Not sure if anyone can help out here.... Think i need to re-wire my el-cheapo a/b box to switch between or combine two separate amps (100w 1972 Super Lead + Danelectro 30 watt w/ 8" speaker). At the moment its creating a ground loop hum with any of my guitars in any combination --- I've been through all the usual ground check things, guitar cables - and dont subscribe to the 'just lift the ground wire' routine.....
I'm sure its a simple operation, maybe it needs additional components, etc.... looked around the web, but can find a suitable circuit plan... anyone got any clues??
....oh yeah George, the shirts look cool!
thanks in advance,
zeeb.
A/B Box Circuit - Help Please!
Moderators: VelvetGeorge, BUG
- zeeb
- Senior Member
- Posts: 202
- Joined: Wed Sep 08, 2004 6:46 pm
- Just the numbers in order: 7
- VelvetGeorge
- Site Owner
- Posts: 7233
- Joined: Tue Oct 14, 2003 5:12 pm
- Just the numbers in order: 13492
- Location: The Murder Mitten
- Contact:
- zeeb
- Senior Member
- Posts: 202
- Joined: Wed Sep 08, 2004 6:46 pm
- Just the numbers in order: 7
thanks for the reply, George ----
....nope. no relays - its just a passive circuit, with a 9v battery for 'added red light effects' ....! one line/guitar in, two switches & two outs -- plus and additional aux in/out for a tuner,etc...
maybe a relay thing IS needed to switch the ground between the two sends to the amps ??? not sure how i'd switch the amp input grounds...
hmmm.....
i'll post a clearer pic or diagram later...
zeeb.
....nope. no relays - its just a passive circuit, with a 9v battery for 'added red light effects' ....! one line/guitar in, two switches & two outs -- plus and additional aux in/out for a tuner,etc...
maybe a relay thing IS needed to switch the ground between the two sends to the amps ??? not sure how i'd switch the amp input grounds...
hmmm.....
i'll post a clearer pic or diagram later...
zeeb.
- flemingmras
- Senior Member
- Posts: 2532
- Joined: Fri Mar 19, 2004 1:39 am
- Just the numbers in order: 7
- Location: Rohnert Park, CA
- Contact:
OK, since you have individual On/Off control of each channel (A and B), that would be kind of hard to use to toggle between A and B.
Here's a little schematic that would work well in that box. Granted it doesn't provide LED status, but that wouldn't be to hard to add with either a relay or using 3PDT switches for the footswitches.
This circuit uses 2 DPDT Carling style footswitches. It grounds the channel not being used, therefore grounding the input to the unused amp.
Hope this helps.
Jon
Here's a little schematic that would work well in that box. Granted it doesn't provide LED status, but that wouldn't be to hard to add with either a relay or using 3PDT switches for the footswitches.
This circuit uses 2 DPDT Carling style footswitches. It grounds the channel not being used, therefore grounding the input to the unused amp.
Hope this helps.
Jon
There's just that fine line between stupid and clever - Nigel Tufnel
- zeeb
- Senior Member
- Posts: 202
- Joined: Wed Sep 08, 2004 6:46 pm
- Just the numbers in order: 7
Hey Jon ---
Thanks loads for that -- will go check a local store for Carling switches -- and brush up on my limited schematic reading! -- seemed a simple thing but i wasnt sure where to start ....
Thanks again -- will let you know how i get on...
Just finished buliding a new guitar - an old 60s' italian (eko? vox?) jazz body & neck w/ two firebird pick-ups... tried it today though the Marshall, and jeezus - it sounds amazing.
speak soon,
John Lee.
Thanks loads for that -- will go check a local store for Carling switches -- and brush up on my limited schematic reading! -- seemed a simple thing but i wasnt sure where to start ....
Thanks again -- will let you know how i get on...
Just finished buliding a new guitar - an old 60s' italian (eko? vox?) jazz body & neck w/ two firebird pick-ups... tried it today though the Marshall, and jeezus - it sounds amazing.
speak soon,
John Lee.
- dosmun
- Senior Member
- Posts: 242
- Joined: Wed Oct 22, 2003 4:51 pm
- Location: Midland, MI
- Contact:
- zeeb
- Senior Member
- Posts: 202
- Joined: Wed Sep 08, 2004 6:46 pm
- Just the numbers in order: 7