synthy filters for guitar..

[nick d]

      Just LP . It's actually 9v adaptation based on VCF 2 from the EFM Wildcat , which in turn was based on the MS20 VCF .
      Probably nothing like the real Korg circuit , but it seems to work well enough !

[nick d]

[/URL]][/img]                                                                                                                                  [/img][/img]

     IT'S ALIVE !!!!!

     Pics above of the outside and a fairly horrific gut shot -  if you don't like off-board wiring , don't even think about attempting
      this project !      Sounds pretty much like the breadboard demo , with a few minor tweaks and an expression pedal input .
   
     Still got to draw up the final schemo , will post that , with a demo , by the weekend ( hopefully ! )

[garcho]

^ bravo, nice filter

[deadastronaut]

Whoooaahhh that's a monster...glad ya got it sorted man..

excellent...

[nick d]

         Here we go chaps..........

[deadastronaut]

in the case of sonic attack on your district follow these rules...play master of the universe...

sounds cool man, love the self oscillation synthy stuff too..very old hawkwind nice...

[Mark Hammer]

So you have a slower LFO modulating a faster one?  That's what it sounds like, at any rate.

[nick d]

      Two LFO's with separate rate and depth controls , mixed at a summing node  along with the CV from the expression pedal .
       All will become clearer when I draw up the full schemo .

[nick d]

   Here's the schemo : -


   Hope you can all read it , let me know if you spot any glaring errors .
   
   A few points to note : -
           I  separate buffered reference voltages for the filter and the LFO's ( Vref , V lfo ) . This might be OTT , but I think it helps to minimise ticking .
           
          The 2nd LFO is identical , just uses the other half of the TLO74 .

           For the exp. pedal I used a Zoom FP-02  ( because I've got one ) , any other passive pedal should do  .
           
           The LFO indicator LEDs don't totally shut off - this can be cured by connecting the emitter of the 3904 to Vlfo instead of Gnd .
             
            The " MOD " stomp just shorts across the 68n caps to stop the LFO's - I added this as an afterthought , so it might not be clear on the schemo .

            The Vero is a bit huge and sprawling , and the off-board wiring is a bit of a mare , so if anyone wants to come up with a nice compact layout with on-board pots ,
              you are welcome to do so !

[garcho]

bravo!

[noisette]

Nice work on this thread.
When I first did the MS20 filter from Esobedo I couldn´t get it to work tried 4 or 5 times - nothing...
6th time was the winner

Now I have build several modules for my synth, like 6 pole (adpted from jürgen haible phaser).
With this quasi sallen-key topology you can get also hp and allpass(phaser).

On a sidenote, the even sicker synthfilter (imo) is the steiner vcf(hp/bp/lp INPUTS!).

http://yusynth.net/Modular/EN/STEINERVCF/

A lot of people are put off by the diode ladder, but you can do this (even 3 or 4 pole):

http://tristandabbles.wordpress.com/2011/06/15/the-steiner-resonant-filter-a-new-adaptation/

I have a demo from my version, I love this filter! Have try!

https://soundcloud.com/noisette-1/wahwahdemo

Edit: You might also look at the Maestro Sample&Hold Filter, it´s the similar to the m20 iirc and s&h is REALLY synthy

[nocentelli]

You might also look at the Maestro Sample&Hold Filter, it´s the similar to the m20 iirc and s&h is REALLY synthy

Thanks for this. I tried a FS+H on the breadboard a long time ago, but couldn't get the S+H working so abandoned it. Now I look at the schem again, the filter portion is obviously closely related to the MS_20: Going to give it another go.

[Strategy]

Madbean has a version of Maestro Filter S&H right now I think?
Strategy

[nocentelli]

  Here's the schemo : -

I breaboarded this on a whim last night (minus the LFO's - exp pedal only) and it sounds great. Thanks again for posting.

[nick d]

     That's nice to hear !  OTA's are lots of fun !

[nocentelli]

I simplified it a bit, I only really want it for a resonant wah with an expression pedal, so no LFO. Here's what I've done to it:

[garcho]

I think the MS-20 is basically textbook, no shame in the game! Looking forward to breadboarding this, thanks for the schemo.

[Mindthecat]

I liked this effect since I found this video on Youtube. It's just really raw. I can understand the scheme (I mean, I get the gist of it). But I see you have made a vero version of it. Do you still have the vero layout? If so, would mind posting it? It would be fantastic. 

   Here's the schemo : -


   Hope you can all read it , let me know if you spot any glaring errors .
   
   A few points to note : -
           I  separate buffered reference voltages for the filter and the LFO's ( Vref , V lfo ) . This might be OTT , but I think it helps to minimise ticking .
           
          The 2nd LFO is identical , just uses the other half of the TLO74 .

           For the exp. pedal I used a Zoom FP-02  ( because I've got one ) , any other passive pedal should do  .
           
           The LFO indicator LEDs don't totally shut off - this can be cured by connecting the emitter of the 3904 to Vlfo instead of Gnd .
             
            The " MOD " stomp just shorts across the 68n caps to stop the LFO's - I added this as an afterthought , so it might not be clear on the schemo .

            The Vero is a bit huge and sprawling , and the off-board wiring is a bit of a mare , so if anyone wants to come up with a nice compact layout with on-board pots ,
              you are welcome to do so !

[garcho]

^ that's the "MS-20" style filter, basically from the datasheet for the LM13700, plus the resonance op amp stage, a la Rene Schmitz. If you can't find a vero version of this in particular, look for "MS-20" vero layouts.

[Hatredman]

Boss is no fun at all.

http://www.bossus.com/products/sy-300/