MIDI stops working when I add the audio cables to the pedalboard

mcvittym

Well-Known Member
I have a MIDI problem and I'd be keen to know if anyone else has experienced and overcome something similar. It's may not be specifically a Mastermind PBC issue but that is the environment.

Background
I am building a pedalboard for myself. It’s a small board and the audio, power and MIDI cables are packed tightly together.

Step 1 - I mounted my four MIDI-controlled pedals to the board (see below), cabled them up them to a Midi Solutions Quadra Thru (two of them via a Chase Bliss Audio Midibox) and thence to the RJM Mastermind PBC MIDI controller. I also mounted the rest of my pedals (Xotic SP Compressor, TC Electronic Spark Mini and GFI Systems Cabzeus) without connecting them

The order of MIDI data flow is PBC->Quadra Thru ->CBA Midibox, Eventide H9, Eventide H9
CBA Midibox -> Meris Mercury 7, CBA Brothers

Step 2 - I connected the PBC, the CBA Midibox and the four MIDI pedals to my Strymon Ojai R30 power supplies.

Each pedal responded to MIDI messages transmitted from the Mastermind PBC and the MIDI indicator light on the Quadra Thru was lit continuously.

Step 3 - I added the audio cables to the board, and connected the remaining pedals to the power supplies.

Presenting problem
Following step 3 above, the MIDI indicator light on the Quadra thru is now blinking on and off and none of the pedals are responding to MIDI messages.

Request for help
I would be grateful for any wisdom that anyone can give me as to the possible cause of the failure of the MIDI network in my pedalboard.
 
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Update - I connected a MIDI cable direct from the PBC to an Eventide H9 (bypassing the cable network in the board). It did not respond to MIDI messages from the PBC. I then disconnected the audio cables from the H9 pedal (wired pre/post rather than stereo) and it immediately started to respond to MIDI from the PBC.

Further information - I am using mostly George L plugs and cable (0.155in) and Hosa insert cables for the stereo pedals.

Again - any thoughts?
 
Wow, that's really odd. Try the same test with each one of your MIDI capable pedals individually. If it happens to all of them, something's wrong with your cables or the PBC. If it only happens with that one H9, then it's probably something going on in the H9.
 
That is strange. I know the H9's can cause problems with doing midi daisy-chaining with the H9's first, but audio and power shouldn't have any effect on midi signals. Have you tried daisy chaining the midi pedals instead of using the midi solutions distribution box. It's not necessary in your setup and may be complicating things.

Also, it looks like the Midi Solutions box is supposed to blink when a midi signal is present. From their website:
MIDI Solutions MultiVoltage Quadra Thru

The MIDI Solutions MultiVoltage Quadra Thru is a 1-in 4-out MIDI Thru Box. All MIDI messages appearing at the Quadra Thru's MIDI input are passed to each of its four MIDI Thru outputs. Active circuitry cleans up any skewing of MIDI data bits that has occurred at the input, ensuring reliable operation in setups that require daisy chaining or long cable runs.

The Quadra Thru is MIDI-powered, and requires no batteries or power supply to operate with most MIDI products (for more information read the Power FAQs). A MIDI indicator LED lights up when the product is powered and flashes when MIDI data passes through it.

MIDI Solutions MultiVoltage products are compatible with both the original 5V and new 3.3V MIDI specifications, for more information read the MultiVoltage FAQ.
 
Thanks

Thanks very much for the input Ron and Boyce!

Update


John Fast of MIDI Solutions was able to tell me that 'If the operating voltage of the Quadra Thru drops below the threshold at which it is able to provide the standard MIDI drive current of 5 mA, its LED will produce a steady on/off warning flash. In most cases this is due to a bad connection in a MIDI cable, if the connection to pin 2 of the MIDI cable has weakened the cable will still work with other MIDI devices which only require pins 4 and 5, but not with the MIDI Solutions products which require the connection to pin 2 in order to draw power.'

The existence and meaning of the warning flash indicator isn't specifically mentioned in the instruction leaflet that comes with the Quadra Thru product, but John's information clarified that because it was flashing, power wasn't getting through.

Resolution

I replaced the MIDI cable and now it's all working. I guess there was an intermittent fault in the MIDI cable eg shorting/grounding somewhere.

Case closed!

Further information and comment

The warning flash on the Quadra Thru is a steady on/off whereas when data is flowing it flashes much more quickly.

I've added a MIDI connection from the Quadra Thru to my Mesa TC-50 also, which is working well.

I could daisy-chain the MIDI connections but things are very tidy with the Thru box - although it does take up precious space. I might try daisy-chaining the next time I rewire the board.
 
Great, glad to hear that it's working! I didn't know about the warning flash, that's very good to know.
 
Hi guys, I’m new here.

I have a mastermind LT and I’m trying to control my polymoon and Mercury 7.
I’m running the mastermind midi into the mini FX gizmo and midi through into the disaster area designs midi box to convert the midi to 1/4 inch jack.
I have set the meris pedals to receive midi and also on their own channels..
although I’m not able to control them yet..?
What setting should I have on the LT to make sure they talk?
Am I missing something..
thanks heaps
Dan
 
Also here’s my set up for reference.
Dan
 

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All you should need to do is set up two generic MIDI devices with the correct MIDI channels. That should be enough to get it going. If you have another MIDI capable pedal that uses a standard MIDI input, you might want to swap that it, just to verify that it works. If it does, then the problem lies in the pedals or the MIDI interface box.
 
To get the PBC to talk to my my Meris Mercury 7 pedal via my Chase Bliss Audio Midibox, I had to set the internal jumpers in the Midibox to the ‘EMP’ setting rather than the ‘CBA’ setting
 
To get the PBC to talk to my my Meris Mercury 7 pedal via my Chase Bliss Audio Midibox, I had to set the internal jumpers in the Midibox to the ‘EMP’ setting rather than the ‘CBA’ setting
Correct. The CBA box has the connections normally reversed internally.
 
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