I doubled up on the transformers after the rectifiers to the same capacitor bank driving both channels. After paralleling the transformers on the dc side of the diod bridges and powering up the amp through 10 ohm resistors on each rail the amp seemingly shorted the positive rail on both channels burning the 10 ohm resistors.
Reversing the change still seemingly shorts the positive rails and on one channel puts a lot of DC on the output so something went wrong/broke.
The only thing "off" with my paralleling attempt was the phase being reversed before the rectifier on one of the four diod bridges but I did not think that would be a problem as I was using the dc side on the diod bridge. Obviously I missed something and when measuring the residual voltages on the rails I had a slight negative on the positive rails hence the assumption or the amp had gotten the wrong polarity on the plus rail even though I don't understand how.
The question/ask for help was to try and understand if a temporal negative voltage on the positive rail could explain the now shorting behavior of the positive rail.
Reversing the change still seemingly shorts the positive rails and on one channel puts a lot of DC on the output so something went wrong/broke.
The only thing "off" with my paralleling attempt was the phase being reversed before the rectifier on one of the four diod bridges but I did not think that would be a problem as I was using the dc side on the diod bridge. Obviously I missed something and when measuring the residual voltages on the rails I had a slight negative on the positive rails hence the assumption or the amp had gotten the wrong polarity on the plus rail even though I don't understand how.
The question/ask for help was to try and understand if a temporal negative voltage on the positive rail could explain the now shorting behavior of the positive rail.
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Yeah, water is wet, no matter if you believe it or not (at room temperature).
The thought is ok, double the power supply and more power is available for the amp, but that's not working.
I've the impression you've killed the supplies (maybe the transformers but surely the greatz-bridges and...) so better have the supply in good condition before connecting it to other circuits. As said above, all semi's & large caps are suspicious now. This is valuable learning money (be proud!). Welcome to the Incineration Club.
Yes its probably fried even though the caps seem ok and at least 2 of the diod bridges.
I swapped the output transistors Sanken SC2922/SA1216 and things changed, now seemingly shorting both rails.
I still don't get what went wrong, the transformers and bridges were identical in terms of make and model and I've seen many designs that double transformer windings this way ie on the dc side of the diod bridges. In fact I have another one that runs this way albeit this one has two different voltages, on +-30 and the other -+40 but I don't see how that makes a difference as in my case one will be slightly lower than the other.
I swapped the output transistors Sanken SC2922/SA1216 and things changed, now seemingly shorting both rails.
I still don't get what went wrong, the transformers and bridges were identical in terms of make and model and I've seen many designs that double transformer windings this way ie on the dc side of the diod bridges. In fact I have another one that runs this way albeit this one has two different voltages, on +-30 and the other -+40 but I don't see how that makes a difference as in my case one will be slightly lower than the other.
I know something went wrong but not what. The PSU and caps are fine, nothing apparently burned and me paralleling PSU's after the diod bridges should not have created an issue (I have another amp set up in a similar way) without issues. The only odd thing was the phase being reverted on one of the diod bridges on the ac side but again, its the ac side so on the dc side it should have been the same polarity.
This was a test/lab set up and the resistors I am referring to are between the amp rails and the psu in part for protection but also soft start as I was testing smps supplies before I started doubling traditional trafo's.
This was a test/lab set up and the resistors I am referring to are between the amp rails and the psu in part for protection but also soft start as I was testing smps supplies before I started doubling traditional trafo's.
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