Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: dearborndave on March 01, 2020, 07:25:00 am

Title: Channel Switching Help
Post by: dearborndave on March 01, 2020, 07:25:00 am

Hello all, it's been awhile since I've asked a question of you amp experts here on the forum, but I'm building a 6V6 version of a Marshall JCM800 and I would like to change the input of the amp from the separate low and high jacks to one input jack and have an internal channel switching relay. I've bought all the stuff for the Hoffman channel switching relay set-up but I just can't seem to figure out how to wire it into the circuit to get it to switch between the two inputs. I've thought I've had it figured out and then I get another piece of information that makes me rethink everything, and I just can't wrap my head around it. If there is any one out there with knowledge of how to use this relay and the proper way to wire it into the circuit, I'd love to hear from you. I haven't started any wiring yet with the project, I just have everything laid out and bolted into the chassis. So I'm to the point of starting wiring, but I'd really like to resolve this channel switching problem before I go any further. I've attached a copy of the schematic of the amp and the switching relay. Any help would be greatly appreciated! Thanks in advance!!!

Title: Re: Channel Switching Help
Post by: sluckey on March 01, 2020, 07:48:33 am

Presented by nandrewjackson...

     (http://el34world.com/Forum/index.php?action=dlattach;topic=25596.0;attach=81690;image)

Title: Re: Channel Switching Help
Post by: nandrewjackson on March 01, 2020, 08:33:54 am

 :icon_biggrin:
Hey, you didn't even let me enough time to jump in with my own drawing.


 :icon_biggrin:

Title: Re: Channel Switching Help
Post by: sluckey on March 01, 2020, 08:39:54 am

Oops. I forgot to give credit. Fixed.

Title: Re: Channel Switching Help
Post by: nandrewjackson on March 01, 2020, 08:40:04 am

To correlate the numbers on your relay picture with the numbers shown for the DPDT toggle


Toggle 2 = relay 4
"            1 =  "       6
"            3 =  "       8


Toggle 5 = relay 13
"            4 =  "        11
"            6 =  "        9

Title: Re: Channel Switching Help
Post by: nandrewjackson on March 01, 2020, 08:42:16 am

Thanks sluckey,  no harm no foul

Title: Re: Channel Switching Help
Post by: dearborndave on March 01, 2020, 11:52:09 am

Thanks! I knew I came to the right place to get the answer I needed. You guys are the best!!! :worthy1: