Mfc 101 with ernie ball vp jr!?

[ajd00m]

So I just went out and bought my expression pedal. I went thru to calibrate it and read the manual and did the whole 9. But its not seeming to work. Im trying to set it up to use it with the delays I have and its not working. I checked the yeks guide and yes I did everything it said to do, so dont send me to that page. What can I do to make this work, also I would like to make a patch for a whammy, but im not sure how people are doing this. WTF lol how can I?

 

[Rex]

A few questions:

1. What are you trying to control?
2. Define "not working." What happens when you try to use it?
3. How is your MFC-101 configured for your pedal?
4. What jack is your pedal plugged into?
5. What kind of cable are you using to connect the medal to your MFC?

 

[ajd00m]

I'm trying to control the delay/reverb. Like have a freeze effect.

By not working I mean I'm not getting any difference in the way the effect sounds (increasing/decreasing reverb swells)

It's configured the way I believe it should be according to the manual.

It's plugged into the expression section in "1".

A monster cable

 

[Rex]

I'm trying to control the delay/reverb. Like have a freeze effect.

What parameters of delay and reverb is the pedal tied to?

It's configured the way I believe it should be according to the manual.

Can you be more specific? For instance, what's on the MFC's Calibration and Expression Pedal Setup pages?

A monster cable

That tells me the brand of cable, but not what kind it is.

 

[Darryl Ramm]

What Monster cable??? Can you confirm you a cable with a 1/4" TRS (tip-ring-sleeve) plug inserted into the expression pedal jack on the back of the MFC-101 and that is split into two 1/4" TS (tip-sleeve) plugs that go to the Input and Output jacks on the Ernie Ball Jr. Expression pedal -- right? An insert style adapter cable (like shown in the manual for the external switches) is what you want and you will get different pedal travel sense depending on what plug is inserted into the input and output jacks on the Ernie ball Jr. Even once you've done this you also have to deal with the Ernie Ball Jr. pedals using a audio taper (logarithmic) pot since they are volume pedals not the linear pot of an expression pedal. And I'm not sure if you have the 25kohm or 250 kohm EBJ pedal, I've never tried calibrating either with an MFC-101 -- I like the Ernie Ball Junior hardware but for use as an expression pedal but I swap out the factory pot for a linear 10kohm CTS pot and remove all the factory wiring and install one TRS jack wired as a standard expression pedal. I can hunt up the part numbers if anybody is interested.

It may also be easier to just buy a nice expression pedal like a Mission or Boss FV-500 series (a volume pedal with built in ability to switch to an expression pedal).

 

[ajd00m]

Hey Rex or darryl is there any way I can contact one of you to maybe walk me thru it. Contact me thru a pm, and give me your Facebook link so a can chat on there, don't wanna clog up the forum with this nonsense.

 

[Rex]

I like the Ernie Ball Junior hardware but for use as an expression pedal but I swap out the factory pot for a linear 10kohm CTS pot and remove all the factory wiring and install one TRS jack wired as a standard expression pedal. I can hunt up the part numbers if anybody is interested.

Darryl, please do post the part(s) you use to do the conversion. I have an EB pedal (not Jr.) that I'd like to convert. Also, are there any "gotchas" to look out for when doing the swap? Thanks!

 

[iaresee]

Also, are there any "gotchas" to look out for when doing the swap? Thanks!

Yes: reassembling the VP-series pedals is a righteous pain in the ass. Seriously. I've done two now for my rig and wouldn't do any more.

 

[Rex]

...reassembling the VP-series pedals is a righteous pain in the ass. Seriously. I've done two now for my rig and wouldn't do any more.

What's the hard part?

 

[iaresee]

What's the hard part?

Keeping the wrapping around the spindle clean while trying to reattach the spring <-> string connection.

 

[Rex]

Thanks, Ian. I think I'm going to tackle it, anyway. Do you have any recommendations for what pot to order? Any peculiar size requirements or anything?

 

[iaresee]

Thanks, Ian. I think I'm going to tackle it, anyway. Do you have any recommendations for what pot to order? Any peculiar size requirements or anything?

I just used some long shaft linear ones I had kicking around in my parts box and then cut down the shaft after I attached the spindle. And the values don't really matter a whole lot. I went with 50k IIRC. The expression pedal setup is done by measuring the difference in voltage values between the wiper and each end terminal on the pot. That's why you need a TRS cable with them.

Check the EB site for tips on restringing. I used their paper clip tip and that helped working in such a tight space.

 

[Rex]

Thanks for the tips. I saw EB's YouTube video on restringing, which helped me get a handle on what's involved. I have a spring puller, so I'm hoping that will simplify the job a little. I'm still debating whether I'll keep the pedal's wiring intact or install a TRS jack.

Are you satisfied with how your pedal performs after the mod?

 

[iaresee]

Thanks for the tips. I saw EB's YouTube video on restringing, which helped me get a handle on what's involved. I have a spring puller, so I'm hoping that will simplify the job a little. I'm still debating whether I'll keep the pedal's wiring intact or install a TRS jack.

I went for TRS jacks. Just easier.

Are you satisfied with how your pedal performs after the mod?

Yea, I guess so. I like their travel and more centered pivot point. But the time to reconstruct it to be a proper expression pedal was a PIA. I'd just buy a Mission pedal next time I need another expression pedal. Plus: the Missions look a little cooler with their new logos now. Vanity...yea...I know...

 

[Rex]

I like their travel and more centered pivot point.

+1. The way the EB pedals move just feels right to the foot.

 

[Darryl Ramm]

I too like the feel of the Ernie Ball Junior pedals. This is what I've used to mod several of them into Expression Pedals...

