H90 with MOTU Interface – TRS to TS Cabling Advice Needed

[zakiddine]

Hi everyone,

I’m looking for some advice regarding the best way to connect an Eventide H90 to my studio setup.

My current setup includes:

– Korg Kronos 3
– Sequential Prophet Rev2
– MOTU UltraLite-mk5
– Eventide H90
– ADAM A7V monitors
– Logic Pro

The MOTU UltraLite-mk5 is the central audio interface in my setup. My keyboards are connected to the MOTU, my monitors are connected to the MOTU Main Outputs, and Logic Pro communicates with the MOTU via USB.

I would like to use the H90 as an external stereo send/return effect, so that I can control how much of each keyboard is sent to the H90.

The intended signal flow is:

Kronos 3 / Prophet Rev2 → MOTU UltraLite-mk5 → H90 → MOTU UltraLite-mk5

Then:

MOTU Main Out 1/2 → ADAM A7V monitors

and

MOTU ↔ Logic Pro via USB

So the H90 is only part of the external FX loop. The monitoring and DAW routing remain handled by the MOTU.

For more clarity, I have also prepared and attached a diagram of my actual studio setup, showing the complete signal flow as well as the proposed TRS/TS cabling between the MOTU and the H90.

MOTU → H90 SEND
For the stereo send, I’m planning to use:

MOTU Line Out 3/4 → H90 Input 1/2

My understanding is:

MOTU side: 1/4″ TRS — Balanced output
H90 side: 1/4″ TS — Unbalanced input

I have been advised to use a custom TRS → TS Ring Disconnect / Floating Ring cable:

Tip → Tip
Sleeve → Sleeve
TRS Ring → left completely disconnected / floating
So the Cold (-) signal from the MOTU balanced output would not be shorted to ground.

H90 → MOTU RETURN
For the stereo return:

H90 Output 1/2 → MOTU Line Inputs

Here we have:

H90 side: 1/4″ TS — Unbalanced output
MOTU side: 1/4″ TRS — Balanced input

I would also like your advice regarding the correct wiring for this direction.

My questions
Before having custom cables made, I would really appreciate advice from Eventide/H90 users:

1. Is the TRS balanced → TS unbalanced with Ring disconnected approach correct for MOTU → H90?
2. What is the recommended wiring for the opposite direction, H90 TS output → MOTU balanced TRS input?
3. Should Ring be connected to Sleeve for the H90 → MOTU return, or is there a better wiring method?
4. Are you using standard TRS-to-TS cables, specially wired Ring Disconnect / Floating Ring cables, or custom-made cables with your H90?
5. If you had your cables custom-made, could you please share the exact wiring you used?
6. Does anyone here use an H90 with a MOTU UltraLite, 828, 16A or another MOTU interface in this type of send/return configuration?
7. Are there any particular H90 I/O level or MOTU output/input level settings you recommend when working with hardware keyboards such as the Korg Kronos 3 and Prophet Rev2?

 

My main goal is to have a clean and reliable stereo signal path, with correct balanced/unbalanced interfacing, minimal noise, no unnecessary ground-loop issues, and proper gain staging.

The attached diagram represents how I am planning to wire my actual setup, so any comments or corrections on the diagram itself would also be very welcome.

I’d really appreciate hearing how other H90 users have handled this in real-world studio setups before I have the cables made.

Thanks in advance for your help and experience!

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[jimfowler]

1. I’d ask a mod to move this to the H90 forum.

2. According to the UltraLite manual, its I/O can accept balanced or UNbalanced signals…so you’ll probably do just fine with standard-issue TS cabling.

[zakiddine]

Thank you jimfowler very much for your helpful feedback.
My main concern is: would using standard TS-to-TS cables between the MOTU UltraLite-mk5 and H90 cause any audio degradation, additional noise, or loss of signal quality compared to a specially wired TRS-to-TS cable?
I just want to make sure I’m using the cleanest and most reliable connection possible.

Best regards

[fiddlercrabseason]

While you’re waiting for mods to respond directly (holiday weekend in the US), following are a few posts that might be helpful:

H90 – using unbalanced I/O with balanced load box/amp sim

balanced TRS I/O to H90s unbalanced TS I/O

(attached screenshot from The Gear Page, which I can’t link you to cuz it keeps timing out for some reason…  shrug emoji…)

 

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[jimfowler]

Given that the equipment you’re working with is designed with UNbalanced signals in mind I think it’s a solid “highly unlikely” that you’d notice any of the issues mentioned.  If you’re nonetheless concerned, there are better ways to go from balanced to unbalanced (or vice-versa) than custom cabling.  See here for details: https://www.ranecommercial.com/legacy/note110.html and plenty of companies build affordable boxes that accomplish the task of balancing/unbalancing.

[tbskoglund]

Hi zakiddine,

I’ve moved this post to the stompbox forum for you. It sounds like you have a pretty good idea of how this can all be hooked up.

As others have mentioned, you will most likely be fine with TS cabling without running into any issues.

I’d suggest trying out the audio interface to H90 connection using TS cables and see if you run into any issues before trying anything else.

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