KOMA Elektronik SVF-201 Vactrol Filter.

Discussion and support for KOMA Elektronik effects pedals, eurorack gear and all the other stuff we do...

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tektoktiktak
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Re: KOMA Elektronik SVF-201 Vactrol Filter.

Post by tektoktiktak » Wed Aug 21, 2013 3:15 am

fragletrollet wrote:
premieklovn wrote:I just got back from a KOMA Elektronik showcase in Oslo and they showed us a prototype of their new eurorack multimode vactrol filter. It is the same filter as in their FT-201 pedal. Lovely!

Say what, KOMA Elektronik showcase in Oslo`?

Where was it? And where can I find info about this in the future?

I want to get into the wiggler scene in Oslo, didn`t know there was one allready!
We hosted a test salon in Oslo in end of last year at the venue Blå. Some of the KOMA artists were there (Serena Maneesh, 120 Days) and we were mainly showing new pedals, modules and a few prototypes... Usually we keep you up to day via our newsletter and our facebookpage (http://www.facebook.com/KOMAelektronik).

Here are the photos of our time in Oslo: https://www.facebook.com/media/set/?set ... 003&type=3

In october we'll be in Stockholm for a test salon and even a performance night and some good KOMA drinking ;-). I know its not around the corner, but that will definitely be your next chance!
http://www.koma-elektronik.com

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fragletrollet
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Post by fragletrollet » Wed Aug 21, 2013 6:38 am

Such a pity! I live 5min from Blå...

Themaybemachine
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Post by Themaybemachine » Thu Jul 10, 2014 6:50 am

I got one with my first modular setup, the only disappointment I have with it compared to others filters I have is that the lowest resonance setting is still very high. I got this second hand Is there a dail on the back that can adjust this ?

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Post by osterchrisi » Fri Jul 11, 2014 4:59 am

Hello, machine. There is a trimmer on the backside to adjust the resonance ("Q") but it is set at the factory to the best results. It also affects the frequency response of the filter as a whole. It could be though that someone tampered with it before it got sold. When you look at the four trimmers in the back of your SVF-201, do they all sort of look to have the same setting?

Themaybemachine
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Post by Themaybemachine » Thu Aug 14, 2014 8:36 am

yeah they are kinda in the same position, I really love the sound as is, its just when I do fast envelopes I get extra kick sound because of the resonance sweep. I am used to Moog filter and when you sweep with a low Q its very neutral. The koma seems to always have a little peak.

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mrtweed
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Post by mrtweed » Sun Nov 02, 2014 5:17 pm

just ordered one of these thanks to the 20% discount koma are running at the moment. can't wait!

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C14ru5
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Post by C14ru5 » Wed Mar 11, 2015 3:57 pm

The link to the KOMA SVF-201 X-Mas LED modification gives a 404 error
http://www.koma-elektronik.com/merry-christmas-our-x-mas-hack/

Can anyone provide the details on how the modification is done?

EDIT:
I was able to find the instructions on the Internet Archive, but not the important image that shows where "point A to point B" is... so I would love to get some help with this!
If you pull the two PCBs of the SVF-201 apart and look at it from the top, all that you have to do is:
  • - Turn off your system’s power
    - Remove the jumper for the ‘Corona’. This disconnects the LED from the fixed voltage source so we can connect another signal to the LED.
    - Solder a short cable/wire from point A to point B (click here for a Hi-Res photo).

tektoktiktak
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Post by tektoktiktak » Wed Mar 18, 2015 9:53 am

This is what we posted online:

The KOMA SVF-201 Corona backlight hack. Make the LED's behind the Cutoff knob respond to the actual Cutoff Control Voltage!

Christian: So, I thought I'll take a lead in this because sooner or later the question would pop up anyway. So the circuit for the LED corona around the Cutoff knob is pretty straight forward. A fixed voltage source, a resistor and a LED resulting in a permamently lit LED. Now what, if you wanted to exchange the fixed voltage source for a changing one, like the voltage that controls the cutoff of the filter circuit? Answer: still pretty straight forward!

