Projecttitel: MOTM 440

Status: 

Startdate: 10.10.2014

Duedate: 01.12.2014

update 08-2020

Manufacture link: http://www.synthtech.com/motm440.html


Here's my latest Build from 2020:

MOTM440 in MU Format. let me know when you want one...


 

copy from old synthtech page:

You have probably heard of the SSM2040 filter chip, used in the Prophet 5 Rev. 2 synth, the Voyetra 8, and others. Although short-lived, the SSM2040 filter had a unique sound different from a Moog, ARP or other 4-pole lowpass. Why? The design used a clever discrete OTA gain cell.

The MOTM-440 offers an updated SSM2040 architecture using matched NPN/PNP pairs and features a switch that adds a second audio feedback path to boost bass response at higher Q levels. This makes the filter "growl and rumble" even more! In addition, voltage-controlled Q allows for more sweeping effects. Three audio inputs and three CV inputs make the MOTM-440 the killer lowpass filter in your system. The internal gain structure is such that over-driving the filter is now possible (unlike the Prophet 5) to get even more nasty sounds. Did we mention it self-oscillates at high Q?

So order a MOTM-440 filter for a fraction of the price of a P5 Rev. 2, but without the worry of obsolete parts!

"The MOTM-440 is the best-sounding analog filter I have ever heard." - Robert Rich

BOM:

M440_bom.pdf


Builders Guide:

MOTM440 User's Guide.pdf


Parts:


        1ea 100K cermet Spectrol 149 VR1  (from Scott)
         3ea 100K conductive plastic log Spectrol 148 VR2, VR3, VR4  (mouser)
         3ea 100K conductive plastic Bourns 95A1 VR5, VR6, VR7  (mouser)





(not happen with pcbs from 2019/2020 from synthcube)

If you have purchased an MOTM-440 PCB that has a "P80316" silk screened in the upper left hand corner by the Synth Tech label, please run a wire descriped in picture (the pcb trace is defective)

http://www.muffwiggler.com/forum/viewtopic.php?p=1175840&sid=f286a3c98a3a58e25cbd2bf90200d1cd



further a other issue was found on one pcb:

http://www.sequencer.de/synthesizer/viewtopic.php?t=87264



if your Input 1 and your Frequenzmodulation dont work,  fix this by run wires:


Picture of missing traces here too: (fixed by above solution)

on my pics are the Polysterene values 1n5 instead of 1n,  1v/oct, CV RES, CV FM1, CVFm2 jack polarisation is wrong .

Pin1 and 2  is for the CV Jacks not with the same polarisation !

tip