Linux: Jack/Hydrogen Loop Jump Sync

Hi all,

I downloaded 2.1 today and played with it. Here’s what I did, and what resulted:

I fired up Hydrogen and created a 1 bar drum loop. I open Renoise and created a MIDI track that triggered Nekobee. Everything syncs up just fine, except when Renoise rolls from step 64 to step 0, there is a “jitter” or “double-trigger” of Hydrogen. I don’t know how to be more specific, but Renoise is doing something on step 0 that’s tripping Hydrogen up.

I’m going to do a little more testing this week to try to better isolate the issue, and I’ll report back.

FYI, running 64 Studio beta, which uses jackdmp, currently running v 0.71.

(Since this is my first bug report, I might be failing to give you some obvious information you might need; if that is the case, please let me know and I’ll fill in the gaps.)



EDIT: typos

Did you read the Jack Transport FAQ?

Ahh, looks like this is the answer I’m looking for:

I’ll try this tonight after work. Thanks for the heads-up!


Hello Josh,

I think what Conner means, is that Jack does not support “Loop” information - Jack clients don’t know when and where the others clients will loop.

This means that, as soon as some of the Jack transport clients loop, they may force all other clients to relocate to the loop start. This “relocation” will in most cases lead to small gaps/artifacts. Especially with apps like Ardour which do need about a second to apply new positions in the timeline.

You can avoid this by creating a simple sequence that only plays one pattern in Renoise. Also try to use Hydrogen either in Song or Pattern mode.

Hi taktik,

I’m not understanding all of your response, so I think I’ll add more information and see if that sheds some light on the issue:

Hydrogen was running in pattern mode, and I only had one pattern in Renoise (simply looping 64 steps over and over). I’m not challenging your explanation of the issue, but I’m not sure, given this information, how to avoid it?



Sorry for the late reply.

What I mean is, that every loop jump Renoise (as soon as the playhead moves from the loopend to the loopstart) will cause bad artifacts in many jack clients. Renoise also loops when just playing back a single pattern again and again.
The main reason for this is that loops are not transfered via the jack protocol, so the applications don’t “know” when such loop jumps will happen.

Theres not much we can do here. You either have to live with these “hickups”, or you have to avoid loops where ever possible.