MGE Ultra-Isolation Noise Transformer, 5 KVA MODEL 91005-31T

ddk

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May 18, 2013
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Now would the isolation transformer in my original question be used as a "balanced" unit if anyone knows the MGE transformers.

Theoretically balanced, but there are so many variables including your preference for sound quality that until you try you really don't know for sure. This was my point before getting side tracked. Using a transformer will change your sound and its possible that you might not like it, so if you're hardwiring give yourself the option to try it out in different ways.

david
 
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TP1

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Apr 2, 2014
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Yes, but we should remember that most of the noise in power supplies is NOT common mode noise and the common mode rejection is very poor at high frequencies.

Irrespective of quantum, common-mode noise poses a greater threat compared to normal-mode noise because of the different path taken to dissipate the noise energy. I would say that is the reason that companies like BPT and Equitech have satisfied customers. Transformer manufacturers can also fit filters for "other noise" but the audible improvement that brings is not of the same scale as common mode noise cancellation.
 

TP1

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Apr 2, 2014
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Now would the isolation transformer in my original question be used as a "balanced" unit if anyone knows the MGE transformers.

Generally the manufacturer would specify "balanced isolating" rather than just "isolating" transformer if it was a true balanced design. Balanced transformers are also isolation transformers ( but not vice versa) so you will get additional sonic benefits above and beyond a standard isolation transformer, which is why I raised the issue in the first place. The MGE looks like it is a non-balanced isolation transformer built for UPS systems.
 

pcosta

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Jul 25, 2010
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Windsor, Ontario, Canada
Thanks

Some of this talk is over my head. So what you are saying my money would be better spent somewhere else?

I have tried the Equi-tech 2Q unit and did not make any gains in eliminating my mechanical hum at my amp.
 

microstrip

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May 30, 2010
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Irrespective of quantum, common-mode noise poses a greater threat compared to normal-mode noise because of the different path taken to dissipate the noise energy. I would say that is the reason that companies like BPT and Equitech have satisfied customers. Transformer manufacturers can also fit filters for "other noise" but the audible improvement that brings is not of the same scale as common mode noise cancellation.

Unfortunately there is lot of misunderstanding about these issues. The input of any isolation transformer is differential and cancels the common mode noise of the mains line. IMHO the important aspect about isolating transformers is the quality of the transformer and the screening between primary and secondaries. A good ground at the transformer is mandatory.

A situation where balanced lines can be worth is noise due to leakage current - if the power transformers of the equipment are low quality and have leaks, in some cases the +/-60V balanced system can leak less current than 120V.

BTW, analogies with balanced audio systems are completely out of place.
 

TP1

Well-Known Member
Apr 2, 2014
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Thanks

Some of this talk is over my head. So what you are saying my money would be better spent somewhere else?

I have tried the Equi-tech 2Q unit and did not make any gains in eliminating my mechanical hum at my amp.

Hi Pcosta

I know you are looking for a practical solution to your problem so I'll keep it to the point and hopefully others may do so also.

If the Equitech unit did not help with the hum then the MGE unit will not either. The Equitech , apart from being balanced with centre tapped earth is also an isolation transformer. So simply using an isolation transformer like the MGE will not solve your problem.

An interesting fact that you supplied earlier is that you did get good results when using the Blue Circle device plugged into your amp. If the amp is indeed reacting to DC in the line, it could have been introduced after the Equitech and before your amp . So to eliminate that issue you should try the experiment again ( if possible) with the amp only plugged into the Equitech and nothing else switched on. If the Amp still buzzes it is not likely to be a DC issue. However, I think this is the best place to start as you will need to eliminate one variable at a time.
 

darkmoebius

New Member
Dec 5, 2014
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Los Angeles, CA
I do not have dedicated power lines for audio. But, I have used multiple 2.4KTopaz Ultra-Isolator trannis wired in balanced configuration, which halves the KVA rating. I had on/off switches placed on input side because unbalanced components will always be "on" in balanced config. All my Topaz are silent in 120V wiring and are placed in the listening room, right next to the components. There was no glaringly audible sonic problems with my power prior to their inclusion, I just added them hoping to get the more out of my system.

