Suitable Expression Pedal & Related Connections

Q & A for building and interfacing your rack gear with Ground Control Pro and GCX-based systems.
Post Reply
mpovoden
Posts: 17
Joined: Sat May 22, 2010 6:31 pm

Suitable Expression Pedal & Related Connections

Post by mpovoden »

Not trying to cross post, but here it is - can the EB VR Jr.25K pedal be used effectively as an expression pedal with the GCP. If so, what kind of cable is needed to connect it to the GCP?

Secondly, can this pedal (EB VR Jr.25K) be used for BOTH volume AND expression by programming the GCP, and if so, what one cable would work for the pedal to be used in both programmed applications?

Thank you,
M.

wake335
Posts: 7
Joined: Fri Aug 21, 2009 2:47 pm

Re: Suitable Expression Pedal & Related Connections

Post by wake335 »

Yeah, the 25k version should be ok The standard saying is that the 250k isn't very good(and didn't work for me), but the 25k works pretty well.

You MAY be able to use just a TRS cable between the output and the pedal insert on the GCP, but you likely will need an insert cable (TRS on one end, splitting to two on the other, split Y cable)

You don't program anything on the GCP, you just activate or deactivate the pedal's jack. Everything that pedal controls is on your midi device that you are controlling and that is where the set-up would take place.
HM Strats : Rhinehart RB (Tele)
Axe-Fx
Ground Control Pro for Midi Control

JohnClark
Posts: 7494
Joined: Tue May 05, 2009 2:33 pm
Location: The Lab

Re: Suitable Expression Pedal & Related Connections

Post by JohnClark »

The Ground Control Pro will read just about any value pot so the 25K VP Jr. will be fine. I do not think the VP Jr. has a TRS jack so you will still need to connect it to the Ground Control Pro using an Insert Cable.

The MIDI Channel and Control Change message that the expression pedal sends is programmable for each Ground Control Pro preset. The actual parameters you can control with the expression pedal depend entirely on the capabilities of the MIDI device you are controlling with the Ground Control Pro.

I hope that helps!
------------------====Cheers!====------------------
Image
---------==Voodoo Lab Magician & Tech==---------

mpovoden
Posts: 17
Joined: Sat May 22, 2010 6:31 pm

Re: Suitable Expression Pedal & Related Connections

Post by mpovoden »

Thank you SO much...

I guess the question was best asked in the sense of, does the cable used 'dictate' the capabilities of the pedal? The EB VR Jr.25k has the 3 jacks as mentioned, input, output and tuner.

Ultimately, I am wondering, I'll be using the GCP in conjunction with the Axe-FX Ultra. If I use an insert cable, understandably, I am HOPING I can program the Axe to work vis a vis with the GCP to allow the EB VR Jr.25k to be used as BOTH an expression pedal as well as a volume pedal.

It was my understanding that with the EB VR Jr.25k:
- standard patch cable = expression
- insert cable = volume

Now I'd like to know if I can do both with the same pedal AND same cable, and if so, what cable will allow this? I am reading this and seeing that the 'insert cable' style connector is my best bet.

If this is wrong, lemme know, otherwise, THANK YOU for your prompt response!!

M.

JohnClark
Posts: 7494
Joined: Tue May 05, 2009 2:33 pm
Location: The Lab

Re: Suitable Expression Pedal & Related Connections

Post by JohnClark »

The confusion perhaps is that the Ground Control Pro can use an Expression Pedal or a standard Volume Pedal to perform Expression duties. All expression parameters within a MIDI device are simply controlled via Control Change data. What dictates the cable necessary for connecting to the Ground Control Pro is simply what type of connections are on the pedal to be used. Once successfully connected, the pedal can be used to control whatever parameters your MIDI device is capable of responding to when sent MIDI Control Change data. You can assign both the Control Change number and the MIDI channel that the Expression pedal will send data on for each Ground Control Pro preset.

It is on your MIDI device that you will assign what exactly should be done with this data. Wah, Whammy, Volume, reverb decay time... are all "expression" type parameters. The only difference between them, in a single processor, is that they would each be set to respond to data on a different Control Change number. Control Change numbers range from 0-120. Control Change 7 is typically reserved for volume control.

Your 25K VP Jr. can in fact be used as either an Expression pedal or a Volume pedal as per the standard definition of these terms, because it has a 25K potentiometer.
If you were connecting it directly to a keyboard or even directly to the Pedal jack on your Axe-FX for expression control over internal parameters, you would likely still need an Insert Cable as the VP Jr. does not have a TRS jack that I am aware of.
When using the VP Jr. strictly as a volume pedal it is implied that it will actually be connected into a physical audio path. Because you have the 25K model it would mean that you would connect it between a guitar (with active pickups) and your amp, or connect it into the effects loop of an amp.

I hope that helps!
------------------====Cheers!====------------------
Image
---------==Voodoo Lab Magician & Tech==---------

mpovoden
Posts: 17
Joined: Sat May 22, 2010 6:31 pm

Re: Suitable Expression Pedal & Related Connections

Post by mpovoden »

Sir Clark,

That is by far the most informative, detailed and quality reply I could have asked for. I greatly appreciate your time and energy in this response... For the record, I'm trying to garner as much info as I can on the Fractal Audio site (for my Ultra and its implicit future uses and connections et al) and the level and detail of replies over there is incredibly lacklustre. Ahem.

This site, and your input (amongst others, thank you) fortifies my satisfaction with purchashing your product. Looking forward to getting this GCP sorted out!!

Thank you, big time!
M.

Post Reply