tashikoma Posted December 9, 2015 Report Share Posted December 9, 2015 (edited) Hi Midiboxers, Line driver breakout CV /gates finished i used AOUT and a tweeked DOUTx4 and of course the line driver receiver! DOUTx4 is stuffed with regular 220 ohm resistors for leds indicators and UDN2981 for gate booster. UDN 2981 are directly linked at the outputs of 74hc595 (before the 220ohm resistors) . the gates assigned to CV have two UDN 2981 (input in parallel) one is powered by 5V (eurorack 5V gates) and go to minijacks and the second is powered by 12V and go to 1/4jacks (oldschool 12V modular gates) same for the extra drum triggers gates: 8 are in 12V and the last 8 are in 5V...need 1k resistor at each outputs of UDN for ground short protection !!!! 3 PSU inside: 12V for 12V gates, 5V one for the 5V gates /line driver receiver/DOUT/AOUT and bipolar 12V for AOUT. the 5V line from the seq is cut on the receiver. i could have used the same 12V from bipolar but a dedicated 12v make sense cause wanted the AOUT "stability" as usual i've got a bug : the CV 1 and 2 have the same problem: at calibration voltage are divided by 2... don't know why...not the ICs , no shorts, ( problem on the 2 first channel!) all other 6 channel working properly. the calibration "max" voltage is 4V on this two channel is it possible to be a log error? i build AOUT because i've got max525 in stock... is someone use this config and could confirm that line driver work with AOUT? Edited January 10, 2016 by tashikoma config protection change 1 Quote Link to comment Share on other sites More sharing options...
TK. Posted December 10, 2015 Report Share Posted December 10, 2015 I don't remember exactly, but it could be that the Curve makes a difference - ensure that V/Oct is selected during calibration.Best Regards, Thorsten. Quote Link to comment Share on other sites More sharing options...
tashikoma Posted December 10, 2015 Author Report Share Posted December 10, 2015 Hi ThorstenYes V/oct is properly selected i tried also with other modes.the bug only affect the voltage range of channel 1 and 2 all others are goodsapproximately (calibration can't really be done):middle =2.5vmax =4.05v1v= 0.26V2V=0.55V4V=1.20V8V= 3.2VApproximately same range value for channel 1 and 2changed the max and tl074, same.resistors are in good place ...trimmers are from the same batch...less than 10cm core to line driver transmitter, less than 10cm receiver to AOUT Next test will be AOUT directly connected to the core. and voltage test of real high note.but it's not really a problem i could use this two channel for filters , 6 goods CV are available , it's perfect for my config! now everybody is using AOUT NG... Quote Link to comment Share on other sites More sharing options...
oozitron Posted December 27, 2015 Report Share Posted December 27, 2015 Wow, I was just looking for a way to boost the trigger outs (for my drum modules) as I am building the CV breakout unit for my Sequencer V4. Several of my drum modules need about 5 volts to fire them off. The UDN2981 looks like the perfect way to do this. Since I am not using any of the triggers for LEDs, can I just replace the 220R resistors with the UDN2981 chip? (and add power and ground connections of course) Are the 220R resistors even necessary if I'm triggering drum modules (or EGs, or advancing step sequencers, etc) ? Drew (thanks for sharing the UDN chip idea Tashikoma!) Quote Link to comment Share on other sites More sharing options...
tashikoma Posted December 28, 2015 Author Report Share Posted December 28, 2015 Hi Drew, (with pleasure! this is not my idea, it comes from somewhere in the forum ! don't remember) Quote can I just replace the 220R resistors with the UDN2981 chip? (and add power and ground connections of course) YES DOUT pins to UDN pins are connected without 220R resistors. if you have just 5v trigger drum module you could drive it directly from DOUT without the 220R and without UDN! UDN is a deluxe solution and protect 74hc595 outputs. a trig signal is little draw but with UDN outputs are stronger : you could drive a solenoid! (but not the big ones!) Have a good end of year! Nico Quote Link to comment Share on other sites More sharing options...
