| Author | Message | ||
     Gilmour Jope (gilmour_jope) Username: gilmour_jope Registered: 02-2012 |
Hello All, A while back I bought a replacement Fender-style, dual-RCA jack footswitch from AES for my 1978 MM 65 Reverb Head (non-12AX7, chassis #2275-65)and it turns out I've got a mystery on my hands: As far as I know, these amps were designed so that these features are always ‘on’; that is, you don’t a footswitch to make the effects work. On my amp, I can make the reverb and tremolo work (without a footswitch) by simply turning the knobs on the front panel—this is normal for this model, correct? When I connect the footswitch, things get very weird. The footswitch has two jacks; one red and one yellow and the amp has two inputs, one with a red dot marker beside the reverb input and one with an unmarked tremolo input. There are two connections and resulting scenarios here: Connection 1: When I plug the red footswitch jack into the red reverb input on the amp (with the yellow footswitch jack into the unmarked tremolo input on the amp), I get NO reverb effect at all when engaging the reverb button on the footswitch; the tremolo effect works, but I get a loud radio signal when engaging the tremolo button on the footswitch, even with no volume on the guitar. Connection 2: When I plug the red footswitch jack into the unmarked tremolo input on the amp (with the yellow footswitch jack into red reverb input on the amp) the reverb works only when engaging the tremolo button on the amp and there is no vibrato effect when engaging either footswitch button. Yikes—I hope this makes sense! It's no bigggie because the reverb and tremolo work fine (and sound great) but a footswitch can come in handy sometimes and I thought this would be an easy add-on. Given the red-to-red matching between the footswitch jack and the red dot marker on the reverb input on the amp, I suppose Connection 1 is the proper way to connect this switch to the amp, no? Does anyone have experience using this footswitch with this amp? Thoughts on what might be causing the problem? With thanks again, Gilmour | ||
| Mike Kaus (mm210) Username: mm210 Registered: 05-2006 |
First off, verify that you have the right type of footswitch. The MM Amps do NOT need a pedal to make them work, you are correct. Using an Ohm Meter, check each plug for continuity with the foot switch switched in both directions. BOTH switches should be just open/closed switches. If one of them is the wrong type, it could be screwing with your diagnosis. The footswitches are just grounding the lead so it shouldn't do anything more than that. I kind of sounds like ONE of ths switches may be wrong type. Mike. | ||
| Gilmour Jope (gilmour_jope) Username: gilmour_jope Registered: 02-2012 |
Thanks, Mike - I found a cold solder joint in the pedal, fixed it and the unit works fine now...cheers! Gilmour |