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fonik
Joined: Jun 07, 2006 Posts: 3950 Location: Germany
Audio files: 23
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Posted: Wed Jan 23, 2008 12:01 am Post subject:
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unit-sound wrote: | i've bought a board a day ago, so once this is there, i might be able to lend it out to you. are you willing to share the pcb design ( as i'd like to make one for my modular as well) |
State Machine wrote: | Will see what we can do to get you up and running .... I have a spare of exactly the same one you have [db50] SO if it's damaged, I can part with one of mine for you |
Thomas Henry wrote: | fonik wrote: | and the LM7912 regulator gets really hot. |
Bummer! When I measured the current drain on mine, the -12V side drew virtually nothing, so something's up here.
Don't be offended, but double check the 26 pin connector and make sure you got the orientation correct. It's pretty easy to trace the ground, and +5V lines on the daughterboard as a check that you haven't flipped things. As I see it, that's the most likely cause of the symptoms you've observed. Next on the list would be a defective daughterboard.
Again, bummer! I really hope you can get this thing up and running.
Thomas Henry |
thank you all for taking care. you are very kind.
the LM7912 was a typo, i meant the LM7812. actually both regulators get hot with db50xg installed.
i measured the voltages at supply and ground pins of the installed daughterboard. the orientation is correct and ground and supply voltages are where they should be - except the +12 dropping to +7.5V.
anyway, i will review the layout today and try another LM7812 if needed.
i will let you know.
BTW i am working with MIDI for 20 years now. i still have a korg 03/rw GM sound module and i wonder how the db50xg sounds in comparison.
i got aware that the db50xg is not just a GM or XG soundcard, but a fully editable synthesizer (using the XGEditor software or sysex) - great... i could post a pdf of the sysex for all parameters, if desired. if one needs the editor PM me. _________________
cheers,
matthias
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Big Boss at fonitronik
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RF
Joined: Mar 23, 2007 Posts: 1502 Location: Northern Minnesota, USA
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Posted: Wed Jan 23, 2008 6:37 am Post subject:
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Update on the GM Voice using the 'Crystal' chipset daughterboard.
The general midi voices sound great - but I'm not finding anything extra. I am also (as Scott calls it) a midiot - so it's possible I'm just not trying the right things. Or, maybe it just doesn't have anything besides general midi?
I bought one of the db50xg boards (e-bay from from Shanghai) mentioned earlier on this thread but have only plugged it in briefly to make sure the board was working. I need to build up another circuit and enclosure as the db50xg does not fit neatly in my first effort. The Crystal daughterboard is about a third of the physical size of the db50xg.
Matthias - I am quite interested in working with the voices on the db50xg! I would love to see what you have! |
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Dan Lavin
Joined: Nov 09, 2006 Posts: 649 Location: Spring Lake, Mi, USA
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fonik
Joined: Jun 07, 2006 Posts: 3950 Location: Germany
Audio files: 23
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Posted: Wed Jan 23, 2008 7:48 am Post subject:
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again thanks for taking care.
the pins are labeled on the PCB. i checked them twice and i verified it by taking a closer look at the traces of the db50xg (which pins are connected on the db50xg, GND, +5V...). i obviously connected the board correct. i will post a close-up later today. _________________
cheers,
matthias
____________
Big Boss at fonitronik
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Dan Lavin
Joined: Nov 09, 2006 Posts: 649 Location: Spring Lake, Mi, USA
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Posted: Wed Jan 23, 2008 11:49 am Post subject:
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Fonik,
If the motherboard is fine w/o the db50XG attached and then pulls the voltages down when plugged in and the connector numbering is correct, I'm afraid your board is the problem. I would take up one of the other member's offers for a replacement board. Just for technical sake, could you take a reading on the board's +V and -V pins to its ground and see what impedance you can measure? I'm guessing you should see a low resistance. One of the other guys with that board can take a measurement and compare it to yours. |
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fonik
Joined: Jun 07, 2006 Posts: 3950 Location: Germany
Audio files: 23
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Posted: Wed Jan 23, 2008 2:44 pm Post subject:
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antman49443 wrote: | Fonik,
If the motherboard is fine w/o the db50XG attached and then pulls the voltages down when plugged in and the connector numbering is correct, I'm afraid your board is the problem. I would take up one of the other member's offers for a replacement board. Just for technical sake, could you take a reading on the board's +V and -V pins to its ground and see what impedance you can measure? I'm guessing you should see a low resistance. One of the other guys with that board can take a measurement and compare it to yours. |
great idea, dan!
i just ordered a spare board!
and here are the measurements:
with the board installed
+12V - GND - 8.55k
-12V - GND - 13.32k
+5V GND - 5.79k
just the bare board
+12V - GND - more than 20M!!!
