What would YOU do with this transformer

[taj]

I'm just lookin for ideas...

I have a pair of 44VCT Plitron transformers that look like 700-1kVA judging by the physical size. They suggest a class A amplifier project, but with 30+ VDC rails a class A amp would require more heatsink than I am willing to buy, lift and suffer the home heat with.

What else makes sense?

..Todd

 

[wg_ski]

Put 'em in series and build a Leach (or similar power level) amp which will double into 4R and darn near again into 2R.

They wouldn't happen to the the 'Phast Microsystems' trafos, would they? I have 3 of them left. I think they were supposed to be for a 6x LM3886 amp.

 

[Andersonix]

Are there choices on how to wire up the primaries to give you other secondary voltages?

 

[Wavebourn]

A bridged amp would be fine, with plenty of output power.

 

[taj]

Good input. Keep the ideas coming...

wg_ski: I have a couple of Leach variations already, but the general idea is worth considering for other amp circuits that use 60V rails. I'm sure there are a few circuits here that qualify. (DX Precision I think; Citation 16 clone; a Quasi Nxxx).

I'm not sure where I got these transformers, it was a couple years ago, from some surplus sale somewhere.

Tosh: I can't recall if these have dual primaries. I'll look when I see them next. But if I use them in 220V mode on my 110v power, I'd end up with ~15VDC rails. That's pretty low for an amplifier.

Wavebourn: Another good idea. My DIY speakers tend to be low impedance (4-ohm-ish) so a bridged amp would be a bit stressful on the all the hardware (I think).


..Todd

 

[Wavebourn]

Wavebourn: Another good idea. My DIY speakers tend to be low impedance (4-ohm-ish) so a bridged amp would be a bit stressful on the all the hardware (I think).

What do you mean? Still the same current, the same power, like in case of non-bridged one, but with +/-60V on rails. And you can use cheaper lower voltage devices there, including filtering reservoirs.

 

[taj]

What do you mean? Still the same current, the same power, like in case of non-bridged one, but with +/-60V on rails. And you can use cheaper lower voltage devices there, including filtering reservoirs.

I guess I don't understand that configuration. Can you give more basic details or show me a simple diagram?

..Todd

 

[Wavebourn]

I guess I don't understand that configuration. Can you give more basic details or show me a simple diagram?

2 identical amps per channel, phase splitter on input, speaker between outputs.
You may use a line input transformers to get counter - phase signals, and get balanced inputs so no ground loops will be possible.

 

[taj]

I understand that part. Isn't a 4-ohm load impedance a problem in that configuration? (2-ohm for each amp circuit?)

How do you configure the power for 60v rails and still use lower voltage parts? There's something basic I'm not understanding. Maybe I just need more sleep. It's Friday.

..Todd

 

[Wavebourn]

Actually, there are 2 amps working with +/-30V rails each, in counter-phase, with a speaker between their outputs. For speaker's side it looks like it is driven by an amp with +/-60V rails, so 200W/channel is easy. That means, 6 Amp peak current is needed. The same, like in case of a single power amp with +/60V rails.

 

[taj]

Actually, there are 2 amps working with +/-30V rails each, in counter-phase, with a speaker between their outputs. For speaker's side it looks like it is driven by an amp with +/-60V rails, so 200W/channel is easy. That means, 6 Amp peak current is needed. The same, like in case of a single power amp with +/60V rails.

I get it now. Thanks Wavebourn. Yes, it's almost a perfect solution isn't it?

Would one 700-1KVA transformer be enough to handle a stereo project (4 amp circuits) I wonder... Probably not, but overkill for one channel I think. I guess I didn't have any different plans for the second one anyway, so I may as well go for overkill.

..Todd