AB 763-2 Ground for Speaker Jacks

[StevenPituch]

Hi All,
I am about to wire up the speaker jacks on my Hoffman AB 763-2 (Deluxe Reverb).  I know the pots and the board use a star ground.  I am wondering how to ground the two speaker jacks.   It seems the  four RCA jacks for the tremolo and reverb are self grounding.  So I am assuming the RCA jacks and the speaker jacks grounds do not go back to the single star ground.   Can I just connect the speaker ground to the ground tab on the Vibrato Pedal jack?  Afraid of ground loops.

Steve

[PRR]

The speaker side of the output transformer is un-grounded. You can ground it any place you like.

[StevenPituch]

Ah so no ground loop.  I understand.  I am learning something new every time I look at this thing.

Thanks, PRR, for the clarification.  I enjoy building much more when I understand why I am doing something.

Regards,
Steve

[sluckey]

Since this amp has a NFB loop from the OT secondary, it's important to provide a good ground to the speaker jacks. If you are using switchcraft jacks they will automatically be grounded to the chassis. I don't like to rely on the phone jacks to provide a ground. I've seen too many loose jacks. I prefer to also run a dedicated ground wire back to the power ground lug.

Here's a great grounding scheme for that amp. I use this scheme with these exceptions...

1. I provide a dedicated ground lug for the power cord ground wire.
2. I provide a dedicated ground lug near the input jacks for all preamp grounds, including the input jacks.
3. I don't solder the pot buss to the back of the pots.

     https://el34world.com/charts/grounds.htm