Hi folks,
I'd like to get a PSU for my LP12 so I can play 45s. I've looked around a lot at what's available and am half toying with the idea of designing one. I'm an electronics engineer by trade and making a board that would produce a couple of sine waves from a DAC would be simple for me.
What I'm not clear about is exactly how the motor voltages need to work. It looks like you need two a.c. voltages out of phase going into the red and blue leads and grey is 0V. The a.c. voltages, I think, are 85V rms,
However, looking at the Valhalla schematics it looks to me like it's not a splt rail supply, but simply rectified mains. (The schematics I've found are not great quality though.)
I'm guessing it's producing a sine wave of around 0-240 pk-pk and then just putting it through the cap to produce the phase difference bwtween red and blue. Is that right?
If so, I guess there's no advantage in a split rail of roughly +/-120Vdc and I should just create two sines 0-240V ish?
Am I mad thinking a better idea would be to produce two sines and have the micro set the phase between the two?
Thanks!
I'd like to get a PSU for my LP12 so I can play 45s. I've looked around a lot at what's available and am half toying with the idea of designing one. I'm an electronics engineer by trade and making a board that would produce a couple of sine waves from a DAC would be simple for me.
What I'm not clear about is exactly how the motor voltages need to work. It looks like you need two a.c. voltages out of phase going into the red and blue leads and grey is 0V. The a.c. voltages, I think, are 85V rms,
However, looking at the Valhalla schematics it looks to me like it's not a splt rail supply, but simply rectified mains. (The schematics I've found are not great quality though.)
I'm guessing it's producing a sine wave of around 0-240 pk-pk and then just putting it through the cap to produce the phase difference bwtween red and blue. Is that right?
If so, I guess there's no advantage in a split rail of roughly +/-120Vdc and I should just create two sines 0-240V ish?
Am I mad thinking a better idea would be to produce two sines and have the micro set the phase between the two?
Thanks!