SubZero SZ-MIX08USB

[James Perrett]

I do not see how even a correct schematic will help? The USB routing is what it is I don't think you can change that.

Maybe the OP is prepared to get a scalpel out and cut PCB tracks. You would need a good knowledge of the circuits used but the data sheet for the USB Codec would probably give quite a bit of the information needed.

[MartinK22]

Another newbie here. First disclosure, I'm the OP's bro' and was involved in the testing last weekend and I am the author of the previously mentioned schematic which I have now updated.
First question, how can I share the schematic? It is a pdf file. I haven't found a way to share directly on the forum here. I can access MS one drive, drop box or google is any of those would provide a solution.
The schematic is based on a little knowledge and testing with analogue and digital (second disclosure we are doing this using Linux) sources and sinks i.e. it is based on empirical evidence. Would be happy to take constructive feedback to improve it once I can share it. Reason for doing the schematic are various, it is easier to understand than page(s) of text, the manual is inadequate and has errors. You get what you pay for, more expensive kit has better documentation. Sharing would gives other benefit too I would hope.
If someone can tell me best way to post the schematic then we can discuss further. Final disclosure, I'm an electronic engineer by education and sometime employment so opening up and cutting tracks isn't out of the question

[James Perrett]

Welcome to the forum Martin. We don't host files here so the best way would be to put it up as a public file on Dropbox, Google Drive, Onedrive or similar and then post a link here.

[ef37a]

Another newbie here. First disclosure, I'm the OP's bro' and was involved in the testing last weekend and I am the author of the previously mentioned schematic which I have now updated.
First question, how can I share the schematic? It is a pdf file. I haven't found a way to share directly on the forum here. I can access MS one drive, drop box or google is any of those would provide a solution.
The schematic is based on a little knowledge and testing with analogue and digital (second disclosure we are doing this using Linux) sources and sinks i.e. it is based on empirical evidence. Would be happy to take constructive feedback to improve it once I can share it. Reason for doing the schematic are various, it is easier to understand than page(s) of text, the manual is inadequate and has errors. You get what you pay for, more expensive kit has better documentation. Sharing would gives other benefit too I would hope.
If someone can tell me best way to post the schematic then we can discuss further. Final disclosure, I'm an electronic engineer by education and sometime employment so opening up and cutting tracks isn't out of the question

I would advise caution Martin about posting that schematic. "Sub Zero" is a brand name 'owned' by Gear4Music Ltd and they might not take too kindly to a schematic of one of their products being bandied on the net. Also the internet is not the 'free lunch' it used to be. Lots of images are copyright now and some companies WILL chase you down!

I shall now make a bit nonsense the above! I personally believe schematics should be freely available to everyone so that servicing can be readily effected. We MUST fix more! This was normally the case with 'professional' audio kit, indeed a 'map' often came in the box. Nagra even put in spare transistors!
However the coming of the rip off artists has put paid to that situation and I personally have a good deal of such commercially valuable information. I have never posted it but that did not stop a certain 'household name" copying at least two of the amplifiers.

Dave.

[Drew Stephenson]

I would advise caution Martin about posting that schematic. "Sub Zero" is a brand name 'owned' by Gear4Music Ltd and they might not take too kindly to a schematic of one of their products being bandied on the net. Also the internet is not the 'free lunch' it used to be. Lots of images are copyright now and some companies WILL chase you down!

If Martin has created the image then he owns the copyright. Likewise if he's backward-engineered the schematic from experimentation there's going to be no trade secrets or other IP involved there that I can think of? If there's a patent involved then it will be registered and searchable at a patent office and design rights just cover the look of the thing.

[Wonks]

I think we’re talking about a signal flow schematic here, not a circuit diagram.

[ef37a]

I would advise caution Martin about posting that schematic. "Sub Zero" is a brand name 'owned' by Gear4Music Ltd and they might not take too kindly to a schematic of one of their products being bandied on the net. Also the internet is not the 'free lunch' it used to be. Lots of images are copyright now and some companies WILL chase you down!

If Martin has created the image then he owns the copyright. Likewise if he's backward-engineered the schematic from experimentation there's going to be no trade secrets or other IP involved there that I can think of? If there's a patent involved then it will be registered and searchable at a patent office and design rights just cover the look of the thing.

I am sure you are right Drew but G4M just might be sufficiently hissed off to 'make an example' and make (probably empty) threats?

Dave

[James Perrett]

I would advise caution Martin about posting that schematic. "Sub Zero" is a brand name 'owned' by Gear4Music Ltd and they might not take too kindly to a schematic of one of their products being bandied on the net. Also the internet is not the 'free lunch' it used to be. Lots of images are copyright now and some companies WILL chase you down!

I can't see there being a problem with a diagram that Martin has drawn himself. This is a generic, Chinese made mixer which is probably available under lots of different brand names and probably uses fairly generic circuits that have been used by many other people.

Chances are that the USB side of things is a copy of the circuit in the USB chip's datasheet which will already be available online.

[MartinK22]

Hi

Thanks for all the replies. Nothing like legal considerations to dampen the enthusiasm.

It is a functional diagram not a schematic, nothing that a person skilled in the art could not work out for themselves from outside the box. SubZero's own documentation leaves a lot to be desired. Similar schematics are freely available for mixers from other manufacturers. So if anything I'm doing G4M/SZ a favour and them stifling this kind of discussion does them no favours.
On the other hand there is nothing on my schematic to say on what basis it was generated or made available, which might be seen as miss leading. I'll add some words to the effect that it is provided on best effort basis by a private citizen with no ties to G4M and then post a link here.
Too late to do this now, hopefully will find time to do after work tomorrow.

[MartinK22]

Schematic can be found here

https://1drv.ms/b/s!AlpUrmBw0Ew2hPxQxxG ... A?e=v32Jcy

Can someone confirm it is accessible.

Not sure anyone can help but the last thing we worked out was that USB D/A is connected halfway down the 2TK output strip. The means that, unlike the analogue 2TK connections, it cannot be used for click track playback via the headphones (we don't hear it on the headphones 2TK route at all). Which makes it of much more limited use as an interface.

[zenguitar]

Yes, I was able to access with no problems.

Andy

[arj]

Hi Martin

Thanks for the schematic. It's really helpful. The supplied documentation is pretty hopeless but your schematic really helped.

Cheers

[MartinK22]

Hi arj

Glad you found it useful and thanks for the complement.

All the best

Martin