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jurekprzezdziecki
Joined: Mar 22, 2016 Posts: 68 Location: warsaw
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AlanP
Joined: Mar 11, 2014 Posts: 746 Location: New Zealand
Audio files: 41
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Posted: Tue May 10, 2016 2:08 am Post subject:
Re: Jurgen's Bergfors VCA build - DIY beginner needs help |
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jurekprzezdziecki wrote: |
also... this circuit uses only a half of LM13600 - so what to do with a second part of the LM13600? it's just unconnected? should be grounded? |
I'd say use the second half for a second VCA |
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jurekprzezdziecki
Joined: Mar 22, 2016 Posts: 68 Location: warsaw
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Posted: Tue May 10, 2016 2:10 am Post subject:
Re: Jurgen's Bergfors VCA build - DIY beginner needs help |
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AlanP wrote: | jurekprzezdziecki wrote: |
also... this circuit uses only a half of LM13600 - so what to do with a second part of the LM13600? it's just unconnected? should be grounded? |
I'd say use the second half for a second VCA |
thanks for your replay. i don't want to make it to complex, it's my first project
do you mean to make a second channel of this VCA? |
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LFLab
Joined: Dec 17, 2009 Posts: 497 Location: Rosmalen, Netherlands
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Posted: Tue May 10, 2016 6:12 am Post subject:
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Nope, a second VCA (was my suggestion on Muffs as well ). |
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wackelpeter
Joined: May 05, 2013 Posts: 461 Location: germany
Audio files: 10
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Posted: Tue May 10, 2016 6:25 am Post subject:
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i'm not sure if i did build it correct or wrong nearly 2 years ago, but i wasn't able to mute the signal totally... it was almost present and with some CV it got amplified more...
maybe try this on breadboard first... i've exchanged mine with 2 others VCA's...
But as i said, i'm not sure if i did some mistake, as these where some of my earlier modules and now the stripboards are plundered... _________________ https://soundcloud.com/bastian-j |
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jurekprzezdziecki
Joined: Mar 22, 2016 Posts: 68 Location: warsaw
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Posted: Tue May 10, 2016 6:43 am Post subject:
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LFLab wrote: | Nope, a second VCA (was my suggestion on Muffs as well ). |
got it:)) just reading! |
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jurekprzezdziecki
Joined: Mar 22, 2016 Posts: 68 Location: warsaw
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Posted: Tue May 10, 2016 6:44 am Post subject:
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wackelpeter wrote: | i'm not sure if i did build it correct or wrong nearly 2 years ago, but i wasn't able to mute the signal totally... it was almost present and with some CV it got amplified more...
maybe try this on breadboard first... i've exchanged mine with 2 others VCA's...
But as i said, i'm not sure if i did some mistake, as these where some of my earlier modules and now the stripboards are plundered... |
thanks! i will test it on breadboard first for sure. |
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jurekprzezdziecki
Joined: Mar 22, 2016 Posts: 68 Location: warsaw
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steved
Joined: Oct 07, 2015 Posts: 18 Location: usa
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Posted: Wed May 11, 2016 8:21 am Post subject:
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i built Bergfors VCA -1 (basically the same VCA )
( http://hem.bredband.net/bersyn/VCA/lm13600%20vca%201.htm )
i don't have any issue with totally muting the signal.
I have made two of these and am able to tune the CV offset / offset to get great results.
I am new to electronics..but i like to experiment - i left the second half of the 13700 disconnected for simplicity and everything sounds great.
I made my PCB using Fritzing - wish i used eagle.
good luck! |
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jurekprzezdziecki
Joined: Mar 22, 2016 Posts: 68 Location: warsaw
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Posted: Wed May 11, 2016 12:52 pm Post subject:
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steved wrote: | i built Bergfors VCA -1 (basically the same VCA )
( http://hem.bredband.net/bersyn/VCA/lm13600%20vca%201.htm )
i don't have any issue with totally muting the signal.
I have made two of these and am able to tune the CV offset / offset to get great results.
I am new to electronics..but i like to experiment - i left the second half of the 13700 disconnected for simplicity and everything sounds great.
I made my PCB using Fritzing - wish i used eagle.
good luck! |
thanks a lot for the reply. i new t electronics as well, it is my first project actually. i leave a second half of 13600 unconnected as well but if everything will be ok i will make a second channel of VCA.
you said 13700 - so you change the IC? i know they are similar but there is a difference, right? can i change them as well with no consequences?
can i import eagle schematics to Fritzing? |
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steved
Joined: Oct 07, 2015 Posts: 18 Location: usa
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Posted: Thu May 12, 2016 8:36 am Post subject:
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yes i used 13700 not 13600.
there is a difference, i think it is something with the bias current, but from what i read it doesn't make a difference in most circuits.
I could be wrong.
I use 13700 in VCF and VCA without any issue. 13700 was stocked on mouser but no 13600
i dont think you want to go from Eagle to Fritzing -
Fritzing is real easy to learn and start with, and easy to outgrow.
hope this is helpful - like i said, i am new and don't really know what i am doing ha |
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LFLab
Joined: Dec 17, 2009 Posts: 497 Location: Rosmalen, Netherlands
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Posted: Thu May 12, 2016 11:06 am Post subject:
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Oh yeah, stick with Eagle for sure, it's a learning curve for sure, but totally worth it if you are progressing into more complicated circuits.
I've never used 13600 myself, I think, but they should be interchangeable (13600 is a slightly lower spec, could indeed be the bias current Steve mentioned). |
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jurekprzezdziecki
Joined: Mar 22, 2016 Posts: 68 Location: warsaw
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Posted: Fri May 13, 2016 5:47 am Post subject:
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ok, so i will try to change the op amp just on the breadboard, let's see.
yes, eagle is very complex.. overhelming in some way but it's great indeed. |
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jurekprzezdziecki
Joined: Mar 22, 2016 Posts: 68 Location: warsaw
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Posted: Fri May 13, 2016 5:50 am Post subject:
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last thing - the pots used in the project should be logarithmic, right? not linear? |
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jurekprzezdziecki
Joined: Mar 22, 2016 Posts: 68 Location: warsaw
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steved
Joined: Oct 07, 2015 Posts: 18 Location: usa
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Posted: Mon Jun 06, 2016 4:27 pm Post subject:
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what are you feeding it for CV?
(i dont know if this is the right way to do it, but)
i tune mine in like this:
I send the envelope in to the cv input alone, and turn the cv offset to the point where i can not hear any pop when i hit play a note.
I next plug in my audio and turn it up until it starts to bleed with out CV input.
then i play with the two knobs until it works just right.
For me i run at +-12 v..
ill try and link my version of the schematic.. looks same as yours i think..
hope this helps. you may want to build one of the single transistor VCAs along with this so you can play around more!
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