TK.

Hi, the 1N4733 (A821) is a 5.1V zener the 1N4738 (A604) the 8.2V zener (I used google to find the specs) Take care for the polarity of the diodes! Best Regards, Thorsten.

You are using motorized faders with the MIDIbox Plus firmware? Did you solve the problem in the meantime? Best Regards, Thorsten.

Hi, I will update the schematics and PCB layouts in the next days due to some quality improvements. Hold the line :) External power pack: w/o LCD the MIDIbox8 consumes about 50 mA - so a battery with 6V, 1000mA/h or more should be ok Best Regards, Thorsten.

Yes, the x-mas and NYe break was fine, but a little bit to long ;-) Where can I download a datasheet for the LC7981-type display? From my experience international requests are handled very slowly by Reichelt, because they know that normaly people will not order there due to the high shipping fees... Schaeffer Apparatebau definitely ships to the UK for EUR 16.70 (see website) Best Regards, Thorsten.

Memon: the LCD graphic layout is not final ;-) I've planned to add a field for the LED digits of the Logic Control (which normaly display the fader mode and the MTC). However, everybody is welcome to create his own skin :) (for example a big MTC display mode could be usefull) Best Regards, Thorsten.

With the help of you I can also write drivers for other graphic LCD displays which are available at Ebay or somewhere else. US people should take a look at http://www.eio.com/lcdprodt.htm where 240x64 displays with another controller chip are available for about US $30 It's really difficult to estimate the costs for the whole MIDIbox, since the designs can be very different. For example, if the motorfaders are too much expensive, they can be replaced by common faders and could also be served by the PIC18F core module (with enabled snap/soft-takeover function!). However, here the estimated costs for my implementation: ca. 100 EUR - electronic stuff (2 CORE, 4 DINX4, 3 DOUTX4, 1 MF, 1 LTC) 66.00 EUR - graphic LCD display 28.80 EUR - 64 high quality buttons 03.20 EUR - 32 Miniature buttons 08.00 EUR - ca. 160 LEDs 22.50 EUR - 9 ALPS rotary encoders 176 EUR - 8 ALPS motorfaders (note: panasonic faders are much cheaper!) ca. 90 EUR - premade frontpanel from Schaeffer Apparatebau ca. 8 EUR - nice looking wooden box (30x40x7) from Obi (a german DIY market chain) makes about 500 EUR The price can be reduced by following meassures: motorfaders replaced by non-motorized faders (saves also one core module) no LED rings (makes the frontpanel simpler) selfmade frontpanel In this case the price can be reduced to about 200 EUR Best Regards, Thorsten.

I would like to say Merry Christmas and a happy New Year to everyone! C U next year :) Best Regards, Thorsten.

The same link for you: see the "internal resistor" section under http://www.nzart.org.nz/nzart/examinat/amateur%20radio%20study%20guide/Course%20Files/Power%20Supplies/STUDY%20NOTES%20-%20POWER%20SUPPLIES.htm Best Regards, Thorsten.

Hi Justin, yes, your transformer works correctly. The voltage falls due to the internal resistance of the transformer - see also: http://www.nzart.org.nz/nzart/examinat/amateur%20radio%20study%20guide/Course%20Files/Power%20Supplies/STUDY%20NOTES%20-%20POWER%20SUPPLIES.htm The internal resistance is the reason why we are using a 7805 to regulate the supply voltage Vdd for the PIC. To your problem: if every tweak fails the only way to get it running is the use of another optocoupler. If I only had known that the CNY17 causes so much trouble, I had replaced it by a better optocoupler years before the first PCB layouts were released :-/ You could try the 6N138 circuit from the MBHP - if this works better with your synth, it's time for me to add a big warning to the MIDIbox Plus page Best Regards, Thorsten.

Hi Justin, yes, your transformer works correctly. The voltage falls due to the internal resistance of the transformer - see also: http://www.nzart.org.nz/nzart/examinat/amateur%20radio%20study%20guide/Course%20Files/Power%20Supplies/STUDY%20NOTES%20-%20POWER%20SUPPLIES.htm The internal resistance is the reason why we are using a 7805 to regulate the supply voltage Vdd for the PIC. To your problem: if every tweak fails the only way to get it running is the use of another optocoupler. If I only had known that the CNY17 causes so much trouble, I had replaced it by a better optocoupler years before the first PCB layouts were released :-/ You could try the 6N138 circuit from the MBHP - if this works better with your synth, it's time for me to add a big warning to the MIDIbox Plus page Best Regards, Thorsten.

The 25V are caps ok. The 2200uF/16V cap is also ok so long as you don't use an AC supply. perfect! Hmmm... the CNY17-II is the most crictial part of the MIDIbox Plus, some people noticed problems with the MIDI In and had to tweak the pull-up resistor. I've no experiences with the CNY17-I --- it could cause problems. However, if MIDI-In doesn't work, just switch to the 6N138 circuit which works much better. should work. The 8.2V zener can also be found in the original schematic; most people are using this diode w/o problems. Best Regards, Thorsten.

The 25V are caps ok. The 2200uF/16V cap is also ok so long as you don't use an AC supply. perfect! Hmmm... the CNY17-II is the most crictial part of the MIDIbox Plus, some people noticed problems with the MIDI In and had to tweak the pull-up resistor. I've no experiences with the CNY17-I --- it could cause problems. However, if MIDI-In doesn't work, just switch to the 6N138 circuit which works much better. should work. The 8.2V zener can also be found in the original schematic; most people are using this diode w/o problems. Best Regards, Thorsten.

