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MIDI thru? Gear ON?


dalpozlead

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If the gear is not ON, how can it pass the signal?

 

If you only want to play ONE device, why do you need MIDI? ;)

 

If you are only playing ONE rack unit (turned ON), why not run the MIDI cable from the controller directly to it?

 

The answers lie before you grasshopper. They are just....asleep. :):cool:

PD

 

"The greatest thing you'll ever learn, is just to love and be loved in return."--E. Ahbez "Nature Boy"

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I have other electronic devices that can bypass the signal physically, even when turned OFF, that is a bypass!

What to do if when playing live one of my racks crash and stops working?

 

Im playing one rack at a time when for example I am programming one of them and dont want to turn all 4 racks.

 

thnx.

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Originally posted by Prague:

You are correct in that many Thru ports are hardwired directly from the In port. Some modules do not do this, however.

 

Put the hardwired devices at the front of the chain.

I doubt any MIDI gear is 'hardwired'. The MIDI spec (and general design principles) dictate the use of optoisolators for all MIDI connections to prevent ground loops; that requires power, either from the unit itself (hence the need for the unit to be powered on, or in a 'standby' mode while connected to AC), or from the 5V MIDI connection itself (as in the case of the MIDI Solutions product I suggested above).

 

There may be some products on the market that provide power to the MIDI connections even if the main power switch is off; I'm not familiar with any like this, but they could be out there.

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Correct, you cannot hardwire a MIDI thru port due to the current loop design of the transmission system. You have to use optoisolators on the MIDI In port, then either buffer it to the MIDI Thru or the module processor generates the MIDI thru.

 

Either way, power has to be on. Period.

 

A buffered MIDI thru has much better latency than a processed thru but distorts the signal slightly - the rising/falling edges of the signal are shifted due to the propogation delay inherent in the buffer. One too many buffered MIDI thrus can render the MIDI signal unrecognizable at the module on the end of the chain.

 

You can disable a processed thru or change it to a MIDI out and it won't distort the MIDI signal. But the latency is longer due to the processor chewing on code. It doesn't take too many processed thru's to generate serious latency problems.

 

Either way, one too many thrus in the chain will either have massive latency or the end module will not recognize the MIDI signal at all being distorted beyond recognition.

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Originally posted by The Real MC:

Correct, you cannot hardwire a MIDI thru port due to the current loop design of the transmission system. You have to use optoisolators on the MIDI In port, then either buffer it to the MIDI Thru or the module processor generates the MIDI thru.

Interesting to note that the MIDI Solutions products don't use optoiso's on the MIDI IN on their boxes, because they run off the +5V on pins 2 & 4. They do use OI's on any other MIDI IN ports, and all MIDI OUT & THRU ports, so they're still avoiding the ground loop problem. :thu:
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