[tongwi]

Hi All,

I have found that if I tighten one of the screws for the chassis at the back of my tube mod player (Pioneer DV-45A), the hum is getting louder.  If I unscrewing (loosing) that screw, and holding the tube power transformer at the back with a little upward pressure, the hum would be less, still a little.

Does anyone has suggestion for fixing this?

Thanks for your help!!

William

Note:  Mine has tube mod with internal power supply.

[ted_b]

Did Dan mod it?

[tongwi]

Yes, Dan modded it for me.  I have done extra mod on it, removing the I-V opamps by replace 200 ohm resistors for passive I-V conversion, and adjust the gain so that the output gain is closer to original.

It is depends on how tight for one of the screws at the back panel, and depends on how I touch the chassis cover or the power transformer.  The hum is noticeable when I turn up the volume.

Dan has replied that might be a matter of tube microphonics.  The player is still sound very good.  I may separate the power supply to different chassis later.

Thanks Dan for all of your help!