# Problem with QC and Midi after update **URL:** \ **Category:** Bug Reports\ **Tags:** quad-cortex, midi\ **Created:** [January 11, 2024, 12:36pm UTC](https://unity.neuraldsp.com/t/problem-with-qc-and-midi-after-update/13127 "2024-01-11T12:36:51Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![DannyEvilAlone](https://avatars.discourse-cdn.com/v4/letter/d/aeb1de/32.png) [@DannyEvilAlone](https://unity.neuraldsp.com/u/DannyEvilAlone)\ **Post date:** [January 11, 2024, 12:36pm UTC](https://unity.neuraldsp.com/t/problem-with-qc-and-midi-after-update/13127/1 "2024-01-11T12:36:51Z")
**CorOS Version:** 2.3.0. **Describe your issue:** I’ve a weird issue with my QC after updating to the newest os (2.3.0). For some reason Midi stopped working. I’m unable to send or receive midi commands. Even when I look at the input list (by swiping down on the touch screen) the midi in and out icons are grey even when the cable is connected (they should be white after connecting a cable). **Steps to reproduce your issue:** 1. Connect midi cable **I expected this to happen:** I expected to be able to use midi controls as they worked before update. **I have tried the following things:** - Factory reset - Connecting different devices - Using different cables ---
**Author:** ![MP\_Mod](https://avatars.discourse-cdn.com/v4/letter/m/ccd318/32.png) [@MP\_Mod](https://unity.neuraldsp.com/u/MP_Mod)\ **Post date:** [January 11, 2024, 12:37pm UTC](https://unity.neuraldsp.com/t/problem-with-qc-and-midi-after-update/13127/2 "2024-01-11T12:37:27Z")
Have you enabled or disabled MIDI-thru? Note that it should be disabled etc. ---
**Author:** ![DannyEvilAlone](https://avatars.discourse-cdn.com/v4/letter/d/aeb1de/32.png) [@DannyEvilAlone](https://unity.neuraldsp.com/u/DannyEvilAlone)\ **Post date:** [January 11, 2024, 8:47pm UTC](https://unity.neuraldsp.com/t/problem-with-qc-and-midi-after-update/13127/3 "2024-01-11T20:47:46Z")
It doesn’t work regardless if MIDI Thru is enabled or disabled. ---
**Author:** ![MP\_Mod](https://avatars.discourse-cdn.com/v4/letter/m/ccd318/32.png) [@MP\_Mod](https://unity.neuraldsp.com/u/MP_Mod)\ **Post date:** [January 12, 2024, 3:47pm UTC](https://unity.neuraldsp.com/t/problem-with-qc-and-midi-after-update/13127/4 "2024-01-12T15:47:35Z")
I am unable to duplicate your issue with MIDI. Please open a ticket by emailing [support@neuraldsp.com](mailto:support@neuraldsp.com) and they will log your issue and hopefully provide resolution. ---
**Author:** ![BrentG](https://sea2.discourse-cdn.com/flex020/user_avatar/unity.neuraldsp.com/brentg/32/3402_2.png) [@BrentG](https://unity.neuraldsp.com/u/BrentG)\ **Post date:** [January 14, 2024, 10:29pm UTC](https://unity.neuraldsp.com/t/problem-with-qc-and-midi-after-update/13127/5 "2024-01-14T22:29:17Z")
I updated to 2.3.0 today and my midi still works. However, I did notice the same thing with the i/o screen – my midi icons are not lit up. I am using Midi-Thru and have both connected, both work, but they look inactive on the screen. ---
**Author:** ![BrentG](https://sea2.discourse-cdn.com/flex020/user_avatar/unity.neuraldsp.com/brentg/32/3402_2.png) [@BrentG](https://unity.neuraldsp.com/u/BrentG)\ **Post date:** [January 15, 2024, 8:54pm UTC](https://unity.neuraldsp.com/t/problem-with-qc-and-midi-after-update/13127/6 "2024-01-15T20:54:08Z")
I’ve used Midi-Thru since I ever set the quad up, and I’ve started advancing my midi usage since upgrading to v2.3.0…no real reason other than the enthusiasm of using more of the capability after checking everything out post-upgrade. But your comment that midi-thru should be disabled made me curious, so I set up one of my loop pedals with the intent to use a quad preset to send a PC to the device when in Scene Mode by pressing Switch E. Then, vice versa, to a second message to the same external device by pressing Switch G. The only way these work is as you point out here, is that if the midi-thru is disabled. I would think if midi-thru is enabled, midi-out messages from the quad should also still work. Shouldn’t midi-out always be on, no matter what the setting of midi-thru? This is my experience with other devices. Anyway, as much as I am getting out of the quad and as much as I like it, this is a bit surprising and disappointing in my current efforts to expand the quad’s role in my live rig. Regards. ---
