Mystery Regulator found in Hicap...

[neiljadman]

I'm still working out how to post pics but in the meanwhile can anyone shed any light on what this is: https://drive.google.com/file/d/1XofznmeKUjDFNmqgqVCKR1Xev2wO3lfB/view?usp=sharing

It was recently found in a Hicap in place of the standard Naim regulator boards.

Many thanks in advance for your consideration, Neil

 

[john.luckins]

Much depends on what the two active devices on each rail are. Can you make out what is written on them? Could be a basic two transistor series regulator or a cap multiplier with a voltage reference to give it some regulation. Given that most Naim kit it will have supplied will have had its own LM317 based linear regulators such a simple but high bandwidth regulator/filter might be no bad thing as it can get rid of a lot of the HF line noise that goes straight through linear regulators and occasionally upsets them.

John

 

[Yank]

Someone let the smoke out of that resistor. And the pass element went bang.

 

[MJS]

That's an Avondale ASR shunt regulator. That should be easy to fix as the whole thing hasn't been potted in with resin like some we've seen. I don't have a circuit diagram and I don't think Les fixes these any more, preferring instead to fit his TPR4 variant.