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Hoffman Amps Forum image Author Topic: Midi relay switching?  (Read 6567 times)

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Offline Captain chunkulus

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Midi relay switching?
« on: February 01, 2019, 09:14:57 am »
Any of you guys ever incorporate midi relay switching into your build?  I have  a channel switch, gain boost and dual master volume switch. I made a footswitch with a 5 pin din to do the switching but I would like to control the functions on the amp with midi. Been looking into the arduino but I don't know enough about that sort of think to make it work. Are there any "add on " midi boards for easy installation to control the relays? Like a midi in that when triggered from a midi controller could make or break the ground connection for the relays in order to activate the amp feature. I think I have enough room in the chassis as long as it's not ridiculously big. Thanks.

Offline nandrewjackson

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Re: Midi relay switching?
« Reply #1 on: February 01, 2019, 09:38:06 am »
Chunkulus,


Please post again here if you ever get this figured out.  I've build two different styles of switching systems so far the past year and a half.  One uses PNP and NPN transistors to switch LDR's on and off, the other uses Integrated chips to switch LDR's on and off.


Both of my circuits work just fine, and they both have their pros and cons.


The PNP / NPN switcher is nice for small numbers of LDR's.  Quick and easy build, but I don't trust it to run the number of LDR's in my new build, so I came up with the integrated circuit switcher.


The new switcher uses a 7404 inverter to interface between the footswitch/and/front panel switches, the inverter sends a signal to a 573N octal latch, which does the actual switching, and the octal latch sends the signal to a 2803 darlington driver chip.  The LDR's "could" possibly be ran from the outputs of the octal latch, but I'll be running about 28 LDR's (and front panel and footswitch LED's) for the 4 channel switching on this build, so I've added in the 2803 chip, because it's MEANT to drive bigger loads (current).


I've got this circuit up and running, on breadboard, and PC board.  (blue goop on PC board is RTV silicone)
I don't have the amp built totally, but I'm confident in this switcher, I've ran it for hours on the breadboard.




I've searched and searched for ready-made systems for channel switching, always come up empty handed.
https://drive.google.com/open?id=1oUemxfybH6QiTEFrnAX0BEZCjCF-mAM7
https://drive.google.com/open?id=1FQ4Raw6WQMxQvB-MOdd9fLmr--VQ2CT1
https://drive.google.com/open?id=1fXpLseDODCohku4qQCWDbCAnh8rlSPNq
https://drive.google.com/open?id=1OP21_bLN3FP0Ot0I1x_yFhESIUZf-CyC


Offline Captain chunkulus

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Re: Midi relay switching?
« Reply #2 on: February 01, 2019, 10:06:36 am »
This is all I've found so far. Looks like it might do the trick but it's in germany. https://www.tube-town.net/cms/?DIY/Amp-Tools/TT_Midi_Switch_%28engl%29

Offline nandrewjackson

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Re: Midi relay switching?
« Reply #3 on: February 01, 2019, 11:01:14 am »
That looks like a great way to tie in DIY amps/pedals into MIDI, and also provides the switching controls too.
 :icon_biggrin:


Offline davidwpack

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Re: Midi relay switching?
« Reply #5 on: February 02, 2019, 10:07:23 am »
Crazy. I had a short coarse on PLC's. We had to program to run timed banks of motors at different on and off times at different durations. Reminds me of that kinda.

Offline Zzomer

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Re: Midi relay switching?
« Reply #6 on: April 13, 2020, 03:26:59 pm »
Hi.
So, did you managed to have this midi to relay running?
I got an amp head with dry contact (1 x TS)  for channel switching which I would like to run in a midi setup so my FX processor when switching a preset will also send midi command to the "midi to relay" and switch the amp channel as well.
I'm all new to this Arduino thing but it looks to me is the correct way to build what I need.
Ideas? Schematics? What is better (in terms of ease of building it and complexity) for me, Arduino or this optocoupler?
Thanks.

 


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