Sources of Noise

[wgscott]

5 minutes ago, Ralf11 said:

ok, summary of things to watch out for in your home

 

- Fluorescent lights (even the 'dead' ones)

- LED lights

- doorbell transformers (good point & I'd never thought of that one)

- heat pumps, refrigerators, a/c units, and other items with electric motors

- wall warts for computers, phone rechargers, cordless vacs & whatever, really any wall warts

- Power Line Communications (there are the small wall warts you plug into an AC outlet to get internet everywhere)

 

Almost all of these are demonstrably harmless.

 

[wgscott]

1 hour ago, Ralf11 said:

Good!  Now, let's see the demonstration...

 

- Power Line Communications:  No audible or measurable sound difference whether on or off.

 

- LED lights:  No audible or measurable sound difference whether on or off.

 

- Wall warts: No audible or measurable sound difference whether on or off. However, I did have one from Oyen Digital that contaminated my Power Line Communications from my solar panels (think of this as a positive control).  Anyway, that too is easy enough to check (simply unplug them and listen/measure any difference).

 

- Well pump:  This causes a measurable surge and subsequent voltage sag.  I can see some changes in light bulb intensity. However, there is no audible interference (apart from the non-electric noise emitted by the pump).  This one is a rather extreme case, so if the DAC etc is insensitive to a well pump, it should handle much lesser noise from other household motors, pumps, etc.

 

 

 

Things that I have seen that are problematic:

 

- Electric dog sheers on the same circuit as the DAC.  Momentary drop-outs when the motor comes on.

 

- Above=mentioned defective wall-wart.

 

- Dimmer switches. (Not all, but many are problematic).

 

All of these are easily testable and repeatable.

 

 

 

[wgscott]

21 minutes ago, Speedskater said:

The posters on the RFI forum don't think so.

 

Most noise (including RFI) on a power line is inaudible.

 

Again, this is trivially easy to test.

 

In the rare instances in which it is not, one can use a surge protector with filtering (eg Brickwall).

[wgscott]

18 minutes ago, Ralf11 said:

Thx Bill - I assume these are tests by you in your home?

 

Yes, my house, my DACs, my potential noise-polluters.  YMMV, but in general, it seems to take a lot to degrade audio.

 

I've even listened when we have our generator running during power outages.  If "dirty" power easily degraded digital audio, this should be the ultimate positive control. No issues.

[wgscott]

I did have a floor lamp, once, that was a major noise-polluter, both in terms of ambient noise (it made a high-frequency irritating sound) and degraded audio.  I threw it out of the house.

 

A few months later I went to my first (and last) audio show, and sitting in one of those demo rooms was another copy of this same lamp, complete with the same set of issues.  The best part was it wasn't part of the hotel furnishings.  The demo folks had brought it with them.  The noise was just killing me, and I assumed the quality of their demo, so I asked if I could turn it off.  Then all these audiophiles started asking me if I was some sort of ultra-sonic perceiving audiophile-savant.  (If they only knew.) 

[wgscott]

I made another change, but without a lot of work I can't tell whether I can hear an improvement.  I have all of the audio stuff on a dedicated, 20 amp circuit.  (I also separate the DAC and analogue components with a filter, but they are on the same circuit.)  I have all of the conventional wall-wart type power supplies on a different household circuit.

 

I'm not sure that this really makes any difference, but the wires were already in place, so I figured I had little to lose.