Snow White Auto Wah (Swah v3)

[italianguy63]

Anyone have any experience with this circuit?  I built one this weekend-- it works, but not what I hoped.  It just does not have enough OMPH/Wah.

It's just alright.  Definitely an effect, but not the pronounced Funkadelic WAH I expected.

I have played with the bias pot, and get a little more pronounced "wha effect" both in the middle, and towards the far end of the throw.

With all 3 knobs at about 2:00 I get the best/most effect.  Anybody else been down this road?

MC

[Kipper4]

Yep been there twice. Vero and PCB
If you really want a good filter try the mutron iii
Theres quite a few differantly named ones. Google it.
You could always try r rings recent filter the mini mu too its sweet.
Good luck in your quest MC
Rich

[Luke51411]

I'd have to agree with you. It's a serviceable envelope filter. I can't seem to get a whole lot of variety out of it, I might need to play with the bias trimmer a bit. I also didn't realize that there is a jumper on that board. It worked but there was a thump when the filter kicked in and no sound when it wasn't engaged I think I had something else incorrect as well, can't remember though. I have it working correctly now I think. I've since built mad beans kraken on vero and I like that a lot, the input sensitivity is very tunable. I stuck a compressor in front do it which gave even more refined control of the envelope.

[italianguy63]

Yeah-- I saw the "jumper" post.  And it works alright.

I did do my first "reverse" etch on this one.  Came out pretty well too.  I will post pics soon, I am re-painting in the background now.

I see the Mutron III mentioned a alot.  I have the stuff to try rolling my own vactrols too.. probably my next quest.
MC

[yeraym]

I built one with some suggested mods which made it work better. If you use the schem floating on the web (cant post from mobile) change r18 to 47k, c8 to 1u and use 1N34A for d6. I included a sidechain input for the envelope detector, this is nice feature to have

[digi2t]

I see the Mutron III mentioned a alot.  I have the stuff to try rolling my own vactrols too.. probably my next quest.
MC

I did a tutorial on making a Mutron III type Vactrol here;

http://www.diystompboxes.com/smfforum/index.php?topic=95269.0

Just one thing that isn't mentioned in the tutorial; do not use the BLACK IC foam. It's conductive, and will cause headaches if you don't get it all out of the cured epoxy. Use the pink stuff (like in the pictures) instead. Test the foam with your DMM to be sure.

There's also a short video of the breadboard test of the Vactrol further down in the thread as well.

I have to agree with kipper, Mutron III circuit is the best I've heard, and the Foxx is just a sup'd up version, adding the pedal control, and LFO. The vero and schematic are here;
http://www.aronnelson.com/gallery/main.php/v/digi2t/veros/Muttroxx/

I must also add, the Guyatone Funky Box is pretty nice too. Right now, UK and I are in the process of finishing the Fuzz Monster, but once that's done, the Funky Box is next on the hit list. Stay tuned for that one.

Hope it helps.

[italianguy63]

Hey Yeraym-- thanks for that.  The build I did already had 2 of the 3 values you recommended changed.  I'll try the resisitor when I put it back together.

Hey Digi2t-- I already saw your tutorial.  Planned on trying it.  What color LED did you find worked best?  I am seeing red or green diffused.  Also, there is some discussion on the LDR's being matched.  Did you do anything on that, is it easy to test?  I got the LDR's from Tayda.  I think I will do what you did, with a good sized tube, and epoxy it all up....  MC

[digi2t]

Matching the LDR's would be ideal. When I built my Infinitphase, I matched them using a small jig I made. Basically, a small piece of wood, with twin holes drilled into it matching the LDR spacing. I clamped the piece of wood under a stable light source, placed an LDR into the jig, ensuring that it lays flat against the wood, and then connected my DMM to the leads underneath. I "auditioned" the LDR's until I get a set that are closely matched. Once you have a set, you can run them through the same test again, at different luminosity levels, to gauge if they match across a range. It's far from scientific, but it works for me.

If I remember correctly, the LED I used is the Kingbright Waterclear WP7113QWC/D White 5mm LED, from Mammoth Electronics. I found it gives me a nice "whap", and on the Foxx, the arpeggio cascade is quite nice. But hey!... you can breadboard it, and experiment with different colors before you epoxy the works.

