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Max number of Daisy chained MIDI devices?

Started by stecykmi, February 21, 2017, 08:22:27 PM

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stecykmi

hi guys, I have several outboard synth units that are controlled from the midi i/o on my usb interface but I have been experiencing missed note on and off commands. i suspect that i have too many devices chained which is causing the lost midi commands. does anyone know the typical max number of devices that you can connect before midi signals start getting dropped? for the record i have 6 units chained.

selfdestroyer

Found this info here: http://sound.stackexchange.com/questions/39370/how-many-midi-in-out-daisy-chaining-i-can-use/39371

QuoteEvery USB-MIDI connection adds at least one or two milliseconds of latency. A single USB connection typically is not noticeable.

Every DIN-MIDI connection also adds latency; at 31250 baud, a three-byte message requires about one millisecond to be transmitted.

A MIDI Through connection does not add latency, but the MIDI input circuitry slightly distorts the signal (depending of the rating of the optocoupler used in this circuit, which you typically don't know). This can result in problems if there are too many steps in the chain.

The jest of it is, the more INs and OUTs you use you will stack up latency. I have personally used over 7 daisy chained and did not hear any issues with outboard gear.

brejna

I have done single sided board for midi splitter with 1 in and 3 outs if you are interested. It is unverified, but it uses very known schematics from internet and I suppose it should work.

stecykmi

Quote from: selfdestroyer on February 21, 2017, 09:31:36 PM
Found this info here: http://sound.stackexchange.com/questions/39370/how-many-midi-in-out-daisy-chaining-i-can-use/39371

QuoteEvery USB-MIDI connection adds at least one or two milliseconds of latency. A single USB connection typically is not noticeable.

Every DIN-MIDI connection also adds latency; at 31250 baud, a three-byte message requires about one millisecond to be transmitted.

A MIDI Through connection does not add latency, but the MIDI input circuitry slightly distorts the signal (depending of the rating of the optocoupler used in this circuit, which you typically don't know). This can result in problems if there are too many steps in the chain.

The jest of it is, the more INs and OUTs you use you will stack up latency. I have personally used over 7 daisy chained and did not hear any issues with outboard gear.

since i'm using the midi THRU jacks, there aren't any latency issues (that i can perceive anyway). it was my thought that the signal was degraded and lost though the optocouplers. tonight i will re-wire and see if there is any improvement, i seem to remember using a very long midi cable interconnect that i will swap with a shorter one, perhaps the excess length is working against me.

stecykmi

Quote from: brejna on February 21, 2017, 09:41:11 PM
I have done single sided board for midi splitter with 1 in and 3 outs if you are interested. It is unverified, but it uses very known schematics from internet and I suppose it should work.

the more i look around, the more i'm starting to think this thing may not be a bad idea. do you have details on the build?

sturgeo

Quote from: stecykmi on February 21, 2017, 11:55:32 PM
since i'm using the midi THRU jacks, there aren't any latency issues (that i can perceive anyway).

Do you know if its hardware or software MIDI TRU?

gtr2

Unless you are bent on DIY.  It's faster and cheaper just to buy one of these than what you'd spend in parts.  I know it's against the spirit of DIY  :o

https://www.sweetwater.com/store/detail/MIDIthru4

Josh
1776 EFFECTS STORE     
Contract PCB designer

Muadzin

If the spirit of DIY is that everything has to be DIY made then its counterproductive. Like with everything in life DIY should be applied where possible within reason.

brejna

Quote from: stecykmi on February 23, 2017, 12:08:53 AM
Quote from: brejna on February 21, 2017, 09:41:11 PM
I have done single sided board for midi splitter with 1 in and 3 outs if you are interested. It is unverified, but it uses very known schematics from internet and I suppose it should work.

the more i look around, the more i'm starting to think this thing may not be a bad idea. do you have details on the build?

I could make pdf with PNP for ething if you are interested. I'll post it in the members project. Here is schematic I used..

stecykmi

Quote from: sturgeo on February 23, 2017, 08:16:05 AM
Quote from: stecykmi on February 21, 2017, 11:55:32 PM
since i'm using the midi THRU jacks, there aren't any latency issues (that i can perceive anyway).

Do you know if its hardware or software MIDI TRU?

not sure off hand but most likely hardware since it's mostly older gear.

i rewired the system a bit and i seem to have eliminated the majority of the problems. i removed the excessively long cable from the loop and replaced it with a shorter one as well as used the midi out jack on one synth as a branch off the main loop. this effectively makes the chain 1 step shorter.

if i ever add another synth to the collection i think i will then be forced to use one of those midi thru boxes but for now i'm going to leave good enough alone.