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pm
Joined: Aug 17, 2008 Posts: 9 Location: belgrade
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Posted: Wed Mar 13, 2013 10:09 am Post subject:
About to start building modular Subject description: part subs |
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Hi,
I'm about to start building your modular. I have a few questions:
1.Can I use (BC550C, MPSA18) instead of BC547C?
2.What parametar-s do I have to match transistors for?
3.What parametar do I have to match 1N4148 for?
4.Is BF245A OK for the random module?
5.Do I need to change R15 to 100k for the VCO if mat02 is used?
6.Any subs for 2SC1583 in the VCA modul?
Thank you |
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elmegil
Joined: Mar 20, 2012 Posts: 2177 Location: Chicago
Audio files: 16
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wmonk
Joined: Sep 15, 2008 Posts: 528 Location: Enschede, the Netherlands
Audio files: 15
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Posted: Thu Mar 14, 2013 7:32 am Post subject:
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Most substitutes are due to matched transistors. 2SC1583 and MAT02 are examples. Hand matched transistors will work equally well. Nowadays transistors from the same batch are already pretty close together.
You can use BC550 instead of BC547, I do it all the time. (Same with BC560 for BC557 for the PNP variants).
You need to match the transistors for equal Vbe (base emitter voltage). The document elmegil linked explains it well. It costs a bit of time, but it's way cheaper then buying MAT02.
For the 1N4148 diodes, match em on equal diode drop. This will be around 0.6V, and you can easily do that with a multimeter. The exact value doesn't matter, as long as they're close enough to each other, for instance within 1mV.
BF245A is okay in the random module. _________________ Weblog! |
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analog_backlash
Joined: Sep 04, 2012 Posts: 393 Location: Aldershot, UK
Audio files: 21
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Posted: Thu Mar 14, 2013 6:09 pm Post subject:
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I liked Ray Wilson's article/projects on transistor matching:
http://www.musicfromouterspace.com/analogsynth_new/TRANSISTORMATCHER/TRANSISTORMATCHER.html
The only trouble is, I don't have the kind of money that his test equipment costs (e.g. a BK Precision 5491A 50,000 count bench meter) so I was a bit more limited in my matching accuracy than Ray...
Gary
P.S. Am I the only person having problems with the latest MFOS site? I keep getting those "could not find and/or connect" type message, since his last update of the site. I've tried using Internet Explorer and Google Chrome as my browser and I get the same result. Is it just me? |
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capicoso
Joined: Nov 19, 2012 Posts: 128 Location: Argentina
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Posted: Thu Mar 14, 2013 8:34 pm Post subject:
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analog_backlash wrote: | I liked Ray Wilson's article/projects on transistor matching:
http://www.musicfromouterspace.com/analogsynth_new/TRANSISTORMATCHER/TRANSISTORMATCHER.html
The only trouble is, I don't have the kind of money that his test equipment costs (e.g. a BK Precision 5491A 50,000 count bench meter) so I was a bit more limited in my matching accuracy than Ray...
Gary
P.S. Am I the only person having problems with the latest MFOS site? I keep getting those "could not find and/or connect" type message, since his last update of the site. I've tried using Internet Explorer and Google Chrome as my browser and I get the same result. Is it just me? |
I'm fine running chromium, iron or firefox on linux |
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pm
Joined: Aug 17, 2008 Posts: 9 Location: belgrade
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Posted: Fri Mar 15, 2013 1:51 pm Post subject:
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Thank you very much.
What do you guys do for a DIY midi to CV?
I've built a lot of studio equipment (pres, compressors, eqs) but I'm not very much at home in the SDIY world.
Cheers |
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elmegil
Joined: Mar 20, 2012 Posts: 2177 Location: Chicago
Audio files: 16
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capicoso
Joined: Nov 19, 2012 Posts: 128 Location: Argentina
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Posted: Sat Mar 16, 2013 1:41 pm Post subject:
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pm wrote: | Thank you very much.
