I have a couple older pro audio amps I will likely never use and am researching what I could do with their overbuilt power supplies.
The big EI transformers are 60-0-60VAC. The filter caps are 15mF/100V. Each amp has one transformer, 2 big caps, and +/-80VDC rails.
Please forgive my ignorance, but I have some general questions about building something with these:
The big EI transformers are 60-0-60VAC. The filter caps are 15mF/100V. Each amp has one transformer, 2 big caps, and +/-80VDC rails.
Please forgive my ignorance, but I have some general questions about building something with these:
- Can a hefty, adjustable bench supply be made from these?
- Can higher voltage transformers be brought down to lower AC voltage to allow for flexibility in application?
- Can an existing +/- 80VDC power supply be converted down without compromising the abundance of VA available?
- Is it feasible to build a modular power supply such that:
- Main power Tx is high VA, higher voltage secondary
- AC is brought down to a specified value
- Rectifier accepts final AC figure and feeds DC to filter capacitor bank?
Attachments
The raw DC voltages can be brought out of the amp (from a point after the rail fuses) to connectors
like banana sockets, terminal strips, etc. This way you can leave the amplifiers otherwise intact.
You can reduce the DC voltages by using a Variac (with a suitable rating) on the line cord. The VA will decrease
directly with the voltage, because the max current cannot increase. You will need a Variac anyway.
The rectifiers won't care if the voltage is decreased.
like banana sockets, terminal strips, etc. This way you can leave the amplifiers otherwise intact.
You can reduce the DC voltages by using a Variac (with a suitable rating) on the line cord. The VA will decrease
directly with the voltage, because the max current cannot increase. You will need a Variac anyway.
The rectifiers won't care if the voltage is decreased.
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Thank you, both.
So a variac would be the only practical adaptation. Understood.
The one I dismantled had physical damage to the back panel, but was electrically sound. The other is working fine.
So a variac would be the only practical adaptation. Understood.
The one I dismantled had physical damage to the back panel, but was electrically sound. The other is working fine.
If you have the need for a +/-70V lab supply (to test amplifiers for example), you can certainly use the power (expensive) part of the amps. Otherwise, recycle them in the best way you can.
I have converted a similar supply (not audio though) into a test supply for amplifiers, but I felt a need for such a thing. If you do feel the need for such a big supply, dispose of them in the most advantageous way for you
I have converted a similar supply (not audio though) into a test supply for amplifiers, but I felt a need for such a thing. If you do feel the need for such a big supply, dispose of them in the most advantageous way for you