alaric smith
Active Member
A couple of years ago, I picked up a "prototype" QS(?), Vario Matrix(?), BMX (?), etc., decoder. It works and gives some weird but excellent results with some stuff (I have a few QS LPs). To be honest, though, I have no idea what it was designed to do, which matrices it was supposed to decode or whether it was ever released into the wild. Mine is marked "Sample 0025" in high-class red and black felt-tip pen on the back and "sample" on the roof.
The board is remarkably simple, with two ICs heatsinked and then shrink wrapped (presumably to hide the ICs from market forces), which seems a little odd to me. Why have a shrink-wrapped heatsink? It would be incredibly simple to come up with a circuit diagram - despite the slightly awkward soldering on the double-throw level pot (the earth seems to wander around the pins like a snake). I daren't take the shrink wrap off, just in case Denon's agents get me :alienrob: ...
I will see if I can add a photo at some point - it is, though, just a little wooden box, with a brushed aluminium front, on which sits a level knob and a on/off toggle switch, and a steel chassis, part of which acts as the rear panel, on which sits stereo-feed rca terminals and quad out rca sockets, a fuse holder and the power cable. The front has "Denon Universal Matrix Decoder / QXU-10" pantographed (screen printed) across the top (from the left had top edge).
I need to clean the pot (it is a bit scratchy) but everything else is fine - no cap crackles or any other pops and whistles.
It does add a little dimensionality to stereo but I wouldn't write home about it (wait a second, I live at home ...). I was hoping that it would have a little ambisonics magic but probably not.
I guess what I am asking is: Has anyone come across this box before? What does it really do? Was it just an UHJ decoder? Is there a manual out there (searches in the www seem to come up with a lot of missed ebay sales of related things but nothing similar)? What are the hidden ICs? Will I be captured by random Denon executives? :yikes So many questions...
Any help would be gratefully received.
Sorry if there is another thread on topic; I searched and searched but might have missed something. Please put me right if I have.
The board is remarkably simple, with two ICs heatsinked and then shrink wrapped (presumably to hide the ICs from market forces), which seems a little odd to me. Why have a shrink-wrapped heatsink? It would be incredibly simple to come up with a circuit diagram - despite the slightly awkward soldering on the double-throw level pot (the earth seems to wander around the pins like a snake). I daren't take the shrink wrap off, just in case Denon's agents get me :alienrob: ...
I will see if I can add a photo at some point - it is, though, just a little wooden box, with a brushed aluminium front, on which sits a level knob and a on/off toggle switch, and a steel chassis, part of which acts as the rear panel, on which sits stereo-feed rca terminals and quad out rca sockets, a fuse holder and the power cable. The front has "Denon Universal Matrix Decoder / QXU-10" pantographed (screen printed) across the top (from the left had top edge).
I need to clean the pot (it is a bit scratchy) but everything else is fine - no cap crackles or any other pops and whistles.
It does add a little dimensionality to stereo but I wouldn't write home about it (wait a second, I live at home ...). I was hoping that it would have a little ambisonics magic but probably not.
I guess what I am asking is: Has anyone come across this box before? What does it really do? Was it just an UHJ decoder? Is there a manual out there (searches in the www seem to come up with a lot of missed ebay sales of related things but nothing similar)? What are the hidden ICs? Will I be captured by random Denon executives? :yikes So many questions...
Any help would be gratefully received.
Sorry if there is another thread on topic; I searched and searched but might have missed something. Please put me right if I have.