-12V - GND - 4.6M!!!
+5V GND - 42.1k
could it be that there are cold solder joints? the header seems to have suffered from something and there is debris (i will clean it and reheat the solder joints tomorrow):
click for highres...
_________________
cheers,
matthias
____________
Big Boss at fonitronik
Tech Buddy at Random*Source Last edited by fonik on Thu Jan 24, 2008 5:02 am; edited 2 times in total |
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fonik
Joined: Jun 07, 2006 Posts: 3950 Location: Germany
Audio files: 23
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Posted: Wed Jan 23, 2008 2:48 pm Post subject:
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Thomas Henry wrote: | Don't be offended, but double check the 26 pin connector and make sure you got the orientation correct. |
BTW thomas, i feel not offended at all. things happen. thanks for your input. appreciated as allways!
i still remember when i once powered up my new built MFOS VCA and it did nothing, absolutely nothing - until i got aware of the missing ICs i forgot to put in their sockets _________________
cheers,
matthias
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Big Boss at fonitronik
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frijitz
Joined: May 04, 2007 Posts: 1734 Location: NM USA
Audio files: 54
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Posted: Thu Jan 24, 2008 10:50 am Post subject:
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Thomas Henry wrote: | Okay, attached is an .mp3 file of a song which illustrates just a fraction of what the GM-Voice is capable of ... | Is there by any chance a *.mid file of this available? I'd like to try it out with my Roland 1080's GM for comparison. Thanks!
Ian |
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fonik
Joined: Jun 07, 2006 Posts: 3950 Location: Germany
Audio files: 23
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Posted: Thu Jan 24, 2008 1:24 pm Post subject:
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i replaced the LM7812, cleaned the header on the db50xg and checked the contacts/joints. nothing changed, the regulator still gets hot as soon as the daughterboard is inserted and the voltage drops to 7.5V.
when the daughterboard is not connected to the GMvoice circuit i measure about -10V at the outputs of the buffers. at the actual output sockets i measure an slowly oscillating offset voltage. is this as it should be considering the 2uF caps?
the 2nd db50xg board is on it's way... _________________
cheers,
matthias
____________
Big Boss at fonitronik
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Dan Lavin
Joined: Nov 09, 2006 Posts: 649 Location: Spring Lake, Mi, USA
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Posted: Thu Jan 24, 2008 1:35 pm Post subject:
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Fonik,
State Machine and I were discussing your issue and both feel that the problem could be the electrolytic cap input to the db50XG. When they go bad, they will pull a whole bunch of current and drag the voltage down. I don't know how comfortable you are with surface mount components, but the caps are fairly large (at least compared to other parts around)so they are not too bad to work on. It will be between +12V and Gnd near the connector. I'm sure it's one of those shown in the picture you posted. It may be the one marked "+ , 47 and 16V" although that one may be -12V input cap. |
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fonik
Joined: Jun 07, 2006 Posts: 3950 Location: Germany
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Posted: Thu Jan 24, 2008 1:46 pm Post subject:
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great, boys!
i measured them and my peaktech says they are working as expected - except the upper right one (47uF, 6V): here i read 58uF. the ratio is not quite the same but it looks relevant for a dilettante like me _________________
cheers,
matthias
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Big Boss at fonitronik
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Dan Lavin
Joined: Nov 09, 2006 Posts: 649 Location: Spring Lake, Mi, USA
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Posted: Thu Jan 24, 2008 2:27 pm Post subject:
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Fonik,
Well the 47/6V unit wouldn't be rated for 12V, it is probably for the +5V line. Tolerances on elec. caps are usually fairly large, plus the rest of the circuit, 58uF wouldn't be bad. The problem might not show up until the cap is energized. Try removing the +12V line input cap and see if the board works. If it does, just buy a replacement cap. If not, well you've at least eliminated one possibility. It's like doing first aid on someone not breathing and no heartbeat....he's already dead...you're not going to kill him any more! |
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fonik
Joined: Jun 07, 2006 Posts: 3950 Location: Germany
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Posted: Thu Jan 24, 2008 2:52 pm Post subject:
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antman49443 wrote: | Fonik,
Well the 47/6V unit wouldn't be rated for 12V, it is probably for the +5V line. |
in this case the 47/6V are positioned right after these SOT89 components that my are 5V regulators...
