Balanced Power

[4krow]

Eric,

  I am divided on this issue. PS Audio products have versatility that I like. For example, the PS regenerators(older ones anyway) can give several different wave forms for the AC output. This can be really cool, depending on how your equipment responds to it. On the plus side, many times equipment responds very favorably with lower noise floor and greater detail, for example. I really like that. But some of my equipment transformers would hum given one or two of the choices that I selected. One Krell cd player actually failed, new, right out of the box! Never did know why. It was replaced with an exact model(and NOT used with the PS Audio P300, and did well). Hmmm. Now, for some reason, there was trouble with my PS Audio premier model here. I do actually blame some kind of radio transmission signaling device nearby, but the unit would turn on for no reason. After sending it back to the factory for a complete checkup, it was returned, and the same problem persisted. I do not think that was the fault of the unit. Having said that, I decided to go another way. That's when I tried other quality conditioners with various results, and just to be done with it. I saw BPT, and decided to take my business there. You see, the balanced power devices offer almost as much in lower noise floor just by design(cancellation due to out of phase or common mode rejection). In addition, they don't the many delicate circuits of the PS Audio units. Since the BPT units added additional passive circuitry, I gave them a try. All in all, there has been improvement and they are immune to airborne troubles from the PS units. As to what model you should choose, it does depend on the needs of your system. Take a look at the site, and then confer with the owner if you need to. He is quite willing to help.

 

[earwaxxer]

wow - thanks Greg - lots of good info.  ;D

 

[Paul Joppa]

Greg,

That seems to be different to your post above.  In the post where you say the primary is rated at 10A (probably at 120V) that gives a VA rating of 1200VA.  The secondary having more than one winding rated at 10A (again, probably at 120V) gives a VA rating of each secondary winding of 1200VA.  So the VA product of the primary, 1200VA, is not equal to the total of multiple secondary windings all rated at 1200 VA. 

What am I missing here?

I assume it's so you can connect the biggest draw (probably your big Krell class A monster, right?) to whichever secondary is convenient. The others just loaf along.

 

[4krow]

Actually, the Krell was a cd player, and I have moved on since to an SACD player made by Yamaha. That was a step in the right direction. I must say however, that after reading your post Paul, it reminded me of a time when I used a PS Audio unit to supply voltage to a Mark Levinson Amp! I'm not kidding. I would first fire up the amp with regular(household current from another household socket), and then when the capacitors were charged, I used the PS300. You may admire my bravery, but dam my judgement. It worked, and it was fun to experiment, but ultimately, the ML did quite fine with 'regular'. Anyway, you are correct in assuming that the secondaries can loaf for the most , allowing maybe one of them to pull the weight by running some bigger draw.

 

[earwaxxer]

It seems like its more common for todays big amps have soft start circuits (my Emotiva). In the old days it was a matter of pride to flick your power amp on and have the lights dim!

 

[Grainger49]

Greg,

So are you saying that the secondaries are wound with wire that can deliver 10A on each winding?  But you can't produce more than 10A on the total secondary.  It is energy, it can't be multiplied.  So if one secondary is drawing 10A, the others can't be used without the primary drawing more than 10A from the wall.

 

[4krow]

Grainger, What I am saying is that the secondaries are RATED for 10amps RMS, each. That doesn't mean that you can draw more than a TOTAL of 10 amps, FROM ALL 5 secondaries at once. This is because the primary winding is limited to 10amps RMS as well. It is an unusual design, but I really like the overbuilt design. Because of the cost of this transformer, Chris Hoff, owner of BPT, doesn't offer this model any longer....DAM!TT Well, keep an eye out for one used. It is the model 10.5 ULTRA

 

[Paul Birkeland]

So are you saying that the secondaries are wound with wire that can deliver 10A on each winding? 

I think it's just a transformer where all the windings are identical, so in practice you could apply your 120V line voltage to one winding and draw 10 amps through one of the other windings on its own.

 

[4krow]

exactly

 

[Grainger49]

That is what I was trying to say in my last post. 

 

[caffeinator]

Soooo....moving on to phasing, if I may.  The transformer I want to use to try this out is a Hammond 182T60.  It has two primaries and two secondaries.  I know what to do on the primary side.  My question is with respect to the secondaries - do I tie them together in or out of phase, or, more to the point, do I connect dotted terminals together, or not together?

 

[Grainger49]

The secondaries should be connected in series.  Done the wrong way they subtract.  So, blue and gray tied together, the output voltage off of red and yellow.  That is undoted of one winding tied to the doted of the other winding.  That is additive.

 

[Paul Joppa]

There is a diagram in the data sheet:

http://www.hammondmfg.com/pdf/182%20Insert.pdf

Note that this transformer will slightly increase the voltage; at full rated current it adds 3 volts (117v primary, 120vCT secondary) while at lower current draw it will add more. The regulation is not specified, but it's probably no more than another 3v. Still, you may want to check your power line voltage to be sure it's not already high.

 

[Skip Pack]

I am presently using a dedicated 240 VAC outlet with two stepdown transfomers to give 120 VAC for my system.
I have done this for a number of years in two locations and like the results. When I build things I use the DPST
switch as mentioned, and also fuse both hot leads. I'm more comfortable with protection on both sides. It seems
to me that your common mode rejection should be more complete (though hardly perfect) pulling at least
semi-balanced power from your panel.

Skip Pack

 

[4krow]

Then, I am to understand that you are stepping down each leg of the 220V(110V, each leg) to 60V? That seems to be balanced power to me.
I used to run each leg of 220V to a mono block amp. For whatever reason, it sounded better.

 

[Skip Pack]

> Then, I am to understand that you are stepping down each leg of the 220V(110V, each leg) to 60V?

Yes, that's correct. My voltages here (80 miles south of San Francisco) tend to run around 250/125 at the
outlet. They sure seem to have crept up over the years.

Skip

 

[Grainger49]

Line voltage is increased because it lowers the current.  Increasing the voltage doesn't cause transmission lines to heat up, but increased current surely does.

 

[4krow]

I had the same problem when I lived 30 miles out of Flagstaff. About 127V, and that was within one volt of 'good enough'. It screwed with everything, and so I bought two transformers with multiple taps that were activated by the voltage being sensed as too low or high. Tripplite makes them, but they are not perfect, and got a pretty good workout where I lived.

 

[Grainger49]

There are things called "constant voltage transformers."  They include a lot of reactance in the form of capacitors.  They will put out 120V from 90V to 150V input.  They are not cheap, they are an industrial device.

 

[Paul Joppa]

I've seen the multi-tap ones as well. The 5v steps can make havoc with some equipment.

I've also seen a very cool General Radio servo motor driven variac. Fun to watch it hunting for the right voltage ...

Grainger, those reactive ones put out a nasty waveform. And IIRC lots of magnetic-field noise as well.