Honeywell/Clariostat 380C110K 10k ohm linear pot. High quality heavy duty construction.

Its a bit difficult to get a good quality ~10k ohm linear pot that will fit and will have the right rotation range etc. and will fit the string pulley used in the Ernie Ball Junior. And its clear from the Ernie Ball Junior pedals I've seen that the pulley does not fit the pot shafts properly on these pedals so even the manufacturer seems to be having problems sourcing potentiometers. But these Honeywell pots fit great.

Switchcraft 1/4" TRS Jack

This is typed from memory so here goes...

Disassemble the Ernie Ball Junior Pedal. Remove the three mono 1/4" jacks and circuit board from the back panel metalwork, discard jacks and circuit board. Save the existing wire between the pot and board to use between the new pot and TRS jack.

Unhook the kevlar drive string, remove the central black plate that the pot mounts on and remove the string pulley and pot.

Drill out the hole where the pot mounts to accommodate the larger shaft bushing on the Honeywell pot. You will also need to drill a new small hole for the anti-rotation/location tab on the pot body. Pay attention to where you drill this location hole so the pot body is rotated so the three solder tabs are pointing back most of the way to the rear of the pedal - so the solder tabs and wires won't foul on the pedal bottom or on the moving pedal top or the TRS jack. Install the pot on this plate and slide on the string pulley and mark the excess pot shaft length protruding past the pulley. Remove pulley, cut off the excess pot shaft with a fine hacksaw and clean up with a file. Reinstall the pulley. Some Loctite on the grub screw is a good idea. Trimming the pot shaft flush with the end of the pulley will make it easier to reinstall the drive string.

Install the 1/4" TRS jack in the rear panel left side hole as shown in the photos below (for most straightforward wiring) and solder wires from the pot to the three tabs on the TRS jack. The wiring is trivial, if in doubt follow the wiring in the photos below.

Reassemble the pedal following this guide on YouTube. If things are not going together don't panic -- just watch the video again, its easy to wind the string on the wrong way etc.

Attached are several quick photos of my modified Ernie Ball Junior....

When I get around to it I'll make a nice plastic label that covers the back panel and hides the two holes no longer used.

Darryl

 

[Darryl Ramm]

One way to make the restringing easier is to use some form of solid hook tool for grabbing hold of the string loop and pulling it tight. I used this one since I already owned it but many other similar tools will do.

If you disassemble your Ernie Ball Junior and can't restring it I'll buy it off you for $15

Darryl

 

[Rex]

Thanks for all the tips, Darryl! A couple of questions:

1. I'm tempted to bend back the location tab and go with a star washer. Might help with the shaft length issue, too, and save me some work with a cutoff wheel and stone. Your comments?
2. I have a regular Ernie Ball pedal, not the JR. Does that change the game?
3. Any particular reason you went with an enclosed jack instead of a plain panel jack?

I've already got a hook thingy that I use to work with trem springs, so I'm hoping it will make the job easier.

 

[Darryl Ramm]

I'm tempted to bend back the location tab and go with a star washer. Might help with the shaft length issue, too, and save me some work with a cutoff wheel and stone. Your comments?

In the JR. pedal adding another star washer won't prevent you needing to trim the shaft length and something subject to hard rotation and abuse I would prefer to rely on more than a star/lock washer. The factory uses a location tab and hole but it's for their smaller diameter pot body. I deliberately looked for a 10k ohm pot with a tab. There is a star washer supplied with the pot that goes on the nut side of the pot shaft. I also used Loctite on that nut. Anything to help withstand abuse.

I have a regular Ernie Ball pedal, not the JR. Does that change the game?

You will need to disassemble the full size pedal and check the pot dimensions, rotation angle etc. I have never looked in detail at one. You may find a part number in the pot to help you. I believe the pedals use different pots - I believe the factory offers different pot replacement parts.

Any particular reason you went with an enclosed jack instead of a plain panel jack?

If building from scratch and drilling my own holes for the jack mount I would use the all metal standard Switchcraft TRS jack but I am pretty sure that is too wide behind the panel to fit the existing holes that are tight in the corner of the rear panel. I don't believe there is technically a benefit of the closed jacks except they are easier for Ernie Ball to manufacture in the pedals, being soldered onto the PCB and they are lower cost than the open all metal jacks. They are not really sealed to keep dirt and grit out. I think Ernie Ball is using clone parts not even genuine Switchcraft enclosed jacks.

I've already got a hook thingy that I use to work with trem springs, so I'm hoping it will make the job easier

That sounds like it may work.

Darryl

 

[Rex]

I disassembled my EB pedal tonight to take out the pot/block and see if I can find a local replacement for the pot. On my pedal, the pulley fit well on the shaft. In fact, the set screw had disturbed the shaft material enough that it took a good tug to get it off the shaft.

I noticed the pot itself is fully sealed and sluggish — almost as if it were damped. I wonder how much of the pedal's resisance is caused by the pot's resistance. All that was holding the pot on the block was a star washer and a nut.

Just for giggles, I had a go at reassembling the pedal, just to find out what I was in for. I found a hemostat to be very helpful in keeping the winds flat while I dressed them in with a small screwdriver, and holding the string with an open loop while I stretched the spring onto it. Total time to disassemble and reassemble was twenty minutes.

I also noticed a couple of other things:

1. The existing jacks are all TRS, but only the input jack has foil traces going to all three pins.
2. There are enough vias in the PC board that I may be able to jumper them to use the existing jack and use it as a single-cable solution. I'll have a closer look at it later.

Thanks again for all the tips. Now to see if I can find a proper pot.