Old Blue Jeans and Flying Machines
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Kenwood receiver....
Wed Aug 15, 2018 9:16pm

VR-6070, 2002?
Why the hell can they 'not' put a removable bottom plate on these things??
But I finally figured a way to have the circuits available and still operable.
.. and Good ol' Tanya had the service prints.
A few solders and a couple caps already.. but I still have the original problem..
A weird intermittent buzz in the output. At first I thought it must be a bad cap in one of the supply voltages to the driver section, but then I noticed that the buzz, and even popping sometimes, was MUCH worse when the input was switched to PHONO. But I have removed the obvious culprit being the phono preamp from the circuit completely. It looks like a great deal of the audio and even most of the A/V circuits run from the same set of + and - 12V supply's from a strange little secondary board mounted almost like an afterthought.
Just asking for tips or any history with this one.

Now that I have the bottom of the main board accessible... of course it has come to be intermittent again and not acting up.
The one thing I HAVE noticed, is that this weird Malaysian manufacturer uses the weirdest grounding setups to avoid ground loops.. even going to the point of isolating the case and even some of the metal structure, and only using a ground when a plug from a secondary supply is connected to the main board.
Sorry a little windy but I am kinda stumped... thanks.

    • Check the screws on the backScott, Wed Aug 15 9:39pm
      Seems to me they ground through some of the daughter board screws. If that's the one I'm thinking of there is one at the coaxial jack that is a ground for one of the op amp rail voltages.
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