I have used a single TX for each amp and component (only because I have so many) and found no negative traits to their inclusions. In my system, there was no loss of timbre or macro-dynamics. The primary benefit in A/B listening was the old cliche of "blacker background". I didn't really know what background noise there was in my system/power until it was gone. The difference is subtle, but noticeable. All aspects of the music stand out more clearly against the quiet. I did try a power regenerator(forget the brand/model) ~8-10 years ago and did not like the result compared to balanced transformers

The effect of power transformers may be more apparent in extremely high efficiency horn systems, or high power amps which could be current-limited. But, my experience was better with them, than without them.
 

Speedskater

Well-Known Member
Sep 30, 2010
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If your component cannot be switched off using it's normal power switch when powered through a balanced transformer, then something is wrong with your component. The unit's AC power Hot & Neutral (don't know what else to call Neutral) should be totally isolated from the chassis. Only the Safety Ground/Protective Earth should connect to the chassis.
 

darkmoebius

New Member
Dec 5, 2014
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Los Angeles, CA
If your component cannot be switched off using it's normal power switch when powered through a balanced transformer, then something is wrong with your component. The unit's AC power Hot & Neutral (don't know what else to call Neutral) should be totally isolated from the chassis. Only the Safety Ground/Protective Earth should connect to the chassis.

Thanks for clearing that up. It was ~10 years ago, so maybe I am wrongly remembering the reason why the on/off switch was placed as a precaution. But, I seem to remember there being a situation where the audio component's switch may guarantee it was truly turned off. So, I had the TX on/off switches added just to be safe.
 

Elberoth

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Just bought one. I should have it installed in 6-8 weeks. I have two identical separate dedicated power lines in my listening room - my plan is to put the transformer on one and compare.
 

christoph

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Dec 11, 2015
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Just bought one. I should have it installed in 6-8 weeks. I have two identical separate dedicated power lines in my listening room - my plan is to put the transformer on one and compare.

I'm very curious about your findings on that
 

Elberoth

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Damn, it is HUGE: 107lbs / 48kg.





I need to find an electrician now.
 

dcathro

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Sep 16, 2016
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Melbourne, Australia
I installed my 5KVA Topaz Ultra Isolation Transformer on Saturday. It took me the whole day to wire it up, including the dedicated earth.

The transformer has brought a definite improvement in the sound, with a more linear and smoother sound. There is less upper midrange hash, and the bass is smoother, with less room node excitation.

I found that I had to play with the wiring configuration to get the sound right. That is, it matters which way round you wire up the active and neutral connections.
 

Elberoth

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Thanks for the info. I still cannot get around installing mine ...
 

Dentdog

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Jan 5, 2014
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I'm reviving this thread because I have purchased the Equitech 50 amp unit, it weighs a lot and I need installation. At a bit of a loss as to how to find a qualified electrician and the ins and outs of proper installation. Mike or anyone have any suggestions. Called Jim Smith and he suggested Angie's list as his electrician has retired.
 

Elberoth

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I'm about to instal my MGE / Topaz Isolation Transformer. In the meantime, I have upgraded from 5kVA model 91005-31T to 7.5kVA model 91007-31T.

A question to those that have already installed one - did you use a soft start circuit before it ? I'm worried that the inrush current will trip the breaker upon powering up.
 

spiritofmusic

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Jun 13, 2013
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I've been running my Westwick 8kVA balanced power transformer, off a dedicated 100A feed seperate from the rest of the chapel, thence to Oyaides dedicated lines to Furutech duplexes.

Just the most fantastic foundation to my sound, real heft and texture into the bass, and clarity into the treble.

No regrets on this one.
 

Elberoth

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Did you use a soft start before it ?
 

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