Guest marr Posted August 6, 2004 Report Share Posted August 6, 2004 I have a Vermona analog drum unit on which the parameter values are all set by pots. (http://vermona.com/en/produkte/drm/drm1.html)I'd like to take some of them out and replace them with components I could control with the SEQ+AOUT.Does that seem like a feasible thing? Is a transistor the right thing to use and is it as simple as that or will there need to be more supporting circuitry? What is the resolution of the AOUT? Is it 0V or +5V only or can it be anywhere between @ 5/128th increments or what?(I'm a relative electronics newb but don't go easy on me; if you're generous enough to take the time to answer and I don't understand I'll go find a book.)many thanks Quote Link to comment Share on other sites More sharing options...
Guest marr Posted August 6, 2004 Report Share Posted August 6, 2004 I have a Vermona analog drum unit on which the parameter values are all set by pots. (http://vermona.com/en/produkte/drm/drm1.html)I'd like to take some of them out and replace them with components I could control with the SEQ+AOUT.Does that seem like a feasible thing? Is a transistor the right thing to use and is it as simple as that or will there need to be more supporting circuitry? What is the resolution of the AOUT? Is it 0V or +5V only or can it be anywhere between @ 5/128th increments or what?(I'm a relative electronics newb but don't go easy on me; if you're generous enough to take the time to answer and I don't understand I'll go find a book.)many thanks Quote Link to comment Share on other sites More sharing options...
chriss Posted August 6, 2004 Report Share Posted August 6, 2004 I'd like to take some of them out and replace them with components I could control with the SEQ+AOUT.  Does that seem like a feasible thing?so far as i can see the vermona is not supporting cv inputs, only triggers but you need cv inputs to control what the pot is doing know. And this is not very easy. maybe you find someone whow did this allready with the vermona but i wouldn´t experiment by myself. Its more than a transistor for sure. What is the resolution of the AOUT? Is it 0V or +5V only or can it be anywhere between @ 5/128th increments or what? The DAC has a resolution of 12bit and right at the moment the SEQ is supporting 7bit, that means you have 0 to 12 volt in 128 steps.chriss Quote Link to comment Share on other sites More sharing options...
chriss Posted August 6, 2004 Report Share Posted August 6, 2004 I'd like to take some of them out and replace them with components I could control with the SEQ+AOUT.  Does that seem like a feasible thing?so far as i can see the vermona is not supporting cv inputs, only triggers but you need cv inputs to control what the pot is doing know. And this is not very easy. maybe you find someone whow did this allready with the vermona but i wouldn´t experiment by myself. Its more than a transistor for sure. What is the resolution of the AOUT? Is it 0V or +5V only or can it be anywhere between @ 5/128th increments or what? The DAC has a resolution of 12bit and right at the moment the SEQ is supporting 7bit, that means you have 0 to 12 volt in 128 steps.chriss Quote Link to comment Share on other sites More sharing options...
moebius Posted August 6, 2004 Report Share Posted August 6, 2004 Hi. Sounds interesting :)You should get the schematics for your Vermona, as it might reveal control voltage insert points. Of course you can check function of the pots by measuring voltages (voltage diviner? variable resistor?)Anyway there are several different schemes for replacing pot with something voltage (or data) controllable:Yes, transistors will do sometimes . I don't remember the site, but it was 'bout adding velocity CV -> to PAiA Fatmans A(S)R.FETs: http://graffiti.virgin.net/ljmayes.mal/comp/vcr.htmVactrol (or similar) optos - warning, kind of slow.OTA's:http://www.uni-bonn.de/~uzs159/ota3080.htmlhttp://www.musicsynthesizer.com/DIY/Grant/OTA.htmlect.Digitally controllable resistors: Source code for a modified AOUT driver already exist.--- Yes, AOUT is capable of 12bit resolution, but MBSeq supports only 7bits, so it isn't optimal choise for doing this kind of thing..Bye, Moebius Quote Link to comment Share on other sites More sharing options...
moebius Posted August 6, 2004 Report Share Posted August 6, 2004 Hi. Sounds interesting :)You should get the schematics for your Vermona, as it might reveal control voltage insert points. Of course you can check function of the pots by measuring voltages (voltage diviner? variable resistor?)Anyway there are several different schemes for replacing pot with something voltage (or data) controllable:Yes, transistors will do sometimes . I don't remember the site, but it was 'bout adding velocity CV -> to PAiA Fatmans A(S)R.FETs: http://graffiti.virgin.net/ljmayes.mal/comp/vcr.htmVactrol (or similar) optos - warning, kind of slow.OTA's:http://www.uni-bonn.de/~uzs159/ota3080.htmlhttp://www.musicsynthesizer.com/DIY/Grant/OTA.htmlect.Digitally controllable resistors: Source code for a modified AOUT driver already exist.--- Yes, AOUT is capable of 12bit resolution, but MBSeq supports only 7bits, so it isn't optimal choise for doing this kind of thing..Bye, Moebius Quote Link to comment Share on other sites More sharing options...
Guest marr Posted August 9, 2004 Report Share Posted August 9, 2004 Thanks for the tips.. Found a good primer on digitally-controlled potentiometers by a Xicor engr here..The devices are either 3-wire, SPI, or a "similar to I2C" 2-wire..http://www.techonline.com/community/ed_resource/feature_article/11188 Quote Link to comment Share on other sites More sharing options...
Guest marr Posted August 9, 2004 Report Share Posted August 9, 2004 Thanks for the tips.. Found a good primer on digitally-controlled potentiometers by a Xicor engr here..The devices are either 3-wire, SPI, or a "similar to I2C" 2-wire..http://www.techonline.com/community/ed_resource/feature_article/11188 Quote Link to comment Share on other sites More sharing options...
Guest marr Posted August 9, 2004 Report Share Posted August 9, 2004 Related thread..http://www.midibox.org/cgi-bin/yabb/YaBB.cgi?board=midification;action=display;num=1080515779 Quote Link to comment Share on other sites More sharing options...
Guest marr Posted August 9, 2004 Report Share Posted August 9, 2004 Related thread..http://www.midibox.org/cgi-bin/yabb/YaBB.cgi?board=midification;action=display;num=1080515779 Quote Link to comment Share on other sites More sharing options...
moebius Posted August 9, 2004 Report Share Posted August 9, 2004 Hi,These topics might be helpful, if you haven't found them already:http://www.midibox.org/cgi-bin/yabb/YaBB.cgi?board=concepts;action=display;num=1074794017;start=0http://www.midibox.org/cgi-bin/yabb/YaBB.cgi?board=mios;action=display;num=1074625363;start=0Bye, Moebius/edit: ok, you found that one :) Quote Link to comment Share on other sites More sharing options...
moebius Posted August 9, 2004 Report Share Posted August 9, 2004 Hi,These topics might be helpful, if you haven't found them already:http://www.midibox.org/cgi-bin/yabb/YaBB.cgi?board=concepts;action=display;num=1074794017;start=0http://www.midibox.org/cgi-bin/yabb/YaBB.cgi?board=mios;action=display;num=1074625363;start=0Bye, Moebius/edit: ok, you found that one :) Quote Link to comment Share on other sites More sharing options...
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