oozitron Posted January 6, 2016 Report Share Posted January 6, 2016 I run +/- 15 modular, and I thought (somewhere here on the site) that I read that +/- 15 volts will work fine with the AOUT board. Is that true? Should I adjust any of the resistor values for 15 volt use? Drew Quote Link to comment Share on other sites More sharing options...
tashikoma Posted January 8, 2016 Author Report Share Posted January 8, 2016 Hi oozitron Yes it works well with +/-15V Quote Link to comment Share on other sites More sharing options...
tashikoma Posted January 10, 2016 Author Report Share Posted January 10, 2016 (edited) ACHTUNG!!! ATTENTION!!! WARNING!!! Latigid on raised a bad point: UDN have no protections on outputs! not good if output is shorted to ground (as this happens every time you plug into a socket). so: 1k resistors after each UDN outputs do the job! Edited January 11, 2016 by tashikoma Quote Link to comment Share on other sites More sharing options...
latigid on Posted January 10, 2016 Report Share Posted January 10, 2016 I can think of one way to build this into a regular DOUT module; solder the UDN chip in standing up on one row, then wire through hole 1k resistors standing up on the other row. Connect in the middle, avoiding shorts of course. Comme toujours! But this looks to be a very good solution for level shifting multiple gates/clocks. CMOS chips like the 4504 and 7407 are an order of magnitude faster, but I don't think it's too relevant in our case. Plus these are hex chips with annoying pinouts and unnecessary /OE pins etc. Good job Nico! Quote Link to comment Share on other sites More sharing options...
tashikoma Posted January 11, 2016 Author Report Share Posted January 11, 2016 (edited) thanks Andy but i just use infos of the forum! (when i success to find them) great idea your building tip be carrefull of the package: UDN have extra millimeter in front and rear so i use extra sockets on half sockets to fit them! you need one pin space between each UDN it can't be equal to doutx4 or not in the same line..... exemple in simple form cause i can't explain in english: for four UDN (a - is one UDN): ---- not good - - - - good -_-_ good Edited January 11, 2016 by tashikoma Quote Link to comment Share on other sites More sharing options...
latigid on Posted January 11, 2016 Report Share Posted January 11, 2016 Okay, the datasheet gives 23.37mm long, is that what you have? So did you stagger the UDNs in the vertical dimension by spacing with extra sockets? Another way might be to put one chip on the top of the PCB, one on the bottom. You have to ensure the inputs and outputs are the correct way around and the power connections will also be mirrored. Also just to mention; Nico did a few tests with fault testing the UDNs like shorting to ground, bipolar (i.e. negative voltage) CV signals and connecting two UDN outputs together. Everything seems to be okay with the 1k resistors in place. It feels like this could be a more robust solution than using CMOS. Quote Link to comment Share on other sites More sharing options...
tashikoma Posted January 11, 2016 Author Report Share Posted January 11, 2016 the package i had is aprox 24.5mm long... 1 Quote Link to comment Share on other sites More sharing options...
latigid on Posted January 11, 2016 Report Share Posted January 11, 2016 Good to know! I have a PCB with some tight placement, so every mm counts! Quote Link to comment Share on other sites More sharing options...
Alasdair Moon Posted September 19, 2017 Report Share Posted September 19, 2017 I am happy that I found this, for I am building the CV/Gate breakout for my +-15 V Modular atm. I already finished the DOUTx4 with bridges and hope the gate/trigger-voltage is sufficient. The idea to add leds with the 220ohm is interresting too. Has someone some schematics on adding the UDN2981 if I have to boost my gates/triggers, please? Where do I have to add the 15V? Or is this too much and I should regulate it to 10V (I think this is the standard voltage on +-15V - yusynth modules generate mostly 10V gates) Confused *** Quote Link to comment Share on other sites More sharing options...
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