Isolation Transformer Use???

[wheezer]

Hi KL,
You cannot get to the windings as it's sold as strictly an ISO and carries a UL listing.
It's a 1:1 which negates any possibility for BP, but great for an ISO on the front end of your equipment.
FIRST
Plug it in and check the voltages to determine the regulation %.
Also L-G and N-G voltages
THis is an overlooked issue and very important.
Second overlooked issue is tranny overshoot.
If you would like details, I'd be happy to elaborate further.
Regards,
Mitch

[KevinLee]

Wheezer,

I measured the voltage at the wall outlet and got 117volts. I checked the secondaries out of the transformer and got 120 volts.

I also checked L-G & N-G & got 70 volts & 23 volts. I am not sure which measurement is the L-G & which one is the N-G.

Any thoughts on these measurements? Also any more guidance would be appreciated on how the carry out the other tests you mentioned.

Thanks

KevinLee

[wheezer]

Hi KL,
Rather impressive 3% regulation.
The wacky voltages means the center tap is not grounded. - a good thing. If grounded boths would/should be equal 1/2 the total. 60VAC each. NOTE, one is floating to ground.
Measure them with a load-- power strip and a light bulb, then note the voltages. to each other and ground.
You won't know which is N or L, with an ISO tranny
As for the Hammond it's designed specifically for ISOLATION.
plug that pup in the wall and your gear into it.
Do check the LOAD of each piece of your gear-the back sticker for WATTAGE.
If you go over the rated VA, the voltage will start to drop and the Temp will start to rise.
A power strip would be good for testing as you can stick you probes into one socket and test for Vout.
You can get up to 6dB of noise reduction from just an ISO.
We can always add some small trannies(185) wired in BP, or filtered BP mode fed by the 171. It does not get better than this!!!!!

Typical is 10% regulation on the average.
FYI, this would mean no load Secondary Vout would be 132VAC from 120 mains.
By adding some load say 250VA or 1/2 the tranny's rating would bring the Vout to 126. Some gear, say a 10va DAC might have some problems with 132V... So, it's important to choose the tranny according to ones load.
We'll deal with the overshoot issue later!
Regards,
Mitch

[KevinLee]

Wheezer,

Thanks for all the info!

I will not be able to test the tranny with my gear for a couple of days.

I will post my results when I get back home.

Best Regards

KevinLee

[wheezer]

Hi KL,
Glad to help and looking forward to the next step. You'll be very pleased with the results from this.
Regards,
Mitch

[mrfeedback]

"One of the best investments you can make is to buy a big surplus 5kVA+ iso trans (try metal recycler) and have your entire system run through it from the main fusebox (check local regulations, and get an electrician to wire it up). Cost might only be a couple of hundred bucks total. Having done the tests and seen the difference in the mains spectrum, bith with and without a big iso trans on an HP spectrum analyser, its a hell of a good investment."

But the idling power consumption of such a transformer will keep you poor paying electricity bills.
In my experience isolation transformers more suitably rated for the load will give very nice sonic improvements.

Eric.

[KevinLee]

Hello Wheezer,

I now have the iso tranny in my place. Here is what I found out:

-Wall voltage, 120.6 volts
-Transformer out no load, 123.9 volts
-Transformer with CD player plugged into it, 124.0 volts
-Transformer with Amp plugged into it, 124.0 volts
-Transformer with Amp & CD plugged in, 123.7 volts

Amp is a Rotel RA930AX (30-40 watts per channel) Power consumption is listed at 180 watts on back of amp.

CD player is Marantz CD63. No power consumption listed. All that is listed is 120volt, 60 hertz, 0.19 amps.

The transformer is fairly warm when plugged into the wall with no load. Is this normal?

Also, there is a slight humm from the transformer, it is not passed to the music.

As before, any thoughts would be appreciated.

Thanks

KevinLee

[wheezer]

Hi KL,
Very interesting, I have an RB930AX, that I have had sitting dormant for several years.I recently decided to use it as a mono bridged for the center channel. Have to ramp it up slowly on the Variac and check for any DC offset. Thanks for reminding me.
I have not played with this particular isolation tranny, but some do get warm, USUALLY when loaded almost to max.Not NO LOAD.
Some do hum, usually the big Topaz. As long as the hum is not passed on AND it does not ge that hot... no problem
Just enjoy it....keep adding more stuff but not to exceed around 400VA. safety margin.
Have you noticed any difference in sound?

If you check the specs you'll see the operating temp s/b pretty high. If you have a temp probe,now's the time to try it. Again another thing I must get, my DMM does C and F but did not come with one.
Regards,
Mitch