I'm looking at doing some experimentation with the various 1stW clones with balanced operation but ran into a question about the power supply I can't find an answer for.
The configuration would be 2 monoblocks with 2 signal boards in each monoblock. One signal board for + and the other for - signals.
I originally had planned for 2 PSs per monoblock in case I had ever wanted to run them in stereo. However, this would put the two signal boards on different rails and got me thinking there might be a problem at the "summation" at the speaker outputs.
For balanced operation, do both signal boards need to be on the same rails?
The configuration would be 2 monoblocks with 2 signal boards in each monoblock. One signal board for + and the other for - signals.
I originally had planned for 2 PSs per monoblock in case I had ever wanted to run them in stereo. However, this would put the two signal boards on different rails and got me thinking there might be a problem at the "summation" at the speaker outputs.
For balanced operation, do both signal boards need to be on the same rails?
My 6-deep balanced BA-3 monoblocks will run with two PSUs. 2x400 VA "standard" PSU per amp. It may depend on which amp. ZM had been very specific re: some advice re: minimizing my ground loops and ensuring the PSUs (each dual rail) were combined properly at a terminal block or similar before running to each amp board and the FE boards. Perhaps the master himself can share the expertise that went into it. I went through about 3 iterations before he told me that I finally had it correct. 😀 This may help to spark some thought. Fully admitting lack of expertise. This was what worked for me, but it may not apply to all FW and similar amps running on dual rail supplies.
This is not what I expected which means it is indirectly very helpful. I'm struggling with the logic and something isn't clicking into place. I keep thinking that having two separate PSs, 1 for the + signal and 1 for the - signal could put them at slightly different operating voltages, possibly creating untrimmable offset at the binding posts. Also, having two PSs, one for each leg, might not give the benefit PS noise rejection since "summing" the two legs wouldn't see the same noise. But, again, something isn't clicking in my brain. I probably need to draw it out. Definitely what you attached has me asking more questions.
I'm at a point where I'm about to sink coin into 2 more transformers so I'm attempting to figure out what will actually work. If I had unlimited pockets, I'd actually go with my two options and test them out because science experiments can be good ol' fashioned fun.
Option 1: a 2nd Hammond 1182g18 and a 2nd UPS CRC board for each monoblock and feed each + and - board with its own juice.
Option 2: replace the already installed Hammond 1182g18 with an Antek 18V x 400VA and re-use the already installed UPS CRC board to feed both + & - boards.
Option 2 will work but I was thinking of Option 1 should I ever want to run one monoblock as a stereo amplifier. The fun!
I'm at a point where I'm about to sink coin into 2 more transformers so I'm attempting to figure out what will actually work. If I had unlimited pockets, I'd actually go with my two options and test them out because science experiments can be good ol' fashioned fun.
Option 1: a 2nd Hammond 1182g18 and a 2nd UPS CRC board for each monoblock and feed each + and - board with its own juice.
Option 2: replace the already installed Hammond 1182g18 with an Antek 18V x 400VA and re-use the already installed UPS CRC board to feed both + & - boards.
Option 2 will work but I was thinking of Option 1 should I ever want to run one monoblock as a stereo amplifier. The fun!
For balanced, both phases of the same channel should run of the same PSU as they need to be identical, Jfets and Mosfets should be matched between +/- phases (channels)
Andy
Andy