Antichambre

Effect pedal, MIDI on a Jack.[SOLVED]

53 posts in this topic

Posted (edited)

On 05/05/2020 at 11:26 AM, Antichambre said:

Hello, this diagram is a regular MIDI input stage, it's not a passive circuit and must be powered, if you connect the 5V to the ring you will get issue when the pedal send data. The ring is the TX point which has idle state at 5V but 0V on data transmit and use it as a power source is also not a good idea, it's a CMOS/TTL signal.

The diagram was shared from Strymon support engineer. I understood it should match their own cable:  https://store.strymon.net/midi-exp-cable/ .

 

If you are right and and the ring from Strymon jack midi port is not a 5v power supply, it means that power should come from din phantom power from the midi controler or another pedal. I understand it means midi din port with 7 pins.

However Strymon pedals with midi din port are 5 pins only. I can no believe that their own cable would not work between their own pedals.

That's why I don't think that you are true and I think that Strymon use a non standard midi over jack pin out with 5v power coming from the slave pedal on the TRS ring and no TX capability.

 

I hope it makes sens!

 

Edited by spinal

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Posted (edited)

I found 2 interesting links:

 https://www.strymon.net/faq/how-do-strymon-pedals-receive-midi-messages-sent-via-14-trs-midi-cable/ where Strymon describe just what you said. Which means  Strymon pedals are bi-directionnal with midi jack. However in the Riverside and Iridium manual, I see that midi out is configurable: ON (pedal can send internal datas) / THROUGH / OFF (which is the default).

 https://www.strymon.net/midi-control-sunset-riverside/ , Hugo (Strymon’s customer support manager) wrote in the comments " As for MIDI IN and OUT, this is done via the EXP jack with the pedal receiving (MIDI IN) MIDI messages at the TIP and sending MIDI back out (MIDI OUT) at the RING of the TRS connection. As the Strymon MIDI EXP cable does NOT support bi-directional communication, you would need to get a device that accommodates for MIDI IN and OUT using a single TRS cable such as the Empress Effects Midibox2. "

->  Strymon MIDI EXP cable does NOT support bi-directional communication

 

My conlusion is that if The Strymon pedal is set for midi out configured as ON or TROUGH it is just like you said (TRS ring is the TX). If it is configured as OFF it is just like I said (TRS ring is the 5V power supply).

Edited by spinal

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34 minutes ago, spinal said:

If it is configured as OFF it is just like I said (TRS ring is the 5V power supply).

If it's configured as OFF the signal just stays in idle state, it does not switch as a power rail, it stays a logic signal. I suppose this was made strong, depends on what is inside, logic buffer, transistor, cpu pin directly, depends on the current it can support;

What I wanted to do here, is avoid any interface box and get IN and OUT, and it works fine with a Merris.
With your solution you just recreate this interface box(regular optocoupled midi input) and power it with a logic line from the pedal and without Output.

Here the original and well known diagram of a regular MIDI IN and Thru.
5iy1u.jpg
Your diagram is just a part of it ;)

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