Sounds like progress!

Hi guys. Continuing to tweak my system. A couple of days ago I had lunch with a friend who sells medical diagnostic equipment to doctors and hospitals. Because the equipment is sensitive to electrical noise he carries his own isolation transformer to plug his equipment in when demonstrating. He had my interest since we are trying to isolate the noise that enters our equipment. He brought over his device to demonstrate. I tested my wall circuit with my meter and it showed 960 mV of noise. He plugged in his device which has 4 outlets on the back. I plugged my meter in it and it showed 14 mV. A dramatic decrease in noise.
It’s a Trip Lite IS 1000HG. HG stands for Hospital Grade. I ordered one from Amazon for about $360. Cheap!!!
Got it yesterday and did some tests. On a power strip with 5 PS Audio Noise Harvesters the reading is 120mV, down from the house current of 960. So they do work, but not as dramatic as the Trip Lite. I plugged the Trip Lite into the power strip with the Noise Harvesters and still got 14mV.
$360 for this device is a lot cheaper than buying a bunch of Noise Harvesters. It measures about 6x7x12 and weighs about 20 lbs. I have my Oppo, Marantz, and two Sunfire amps plugged into it and the results in audio are perceptible.
Now very happy and don’t know what else I can do to tweak.
Would be interesting to compare it to Charlie’s P20.
Fred

Fred,

Yes, that's an interesting experiment, and it would be interesting to compare.

The P20 has a display that shows the upstream power waveform and the output waveform, along with distortion readings. It shows that my upstream power isn't a perfect sine wave. The top of the upstream waveform is "soft" clipped a little, and the bottom is also clipped to a lesser extent. And, of course, there's noise riding on it all. The P20 oscilloscope has relatively low bandwidth, but a friend brought over a high frequency oscilloscope and it showed essentially the same waveform as the P20. So there didn't appear to be a lot of ultra high frequency digital noise on the upstream power. The P20 output wave is a very clean and pure (looking) sine wave.

Bottom line is that the upstream power is pretty dirty (mine is relatively clean compared to some I've heard of). So I'm not surprised you got an improvement with an isolation transformer.

A possible downside to the transformer would be the inductance, which creates reactive impedance at higher audio frequencies. There may also be some dc resistance.

With the P20 I noticed an increase in both bass slam (dynamics) and better higher frequency detail. I attribute these to the low output impedance of the P20.

What differences did you notice with your transformer? Lows? Highs? Detail? Slam?

Charlie

It would be a good test. I will need to find someone with a good scope to Get a visual representation of what I have. I do know that the power coming into my house is really crappy. I had three power outages last night . I live in an upscale neighborhood and all the neighbors are also complaining. We have sent letters to the director of our power company asking them to upgrade the transformers, but all they do is provide a bandaid fix. Had a small hurricane two years ago and was without power for five days
I had planned a test to add one of the Audience PC’s one at a time and to listen to my speakers after each was installed. But because I had to dismantle all my equipment to run a new speaker wire I put in the cords all at once then listened. I did notice some improvement with overall clarity. After I put in the Trip Lite it seems the mid range and bass have more resolution and kick. I don’t have audiophile ears anymore, my wife is a little tone deaf. I do like what I am hearing so I guess that’s all that counts.
Will try to find someone with a scope to leak at waveforms , etc, then we can compare results.

Fred

Good for you for exploring yet another path to cleaner power, Fred!

I’ll be interested in any/all observations you have about how the Tripp Lite affects sound quality, especially clarity, “naturalness”, and dynamics.

Rick

My thoughts: with high end audio gear, such as I have (GE speakers, Oppo 105, Marantz 8802, Sunfire 7401 amps) it is very difficult to improve the audio quality with any add ons. My gear does a very good job of providing a good signal to my speakers which are phenomenal in reproducing sound.
I do have noise in my house current. Not sure what the Audience power cords have done to improve the electricity to my gear because I can’t measure it. I do know the Tripp Lite decreased this noise dramatically because I can measure it. So, I do have cleaner electricity going to my gear. What effect does this have on the sound coming out of my speakers? It is hard for me to tell. I listened to the entire Eagles concert last night with my wife. She was a real trip to watch. Normally reserved, she was up and dancing by the end of the concert. I wish that I had some kind of AB switch to go before and after my upgrades. All I can say is I don’t know how to make my sound any better. It is phenomenal and as good as it gets for my ears.
There are some threads in Audioholics that discusses my specific Tripp Lite.
Another gadget I have that actually works is a Darbee. It resides between my AVR monitor out and Epson projector. It is adjustable and adds sharpness to the picture via its remote. I have it set at 90 and my HD projector picture is HD plus.
The Tripp Lite does emit a hum, but I can only hear it if I put my ear on it.

Fred