[italianguy63]

I got the parts yesterday to try this.  I am going to try rolling my own, going to try red, green, and waterclear LEDs for the vactrol.  I have 3 sets of LDR's pretty well matched up.  I also ordered a Neutron board... I'll report back in a couple weeks.  I have about 5 projects alive right now...

[Kipper4]

I wish you every success my friend

[italianguy63]

Thanks!   

[italianguy63]

Hey Dino--

My Bussman surplus fuse must have been of Columbian manufacture.  It was full of a mysterious powder:



I was able to score some cheap plastic plugs with the same diameter as it ID of the buss fuse casing.  So, able to hold the LED and LDR's square and stationary, as well as provide light protection (black plastic on the LDR side).  I just put the LED side in the tube, filled it with epoxy, and squished it together...  Came out perfect.  Measurements and performance to follow eventually..



MC

[Luke51411]

That's a great idea. I've been recently trying to match some LDRs. I'll have to rig up something similar!

[digi2t]

Looks amazing. Nice job. Bonus points for the caps. 

Looking forward to hearing your thoughts on it's performance. Are you going try different color LED's before you seal it up?

[italianguy63]

I'm going to order some 14 pin headers, and make up a few different sets with different components.  Then I can just "plug" them in the circuit.  I even found some opto-isolaters I can't find a data sheet on...  I'll plug them in and see what they do too.

[PRR]

> My Bussman surplus fuse must have been of Columbian manufacture.  It was full of a mysterious powder:

I suppose you already snorted it.

That may be a Time-Delay agent (absorbs heat so the fuse don't blow so fast); or some Gross Overload protection (put 10,000 Amps through a 10 Amp fuse, it will *explode*; the packing may absorb some of the shock).

Either way it is likely to be Silica (burn-proof and cheap), fancy sand, and not good to breathe.

If you like cutting-up costly fuses (I pay $20 for certain fuses like that), fine.

But I've always got-by with cardboard. Shirt or shoebox stuff. Can make it any size or shape. By itself, pretty light-proof. Since there are always holes and cracks, I goober the gaps with glue then apply thick black paint. Flat black on the inside so any stray light does not ricochet around. (More critical in studio compressors than in vibratos.)

> some 14 pin headers

You *used* to be able to find DIP headers with a (black) plastic box. Good for secret circuits. IIRC, a bit tight for LDRs, but those things keep getting smaller.

[PRR]

>> some 14 pin headers
> You *used* to be able to find DIP headers with a (black) plastic box.

Still around:
http://www.arieselec.com/products/data/12033-header-covers.htm

http://www.mouser.com/Connectors/IC-Component-Sockets/_/N-211lk?Keyword=DIP+Cover
IC & Component Sockets 14P DIP COVER .895" * (stocked, $3.63)
* Max. Component Height 0.750

That does not include the header.

http://www.mouser.com
14-600-10 Aries Electronics  IC & Component Sockets 14P FORK DIP HDR
In Stock  $2.07

[italianguy63]

Paul you amaze me-- you are a fountain of knowledge!

I was wondering why they would put filler like that in the fuse.  I was thinking just to firm up the element, in case it got dropped or something.  Neat to know-- no worries on the fuses, I picked them up at my surplus house (used) for .$50.  I looked for other plastic tubing that could be used, but no luck.  Dino found a good option here as the plastic is good and thick in the fuse, and solid to work to.  The other plastic caps were a dime.

I said "header," maybe I should have just said sockets.  I am going to put a socket on the PCB, and as I make these up, I will solder them to another socket.  So, I can swap the different "assemblies" in and out (stacking the sockets).

MC

[italianguy63]

And Paul I mean a "useful" fountain of knowledge; my brain is clogged with "useless" knowledge, interesting, but useless.

Here we go.  Made up a 5mm green diffused, a 5mm red diffused, a 3mm white water-clear (the small one), and found 2 sets of opto-isolators at my surpluss dungeon-- just to try out.



It will be awhile before I update.  I need to finish up a bunch of other stuff I have already started before doing yet another project!

MC

[chemosis]

i was wondering how i could incorprate other mods besisdes the few common mods that have already been done. mods like attack. stronger sweep. more resonance, etc. im not really a fan of mutron 3 variants or filters that use optocouplers but love all the options that the meatball or riddle q balls has. i love the OTA style filters because they sound more synthy to me and smoother. example absolutley love my frostwave funk a duck which i believe is a ms-20 variant