So here's how this goes: If you pull the two PCBs of the SVF-201 apart and look at it from the top, all that you have to do is:

Turn off your system's power

Remove the jumper for the 'Corona'. This disconnects the LED from the fixed voltage source so we can connect another signal to the LED.
Solder a short cable/wire from point A to point B (see attachment for the photo).

Done!

PLEASE MAKE SURE YOU REMOVED THE JUMPER BEFORE TURNING ON THE POWER AGAIN!

And here's how this looks like: https://www.youtube.com/v/LG8IIrMlE3s

And here is the image:

Image
http://www.koma-elektronik.com

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tektoktiktak
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Post by tektoktiktak » Wed Mar 18, 2015 9:55 am

C14ru5 wrote:so I would love to get some help with this!
sorry it took so long before we responded, we are usually wayy quicker via support@koma-elektronik.com!

Happy modding! :yay:
http://www.koma-elektronik.com

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C14ru5
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Post by C14ru5 » Wed Mar 18, 2015 10:04 am

Well, this wasn't exactly a question of life or death (and strictly not a support issue either). So I thought I'd post the question here in case some other users had already performed the operation, and simultaneously put some pressure off the official KOMA support channel.

Nevertheless, it's wonderful that you took the time to respond here! :)

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Roy72
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Post by Roy72 » Sun May 03, 2015 5:55 am

I just picked one of these up - I am curious what the microprocessor does?

Great filter btw.

tektoktiktak
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Post by tektoktiktak » Sun May 03, 2015 2:08 pm

Roy72 wrote:I just picked one of these up - I am curious what the microprocessor does?

Great filter btw.
thanks! the microprocessor controls the MIX Out.
http://www.koma-elektronik.com

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Geordsta
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Post by Geordsta » Wed Jul 01, 2015 2:51 am

Just recently picked this filter up and am having some issues with it, I was wondering if anyone has encountered a similar thing. I've emailed Koma but figured I'd ask here as well for double the knowledge.

For the most part I can't get sound out of the filter, I have checked my osc, vca etc. and everything is fine, the module seems to be powered fine (the light is on) however it will only output very quiet unaffected signal (with input gain at full) out of the Low Pass output and a slightly louder unaffected signal out of the High Pass output, I can hear the osc but the filter and resonance do nothing.

I tried it in my friends rack and it worked as it should but only when the cutoff cv modulation pot was turned all the way down. When it was turned a couple of degrees clockwise, similar deal, little to no signal out, except out of the high pass (still unaffected by the filter itself).
I'm completely stumped as to why this is, both power supplies are of decent quality (One Elby Designs and one synthrotek) and almost brand new. The module behaves differently in both but in neither of them does it work 100%
I also can't get the filter to self-oscillate at any frequency in either rack.

Any ideas would be greatly appreciated!

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Gouragaja
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Post by Gouragaja » Tue Oct 20, 2015 10:28 am

Hi Geordsta,

I've had this module for about 8 months, and it's been working flawlessly, but recently I've been having the same issue as you, except for me its only the BP OUT that outputs anything, and the input/cutoff/resonance all seem broken, with only the occasional reaction happening to any changes.

Have you tried contacting Koma support? Any advice offered by them? Otherwise I'll get in touch with them...

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Gouragaja
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Post by Gouragaja » Tue Oct 20, 2015 11:02 am

Interesting development, just plugged my rack into another power outlet, and now the SVF-201 is working fine again. Strange, other gear runs just fine on that outlet. I guess I'll have to stick to the one that works :)

Anybody have any input on why that may be? Noise or something? Seems odd that it would affect the filter in the way that it does...

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Brendanleespengler
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Post by Brendanleespengler » Sat Jan 19, 2019 10:24 pm

Just got my KOMA Filter and love it. It’s got completely different character than my Verbos filters. And the post on the LED hack is appreciated. That’ll be icing on the cake. I’ll update with any useful info + results.
Brendan Lee Spengler / Electronic Sound Research: The Electric Cowboy, Sinner Frenz, MacMillan & Spengler, Viva L'American Death Ray Music, Teledildonics5000, etc.

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