Hope no-one minds me asking about this stuff.
I’ve just picked up a cheap roland D5. Seems in reasonably good condition, and it’s fired up OK, however it’s got a couple of problems.
First of all, as expected, the backup battery was flat as a pancake. I’ve swapped it out, but I’m having troubble re-loading any patches; I’m using a one-way midi connection (At the moment, that’s all I’ve got enough kit for), and I’ve tried various patch banks with no success. The D5 default patch bank just came up with an error, and the one for the D10 worked better, but came up with a data mismatch.
The second, and more major problem, is the sound output. It doesn’t work. around half the time, it hits some sort of booting error, and produces a constant drone from the audio output, usually the same each time, but occasionally totally different in tone (it’s not just an even waveform or hum, it’s a bit of a more complex timbre). The rest of the time, there’s nothing at all. When I do get a tone through, the volume control etc. works fine, however it’s usually just out of one channel.
If you try and make it play a note, either using the keyboard, ROM play, or external MIDI, the system seems to hang. Otherwise, the interface seems pretty stable. I haven’t tested the MIDI ouput from the keyboard yet, as I’ve got to rig up something to test it with, however when the local midi connection is turned off, playing the keyboard doesn’t hang the system. It does hang on the keyboard test routine, though.
I’ve done a few basic tests; the voltage test points read correctly, and all the test routines listed in the service manual checked out as correct bar the audio output test and keyboard test (there’s a few dud switches, but I’ve got a load salvaged of some dead PCB or other that’ll work OK as replacements). I’ll check the audio path with a oscillioscope later on; I’m back home over christmas at the moment, and my scope’s up in my uni room. I’ve had a bit of a look at the schematic, and I suspect that there might be something up with the LA32 IC, which would be rather a nuicance.
Anyone any ideas of what might be up, or what’s worth checking?
Thanks in advance.
(PS; the service manual’s here: http://www.synfo.nl/servicemanuals/Roland/D-5_SERVICE_NOTES.pdf )
Done a little more testing; The midi output works fine, so I can use it for that, if nothing else (bit of a roundabout way I had to use to test it; I didn’t have anything with a midi input, so had to go through an arduino to alter the baud rate to something that the serial-midi software would accept). Hope everyone had a good christmas.
1: Is there a factory reset or some such procedure? Some synths don’t take kindly to garbage data after a battery change.
2: Get a proper MIDI interface. A cheap Chinese USB thingy will most likely not transmit SYSEX correctly.
3: Check it against the blacklist over at MIDIbox.org
4: Lots of synths like their MIDI to be bidirectional if you’re using an editor and not just a patch dumper.
5: Easy does it, if you dump sysex via C6 for instance you should put pauses between the packets.
1: There’s no reset procedure; I looked it up. There is for the d10/20 etc. but not the d5. I tried the d10 procedure, but no dice. There’s no patch names, but there are names for the timbres; don’t know if that means that the data for them’s correct, or just garbage.
2: When I tried to dump data to the synth, I was using unidirectional transfer via the MIDI out on a behringer UMA25S keyboard (that’s all I’ve got at present that’d do the trick). I’ve just ordered a couple of midi-usb interfaces; I’m afraid that they do definatly come under the classification of “Cheap Chinese USB thingy”, coming in at just over £5 including postage for the two. While I know they’re not going to be great, I figured they’d do for use as a midi keyboard (if they work), and my dad needed something for an old keyboard he had lying about too, so I’ll find a use for them somewhere. I’ll try and get hold of something better when I can; it’s just a question of budget. When I do, I’ll check it aginst the list on midibox. Didn’t know it existed before today.
4: When I was dumping data, I was only using unidirectional, but the pieces of software I tried (MIDI-OX and Bome’s SendSX) are just dumpers, not editors. I should probably have tried bidirectional transfer when I had it hooked through the arduino. Don’t know what the arduino will do with sysex; The program I wrote’ll have no trouble, as it just changes the baud rate and doesn’t touch the data. Don’t know about the software, though.
5: When I was sending the dumps, I throttled back the send rate as slow as it’d go. Not sure how to add pauses between packets using the software I used. I’ll might try C6 next time, see how that goes.
I’m a bit limited on kit at the moment, hence the rather bodged methods. I’ll try doing a sysex dump through the cheap adapters when they come through, but I don’t hold too much hope there. The electronics school at my uni runs a music, multimedia & electronics course, and they’ve got a bit of kit that I could probably blag use of as a one-off when I get back, so I’ll try that, too.
Thanks for the help.
You will get some mileage out of your cheaper USB MIDI interfaces for sure, they will handle playing and transmitting normal MIDI. Whatever was cloned either had Sysex filtering or never considered it. The blacklist is here - http://www.midibox.org/dokuwiki/doku.php?id=midi_interface_blacklist
Check the corresponding whitelist, there could be something cheap lurking there that might work. The C6 procedure ought to be described when talking about firmware updates or patch transfer for the Shruthi.
If you have a multimeter you can check that the opto isolator works for the MIDI port, amongst other things. If you’re lucky it’s just a straight swap. Ditto for any output opamp.
I have a cheap junk Chinese one that works fine with sysex. But even with two units that have an identical casing the insides can be totally different.
Just get an ESI MIDIMATE II if you want a cable-style USB to MIDI interface. Might not be the cheapest, but still extremely affordable.
Well, the cheap interface came through in the post; full marks on speed of delivery, 0 on functionality. can’t handle polyphonic note off messages. Based on that, I somewhat doubt there’s much chance of sysex working.
The midi self-test comes through correctly, so I’m pretty sure that the optocoupler’s fine. Output op-amps I’m not so sure; They’re in line for a test when I’ve got access to my scope.