DMX #s? I'm not sure what you mean. I was asking about the old AMS delay unit. I haven't dug into one for a while, and have an upcoming call where that will be one of the issues. I was wondering if someone had put the schematics up online, as with so much other stuff, but hadn't been able to find anything.
Each circuit card in an AMS is designated a number, for instance DMX 24 is a 16 bit ADC board, DMX 2 is a mono sampler board, etc. If you have a faulty unit and can figure out which board is at fault I may be able to help you out.
Originally posted by aurt DMX #s? I'm not sure what you mean. I was asking about the old AMS delay unit. I haven't dug into one for a while, and have an upcoming call where that will be one of the issues. I was wondering if someone had put the schematics up online, as with so much other stuff, but hadn't been able to find anything.
Last time I dealt w. them for docs it was $100 for a set. That only got me schems for the DMX-1580 S cards and some of the original 1580 cards. My 1580 as-built doesn't exactly match any of the card schems in the printed docs, but it's all they had.
And in all cases I didn't get any 'Theory of Operation' or troubleshooting or anything like that. Just raw card schematics.
The RMX-16 was a bit better and I haven't tried to get a full set for the DM 2.20. If someone has full DM 2.20 docs and/or docs for the original 1580 cards, I'd be happy to trade.
My solution was to buy another 1580 and troubleshoot by swapping cards.
The AMS service manual doesn't have any block diagrams or theory of operation section. It has, (or at least mine has) schematic drawings and PCB layouts only, plus a very large section on calibration and setup. I an not sure that they did service manuals for each unit, the manual I have has all their units in the one manual, probably as the delay and reverb share so many common parts. Along with the ECO updates it weighs in at 360 sheets so it is a big folder.
Somewhere in the distant past someone has taken the sheets for the reverb multiplier PCB from mine and lost them, so if anyone has a copy of the sheets for that PCB please let me know! Oldgearguy, if you happen to have these couple of sheets I am happy to trade you for others if I have them.
I haven't heard back from the client yet anyway. Last time I dealt with one of these on a regular basis, I seem to remember that it was very sensitive to card seating. It would come back after a bit of fiddling. I'm not sure if that's just that one, though. I figure I'll give that a try, and if it doesn't like me, I'll punt. Anyone know someone who specializes in these?
Much of what people think is bad card sockets is poor solder and hairline cracks on the tracks of the cards themselves, which also responds to wiggling the cards. The CPU clock crystal is a good candidate for cleaning the solder from it's connections to the PCB and replacing with fresh solder (not just re-soldering over the old solder). Something about that clock signal seems to do something to the solder, which I think wasn't very good quality to start with. Battery corrosion tracking around the board is another thing to look out for.