There are both going to have the same input noise anyhow.
It is possible in theory that there could be some loss of channel separation on a class B amplifier if there isnt much filtering (the transformer doesnt directly see the final rails) with magnetic coupling between PTs. Ideally the transformers are 90 degrees to each other, which is not very conducive to stacking. Toroidals should have low leakage fields, though stacked is about the worst case.
Steel or more exotic materials could be used as a magnetic shield.
It is possible in theory that there could be some loss of channel separation on a class B amplifier if there isnt much filtering (the transformer doesnt directly see the final rails) with magnetic coupling between PTs. Ideally the transformers are 90 degrees to each other, which is not very conducive to stacking. Toroidals should have low leakage fields, though stacked is about the worst case.
Steel or more exotic materials could be used as a magnetic shield.
My project is going to consist of 2 LM3886's per channel with 34vdc+-(34+ 34-). I am doing this because the chips can share the load with 4 ohm speakers quit well. With each trany at 28.7 0 28.7 and 2 amps I should be looking at 100wpc clean. I will post when I am done. While I am here can you guys recommend a good source for the pcb's for the LM chips?
Thanks
Ben
Thanks
Ben
Tweeker,
I agree this isn't the ideal setup in terms of magnetic separation.
I was thinking more of the capacitive coupling as the secondary
windings will be practically touching. This would transfer the HF
noise from the rectifiers which could be at different times due to
different loads on each transformer.
But, as you say provided there is enough power supply filtering
this may not be significant in practice.
Symon
I agree this isn't the ideal setup in terms of magnetic separation.
I was thinking more of the capacitive coupling as the secondary
windings will be practically touching. This would transfer the HF
noise from the rectifiers which could be at different times due to
different loads on each transformer.
But, as you say provided there is enough power supply filtering
this may not be significant in practice.
Symon
It's an STC Class A power amp, only a few dozen were made.
The transformer secondaries of the amplifier are push-button selectable for parallel or series operation to deliver a continuous Class A output level of 100W in either 2, 4, 6 or 8 Ohm.
The stuff between the toroids handles the automatic bias adjustment for each impedance setting, sort of a Blower Bentley of power amps.
The transformer secondaries of the amplifier are push-button selectable for parallel or series operation to deliver a continuous Class A output level of 100W in either 2, 4, 6 or 8 Ohm.
The stuff between the toroids handles the automatic bias adjustment for each impedance setting, sort of a Blower Bentley of power amps.
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