Tap Tempo Pedal Build for the GCP

Q & A for building and interfacing your rack gear with Ground Control Pro and GCX-based systems.
ctsanjoures
Posts: 1
Joined: Wed Jul 25, 2012 10:26 am
Location: Putnam, CT

Re: Tap Tempo Pedal Build for the GCP

Post by ctsanjoures » Wed Jul 25, 2012 10:29 am

Just brilliant, thank you for this post. I have ordered the parts, and look forward to putting it together. What size drill bit works best? - C
guitar rig : AXFX Ultra, Ground Control Pro, Pedal Power 2, mesa 4x12, Marshall JCM2000, fender and G&L guitars, other odds and ends and various rig connecting items.

RTFM then ask questions.

BurnTheSky
Posts: 16
Joined: Sun Jan 10, 2010 7:05 am

Re: Tap Tempo Pedal Build for the GCP

Post by BurnTheSky » Wed Sep 05, 2012 2:33 am

Stupid question: does it require a latching or momentary switch ?

David Hess
Posts: 4
Joined: Tue Oct 02, 2012 12:02 pm

Re: Tap Tempo Pedal Build for the GCP

Post by David Hess » Tue Oct 02, 2012 12:13 pm

Another question. By going this route with the TT ie; connecting to one one of the pedal inputs instead of sending a momentary CC on one of the housings switches, are you able to address more than one midi device/midi channel with that momentary command ? I'm trying to send TT to an Eventide and a EchoPro in my rack. Both are on different midi channels. Both use a different CC for the TT. Neither will do an out+thru via midi unless I downgrade the firmware on the Eventide pedal. Then it will allow the midi out to also pass info like a thru. This allows me to have the Echo pro sync to the Eventides tempo clock. But I'd much rather be able to send both a TT with one button on my rig.

Any help with that ?

BurnTheSky
Posts: 16
Joined: Sun Jan 10, 2010 7:05 am

Re: Tap Tempo Pedal Build for the GCP

Post by BurnTheSky » Thu Nov 08, 2012 4:47 am

I built this box, and it's sort of working, except I have an issue: tempo isn't registering correctly when using it to tap tempo for my Eventide Time Factor.
It sometimes sets tempo to 500bpm, and most of the time tempo is quite off.
By comparison setting up an IA button on the GCP (set to momentary) works flawlessly and very accurately, so I figure it's not related to the TF itself.
Might it be related to the switch I'm using on the tap tempo box ? I bought this one:
http://www.musikding.de/Switches/Foot-S ... :3372.html
Wiring between the switch and TRS jack seem to be correct, but could inverting polarity help ? Or should I get a different switch ?

Thanks in advance, I'm pretty much stuck here !

JohnClark
Posts: 7077
Joined: Tue May 05, 2009 2:33 pm
Location: The Lab

Re: Tap Tempo Pedal Build for the GCP

Post by JohnClark » Thu Nov 08, 2012 10:45 am

BurnTheSky wrote:I built this box, and it's sort of working, except I have an issue: tempo isn't registering correctly when using it to tap tempo for my Eventide Time Factor.
It sometimes sets tempo to 500bpm, and most of the time tempo is quite off.
By comparison setting up an IA button on the GCP (set to momentary) works flawlessly and very accurately, so I figure it's not related to the TF itself.
Might it be related to the switch I'm using on the tap tempo box ? I bought this one:
http://www.musikding.de/Switches/Foot-S ... :3372.html
Wiring between the switch and TRS jack seem to be correct, but could inverting polarity help ? Or should I get a different switch ?

Thanks in advance, I'm pretty much stuck here !
Because the port you are using on the Ground Control Pro is intended for an expression pedal, it will not correctly read a momentary switch... actually, it is reading it "too correctly" ;)
When you press the switch, the contacts bounce against each other. The Ground Control Pro is reading this bounce and interpreting it as movement between the endpoints. Neither the TimeFactor or the Expression Pedal port on the Ground Control Pro have data filtering to prevent this unwanted data from false triggering a Tap. The next Ground Control Pro software update will include the necessary filtering to use a momentary switch in the Expression Pedal Port, but for the now you will have to use an Instant Access button for controlling the tempo on the Time Factor.

