Muff's Modules & More

kindredlost

A thread started in the DIY section might be of interest here for some dotcom'ers...

http://www.muffwiggler.com/forum/viewtopic.php?p=773403#773403

Basically it is to use a toggle switch to select the 1, 2 or 3 pole slopes on the -12dB setting of the Q150 Transistor Ladder Filter from synthesizers.com.

I ran out of time to do a demo of what these settings sound like. The 3 pole setting approaches the Q107 standard sound without reaching Q oscillation. The 1 pole setting is very flat and subtle but lets almost full spectrum frequency range through. Or at least that was my late-night impression of the settings.

A fun modification. It took me forever to find this switch and there are only a couple left in inventory at Mouser in case anyone wants to do this mod for themselves. Just sayin'

Jsantos360 · Posted: Wed Apr 11, 2012 11:07 am Post subject:

You can't eliminate the "pops" that are caused by the slope switch very frustrating

Im taking a pass waah

kindredlost · Posted: Wed Apr 11, 2012 1:51 pm Post subject:

Squattamolie · Posted: Wed Apr 11, 2012 5:38 pm Post subject:

I did this a while ago, the link is to a video showing the slope selection on the Q150

Q150 switchable slopes

Scott

Jsantos360 · Posted: Wed Apr 11, 2012 6:02 pm Post subject:

kindredlost · Posted: Wed Apr 11, 2012 7:02 pm Post subject:

Squattamolie · Posted: Thu Apr 12, 2012 9:21 am Post subject:

Thanks for the kind words!

As to the "pop", my semi-lame-but-still-effective workaround is that I set the factory 12/24 toggle to "24", then I can turn the rotary to select 6/12/18 dB slopes without the pop, then switch the 12/24 toggle back - it does the job, and "pop-lessly".

As to the "shunt array" - I am i_g_n_o_r_a_n_t of electrical things, I've never even heard the term. No clue, no kidding!

I just figured out that if I could get a rotary switch to move the contacts that a user moves manually with the jumpers, it should work - right? And it did.

One thing that made it easier was . . . (I have no idea how to describe this) . . . I only had to attach 8 wires to the set of jumper pins instead of 12. I'll try to upload a graphic of the jumper pins . . .

For one slope (6 or 18, I forget), you need yellow/blue and yellow/magenta, for the 12dB slope, you need green/blue and green/magenta, for the last one you need orange/blue and orange magenta - (I realize this is probably about how a 10 year-old would try to explain this - like I said, I'm a complete noob). What this meant was that I only needed one wire from the rotary to (just) one of the blue pins, and another single wire for the magenta, then the six wires to the other six pins.

kindredlost · Posted: Thu Apr 12, 2012 11:35 am Post subject:

Right.

The same technique for me. Not enough knowledge to prevent me from making it work. Mr. Green