Thanks Mark, I think we've exceeded my capabilities in that I thought i'd already tested the SEND port by using a Mono Jack, and indeed variations of Mono > Stereo, Mono > Mono, (and even Stereo > Mono just to see) - with the results I reported on my last note.
The internal wiring is a bit brain scrambling for my autism, so maybe if you could give me a note on exactly which points need to be wired how at each end, I'll take it to my friend at the music shop and get him to make me up a custom cable.
My other suspicion is that it may be a faulty SEND port on the mixer (but don't have any speakers etc to check for the moment), but the other reason this is likely, is that i've checked, and I now remember that when the TBU was working fine last (with stereo jacks at either end of the output going back to the TBU), it was using another mixer, albeit exactly the same model, so i'm going to dig my spare one out of the loft and test that when I can.
As another cross test, I borrowed a Sonifex HY-02 TBU from a friend, and although it needed BT connectors (rather than RJ45 end) and XLR's rather than 1/4 Jacks, after countless adaptors etc I got it setup in an equivalent way to the D&R, and the problem was exactly the same, i.e. the caller couldn't hear me at all.
To test the leads, if you unplug the lead from the "FX send" (with your mic faded up) and touch the tip on the tip of the cable from the "Line In" you should hear the microphone signal coming back (potentially a bit loud).
The cable you want from "FX send" to D&R Hybrid "to Cleanfeed output"is as follows. This is a version of the cable at the top of page 6 of the D&R manual but with a mono jack (not a Cinch/RCA/phono) at the mixer end.
Perfect, thanks Mark, will get on to it
Chris Pitchford
With much gratitude to Alex James for the vital advice on his post, I have now got Stereo Tool working with Playit Live, using the Virtual Cable (from https://vb-audio.com/Cable/index.htm), and it sounds great, but there are just a couple of issues remaining, and I'd be most grateful for your thoughts on these.
Firstly there's roughly a second's latency between firing the audio in Playit Live and the sound coming out of Stereo Tool, and despite tweaking as many buffer settings as I can find in both products and my sound card, I don't seem to be able to fix it. (I've found it safest not to go below 200ms buffer setting in Playit Live).
There is also a restriction with the Virtual Cable System which doesn't suit the way I work, and I would like to know if there is a system which uses multiple virtual cables, as the one mentioned above comes as a single pipeline, so all the decks from Playit Live have to be routed through this one channel, I/O Stereo Tool; as a full mix, wheras i'm used to having carts and each separate playout deck on separate mixer faders for manual control/fading/mixing etc.
Many Thanks