Quote: | Tolerances on elec. caps are usually fairly large, plus the rest of the circuit, 58uF wouldn't be bad. The problem might not show up until the cap is energized. Try removing the +12V line input cap and see if the board works. If it does, just buy a replacement cap. If not, well you've at least eliminated one possibility. It's like doing first aid on someone not breathing and no heartbeat....he's already dead...you're not going to kill him any more! |
good idea. unfortunately i will not be able to work on that before saturday...
i'll keep you posted. _________________
cheers,
matthias
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Big Boss at fonitronik
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State Machine
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Joined: Apr 17, 2006 Posts: 2809 Location: New York
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Posted: Fri Jan 25, 2008 5:49 am Post subject:
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Quote: | State Machine and I were discussing your issue and both feel that the problem could be the electrolytic cap input to the db50XG. |
Dan,
Thanks for posting this. I meant to do that. been busy at work ..... Fonik, yes, please let us know your outcome.
Also, the fact that 12V is the bus that misbehaving may make it easier for the repair since all the logic is likely powered by the 5V bus. If the capacitor does not do it for you, then it might be one of just a few components that use this voltage. I know this becomes difficult without any schematic as you are mostly relegated to just educated "guess work".
Bill |
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Dan Lavin
Joined: Nov 09, 2006 Posts: 649 Location: Spring Lake, Mi, USA
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Scott Stites
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Joined: Dec 23, 2005 Posts: 4127 Location: Mount Hope, KS USA
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Posted: Sat Jan 26, 2008 3:15 pm Post subject:
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Quote: | Update on the GM Voice using the 'Crystal' chipset daughterboard.
The general midi voices sound great - but I'm not finding anything extra. I am also (as Scott calls it) a midiot - so it's possible I'm just not trying the right things. Or, maybe it just doesn't have anything besides general midi?
I bought one of the db50xg boards (e-bay from from Shanghai) mentioned earlier on this thread but have only plugged it in briefly to make sure the board was working. I need to build up another circuit and enclosure as the db50xg does not fit neatly in my first effort. The Crystal daughterboard is about a third of the physical size of the db50xg.
Matthias - I am quite interested in working with the voices on the db50xg! I would love to see what you have! |
Hey RF,
Do you by any chance have MIDI-Ox (and MIDI-Yoke) yet? That's been helping me cure my midiocy, a little bit at a time. If you have a link from your computer to MIDI, MIDI-Ox/Yoke is a great way to make the GM jump through hoops, I think, plus it does a lot more.
For example, you can filter messages in special ways - one can create a split keyboard with it, for example (you could do something different with each key if you want).
Another example is that, though I wish it would do more, the pitch bend on my SH-201 will only affect, well, the pitch of both oscillators for the voice(s) it's assigned to. I thought it would be cool to control other things with it, like filter cutoff. No problemo, I just used the SH-201 to not send pitch bend data to a voice and from there I had MIDI-Ox translate the pitch bend data to to cutoff CC, and badda-bim, badda-bam, my pitch bend now controls filter cutoff instead (if I want it to). Or, for that matter, any CC-able parameter. In fact, I did the same thing with the modulation control. As another example, SH-201 has sync, but no facility (beyond the VCO EG) to move the pitch of the synced oscillator (the VCO EG is only like two octaves). I just assigned the pitch CC for VCO1 to the bend control (or modulation, also) and it'll bend all you want, though, with an SH-201, it'll get a bet steppy. Still, it's a whole realm the SH-201 wouldn't go to before....MIDI-Ox.
Take a look around for Soft Step V1.3 - it's free, and it'll step sequence the bejesus out of your GM voice. It'll do everything but Klee sequencing. Probably even that if you think about it long enough.
I'm lovin' it.
Cheerio,
Scott _________________ My Site |
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frijitz
Joined: May 04, 2007 Posts: 1734 Location: NM USA
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Posted: Sun Feb 03, 2008 12:30 pm Post subject:
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Hmmm ... so I guess that's a "no", right.
Ian |
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fonik
Joined: Jun 07, 2006 Posts: 3950 Location: Germany
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Posted: Thu Feb 07, 2008 2:29 pm Post subject:
Subject description: trouble with the 12V reg on my motherboard... |
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i received two spare db50xg boards from shanghai yesterday. i tried one and guess what: same effect as the first one. the 12V regulator gets hot and i see only about 8V as soon as the daughterboard is connected.
now the sensational news: first i heard no sound as before. then i tried the reset switch, and as long as i pressed that momentary switch it worked. i measured the switch and recognized that it s normally closed and opens when pushed! never had such a switch before!
so what about the 12V? i am powering the module from a very cheap chinese switching supply (+15V/com/-15V). it is rated at 800mA for each rail. could this affect the 12V regulator on my motherboard as soon as the db50xg draws current?
maybe the supply is much weaker than 800mA, who knows... i will try my cabinets power one on weekend. _________________
cheers,
matthias
____________
Big Boss at fonitronik
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blue hell
Site Admin
Joined: Apr 03, 2004 Posts: 24083 Location: The Netherlands, Enschede
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Posted: Thu Feb 07, 2008 3:09 pm Post subject:
Subject description: trouble with the 12V reg on my motherboard... |
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fonik wrote: | i measured the switch and recognized that it s normally closed and opens when pushed! never had such a switch before! | [/quote]
But I had such a switch as well, just a few weeks ago some software was not working properly it seemed, but the damned switch was inverted
When chinese PSUs use the same type of Watts as are used for chinese computer speakers the actual output drive capability will probably be 0.8 mA (And I'd check it for danger of electrocution as well ...)
