Power cords...Anybody done ANY measurements???
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| Posted on November 14, 2002 at 15:42:29 | ||
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Posts: 4425
Location: Long Island Joined: October 3, 2002 |
Not listening tests, I've seen the posts...(tastes great, less filling). Sorry, just had to say that!!! Electrical..Reproduceable.. My first question: When the power amp draws any large current from the wall (haversine currents), has anybody measured the voltage between the preamp and poweramp chassis? This requires driving the amp from a third source, and disconnecting the cable to the pre. Use a meter (good high bandwidth meter, or differential scope input) to measure the chassis differentials. And a dummy load, no reason to disturb the neighbors (or wife). I would suspect, that if an inter-chassis potential exists, it would be in the 1 to 10 millivolt range, and would modulate the input signal to the amp. That would definitely color the output of the amp. Second... Has anybody looked at the line current spectrum to look for the higher frequency components of the audio signal being put out by the power amp. Decoupling the output currents from the line is VERY difficult, and does not depend on the filter capacitor parameters (esr, esl, etc.), but depends heavily on wiring configuration. And third, WITH the pre connected to the amp, (connect grounds, but not pre to amp signal), measure the ground currents in the pre to amp connection with high power being drawn by the amp. (This is to look at the possibility of ground loop intercepting db/dt signals). Cheers, John
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| No apologies, this IS supposed to be a technical forum!!!, posted on November 14, 2002 at 15:45:18 | |
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Posts: 4425
Location: Long Island Joined: October 3, 2002 |
nt.
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