Plitron Balanced Power Transformers

mgalusha · « **on:** 10 Sep 2003, 04:14 am »

The folks at Secrets of Home Theater and High Fidelity published an article about building a DIY balanced power setup and made a special deal with Plitron for the transformers.

Plitron is selling a 2kVA transformer for use in a balanced power system for $250.00. The price goes down to $204 if you buy 10... More information available here.

Note - I am not affiliated with either company, just a happy balanced power user (I have three BPT units) trying to help.

Mike

MaxCast · « **Reply #1 on:** 10 Sep 2003, 11:42 am »

That's all it takes to build a balanced xformer? Granted, by the time you find a case, sockets and some wire you can buy a prebuilt unit, but still....

What is the output? It says 2000VA at 97% efficiency??

Jay S · « **Reply #2 on:** 10 Sep 2003, 01:24 pm »

I only recently realized how a transformer could clean up the power going into audio gear. May need to find a cheap source for 220v isolation transfomers!

MaxCast · « **Reply #3 on:** 10 Sep 2003, 01:35 pm »

I guess one could wire one of these things up to a power strip and have BP. Still would have to find a box

Better yet, put it in the wall behind the first outlet. Jman could put his right after his wall switch

The Stratos uses Plitron transformers. I wonder if Odyssey uses a balanced type. Maybe that is why he recommends going directly into the wall. I wonder how many other mfgs use a balanced tranny? Manufacturers could certianly do a better job on their web sites explaining things like this and those pesky volume controls.

blizzard · « **Reply #4 on:** 10 Sep 2003, 02:10 pm »

Hi,
I had looked into building a BPT a while back (project is on hold). But, I did come across Jon Risch's site: http://www.geocities.com/jonrisch/catch2.htm
About 4 paragraphs down, he recommends not using a toroidal tranny for this application. He lists his reasons why.
The other thing you might want to look into is how the secondaries are wound. Some are wound side by side (I think that is bifilar). Others are wound -- one first then the other on top. The first scenario is preferred since it gives identical resistances on both secondaries. The second method gives a slightly higher resistance on the second winding. Optimally, you want the 2 secondaries to be matched. The signal trannys that Jon recommends are not wound together (not preferred).
I don't know how critical the difference in secondary resistances is. But, I would look into it before spending significant dollars.
It was a little while ago, so excuse me if I made any errors above.
Thought you might be interested,
Steve

Monolith · « **Reply #5 on:** 10 Sep 2003, 02:51 pm »

Quote from: MaxCast

The Stratos uses Plitron transformers. I wonder if Odyssey uses a balanced type. Maybe that is why he recommends going directly into the wall. I wonder how many other mfgs use a balanced tranny? Manufacturers could certianly do a better job on their web sites explaining things like this and those pesky volume controls.

Generally speaking, transformers in electronic devices "transform" the voltage from the wall down to a lesser voltage level required by the electronics. Odyssey uses a transformer in this manner. A balanced transformer does not change the voltages. It creates a symmetrical plus/minus waveform and also provides electrical isolation.

Amps that draw large currents during demanding music peaks work better by having an uninhibited current draw capability (i.e., plugging it directly into the wall). This eliminates many of the current limiting components used in typical AC filters.

In the link provided above, I could not find any group buys regarding the Secret Plitron transformers. Did I miss it?

MaxCast · « **Reply #6 on:** 10 Sep 2003, 02:59 pm »

Thanks for the clarification, Monolith.

The group buy is probably at the AVS forum under a forum titled group buys or something to that effect.

Tonto Yoder · « **Reply #7 on:** 10 Sep 2003, 08:27 pm »

Quote from: MaxCast

Thanks for the clarification, Monolith.

The group buy is probably at the AVS forum under a forum titled group buys or something to that effect.

That's what I thought, but couldn't find it either under "Power Buys" or entering "Plitron" in their search.

mgalusha · « **Reply #8 on:** 11 Sep 2003, 01:29 am »

More random thoughts on this.

I couldn't find anything on the AVS site about a group buy either. I was just mentioning the prices that Plitron has on their site.

I have read Jon Risch's article on building a balanced power system. I don't know if the Plitrons' are bifilar wound but I wouldn't be surprised if they are. From what I have read and observed, Plitron is generally considered one of the better suppliers of toroids.

I do know that B-P-T and Equi=tech both use their transformers and both are quite well regarded.

Plitron shows a max load current of 17.39 amps. I would not load it to this point as it would be saturating but even so, it's capable of supplying enough current to feed most equipment. Still, Monolith makes a very valid point in that some amps sound better plugged directly into the wall since there is less current limiting.

