Help with XK1c and Exp Ped

[Craig Jerel]

I recently picked up a used Hammond XK1c. Everything is working as expected and the sound is good enough going through my Vent for its purpose. The only issue I am running into is connecting an Expression pedal. I first tried a Yamaha FC7 which I read others had working with this board using a setting of PED(REV). That did not work for me, the sound volume did not change at all. I returned that pedal and then bought a Hammond EXP-20 since that one is actually mentioned in the manual. EXPR ESSN set to PED(NORM) and the result is the same, no volume change. I can see that some communication is happening as the MON value is going from 0 - fluctuating between 10 and 11. Don't want to sink in further money into this board and will resort to a Vol pedal if it's the only option but prefer not to do that. Any thoughts on this would be greatly appreciated.

[Delaware Dave]

Post a video showing the pedal moving and the related audio, it will make it easier to diagnose.  Also, do a factory reset just to ensure there isnt a setting somewhere causing the issue.

[mate stubb]

I used an FC-7 with my XKC1 without issues.

 

Could be some damage to a jack or the circuit that reads pedal values.

[Craig Jerel]

Thanks for the feedback.

I do not doubt there could be internal damage here but in case I'm missing something here is a quick video showing the issue.

Sorry about the sound quality but I think you get the idea.

Thanks

[JMcS]

The gain can be raised higher than 100%. Does that make a difference? IIRC, the expression pedal can be used for other effects/functions. Does it work properly with those?

 

I found the manual (Hammond UK http://www.hammond.eu/Support/OwnersManuals ) Maybe this is the cause:

 

❸ OVERDRIVE - EXPRESSION Sets the response of Overdrive to Expression Pedal Value. EX-OD: Overdrive eff ect increases/decreases along with volume. OD-EX: Overdrive eff ect remains constant, only volume increases/decreases. OD ONLY: Volume remains constant, Expression pedal increases/decreases overdrive eff ect. INPUT: Expression pedal attenuates INPUT level to Overdrive eff ect. Lesser Volume control.

 

 

[Delaware Dave]

JMcs above offers a good suggestion to check.  I still would do a factory reset, if there is a funky setting on the board the reset should restore the settings so that the pedal would work normally.  MateStubb's suggestion is also a good point, could be a bad jack connector.  You could open up the keyboard and bypass the connector by tapping the wires leading up to the connector.  Then you could eliminate whether or not that it is a connector issue.  The fact that it consistently goes 0-10 when you move the pedal as shown in the video would indicate to me that it might be the setting that JMcs mentions. That is why you should do the factory reset.

[JMcS]

The XK-4 (and probably the SK models have a similar feature so for future reference on those models it would be useful to verify that the expression pedal control of overdrive is the cause of the issue. I suggest checking the setting, changing it to see what happens and then doing a reset. Then post the results. 

[Craig Jerel]

Good suggestions, thanks. Definitely, useful in terms of troubleshooting

When telling the Expression pedal to only affect the OD it had no effect at all. I tried multiple setting changes with the pedal and it unsuccessfully was able to change those values. When I raised the gain above 100% it had a minor effect on the MON from 10 - 14 with a minor bump in vol but still the same issues persist.

I did complete a factory reset as listed in the manual and watched it restore "default settings" and still no go.

When I unplug the pedal I see the volume go from 0-127 and OD and other settings work as expected. 

 

Unfortunately, the reset did not help in terms of pedal functionality. 

 

Are there any firmware upgrades that could possibly be of value? The one I found online talked about USB improvements but nothing else that could potentially impact the Exp pedal connection.

 

I think all this just leads me to some kind of internal physical issue with the jack or circuitry.

 

Thanks for all the time and help. 

[Delaware Dave]

Other than bypassing the jack connector on the hammond (i.e. tapping the connecting wires directly) to ensure the jack isn't the problem I am out of suggestions.

[Jim Alfredson]

The monitor screen that shows the pedal working should go from 0 to 127. That it's only going to 10 in your video tells me that the jack is either damaged or it's connection to the PCB (circuit board) is damaged. Either a bad solder joint or a broken pin. In either case, when you switch to MIDI, the monitor jumps to 127 and the volume increases, so the actual volume control is working.

The expression pedal jack is jacked.

[Craig Jerel]

Thanks Jim, all that helps confirm my suspicion.

At least now I feel like I have a good idea what I'm dealing with.