What do you guys do for a DIY midi to CV?
I've built a lot of studio equipment (pres, compressors, eqs) but I'm not very much at home in the SDIY world.
Cheers |
I made this one. http://m.bareille.free.fr/mcv628/mcv628.html
Easy, simple, stable...
Just 1 pitch CV and AUXCV for velocity or any midi message, 1 gate out... midi learn...
Pcb size is about 5x6cm. Uses 083x DACs. I couldn't find the REF01 so i had to replace it with a 431 and a trim pot to get a stable 10v ref.
The only thing(with most midi2cvs) is that you have to program the pic with the midi2cv code. Some electronic stores may do it for you |
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pm
Joined: Aug 17, 2008 Posts: 9 Location: belgrade
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Posted: Sun Mar 17, 2013 8:14 am Post subject:
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Thanks, but my programing skills are zero I'll just buy Doepfer Dark Link, I think it'll do for now.
Cheers |
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capicoso
Joined: Nov 19, 2012 Posts: 128 Location: Argentina
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Posted: Sun Mar 17, 2013 8:11 pm Post subject:
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pm wrote: | Thanks, but my programing skills are zero I'll just buy Doepfer Dark Link, I think it'll do for now.
Cheers |
Ok, but maybe you misunderstood me. You don't have to program it... with program i wanted to say burn. Burn the program(HEX file) to the pic. The creator of the midi2cv already programmed it, so you have to download that HEX file and copy it to the pic |
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pm
Joined: Aug 17, 2008 Posts: 9 Location: belgrade
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Posted: Mon Mar 18, 2013 3:33 am Post subject:
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That changes things a bit than.
MIDI to CV-Gate interface MCV876, from Paparail looks even better. |
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sebsongs
Joined: Feb 09, 2013 Posts: 49 Location: Malmö, Sweden
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Posted: Mon Mar 18, 2013 7:38 am Post subject:
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pm wrote: | That changes things a bit than.
MIDI to CV-Gate interface MCV876, from Paparail looks even better. |
I've purchased the MIDIMPLANT from a company in poland.
It has not been delivered yet but it seems really sweet.
http://www.midi-hardware.com/forums.html?section=prod_info&product=MIDimplant
I'll probably get it this week so I can let you know what I think then.
Sebastian |
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pm
Joined: Aug 17, 2008 Posts: 9 Location: belgrade
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Posted: Mon Mar 18, 2013 11:21 am Post subject:
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Thank you, I'm looking forward. |
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capicoso
Joined: Nov 19, 2012 Posts: 128 Location: Argentina
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Posted: Mon Mar 18, 2013 10:23 pm Post subject:
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pm wrote: | That changes things a bit than.
MIDI to CV-Gate interface MCV876, from Paparail looks even better. |
Yes, that one is very good. I'd have build it, but i like etching my own boards(i'd be happy buying a board from him and helping, but i can't)...
this is another good one http://www.acxsynth.com/midi2cv/midi2cvfr.htm |
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elmegil
Joined: Mar 20, 2012 Posts: 2177 Location: Chicago
Audio files: 16
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Posted: Mon Mar 18, 2013 10:47 pm Post subject:
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Hexinverter is planning to sell a PCB for a new/current version of the ACXSynth MIDI2CV, currently waiting on prototyping to finish. |
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sebsongs
Joined: Feb 09, 2013 Posts: 49 Location: Malmö, Sweden
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Posted: Fri Mar 22, 2013 4:52 am Post subject:
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pm wrote: | Thank you, I'm looking forward. |
I've tested the MIDIMPLANT now and it works perfectly.
It tracks within 0.5 cent over 5V.
I learned by using this product that the yusynth VCO also tracks really well over a 5V octave scale. I built the BC547 version.
So I can only recommend the MIDIMPLANT!
Totally worth the money! |
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