I hope that helps!


p.s. I see you asked about the switch type earlier, sorry to have missed that :oops:

JohnClark
Posts: 7077
Joined: Tue May 05, 2009 2:33 pm
Location: The Lab

Re: Tap Tempo Pedal Build for the GCP

Post by JohnClark » Thu Nov 08, 2012 10:55 am

David Hess wrote:Another question. By going this route with the TT ie; connecting to one one of the pedal inputs instead of sending a momentary CC on one of the housings switches, are you able to address more than one midi device/midi channel with that momentary command ? I'm trying to send TT to an Eventide and a EchoPro in my rack. Both are on different midi channels. Both use a different CC for the TT. Neither will do an out+thru via midi unless I downgrade the firmware on the Eventide pedal. Then it will allow the midi out to also pass info like a thru. This allows me to have the Echo pro sync to the Eventides tempo clock. But I'd much rather be able to send both a TT with one button on my rig.

Any help with that ?
Sorry for the delayed reply...

Unfortunately this currently cannot be done due to both your devices requiring a momentary switch action. You could wire the two different sides of a DPDT switch so each side connects to its own Expression Pedal port but the momentary action will not read correctly.

I hope that helps!

BurnTheSky
Posts: 16
Joined: Sun Jan 10, 2010 7:05 am

Re: Tap Tempo Pedal Build for the GCP

Post by BurnTheSky » Thu Nov 08, 2012 3:33 pm

JohnClark wrote:
BurnTheSky wrote:I built this box, and it's sort of working, except I have an issue: tempo isn't registering correctly when using it to tap tempo for my Eventide Time Factor.
It sometimes sets tempo to 500bpm, and most of the time tempo is quite off.
By comparison setting up an IA button on the GCP (set to momentary) works flawlessly and very accurately, so I figure it's not related to the TF itself.
Might it be related to the switch I'm using on the tap tempo box ? I bought this one:
http://www.musikding.de/Switches/Foot-S ... :3372.html
Wiring between the switch and TRS jack seem to be correct, but could inverting polarity help ? Or should I get a different switch ?

Thanks in advance, I'm pretty much stuck here !
Because the port you are using on the Ground Control Pro is intended for an expression pedal, it will not correctly read a momentary switch... actually, it is reading it "too correctly" ;)
When you press the switch, the contacts bounce against each other. The Ground Control Pro is reading this bounce and interpreting it as movement between the endpoints. Neither the TimeFactor or the Expression Pedal port on the Ground Control Pro have data filtering to prevent this unwanted data from false triggering a Tap. The next Ground Control Pro software update will include the necessary filtering to use a momentary switch in the Expression Pedal Port, but for the now you will have to use an Instant Access button for controlling the tempo on the Time Factor.

I hope that helps!


p.s. I see you asked about the switch type earlier, sorry to have missed that :oops:
Now worry, and thanks for the answer :)
Would you have an ETA for next software ? I'll make do with using an IA button for the time being, but having a separate switch would be much easier.
Thanks again, loving my GCP/GCX (and PP2+) rig !

midifail
Posts: 24
Joined: Sat Aug 24, 2013 2:59 pm

Re: Tap Tempo Pedal Build for the GCP

Post by midifail » Wed Sep 11, 2013 2:05 pm

Thanks for sharing this!

I had to build this Box.

Image

ysmth
Posts: 17
Joined: Thu Apr 17, 2014 6:41 am
Location: Switzerland
Contact:

Re: Tap Tempo Pedal Build for the GCP

Post by ysmth » Sun Nov 16, 2014 9:19 am

Awesome!!!
:: Diezel Herbert MKII :: Strymon Timeline :: Voodoo Lab GCX / GC-Pro :: www.facebook.com/blackmountrise ::

softmachine72
Posts: 1
Joined: Mon Dec 01, 2014 7:19 pm

Re: Tap Tempo Pedal Build for the GCP

Post by softmachine72 » Wed Dec 03, 2014 4:58 pm

Should it be a momentary or latching switch? seem slike it would be tough to latch and unlatch that quickly.

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