Ok serious mode on again ... is it a switched mode power supply? Sometimes the over / under current protection is only present in one of the outputs and that can act weird. _________________ Jan
also .. could someone please turn down the thermostat a bit.
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fonik
Joined: Jun 07, 2006 Posts: 3950 Location: Germany
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Posted: Fri Feb 08, 2008 5:28 am Post subject:
Subject description: trouble with the 12V reg on my motherboard... |
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Blue Hell wrote: | ... is it a switched mode power supply? Sometimes the over / under current protection is only present in one of the outputs and that can act weird. |
why would the regulator on the motherboard get hot then (it is rated up to 1000mA)?
for now i mounted a heatsink and will investigate further on weekend. _________________
cheers,
matthias
____________
Big Boss at fonitronik
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Dan Lavin
Joined: Nov 09, 2006 Posts: 649 Location: Spring Lake, Mi, USA
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Posted: Fri Feb 08, 2008 9:59 am Post subject:
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Matthias,
It seems now, you'll want to concentrate your efforts on your motherboard. Maybe your motherboard has a short somewhere? Or perhaps your capacitor on the +15V input line isn't performing? Definitely look along the +V and +5V lines.
If you want me to check over your pcb artwork as a second set of eyes, feel free to PM me. |
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fonik
Joined: Jun 07, 2006 Posts: 3950 Location: Germany
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Posted: Fri Feb 08, 2008 12:31 pm Post subject:
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you are such a great troop! _________________
cheers,
matthias
____________
Big Boss at fonitronik
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blue hell
Site Admin
Joined: Apr 03, 2004 Posts: 24083 Location: The Netherlands, Enschede
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Posted: Fri Feb 08, 2008 3:10 pm Post subject:
Subject description: trouble with the 12V reg on my motherboard... |
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fonik wrote: | why would the regulator on the motherboard get hot then (it is rated up to 1000mA)? |
Had missed that part, really wouldn't know _________________ Jan
also .. could someone please turn down the thermostat a bit.
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RF
Joined: Mar 23, 2007 Posts: 1502 Location: Northern Minnesota, USA
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Posted: Fri Feb 08, 2008 8:20 pm Post subject:
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Scott Stites wrote: | If you have a link from your computer to MIDI, MIDI-Ox/Yoke is a great way to make the GM jump through hoops, I think, plus it does a lot more.
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Scott - I've never used midi before so have no computer to midi interface. I may make one in the future - but for now I am using the GM Voice stand-alone with a basic midi keyboard controller. If I pursue midi sequencing etc. I'll keep those programs in mind.
Thanks in part to you and Thomas I'm still waist deep in unfinished analog projects, Scott.
Dan - I appreciate the list of voices - thanks for that.
Glad you are making some headway, Matthias.
bruce |
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Dan Lavin
Joined: Nov 09, 2006 Posts: 649 Location: Spring Lake, Mi, USA
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Posted: Tue Feb 26, 2008 1:28 pm Post subject:
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Hi Gang!
Here's a couple more daughterboard possibilities:
1. Try looking for Turtle Beach Cancun FX and Rio daughterboards on ebay, etc. I believe they used the "Dream" chipset. The Rio is 4MB. Also try looking for the Monterey which = tahiti + Rio. Throw away the tahiti or resell it and you still have the Rio!
2. It seems daughterboards are also available in Thailand. Apparently they are mostly used for Karaoke machines!? Makes sense: music=midi file. THe machine is basically a midi file player.
One company is Tahorng Music Instruments. Another is Final Extreme. They make a 1MB, 4MB and 32MB daughterboards.
The 1MB board is based on the Dream chipset and is 32 voice
The 32MB board is also based on the Dream chipset and is 48 voiced.
Interestingly, the 4MB board is 64 voice and is Roland Sound Canvas SCC-1 compatible 18 bit. The website says they have a license from Roland. That might be the best of their boards if so.
I found one dealer selling the 4MB Tahorng for US$87.87 and a 32MB Final Extreme for US$148.47. I have not found any western dealers for these, though. |
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