What really does the Malekko Wolftone Sloika do ?

[Vivek]

Recently someone posted about a pedal called the Malekko Wolftone Sloika

https://www.youtube.com/watch?v=ov3xz20inlM

I checked the Schematic, it seemed a bit different than the regular distortion pedals.



Here is a link to a high rez schematic: http://guitar-fx-layouts.42897.x6.nabble.com/file/n9107/GNW3w38.png

What does this pedal really do ? How does it do it ? Does it add sufficient good stuff over the traditional distortion pedals ?

[Mark Hammer]

This video from the designer mentions, in passing, what may be central to what he wanted from the pedal: https://www.youtube.com/watch?v=xU6zkUdHVc8  The designer notes that the decay of a chord tends to come out cleaner.

Consider the string of 150R resistors as one leg of a voltage divider, and the "Saturate" pot and R42 as the other leg of that divider.  For each of the individual clipping paths. going from the top one (with a 39nf filter cap) to the bottom (with a 1nf cap) there is an additional 150R series resistor. When the "saturate" pot is set to maximum resistance to ground (wiper moved towards C1), the 150R string  creates little difference between paths.  Move the wiper towards C17, and now each successive 150R resistance attenuates the signal reaching successively "higher" paths.  So, labelling them as paths 1-thru-8 from top to bottom, the signal entering path 8 is attenuated by 7x150R/150R, while the signal reaching path 2 is only attenuated by 150R/7x150R.

I'm guessing that the intent was to provide less clipping for successively higher "bands" as the signal moved quickly from pick attack to decay phase.  The band separation doesn't strike me as sufficient, given that there is no cap in series with each of those 22k resistors, but that's my view.

[Vivek]

Should the 150 ohm resistors followed a logarithmic series ?

[Mark Hammer]

I don't know what they should or shouldn't do.  I'm just explaining what the designer did, and how it appears to have achieved something close to what he was aiming for.

Could it have achieved those objectives more closely if some other arrangement was used?  Perhaps.  But that's his experiment to follow up on...or maybe yours.

[Rob Strand]

Should the 150 ohm resistors followed a logarithmic series ?

There's no rules but I suspect not.

The main features I see are:
- it filters more at high drive
- forms a kind of bendling (although not 100% clean)
- sets-up the feedback so the circuit becomes more transparent when you back-off the drive & sat.

The circuit only 150ohms as divider when the Saturation control is set towards ground.   There are settings where both ends of the 150ohm string are at near equal voltages and the clippers with more or less clip at the same point - but probably not heavily.

At high drive the clip threshold is effectively higher and the blend level is lower.    After about the 4th band the amount of clipping from the diodes is going to be minimal because of the high effective clip level.    Notice this is exactly where the caps break the pattern.   IMHO the top bank bands are more about blending highs back in.   The "taper" of the filter frequencies is entirely empirical.