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In the Forum: Audio Discussions
In the Thread: It’s mad, mad, mad... electricity.

Post Subject: Another example of…Posted by Romy the Cat on: 3/9/2011

Lx_ wrote:
Another example of cannot-measure-it-but-can-hear-it?

Oh, yes, there is plenty of it in the audio electricity world. It is not that “cannot-measure”, everything might be measured the problem is that we have no idea what to measure on order to give any more or less objective prediction about contribution of electricity to Sound. That is my old song…..

Lx_ wrote:
Anyway, the fact that output noise decreases with load seems an interesting lead to me. Less load means less current through the AC-DC input stage. Why would that generate more noise (unless noise is generated further down the PP, but the input stage seems more likely)? Could you be more specific about what you mean by "huge amounts of nasty shit" -- especially the what rather than the how much?

I did post a picture how much noise my old PP2000 out back to the power line. I can make a picture how much the current PP2000 does at different load – significantly lower. BTW, I do not make claims that it affect sound – I have no idea what affect sound. In you case no one know what version and what specific problem you have. You might have unit with very specific problem that has no wide application. No one know what you have not to metion that you have 220V version - I have no idea if they are the same units as 120V.

Lx_ wrote:
Also interesting. I never tried to invert AC input. Do you know if this also inverts PP outputs? If not I can easily try changing input polarity and listen to how it sounds.

Look for my old post about hyper-resolution of PP1050. At that time I was placing a lot with inversion of PP input and outputs. I would not do it now. Still, the brightness I got when I use my second PP2000, the Black Gates effect is in a way similar (not the same however) to what I had with inversion of PP1050 inputs. Actually the best it would be illustrated by not Black Gates effect buy the sound we got when a MC cartridge is magnetized. No matter how much you EQ the cartridge it still pushes that hyper metallic crap.

Lx_ wrote:
Yes, I even started to look at the CDE parts catalog online but could not find what I was looking for. I'd be glad if you could send additional details about what you have used.

Get any caps for 20% more voltage then your buttery has, I have no idea what buttery is use in 220V version. You do not need CDE parts catalog, Get a few caps from eBay – it will be cheaper. All bit name cap distributors sell caps off eBay for fraction of price.

PurePower wrote:
We recommend strongly every PurePower 2000 be supplied from its own dedicated 20 amp isolated ground receptacle. For 2 units it is preferable that each will be separately wired directly back to the main panel, and if possible fed from the opposite split phase bus bar.

In all likelihood this strategy will provide more than enough attenuation.

Reasonable warning but I did not see that you ever “recommend” using opposite split phase for more than two units. I do not think that your customers who use multiple PP even acknowledge the problem. Yes, I did measure today that running across the 220V split does expectedly attenuate the noise penetration, not eliminate it completely. I however did not listen what sonic consequence this type of connection had. How about to extend another recommendation? If running two PP2000 I need to use two opposite side of 220V split then where shell I plug my third unit? On the bigger scale I am not to wild to run one system from two sides of 220V split. It is dangers in many cases and I would not recommend to you to advise it to other people. Also, different half do have very different sound and even very different distortion pattern – it all depends how they loaded. I do not think that use of the 220V split is a good idea, even though I will try it.

PurePower wrote:
We certainly cannot recommend plugging 2 PurePower devices into the same duplex receptacle in the same circuit since each PurePower 2000 is rated at 20 amps and together represent a potential 40 amp load fed from a single 20 amp circuit.

I am sorry, Richard, but it is irrelevant BS. I have 8Ga line and 20A breaker. If I wish I can reprovision this line for 40A but it is not the subject. I agree that running two PP2000 from same duplex receptacle is not might be a greatest idea but my ENTIRE SYSTEM LOAD sucks 8.9A out of PP2000 and it is in class A, menace the current NEVER go higher than 8.9A. So, what problem I have running even 3 PP2000 from the same receptacle? The point is not my wiring or receptacles but about multiple PP2000 affect each other if they are in close connection proximity. To running my two PP2000 from the same receptacle, regardless what current is serve sis a good way to illustrate, test and find ways to deal with the problem.

The Cat

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