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Does an isolation transformer improve a power cable?

In a post dated 12/14, I described how I built my DIY AC power cables. In evaluating these new cables over the first 100 hours, I am hearing parts in music I did not know where there--instruments are standing out in sharp relief with a more robust dynamic and improved clarity. All of this is coming through via Furutech's Ohno Continuous Cast copper, a brand I am not here to promote--rather, it is the one I chose to obtain a legitimate OCC material. These cables are feeding two ARC Reference 210's, modifed to 250's. But, what appears to make as important a contribution is what is feeding the AC cables their current--a large 240V/120V isolation transformer weighing 120 pounds and supplying 4000 watts of work to all of my devices via six outlets on the back. What I am understanding is that this thing provides a more ideal supply of current that is independent of the rest of the house and its appliances and devices. With all that is said about power cables and what they can and cannot do, depending on one's beliefs about alternating current, i.e., what is upstream, how could it matter, what about the rest of the grid, the last six feet is important, etc, I suspect that, in using a true induction transformer in this manner, the last six feet is the only six feet in my power supply, and this is why these OCC cables sound so stunningly good. Is this the purest AC energy pathway possible?
jafreeman
jea48
2,944 posts
 
Jafreeman,

Just a guess the old power cords you were using on your amps was affecting the sound quality of your amps. It could be they might be shielded in some way, or maybe the design construction of the cable was adding capacitance or inductance to the power being delivered to the power transformers of the amps. It is amazing how a power cord can affect the sound quality of a piece of audio equipment. It is obvious from your comments the amps prefer the new power cords better.

I do have a question about the Richard Gray RM PRO isolation
power unit, is it "Balanced Power" out there in 60V - 0V - 60V when referenced to ground, or is it so called single ended out 120V to ground? I cannot find a picture of the back of the unit anywhere.

Designed to provide 4.0KVA 240V/120V Isolated Pure AC Power utilizing AV grade magnetics for optimum
performance, allows you to deliver true balanced power all the way to the equipment rack before it is
stepped down to 120V. This results in added protection against lightning, EMI/RFI and Harmonics and a
more efficient way of Powering and Protecting your equipment.
The SubStation RM Pro has 6 (5-20R) protected outlets and a 7 ft 12 AWG power cord terminated to a
NEMA 6-20P plug.
http://www.richardgrayspowercompany.com/isolation_manual.pdf

Edit.
Reading the PDF info again I think it is saying the primary winding of the isolation transformer is being fed by 240V balanced power. Just a guess, I think, the secondary is configured straight single ended 120V out.
.
Jim
mikelavigne
1,274 posts
 
reading thru this thread there are lots of numbers being tossed around about output of isolation transformers, gauge of wire, and such things.

what appears to be unclear is what sort of amperage is being supplied to these devices from the power grid of the household. an isolation transformer plugged into a 20amp circuit cannot output 4000 watts.....no matter what it's output capability might be. the limitation will always be the amount of amperage input.

stand alone boxes not hard wired into the power grid have limitations as to output. and they typically cannot fully supply the needs of high powered amplifiers.....although there are exceptions. mostly they will limit dynamics of very high powered amplifiers. it's about how much headroom the power grid has to handle musical peaks at those moments when the amplifier demands lots of power right now. line sag comes thru as compression and hardness in the music.

stand alone isolation transformers plugged into a wall outlet can predictably effectively power source gear as they don't have the same huge momentary demands on the amperage.

it can become a choice between lower noise and more dynamic energy when deciding to use a stand alone isolation transformer....or not on power amplifiers.
jea48
2,944 posts
 

an isolation transformer plugged into a 20amp circuit cannot output 4000 watts.....no matter what it's output capability might be. the limitation will always be the amount of amperage input.
12-31-14: Mikelavigne

Hi Mike,

Jafreeman's Richard Gray 4KVA isolation transformer unit is fed by 240V, 20 amp circuit.

240V X 20 amps = 4800VA

4000VA / 240V = 16.67 amps.

Jafreeman installed # 10 AWG wire. Wire is rated for 30 amps.
I would have installed # 10 wire as well.
16.67 amps X 125% = 20.8 amps

Gray/Manufacture specs the unit be fed by 240V, 20 amp circuit.
Receptacle needed, NEMA 6-20R 250V 20 amp. Breaker at main electrical panel a 2 pole 20 amp.

FLA continuous available amps at 120V output.
4000VA / 120V = 33.3 amps.
.
Jim

jafant's avatar
jafant
10,525 posts
 
Jafremman,

Richard Gray Power Company makes the "Sub station" isolation transformer in both 102/240V options. It has been in production for more than 10 years. Yes, these devices serve as a resivor for clean power reserve. Additionally, these devices clean your power coming into your dwelling from your power company's line-transformer. Very cool stuff indeed. Lastly, consider a dedicated line for your gear if you live on the "grid". Keep me posted & happy listening! JA
scvan
99 posts
 
I am getting at is that, if this is a truly isolating transformer, then there is nothing upstream of it--forget about the house and all the big appliances.

No.... If you have a drag on your power system, like a big appliance you will have the same drag on the other side of the transformer. The electricity is not made at the transformer it just isolates it from the other side.
If you want to eliminate the reactive noise coming back up the ground you can lift the ground. I don't recommend doing it long though.

As stated above by another poster, these sorts of things are really used in hospitals, industrial use and labs that need to protect incredibly sensitive electronics.
Remember, in your amp there is already a transformer so theoretically your rails are already separated from the electrical mains. And those transformers are typically balanced out so you are getting those same effects of cancellation already.
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