Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: chuggy on September 11, 2011, 10:22:34 am

Title: Grounding Hoffman 6g15 reverb
Post by: chuggy on September 11, 2011, 10:22:34 am

I seek advice about grounding a Hoffman reverb unit board being installed in a RI chassis.
Looks like there are three ground busses.  I was contemplating grounding the bus with two filters to a spot close to the power tranny.  The other two busses, pan input, pan output, unit output jack, and footswitch jack would go to the unit input jack grounded to the chassis.   Any suggestions?
 
Thanks
Jim R

Title: Re: Grounding Hoffman 6g15 reverb
Post by: chuggy on September 12, 2011, 07:00:33 am

Help please. Board arrives today.
Jim

Title: Re: Grounding Hoffman 6g15 reverb
Post by: sluckey on September 12, 2011, 07:55:28 am

Doug's grounding scheme for the 6G15 looks solid. Just wire yours exactly the same.

Title: Re: Grounding Hoffman 6g15 reverb
Post by: EL34 on September 12, 2011, 02:11:51 pm

This scheme is proven to work , no need to re-invent the wheel.

The ground arrow to the left of the pots is a buss wire/chassis ground
There is buss wire soldered to the back of all the pots and the jacks
The pots and jacks bodies make that ground by being bolted down to the metal chassis

The only other board ground is on the far right, by the two 100 ohm resistors
That can go to a transformer bolt, which is bolted to the chassis.

The RCA reverb jacks are bolted to the chassis, so that takes care of that ground.

The reverb tank itself only has one jack grounded to the outside of the tank
This prevents a ground loop.

 (http://www.el34world.com/Hoffman/images/6G15Old.gif)