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Overview 

This is a must-have for your pedalboard. Depending how you use it, it can be: 

 

Signal Splitter, 

 

Signal Mixer, 

 

24dB Highpass filter 

 

24 dB Lowpass filter 

 

Two parallel effect loops 

 

…. 

The V4.2 release has a smaller footprint and cutouts on the sides. 

General 

The pro-cessor is designed around standard circuits like OpAmp Buffer, Sallen Key Filter etc. The combination is 
unique leading to a very flexible workhorse in any effects setup. 

Due to your personal needs regarding filtering you will want to choose other component values for the 4

th

 grade Sallen 

Key filters. The current values will set corner frequencies for the filters as follows: 

Lowpass:  250Hz      Highpass: 400Hz. 

A lot of work has gone into the development of the filtering. The initial idea I had with variable filters (using pots) did 
not work as the steepness only is 12dB which was not enough to do efficient frequency cutting. 

Now with the 4

th

 grade filters there is 24dB action which is highly efficient. Feel free to use other values for your build. 

Example of usage

 (see more at the end of the document) 

 

Pro-cessor 4.2 

 

Not really an effect 

– better ! 

 

Ease of build

Medium

-partscount

Medium

-density

Medium

Parts sourcing

Normal

Enclosure fitting

Advanced

Debugging level

Easy

Summary of Contents for Pro-cessor 4.2

Page 1: ...ponent values for the 4 th grade Sallen Key filters The current values will set corner frequencies for the filters as follows Lowpass 250Hz Highpass 400Hz A lot of work has gone into the development of the filtering The initial idea I had with variable filters using pots did not work as the steepness only is 12dB which was not enough to do efficient frequency cutting Now with the 4 th grade filter...

Page 2: ...Schematic ...

Page 3: ...1 6 6 NRJ6 HM 1 Mouser Link alternative 6 NRJ4 only metal nuts will fit Rotary Switch 2 rotary 2PT3 Musikding Link alternative on on on 2 on on on alternative switch Mouser Link Pay attention when selecting the jacks Unfortunately there are no NRJ4 with metal tip anymore so you need to buy the stereo version NRJ6 when you want them grounded to the enclosure HM You can also use the plastic version ...

Page 4: ...e first then IC sockets and capacitors Then go the jacks Last mount the BLEND pot and the rotary switches from the backside see detail Due to the small size of the PCB and the narrow layout you should check if the capacitors you choose do fit in ...

Page 5: ...the rotary switches are mounted If you use the on on on switch you need to wire it externally This will need a 125B enclosure First make the connection between pin 3 and 5 of the switch Then wire 2 to X_FILTER 1 to X_DIRECT 4 to LP 6 to HP ...

Page 6: ...y thcustom com drill templates Here are the measurements for the backside drilling 1590B enclosure If you use a 125B or different make sure to measure the 21mm from the top 1590B needs the holes to be slotted to the bottom as shown above Otherwise the PCB will not fit in ...

Page 7: ...EXAMPLES of use ...

Page 8: ...f the possible uses of this tool And if you only want to put effects on your pedal board Try it with channel A running through LP channel B running through HP and use the blend control to apply 24dB filtering That can be called an effect for sure It will be interesting what you did with the Pro cessor Please let me know This is a picture of one of the prototypes Disclaimer License PCBs purchased f...

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