Aleph X transformer thread

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North America building code

I am not sure is this the right thread to ask this question, but here it is anyway;

My concerns is the AMPERAGE rating for the house wiring in Canada. Should I worry about how this might impact the safety issue.

For example if I have five mono blocks of the Aleph-X that bias at around 6A each for the HomeTheatre set up. They would be plugged into the wall in a three walls like a U shape surrounding the TV screen. Does this mean I am drawing 6A X 5 = 30A off the house wire from the same supply box which is normally housed in the basement where the hydro comes into the house.

Please comments, because this may break our building codes and void the home insurance too.

Regards,
Chris
 
Chris,

The power actually used is more like <200VA per mono block steady state max. That would still be > 12A continuous. Most home branch circuits are on 15A breakers with 12ga or 14ga wire. I would recommend having an electrician install two dedicated 20A circuits (10 or 12ga wire) for your system.

Highly recommended! The power on surges would also dim everything else on those circuits...
 
Chris,

This is definitely the right thread to ask the question. Let me take a crack at this. Please correct me if I'm way off.

Let's assume that you are using 600VA transformer for each channel and we're going to assume the worst case.

Primary Full Load Current = 600va/120v = 5A
For 5 channels = 5A x5 = 25A total load

Since we have 15A circuit breakers for normal receptacles in the residential house, I would say the chances that you will be overloading or tripping the breakers is very high.

There are a couple of options that I can think of:

1. Buy a circuit breaker tracer and trace out the outlet to see if the outlets that you are going to use are at 2 different circuit breakers. If you do have 2 circuit breakers for your room, then hook up 2 channels to one breakers and another 3 channels to the other breaker (since we're assuming worst case, it'll probably not trip the breakers).
2. Hook up your amps to one of your Kitchen's outlets - the ones that are for dishwasher machines (those heavy equips where they normally have 30A breakers).
3. Hire a electrician to wire up a couple dedicated circuits breakers for your home theatre room.
4. Wire up the dedicated breakers yourself. You basically just need some #10 or #12 conductors and some PVC conduits and start drilling your walls.

PLEASE KEEP IN MIND THAT MY DISCUSSION HERE IS FOR WORST CASE.
 
I live in an apartment with crappy wiring and even turning on a 500VA toroidal with 40mF filtering causes the light to dim for an instant. Resistivity of the AC wire is good to have at turn-on because it provides a sort of current damping mechanism, but then the wire start to heat, the resistivity increases etc etc.
For a home theather setup that uses 5 alephX's a dedicated line with dedicated plugs and braker is a must. I would say a couple of parallel 8 gauge lines should suffice, but then again my dad is an old school electrician that always rounded up to the higher gauge rather than the lower.;)
 
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chris ma said:
Thank you guys for the comments. I like the idea of always overkill and have a peace of mind. Don't really want to play with fire here. Most likely I will get an qualify/certified electrictian to set up dedicated line and breaker box for this.
Thanks,
Chris

Hi Chris,

Ah, safety first. Very important.

BTW, have you decided on what to do for the transformers?
At one point you were considering heavy regulation vs
custom transformers.

Cheers,
Dennis
 
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chris ma said:
Dennis,

The decision has not been finalized yet. I have to weight the two options for practicality and cost benefits. Do you have any idea how much for the custom transformer would have costs in Toronto?

Chris

Chris,

I don't know about the cost of custom transformers, though
I seems to remember someone mentioning in a thread that
it's not much for Plitron. (Whatever that may mean.)

If a common design can be arrived at and if there's
sufficient interest, perhaps we can organize a Pilitron
group purchase.

Cheers,
Dennis
 
Pliron Surplus Trannie?

Has anyone investigated using the surplus Plitron trannie that was mentioned on page 2 of this thread? It's 1500VA, 4x18V @ 21A. It looks to me that this would work well for a stereo Aleph-X with CRC filtering. The question I would like to ask the gurus is this:
Assuming I purchase 4 of the r-theta heatsinks from the group buy, will this be sufficient to handle an 18-20 DC supply rail? If not is there anything that can be changed, ie. biasing resistors to reduce the output device dissipation?

Andrew
 
Just a quick report:

I've had the chance to use my VM trannies now, and I have to say, these things are really nice!

...oversized core, magnetic shield included (!), consistent windings and wrapping, and very good quality lead wire. I couldn't be happier with these trannies. :up:

These trannies are just over 5 inches in diameter (maybe 5 1/8).

My Aleph-X configuration is to use 11.5V rails, at 5A total bias per channel. So I ordered a trannie with 11V secondaries, and use a single bridge per channel, made from discrete Shottky rectifiers (more efficient than other types), through a 62mF-0.25R-100mF CRC filter. At the moment, I'm powering the amp directly from the first 62mF stage, and have found that the variac output needs to be around 99V to give me 11.5V rails. I've got about 430mV ripple on this cap. Accounting for R losses when I apply the CRC filter, the 11V secondaries look to be just about right for maybe 12V rails or slightly higher, so it appears I've made a good choice for secondary voltage. Switching to a different rectifier type and/or increasing the R value will yield lower rail voltages.
 
Re: Pliron Surplus Trannie?

ungie said:

Assuming I purchase 4 of the r-theta heatsinks from the group buy, will this be sufficient to handle an 18-20 DC supply rail? If not is there anything that can be changed, ie. biasing resistors to reduce the output device dissipation?

Andrew

I'm using two of those sinks per channel with 15V rails and 6A bias. If you increase the rails the heatsinks will be rally hot and might not handle the dissipation. You can always reduce the bias to get less heat. (I'm assuming you want to use 2 sinks per channel).
 
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