Thanks heaps Utz.
Have played around with moving bits 3 & 4 to our bits 0 and 7 in WT and also changed your listed hex within all of the sample files - alas, there really wasn't any improvement unfortunately. I'm guessing I'm just missing something. I also played with shifting bits 3&4 in some of the other engines that I haven't managed to get any audio out yet; so far with little success, but I'll keep at it as I'm still currently really enthused in all of this. Whenever I find any spare time I just tinker with various ideas to no end to try to get something working.
I also did actually finally get around to start to properly count cycles for the heck of it, for the replacement LD opcode instead of ZX's OUT; trying to get the code in blocks of 8-states. Has improved sound quality in one or two engines; Still needs a lot more time spent into it, so it might be worthwhile me in doing this to all current players that I have working to reduce noise.
A few very rough grabs of a few engines playing on an Emulator are shown below. Sorry for the useless video and audio capturing, but does give a rough indication of the varying engines that I've managed to get working.
https://youtu.be/_5EdaxGSf4U Tritone. Song: Journey.
https://youtu.be/eH4I1I7XuJo Tritone FX
https://youtu.be/oDN6jTbStY8 PhaserX. Song: Frohen Mohawk
https://youtu.be/aimDaYDt2FU PhaserX. Song: Last Summer, with equaliser demo.
https://youtu.be/PE52gYiFWw4 Pytha.
https://youtu.be/ZyS1Vlr1jX0 Quadtropic with lores and hi-res equaliser.
https://youtu.be/Stm_25S97zk Betaphase
https://youtu.be/uFYL9rsO410 VZ demo game with ZX10 engine
https://youtu.be/EQDAdN9sNFs PhaserSqueek
Phasersqueek is the best sounding engine yet. It is just clean and crisp, and was just a cinch to convert. And I was gobsmacked upon the first running and hearing it.
PhaserX, Quadtropic, ZX and Huby seem to be the engines that can be used for games / demos without effecting performance too much. Trying to run the same code for the text equaliser in Pytha, Phasersqueek, Beta, Octonode etc just either fails from my lack of programming knowledge or the VZ simply doesn't have enough grunt to do whatever as well as the music engine.
I really want to get zbmod working; however, have already had two separate good attempts at it now, and unfortunately both were a failure.