Isolation transformers...Is there a sonic benefit?

[george_k]

I've been looking at medical power isolation units from Plitron.

Typically these type of units are used with sensitive medical instruments, equipment and computers.

I've been thinking about using one at home to use with my equipment and TV. Can anybody, speaking from experience, tell me if there will there be a perceivable sonic benefit in adding in one of these?

[Glen B]

Yes, many persons have obtained sonic benefits with balanced isolation transformers specifically. If you do a search of the DIY forum you will find lots of information on projects involving the use of balanced power. My personal experience with balanced power has been a lowering of system noise floor resulting in blacker background, increased transparency and resolution of low-level details, and increased low-frequency weight and extension.

[Karma]

HI,
I have isolation transformers, two of them, in my system. One is used for my ARC D-250 power amp (250 tube watts/channel) and the other is on my ARC tube SP-11 preamp and the other front end components. The description above pretty much describes the sonic benefits I hear but it is subtle, not night and day. A lot depends on the quality of your existing AC service. Mine is quite good.

You need to be very careful to get a transformer that can handle the power needs of your system. Mine are 2000VA each. In other words, BIG. Such isolation transformers are actually industrial quality heavy duty units. Do not expect to find an adequate transformer at Radio Shack or your local computer store. Those as big as mine are also expensive but I bought mine surplus. I think that much of the controversy that surrounds the use of isolation transformers is the result of folks using units that are too small for the task.

Sparky

[george_k]

I plan on buying one big or two smaller medical grade isolation units from Plitron.

http://www.plitron.ca/shopping/shopdisplayproducts.asp?id=106&cat=North+American

I just wish there was a way to demo one of these or a similar product at home to see just how noticeable the improvement will be

[Glen B]

I plan on buying one big or two smaller medical grade isolation units from Plitron.

http://www.plitron.ca/shopping/shopdisplayproducts.asp?id=106&cat=North+American

I just wish there was a way to demo one of these or a similar product at home to see just how noticeable the improvement will be

Why not try DIY based on the transformer featured in the following article by Secrets of Home Theater ? Its only going to cost you somewhere in the vicinity of CAN$300.00, plus an enclosure, receptacles and circuit breaker. If you insist on buying a Plitron "medical grade" tranny, then you may be better off getting a balanced power conditioner from BPT which is specifically geared to audio use and is going to cost you about as much. BPT uses Plitron Lo-No (low noise) transformers in their products, which I don't think you are going to get in a medical grade unit.
http://www.hometheaterhifi.com/volum...er-8-2003.html

http://www.b-p-t.com/products.shtml

[Victor]

...Can anybody, speaking from experience, tell me if there will there be a perceivable sonic benefit in adding in one of these?

George,

Isolation transformer will give you a perfect galvanic isolation between the main power line into your house and your equipment. You will also get a minor noise reduction, but nothing else.

Isolation transformers are used in hospitals so that there is no electrical influence by the equipment in one room on the equipment in the other room. Naturally in the hospital setting it does make some sense because we are talking about people’s wellbeing. Mostly the concern is with power fluctuations and the consequences thereof on the possible equipment performance. This concern is mostly of theoretical nature, because all hospital equipment has power-stabilization circuits per code. However, why take chances, - right?

Now, - what benefit will isolation transformer will do for your Hi-Fi or HT set-up? I have no idea. If noise is your concern, then you will need more then just and isolation transformer to deal with it. However, it is a fallacy to think that you friendly power company supplies you with bad power. The noise content in the power line is truly negligible again by law, and besides the noise gets dealt with the power supply and the electronics of your Hi-Fi or HT gear anyway.

You may have two music rooms and use them at the same time and you do not want the power cross-talk, - well, - that is a good reason for isolation transformer installation, but unless you have a truly monstrous megabuck power amps and then have many of them, the isolation transformer is not really necessary.

In my view you must have a reason to do things, but be it as it may, - no 'sonic' impact has ever been traced to isolation transformers in any properly set-up tests that I am aware off.

Regards,
Victor

[george_k]

Glen,

The reason why I don't build one is not because it technically challenging but it's more a questions of aesthetics, I simply cannot build a professional looking unit with a properly sized (and not excessively large) chassis for much cheaper than the Plitron.

Also the Plitron units are CSA and UL certified my home grown unit will not be, so for insurance reason I want to make sure I'm covered even though I technically capable of producing a fully safe unit that will comply with standards...you know how insurance companies are...

The BPT units look interesting but living in Canada the shipping and taxes will be a burden.

Victor,

The power here in Montreal is generally good if your living in a single family dwelling a dedicated outlet in your listening room will go a long way from isolating you from other sources of noise withing your home.

In my case I live in an apartment building where outlets are scarce. I own quite a few torch-style standing halogen lamps, there is florescent lighting in the kitchen and quite a bit of equipment uses switching power supplies...so I thought there may be a benefit in adding isolation.

Also, with my speakers and equipment there is some hiss that can be heard when the sources are turned off even at very low volume. I can hear this hiss from as far as 2 ft away from the speakers (most people report hiss only to be audible when the press their ears against the speaker).

So I'm wondering if any benefit can be realized, will it make a moderate improvement in my case or will it be minuscule at best?

[Glen B]

Glen,The BPT units look interesting but living in Canada the shipping and taxes will be a burden.

Apart from BPT there are other manufacturers of balanced power units like Equi=Tech, Blue Circle, Furman Sound, Exactpower, etc. I can't believe that there are no dealers in Canada that carry any of these products. Have you investigated ? I live in the US and my systems include Canadian made products (Classé, PSB and Paradigm). I have also purchased parts and accessories from Canadian dealers when I could not find what I needed in the United States. IMHO, being across the border should not be an excuse.

[Victor]

Victor,

The power here in Montreal is generally good if your living in a single family dwelling a dedicated outlet in your listening room will go a long way from isolating you from other sources of noise withing your home.

In my case I live in an apartment building where outlets are scarce. I own quite a few torch-style standing halogen lamps, there is florescent lighting in the kitchen and quite a bit of equipment uses switching power supplies...so I thought there may be a benefit in adding isolation.

Also, with my speakers and equipment there is some hiss that can be heard when the sources are turned off even at very low volume. I can hear this hiss from as far as 2 ft away from the speakers (most people report hiss only to be audible when the press their ears against the speaker).

So I'm wondering if any benefit can be realized, will it make a moderate improvement in my case or will it be minuscule at best?

George,

While I realise that the isolation transformer might be useful, particularly in your setting, - I still think that the effort of simply using an isolation transformer is not worth the end result. What you might benefit from is a line filter. But then again, if you are going to get the filter, may as well use the transformer.

In general, I have yet to see a real benefit to the sound quality, or shall I say, a noise reduction when the IT is used. I did however see a subtle improvement in video quality of a CRT projector running out of an isolation transformer hook up. I guess you might need to try it in your set-up and see what happens.

[george_k]

Meh, if it won't net a sonic benefit I won't bother with it then :-)

Luckily enough (for my pockets that is), I don't really care much about video quality.

I am pretty happy with my 720p/1080i CRT Sony HDTV though at some point in the future I'd like to get get a bigger 42"+ LCD 1080p capable tv.

For now I want to focus on finishing with my audio system.

[ThomasW]

My experiences with balance power trannys have put me solidly in the true believer camp. It's the only thing that made across the board global improvements in both sound and picture quality.

Seems to me there should be a dealer in somewhere Montreal were you could arrange for a unit to audition rather than speculate...

FWIW I have both Plitron and Equi=tech units...

[Victor]

Agree, - balanced power set-up is a good idea...My comments on the use of Isolation Transformer did not take this into the account...