SMR4 VCF tuning

I still need to tune the VCF. In the manual i read: “To do this adjustment, start from a blank patch.” First of all: how to open a blank patch? When i go to an empty patch, i hear the last played preset. Second: " Set all oscillators to none," -> So i have to set the waveform to none?

Load up an empty User Patch.

Oscillator 1 to WAVEFORM: NONE
Oscillator 2 to WAVEFORM: NONE

Filter Cutoff: 64
Filter Resonance: 63 (maximum)
Filter ENV and LFO both to: 0

Download the VST GTune (for Win)

open it up and send audio input to the VST.

On your Keyboard press a C… you should see something like in the picture.

Turn the trimpot till you are as close to C as you can get.

You should be able to get a C on it for 4 octaves (not spot on, but at least they should be C’s), i tuned in the correct value for C4 (thats the octave i use the most).


> Load up an empty User Patch.

Might work or not!

If this is an official eeprom from MI, the empty user patches all contain the “init” patch. This works.

If this is a self-build… who knows what they might contain?! If they are empty, attempting to loading them will not do anything at all.

> how to open a blank patch?

Use the S6+S1 “init” function described in the manual, Or just power the Shruthi on - it starts with the default patch.

> So i have to set the waveform to none?


To add: Use Tubeohm’s outstanding free tuning app if you want to make this easy. There are a bunch of ways to do this but the trickiest part is figuring out which direction you are going (better or worse) and Andre’s makes that simple across two octaves since you can easily see how close the tuning is. It is also a good learning tool since getting comfortable with the modulations is pretty key to the programming of the device and you should know exactly which parameters you need to adjust to get a pure sine out of the VCF (there isnt much to it, but it’s REALLY important to understand)

Thanks guys! Will test it tonight / tomorrow when i’m back home.

s. 1: it’s for the Ambika, not the Shruthi :wink:
p.s. 2: i know the app from Tubeohm, but i’m running mac here :slight_smile: So i can’t use it!

process is the same for both. Ambika you simply do it one voice at a time

Hi, the filter tuner works with AMBIKA and Shruthi.
In Ambika the trick is to set only one voice on. Tune it , than the next voice and so on.
So you get the 6 Voices tuned.