A Hammond 10 x 17 x 4 steel chassis and bottom plate would hold the transformer, a circuit breaker/switch and a 20A IEC nicely. The above items can be purchased from Allied for about $100 or so, bringing the cost to about $350. You would still need some wire, some type of power strip or outlets and possibly some MOV's or some type of surge protection, but still, you could build a very nice balanced power unit for less than $500.

Hmm.. maybe I should have posted this in the Lab Circle.

Mike

Monolith · « **Reply #9 on:** 11 Sep 2003, 02:15 am »

Quote from: mgalusha

I have read Jon Risch's article on building a balanced power system. I don't know if the Plitrons' are bifilar wound but I wouldn't be surprised if they are. From what I have read and observed, Plitron is generally considered one of the better suppliers of toroids.

You might want to inquire about magnetic shielding as well when ordering. Just another option that Plitron does depending on the number of pieces ordered or on their mood. I only saw the electrostatic shield between the primary and secondary indicated on the schematics. Primary/secondary shielding is also an option over a standard Plitron toroid.

mgalusha · « **Reply #10 on:** 11 Sep 2003, 03:44 am »

I don't believe the version being offered has any magnetic shielding. One good thing about a steel chassis is that it will block a pretty fair amount of the stray field. I'm not planning on ordering any of the transformers as I have three B-P-T units already. Just trying to call attention to a decent deal.

shokunin · « **Reply #11 on:** 11 Sep 2003, 03:45 pm »

Hopefully, I'm not breaking any rules here, and if I am, just delete this post. I was about to order 2 of the units to try them out but would love to get a 20% discount on a group order. I didn't see an AVS powerbuy but maybe we could pull together an Audiocircle powerbuy?

JoshK · « **Reply #12 on:** 11 Sep 2003, 04:43 pm »

I'd be interested in an AC powerbuy.

Monolith · « **Reply #13 on:** 11 Sep 2003, 08:04 pm »

Three things to keep in mind:

1. Plitron is a Canadian company and manufactures to order (so expect a few weeks delay)

2. Price will fluctuate depending on currency exchange rate (you will be billed in Canadian dollars)

3. Shipping costs may make the 20% discount much smaller in reality. I assume a group buy means one person placing an order from one address. You would need to contact Plitron and see if they would be willing to take a group order and ship to mulitple addresses. Otherwise, shipping costs to individual buyers from the group buyer might eat up most of the savings depending on weight of the unit.

Carlman · « **Reply #14 on:** 11 Sep 2003, 08:37 pm »

Are there any US distributors/resellers of Plitron? It took me a month to get 2 300VA transformers from Plitron. Shipping was pricey and the wait was long. Seems like if a PartsExpress or whatever had Plitron, a group buy would make even more sense.

Psychicanimal · « **Reply #15 on:** 11 Sep 2003, 10:23 pm »

This all sounds very interesting. There is one crucial element missing here: specifications. What are the noise reduction specs vs frequency?

John Casler · « **Reply #16 on:** 12 Sep 2003, 01:44 am »

As a new BPT dealer, I might be able to arrange a BPT powerbuy, if you all collectively knew what you wanted.

(keep in mind this is specualtion on my part but I would be happy to check)

Chris will somewhat customize most of his units and in a group buy it might make more sense (or dollars) unless all are skilled enough to make DIY pay off.

This way most of the fabrication/detail work is already done.

Check the BPT site and see which "base" unit would make the most sense and if interested let me know.

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

To see a list of upgrades (like caps, silver wiring, Bybees, Hubbells, etc) look here:

http://web.valuenet.net/cjh/page12.html

If not, have fun with the DIY route and let us know how they turn out.

I just ordered a "customized" and Bybee'd, 20 AMP BP1 and look forward to seeing how well it works with my toys.

satfrat · « **Reply #17 on:** 12 Sep 2003, 05:30 am »

Quote from: mgalusha

I don't believe the version being offered has any magnetic shielding. One good thing about a steel chassis is that it will block a pretty fair amount of the stray field. I'm not planning on ordering any of the transformers as I have three B-P-T units already. Just trying to call attention to a decent deal.

As a thought Mike, may I suggest lining the interior casings of your units with Stillpoints ERS? I did this to my BP2.5 along with the Bybees and Chris is doing this to his BP3.5. It`s a good easy tweak to do and a win/win situation. Regards, Robin

JoshK · « **Reply #18 on:** 12 Sep 2003, 12:47 pm »

John,

Isn't a 20Amp BP1 a BP2.5?

Hantra · « **Reply #19 on:** 12 Sep 2003, 12:49 pm »

John:

Have you tried these on power amps? I have a Plinius 8200i MkII, and I wonder if this would be okay to put on there.

Thx,

B