Parallel LM3886 with 40 volt supplies

[ashok]

Has anyone being using a dual parallel LM3886 at +/- 40 volt supplies.
I tested the chip at +/- 40 volts ( unregulated) and it seemed to work well without shutting down. Any danger of breaking down in the long run ? I would guess that a mains surge might kill the chip ?
That might mean a supply surge up to +/-46 volts unloaded.

[Panelhead]

I have one, but the most I have seen is 40 - 41 volts. It will run hotter. I think that this is the way to go, will drive almost anything and should put out about 100 watts for headroom.
Without knowing your details, a 27 - 28 volt transformers will yield about all the chips can handle longterm. This may drop a little under load, but if the trannie is up to the task it should not be too bad.
Mine uses a single 600 va Anatek 28-0-28. They say is is a 660 va with 60 hz power. Seems about right. There is a discrete diode bridge for each chip and has 12,500 ufd on each rail. So 100,000 ufd total. There are eight rails, two for each chip. You might need a servo on each chip also.
Servos are nice, takes care of turn off clicks and pops.

George

[carlmart]

Originally posted by ashok
Has anyone being using a dual parallel LM3886 at +/- 40 volt supplies.
I tested the chip at +/- 40 volts ( unregulated) and it seemed to work well without shutting down. Any danger of breaking down in the long run ? I would guess that a mains surge might kill the chip ?
That might mean a supply surge up to +/-46 volts unloaded.

You didn't mention what load you are using. If you go above a certain value, in voltage or load, the chip's internal protection will kick in and cause distortion.