Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: rafaelctt on November 02, 2022, 03:10:17 am

Title: hammond 372BX connections
Post by: rafaelctt on November 02, 2022, 03:10:17 am
Hello!! are the ground connections correct on the Hammond 372BX?
Should I connect the gray cable (electrostatic shield) also to the chassis?
Thank you
(https://i.postimg.cc/tC97Fbgz/TIERRAS-CIRCUITO-DE-ALIMENTACIONES.jpg)
Title: Re: hammond 372BX connections
Post by: Esquirefreak on November 02, 2022, 09:43:26 am
I'd use 110-0-110-0 primary taps for 220v. You're current setup makes for 240v. Of course, knowing you're wall voltage makes it easier when deciding wich taps to use.

The "GRY" lead isn't always there on Hammond PTs, is my experience. On some PTs it's really an internally connected shield.

/Max
Title: Re: hammond 372BX connections
Post by: pdf64 on November 02, 2022, 09:51:17 am
The grey wire should connect to the chassis.
The red/yellow wire should best be connected to the negative terminal of the reservoir cap.
Title: Re: hammond 372BX connections
Post by: rafaelctt on November 02, 2022, 01:23:23 pm
The grey wire should connect to the chassis.
The red/yellow wire should best be connected to the negative terminal of the reservoir cap.

Shouldn't I connect the red/yellow wire to the negative common?
Title: Re: hammond 372BX connections
Post by: PRR on November 02, 2022, 02:00:32 pm
Shouldn't I connect the red/yellow wire to the negative common?

What pdf64 said. Rectifier negative (in this case the PT Red/Yel lead) directly to first filter cap. If you make that spike-current go round-about it infects buzz all over.
Title: Re: hammond 372BX connections
Post by: rafaelctt on November 02, 2022, 02:36:48 pm
Shouldn't I connect the red/yellow wire to the negative common?

What pdf64 said. Rectifier negative (in this case the PT Red/Yel lead) directly to first filter cap. If you make that spike-current go round-about it infects buzz all over.
Do you mean the point marked with *?


(https://i.postimg.cc/qqDdJ5hc/TIERRAS-CIRCUITO-DE-ALIMENTACIONES-v2.jpg)
Title: Re: hammond 372BX connections
Post by: pdf64 on November 03, 2022, 09:14:00 am
Yes
Title: Re: hammond 372BX connections
Post by: rafaelctt on November 03, 2022, 10:53:42 am
Yes

Ok
Thanks!!