Muff's Modules & More

[Navs]

Repurposing an unused A-180 multiple as a quad passive slew:

http://navsmodularlab.blogspot.com/2010/07/diy-quad-slew.html

[dude]

more slew!

[en.]

uhuh! thank you navs and fonitronik!

[Smooth Operator]

Great idea!

[Monobass]

brilliant.. am I right in thinking the A180 has no other components, purely ganged connectors? If so then this is a very simple DIY project without an A-180 also.

[fonik]

absolutely, monobass.

it is actually nothing but a fixed lopass filter. there are quite a few passive module designs you could easily build as a start. what about a switch to select from different cap values? this would give you a passive 6db lopass with selectable cutoff (has been made by moog in the past millenium - see below). or what about fixed hipass, attenuators, multiples, switches (selectors)... all you need is a cheap soldering iron from the hardware store, believe me, it is sufficient for a start.

anyways, navs module will be very useful for everyone who frequently uses gates for VCAs...

[stk]

Could this be modified to use a pot for variable cutoff/slew?

[fonik]

no, actually not.
by replacing the resistor with a pot you would not just change the slew rate but also change the level. in other words, the slower the slew the lower the signal level. for your ears the lowering of the level would simply whitewash the effect of changing the slew.
to prevent this you would have to use opamps as buffers, thus having an active module.

as i mentioned above you could use a switch for selecting capacitors of different values (as seen on the moog schematic above). the larger the cap, the slower the slew...

[haesslich]

with a 4051 and a counter you could replace the switch by a trigger signal... okay, again this would be an active module ;-)

[stk]

Thanks for the info, fonik.

[itijik]

This is nice. I was thinking that this would be perfect to use with the A160-161 outputs!

(oh, you mention the RCD on your article...YAH!)

[itijik]

Are the values used for this filter the same values used on the fonik mixer, heard here?... http://navsmodularlab.blogspot.com/2010/06/patch-tips-11-ac-coupled-mi xing.html

[fonik]

no. far from that. in fact it is a different configuration. the fonitronik attenuverting mixer uses a highpass configuration to remove offset.
and it uses a 22uF, that gives much longer times anyways.
nav wanted to remove the 'pop' of the VCAs caused by those steep rising edges, so he wanted to smooth them just a little bit. yo won't even recognize it on slowly changing CVs.

[Monobass]

[itijik]

Thanks fonik!

[dequalsrxt]

that'd be nice to do to one of the sets of multiples on the 1u modular world utility strip... might have to do that. cheers!

[fonik]

[DGTom]

Great use for a "useless" module

For "random" slew, use an LDR instead of a normal resistor (or in parallel)

Bend the LDR so it faces inside the case or towards the crack in between modules for differant amounts of "random"

@Navs; have you tried stacking multiple RCD outs into the input?

[[Djo]]

Thank you for this tip navs!

I made mine with a switch. I use 1µ and 4.7µ.

Edit : 4.7µ is too small, I put a 6.3µ on parallel and it's great.

Sound example :
Soundcloud A180 Mod Slew

[en.]

it could be nice also with a three position selector 1-off-2