps are not charged up so they offer very little resistance to the in-rush current. This happens only briefly and the lights should go back to normal. Some amps have a soft start circuit that reduces the in rush current and after things have stabilized the circuit is bypassed so that current can flow freely. As long as you don't trip the circuit breaker things will be fine. I don't see how tightening screws would do anything to reduce such in-rush current so I would not bother doing that. |
Even modest power amps can draw a lot on startup. If your lights remained dim after that I’d say you have an issue. Now, is it bad sounding? Of all the gear we use, linear amplifiers are more susceptible to AC voltage changes due to using unregulated supplies. If it drops but comes back up you are fine. To be clear, part of what has happened is your own fault here. With 10 gauge wiring your startup current is going to be unusually high, so may affect the other circuits on the same leg for a moment. You probably wouldn’t have this problem on a normal 12 or 14 gauge circuit! :D If in doubt the first step is to monitor how bad the issue is. Get a cheap tester like this one and plug it into your outlet at your stereo and also at another circuit which shares the same phase. See how bad the drop is, and especially measure the N-E voltage. If you find an excessive drop, or more than 2V on N-E it’s time to contact an electrician. On a related note, my home suffers seasonal + episodic voltage swings due to weather and HVAC turning on and off, as well as different voltages during the day vs. at night. All within spec but to keep my system voltage regulated I use a furman with the AR + SMP features. To be clear, don't fix house wiring problems with a power conditioner. Only if you know your power is good/safe should you use a conditioner to improve the stability. Also related, I moved in when this house was about 15 years old and I did have flickering lights when certain appliances were used. Like, my living room lights would flicker when the bathroom fan was on but on different circuits. Little things like that all around the house. I ended up replacing 100% of the wall switches and all the 120V breakers which fixed the problem. My point is just that at 15 years, you start edging into breaker reliability issues, though they should overall last another 20 years. If you end up replacing, get an in-panel surge protector as well. |
- 30 posts total