**Author:** ![ToH2002](https://sea2.discourse-cdn.com/flex020/user_avatar/unity.neuraldsp.com/toh2002/32/1768_2.png) [@ToH2002](https://unity.neuraldsp.com/u/ToH2002)\ **Post date:** [January 17, 2024, 11:15pm UTC](https://unity.neuraldsp.com/t/problem-with-qc-and-midi-after-update/13127/7 "2024-01-17T23:15:11Z")
> [@BrentG](#): > > Shouldn’t midi-out always be on, no matter what the setting of midi-thru? Typically (and according to the MIDI specification), MIDI thru is implemented via direct electronic routing of the input signal to the output port - no active processing of MIDI data happening, simply the electric signal forwarded (with a bit of optical isolation). I’m not sure if the QC implements it the same way, but in that case, it would be impossible to send MIDI out to the same port that is working in MIDI thru mode, since the port is “blocked” for the thru signal. I think what you are looking for is a “MIDI merge” capability - this involves actively processing the MIDI input and logically combining it with the signal that the QC is sending internally to its output port. This requires actually reading the MIDI input, combining it with the internally generated MIDI stream, ensuring that no MIDI messages overlap (which can be a bit of a challenge with stuff like MIDI running status and system exclusive messages) and buffering one of the two streams while the physical port is busy outputting events from the other (especially for system exclusive messages). This is typically what a “MIDI merge box” does. Note: merging MIDI streams will cause a (variable) delay of the forwarded MIDI stream (since input needs to be read, assembled, buffered, sequenced, and output again), while “electronic” MIDI thru will only have the delay of the opto-coupler to deal with and therefore is much faster and more reliable timing-wise. It should be possible to implement a MIDI-merge functionality inside the QC to enable the combination of MIDI-Out and MIDI-Through. I’d like the idea of having a choice between the MIDI output port working as “merged output”, “output only” or “classic thru”. Maybe worth a feature request? TBH, the manual isn’t really explicit on the function of the “MIDI Thru” switch in settings - I guess Neural expects us to know how MIDI thru works according to the MIDI spec. I’d recommend Neural to spend a few more words of explanation regarding the Thru function in the manual to avoid ambiguity and confusion of less “Midi-spec-conversant” users… Cheers, Torsten ---
**Author:** ![ToH2002](https://sea2.discourse-cdn.com/flex020/user_avatar/unity.neuraldsp.com/toh2002/32/1768_2.png) [@ToH2002](https://unity.neuraldsp.com/u/ToH2002)\ **Post date:** [January 18, 2024, 12:07am UTC](https://unity.neuraldsp.com/t/problem-with-qc-and-midi-after-update/13127/8 "2024-01-18T00:07:51Z")
Quick addition: actually, there is already a feature request for a “MIDI merge” option: > [@Merge MIDI IN messages with QC Preset MIDI OUT when MIDI THRU is enabled](https://unity.neuraldsp.com/t/merge-midi-in-messages-with-qc-preset-midi-out-when-midi-thru-is-enabled/7769): > > As the QC does not send MIDI clock, I have a MIDI controller that connects to the QC’s MIDI IN port. I enabled MIDI THRU on my QC to sync my other pedals’ clocks. But I also have Preset MIDI OUT on many of my presets to change some of my pedals’ parameters when scene changing on the QC. The problem is that when MIDI THRU is enabled on the QC, Preset MIDI OUT will not work. This behavior is not documented anywhere, and I can still set Preset MIDI OUT messages. We need the QC to merge its own Pre… Actually, I wouldn’t really recommend using a merged output for real-time MIDI messages like MIDI clock (as the original poster of that thread wants to do), since the merging can actually mess up the timing royally, so be warned! But generally, having the option of merging internal and received MIDI would certainly be appreciated… ---
**Author:** ![BrentG](https://sea2.discourse-cdn.com/flex020/user_avatar/unity.neuraldsp.com/brentg/32/3402_2.png) [@BrentG](https://unity.neuraldsp.com/u/BrentG)\ **Post date:** [January 19, 2024, 2:23pm UTC](https://unity.neuraldsp.com/t/problem-with-qc-and-midi-after-update/13127/9 "2024-01-19T14:23:57Z")
Very informative. Thank you. I suppose it boils down to the application. In my application I am only sending PC messages in both scenarios of midi-thru and midi-out. I can follow your logic well enough with a 25 IT career background, but it would seem possible I think with a software option. The merge option might not work well for folks using CC messages I guess. But I think the SysEx stuff could be managed. We will see. I did send in a support question / request. It was forwarded on to the tech team but will probably end in a similar development scenario impasse as you touch on. Thanks again. Regards Brent