After one day playing with a almost complete LC emulator I must say: I've found for what I'm looking for :D But still some effort is necessary to program an alternative mode which allows the use of the controller without help of a host application... LCD: yes, it's a "Displaytech 64240A" for 66 EUR - I love those Displaytech LCD's because of the high quality. :) But for people outside Germany I cannot recommend to buy the stuff at Reichelt due to the high shipping costs to foreign countries of about 35 EUR! Please post here if you know any alternative distributors for Displaytech products or KS0108 compatible displays Best Regards, Thorsten.

For everybody who is interested in making his own Logic/Mackie Control: here are some insights in the current development state. Yesterday I got the graphic LCD and started to write the PIC18F driver. I noticed that the performance is much better than expected, mostly the chip is in idle state, and the LCD can be served very fast due to the new instructions (i.E flash read is appr. 32 times, multiplications appr. 50 times faster!). So I'm assuming that beside of the display all encoders and buttons can also be handled by one PIC18F --- the MIDIbox NG design phase begins right now (ok, next year, because I'm not at home in the next days... ;-)) The next interesting notice I made was, that the resolution of the LCD (240x64) is good enough for this application. All characters are displayed in a 3x8 font. Not all chars are looking aesthetical (especially the small letters like "m" and "w"), but can be read without problems. Here some snapshots (sorry for the bad picture quality): The surface I plan to reallize looks different from the original design, because I'm planning to use it also with other applications (Reaktor): Maybe I will add some more buttons at the right upper edge... And finally here the current state of this surface - far from perfection, but everything is working well :) Best Regards, Thorsten.

For everybody who is interested in making his own Logic/Mackie Control: here are some insights in the current development state. Yesterday I got the graphic LCD and started to write the PIC18F driver. I noticed that the performance is much better than expected, mostly the chip is in idle state, and the LCD can be served very fast due to the new instructions (i.E flash read is appr. 32 times, multiplications appr. 50 times faster!). So I'm assuming that beside of the display all encoders and buttons can also be handled by one PIC18F --- the MIDIbox NG design phase begins right now (ok, next year, because I'm not at home in the next days... ;-)) The next interesting notice I made was, that the resolution of the LCD (240x64) is good enough for this application. All characters are displayed in a 3x8 font. Not all chars are looking aesthetical (especially the small letters like "m" and "w"), but can be read without problems. Here some snapshots (sorry for the bad picture quality): The surface I plan to reallize looks different from the original design, because I'm planning to use it also with other applications (Reaktor): Maybe I will add some more buttons at the right upper edge... And finally here the current state of this surface - far from perfection, but everything is working well :) Best Regards, Thorsten.

No - you got exactly the right ones :) Best Regards, Thorsten.

No - you got exactly the right ones :) Best Regards, Thorsten.

The MB16E not only supports encoders, but also 64 buttons, like the other firmwares. So, for the traktor control surface the combination of two core modules, one running with MB64, the other with MB16E, was the ideal solution. Concerning MIDIbox NG: please read the news section, where the details are listed! Yes, the MIDIbox NG firmware will allow to handle with encoders and pots in a single core application - everything will become easier and cheaper :) But I think that first of all you should explore the news section of this forum and my website, because the answers to your questions can already be found there. It's important that you understand the possibilities and the principle of the projects before you begin with the realization, this will help you to plan the ideal controller for your needs. Best Regards, Thorsten.

The MB16E not only supports encoders, but also 64 buttons, like the other firmwares. So, for the traktor control surface the combination of two core modules, one running with MB64, the other with MB16E, was the ideal solution. Concerning MIDIbox NG: please read the news section, where the details are listed! Yes, the MIDIbox NG firmware will allow to handle with encoders and pots in a single core application - everything will become easier and cheaper :) But I think that first of all you should explore the news section of this forum and my website, because the answers to your questions can already be found there. It's important that you understand the possibilities and the principle of the projects before you begin with the realization, this will help you to plan the ideal controller for your needs. Best Regards, Thorsten.

Did you buy linear or logarithmic pots/faders? (Part-Number?) Because based on your description it seems that these are the log ones and they are not accurate for the MIDIbox :-/ Best Regards, Thorsten.

Did you buy linear or logarithmic pots/faders? (Part-Number?) Because based on your description it seems that these are the log ones and they are not accurate for the MIDIbox :-/ Best Regards, Thorsten.

Do you notice a flickering of the pot values, or do you see unwanted MIDI events (i.E pitch bender, Aftertouch) although these events haven't been assigned to the pots/buttons. In both cases this could be related to the power supply. The core voltage should be about 5V, lower voltages can cause problems with the MIDI transfer (...and much higher voltages kill the chip!) Best Regards, Thorsten.

Do you notice a flickering of the pot values, or do you see unwanted MIDI events (i.E pitch bender, Aftertouch) although these events haven't been assigned to the pots/buttons. In both cases this could be related to the power supply. The core voltage should be about 5V, lower voltages can cause problems with the MIDI transfer (...and much higher voltages kill the chip!) Best Regards, Thorsten.

The knobs are great - I will order some (you've got mail :)) Best Regards, Thorsten.

The knobs are great - I will order some (you've got mail :)) Best Regards, Thorsten.