MIDI Thru in Series VS MIDI Splitter Box (e.g. MIDI Solutions QuadraThru)

[parhelia_0000]

This has been a debate among guitarists and rig builders for quite some time - should one always have preference to a MIDI splitter box such as a MIDI Solutions QuadraThru, or are there cases where one can daisy chain MIDI via MIDI Out/Thru ports of the MIDI devices?

Reason why I'm asking: I'm currently using the Quadra Thru to split MIDI between the Axe-FX III Turbo, Strymon BigSky and Voodoo Lab HEX. I've discussed about this with some of my friends who build guitar rigs, and also brought up this topic with RJM support via email before.

My friends argue that MIDI daisy chain should be limited to 2-3 devices after the MIDI controller (1-2 if at least one of them requires real-time expression pedal inputs, as those are far more temperamental to MIDI latency), especially considering how not all MIDI Thru are designed equal and some devices such as the Voodoo Lab HEX (from my personal experience) and Eventide boxes (e.g. H9, H90, Factor pedals, etc.) are notorious for not having a clean MIDI Thru.

However, RJM support disagrees. I recall Mario mentioning this to me via email that 3-4 devices connected in series via MIDI Thru shouldn't be of a major issue.

So, who to trust in this case? I've been trying to see if there's a way for me to consolidate bidirectional MIDI between the RJM Mastermind GT-16 and the Axe III Turbo to one specialized cable, but if it's going to be more trouble than it's worth, then it might be best for me to keep it to two separate MIDI cables...

 

[rjmmusic]

A lot depends on the specifics of your rig. The MIDI spec says that you can chain 4 devices after a controller. This does seem to be a generally safe number. However, the quality of the MIDI ports on each device varies. Each time you pass through a MIDI device, the signal degrades a little. Depending on the circuit, it could degrade a little or it could degrade more. Eventually it will degrade to the point that it's not readable by the next device.

Latency is a separate issue. A MIDI device can pass through data in two ways. A true MIDI thru port is a hardwired connection, basically the input is connected directly to the thru port and it's just passing data along. There's no appreciable latency in a real MIDI thru. However, some devices use a soft MIDI thru, where the MIDI messages are received, sent to a microprocessor for processing, then retransmitted. This will introduce some amount of latency, depending on the processor and the code it's running.

 

[parhelia_0000]

A lot depends on the specifics of your rig. The MIDI spec says that you can chain 4 devices after a controller. This does seem to be a generally safe number. However, the quality of the MIDI ports on each device varies. Each time you pass through a MIDI device, the signal degrades a little. Depending on the circuit, it could degrade a little or it could degrade more. Eventually it will degrade to the point that it's not readable by the next device.

Latency is a separate issue. A MIDI device can pass through data in two ways. A true MIDI thru port is a hardwired connection, basically the input is connected directly to the thru port and it's just passing data along. There's no appreciable latency in a real MIDI thru. However, some devices use a soft MIDI thru, where the MIDI messages are received, sent to a microprocessor for processing, then retransmitted. This will introduce some amount of latency, depending on the processor and the code it's running.

Gotcha. So true MIDI Thru's can be daisy chained (up to 3-4 depending on whether or not any of them require real-time expression pedal inputs), but soft MIDI Thru's are a higher risk factor. That's good to know.

One thing to note about the Strymon BigSky (as well as all other Strymon stompboxes) is that it does not have a true MIDI Thru - you have to select MIDI Thru in the global settings in order for the MIDI to pass through, and several folks reported mixed results with it. Some rigs, the Strymon passed the MIDI Thru clean, others not so much.

I guess in my particular situation it would be safer for me to use two separate MIDI cables for bidirectional MIDI between my rig and the RJM Mastermind GT-16, but then the tradeoff is I won't be able to automate preset switching on my rig via the GT-16 (but then again, bidirectional MIDI most likely won't like MIDI automation from a DAW since there is a risk of a MIDI loop anyway).

I could also try routing the MIDI Solutions QuadraThru after the Axe-FX III's MIDI Thru, but considering how the Axe III's MIDI Thru is spec'd at 3.3 V instead of the traditional 5V, the chances that this will work is half-half. Granted, my Quadra Thru is a MultiVoltage variant, but then again I have no idea if this will even work at all.