[Randy]

I have a system entirely off the grid, battery driven amp and CD player, passive tvc preamp. During daylight hours the sound is as pure as the driven snow, much as it was before I went off the grid. No complaints there. What surprises me is that in the evening hours, I STILL have the same kind of degradation in the sound I had before. It was in an effort to escape this that I went off grid in the first place. While the sound does not go downhill to the extent it did when I was still plugged into the wall, it is definitely still there and of the same quality, if not quantity, and certainly diminishes the listening experience. What gives? No on-line electrical noise should be entering the system, so where is that noise coming from? I might add that when I was still on the grid, I tried several brands of power conditioners, and none of them, even two different "power regenerators" had much effect. Without doubt, I have noisy, contaminated electricity in the evening here, but it shouldn't matter now, or at least I thought. Any thoughts or suggestions would be welcome.

[JoshK]

Few simple questions first.

Are the batteries connected to a recharger during listening?  There is some chance the recharger is still part of the circuit even though they aren't actively charging.  Simple check is to unplug the charger at night after you notice the noise and compare to before. 

Second, stop the music and listen to see if its really something external to your system that is creating the noise, like a fridge that might not be as easy to hear during the day when ambient noise levels are higher.  Sounds like a stupidity check, but simpler things can getcha. 

Lastly, batteries aren't completely noiseless, they do generate some noise of their own, but I am not sure as to the audibility of this.  In my experiments with SLA batteries, I heard no noise. 

[Randy]

Thanks. I thought that while the battery chargers remain plugged in, they are isolated from the audio circuitry. I have listened a while unplugged, but didn't notice a difference in sound and believe it is not recommended to listen that way since you lose grounding or something like that. Not really sure. I haven't actually tried it as a check to the nuisance noise.  I have thought to go out to the circuit breaker some time at night and turn off the electricity to the entire house, but haven't yet. Anyway, you can see I haven't really experimented much yet, since I was sure there shouldn't really be a problem, and it took a while to get convinced there was. I don't think it's the fridge since the problem crops up only in the evenings.

[Niteshade]

Hi Randy- Please be more specific about the equipment you're running and the exact nature of the noise. Would you say it's a hum, buzz, etc..? Have you tried relocating the equipment to see if you're getting EMI from a neighboring gadget? Are you near a light dimmer? A compact fluorescent bulb? Provide all the specifics you can.

[JoshK]

I am pretty sure it is the charging circuit and/or the grounding causing a ground loop that is causing your problem.  Again, when you notice the problem, unplug the charger and compare.  You don't need a real earth with batteries, at least for audio.

[Randy]

niteshade - the noise is the type of hash normally attributed to bad electricity. It used to be the bane of my existence, but has been alleviated somewhat by getting off the grid, but there's still a definite degradation just as there always was beginning around 6:00 P. M. It's not nearly as bad as before, but as I said, it is noticeable and detracts from the pleasure of listening to music. I had a PS Audio unit, the latest model regenerator, that had distortion readouts. The in distortion was typically 5.0 db, the out (after regeneration) was often still near 2.0, usually more than 2.0. I discussed this with McGowan, the company owner, and found that most users get a output distortion level of less than 1.0. He did believe that the unit was not defective and doing all it could with the electricity here. I didn't notice much improvement in the sound, however. The only power conditioner that seemed to at least work a little, was a Running Springs Haley which I used for a number of years. My amp is a Red Wine 30.2, the pre is a Prometheus TVC, and the CDP is a nos Sony powered by SLA battery unit from ALO audio. If the sound can be rated a 10 during the daylight hours, it degrades to, say 7.5 in the evening. Before I used these units and was plugged into the wall the sound wouid be essentially unlistenable in the evening, the hash was so overwhelming I could barely hear the music. The entire environment seemed to be noisy. I expected that there'd be no difference in sound between daylight and evening hours once I got off the grid.  The answer to all your questions is no. I have dimmer switches in the ceiling lights but learned long ago to keep them off.

[Randy]

I am pretty sure it is the charging circuit and/or the grounding causing a ground loop that is causing your problem.  Again, when you notice the problem, unplug the charger and compare.  You don't need a real earth with batteries, at least for audio.

But Josh, if it was the chargers it wouldn't be dependent on time of day, right? The odd thing is that the noise is just the same as it was before, but not to such an extreme extent and starts at the same time each evening. (Some days are worse than others, it seems to me.) I will try it tonight, anyway.

I thought about it some, and found I am not making sense. If the noise is not present during the day, the chargers wouldn't be picking it up, so the chargers could be the culprit in the evening when it is present in the lines.

[Niteshade]

What happens when you short the amps inputs out and/or have nothing at all connected to them? Are you near a TV or radio broadcast station? I have a feeling that your issues are based on something inside the amp or one of your sources. Something in one of them is acting like an antenna and EMI can get worse at night due to what is called 'skip'- radio waves bouncing off the ionosphere. There's also more appliances on at night. High impedance circuits are EMI magnets and you may have an "antenna" in your system somewhere. I have done a considerable amount of work with RF and high impedance circuits. BTW: If you have a pocket AM radio, see if it picks up the same noise at night.

[timind]

niteshade - the noise is the type of hash normally attributed to bad electricity. It used to be the bane of my existence, but has been alleviated somewhat by getting off the grid, but there's still a definite degradation just as there always was beginning around 6:00 P. M. It's not nearly as bad as before, but as I said, it is noticeable and detracts from the pleasure of listening to music. Before I used these units and was plugged into the wall the sound would be essentially unlistenable in the evening, the hash was so overwhelming I could barely hear the music.

So loud you could barely hear the music? Holy crap that's loud! What kind of neighborhood do you live in and what are your neighbors doing to produce such interference? I once lived very close to an AM radio antenna and the noise would creep into my system at certain times; especially the phono.

[Randy]

So loud you could barely hear the music? Holy crap that's loud! What kind of neighborhood do you live in and what are your neighbors doing to produce such interference? I once lived very close to an AM radio antenna and the noise would creep into my system at certain times; especially the phono.
[/quote]

Not like that. The hash coming through the system obscured and disfigured the music. The interference itself wasn't audible. What was audible was what it did to the sq of the music. Think of it as being pure and transparent during daylight hours versus wiry, hashy, and hard to hear clearly during the evening. It obscured details and made treble esp. grainy and dirty sounding, if you get my drift.

[Niteshade]

I think you should contact the manufacturer. Nobody else will know their circuit like they do. You should also try subbing parts (different amp, different CD player, etc,etc.... You need to start troubleshooting via the process of elimination route, as well as what I mentioned earlier.