Dedicated Lines - Sub panel or no?

I use a subpanel but my requirements are unique.

I have 3 amplifiers (2400W combined) for stereo. Much of that in class A.

I supply a large step-down transformer with 240V for balanced AC output for 2 of the amps.

A TVC line stage provides galvanic isolation between the CDP and amps. There can be different voltage between legs which can cause noise but that has not been an issue in my case.

I have the subpanel/transformer located in a closet directly behind the equipment.

The origional main panel is obsolete and breakers are no longer available.

I was able to run 6/3 wire through the crawlspace.

I rent.

I think the comment by Liquid Hi Fi is very valid and should be a major factor in your decision. You provide a foundation for future upgrades in vital power supply area.

Mick, I have tried both of your options and found locating a subpanel just outside the room vs next to the main panel by far the easiest and least expensive. Once your subpanel is close at hand, it is quite simple to run separate dedicated and star grounded circuits to each component which minimizes any interaction between them (see diagrams in my system).

Plus, by putting the subpanel on an 4kva iso transformer, I found it eliminated the need for separate or multiple power conditioners, eliminated any possibility for ground loops, and minimized the need for exotic and expensive PCs.

I assume you have a fairly simple way to route the power line to the subpanel and a way to hide the subpanel in the room? If you do explore the iso transformer, be aware that they to make an audible humming noise that would need to be taken into account.

Hi all,

Thanks everyone for your responses.

Zargon, I am intrigued by your mention of using a transformer. Does it have any downside? I have found in the past that, in my system, power conditioners flatten the soundstage, or somehow rob the music of life.

Also, over here in Singapore, we are 220-240volts AC. If I was to follow your setup, would that in any way affect the topology?

Kind Regards
Mick

There are a number of benefits to be derived from a good properly selected and sized power iso transformer. This approach is equivalent to moving the transformer on the pole down the street next to your room, thus eliminating the hash and trash that gets introduced by all electrical appliances inbetween. An ISO has no direct connection between the input and output sides, and with proper internal shielding can provide over 120db reduction of common mode voltage disturbances. An iso will also filter harmonics on line noise and reduce ground loop currents. Some iso transformers also have output taps allowing you to compensate for consistently high or low line input.

The most immediately noticable result is a blackness or lack of background noise in the music that allows for more detail and dynamic range. I have not experienced any negative effects on soundstage or the life of the music and do not know of a reason why that should be a concern.

The iso must be an iron core internally shielded design - the heavier the core the better. The iso must also have a capacity of at least 2.5 times the peak power demand of your system. Both these are critical. These transformers can be found used in electrical power supply houses for a fraction of the new price. My TOPAZ 4kva iso line noise suppression ultra isolation transformer with 4 output taps weighs 90lbs and cost only $300. Some of these transformers are also setup for use with either 120 or 220v. The basic connection topology is the same.

The negatives are managable. These beasts do make an audible hum, but only noticable within a couple of feet. They also generate some heat (the core is warm to the touch), and use some amount of power in idle due to the internal resistance. They should have a sturdy mount and are best bolted down especially if you have a possibility of earthquakes.

As an added feature: The iso is connected to the subpanel on only one of the two phases. This means that any individual breaker can be moved from the filtered side to the unfiltered side for comparison. This means you can have either the dedicated line only or the dedicated line with isolation on any circuit.

I hope this helps.