EF440 clone. Help needed for Fixed Wah please. Shematics & Pics included.

[ke4unr]

I've built a DOD EF440 Envelope Filter clone and have added the Fixed Wah mod like the BYOC version. I had everything on hand except the optocoupler, so I decided against buying the kit. They're not offering PCB's right now, so I am using one from JD Sleep at GGG. Nice board!

So, the envelope filter is working fine. It's the Fixed Wah that doesn't seem to want to cooperate. The SPDT toggle doesn't seem to be doing anything. Thrown either way gives me the EF.

I used the schematic from BYOC's site and also the one from GGG. Both can be found here:

http://buildyourownclone.com/filterinstructions.pdf     (page 13)
http://www.generalguitargadgets.com/pdf/ggg_ef440_sc.pdf

I also took high res photos of the guts while I'm doing final prep on my enclosure:



Other photos can be found here:

http://members.cox.net/curtiskband/Say%20Wha%20Pedal%202.jpg
http://members.cox.net/curtiskband/Say%20Wha%20Pedal%203.jpg
http://members.cox.net/curtiskband/Say%20Wha%20Pedal%204.jpg
http://members.cox.net/curtiskband/Say%20Wha%20Pedal%205.jpg
http://members.cox.net/curtiskband/Say%20Wha%20Pedal%206.jpg

I'm coming off the L2 pad of the PCB, which traces to the + side of the LED of the Vactrol (VR1). This is connected to the center lug of the SPDT toggle switch. One of the side lugs goes to lug #2 of the Level pot (R15). The other side lug of the switch goes to lug #1 of the Manual pot. I am using a A100k. I've tied lugs #2 & #3 of the Manual pot together. I added the 10k resistor to lug #3 and have taken that to ground on the Input jack.

This seemed too simple, so I've been racking my brain. Time to let someone else have a look. I would appreciate any help. If more information is needed, I'll be glad to provide it.

Thanks,
Ray K.

[Dan N]

No, the 10K goes to pos, not ground, to power the led.

[slacker]

Like Dan said the 10k goes to +9 volts not ground.
I don't think your connections to the switch are correct though. The way you've done it you are just selecting between connecting the level pot or the manual pot. The envelope follower is still connected to the + side of the vactrol LED through R6, so that's why you get the EF in both settings. If you look at the BYOC schematic you need to break the connection between R13 (R6 on the GGG layout) and the + side of the vactrol LED. The switch then either connects the EF or the manual pot.
To do this leave the switch and the wiring to the level pot how it is now and cut the PCB trace between the right hand side of R6 and the + side of the vactrol LED. Then connect a wire from the right hand side of R6 to the middle lug of the level pot.
Now putting the switch one way connects the output of the EF and level pot as normal and the other way disconnects the EF and connects the manual pot.

Hope that makes sense

[ke4unr]

Dan & Ian,

Both of you were spot on! Thanks to each of you, I now have a successful build! 

Your time and advice are greatly appreciated!!!

Thanks,
Ray K.

[Dan N]

Nice build! Good thing Slacker came along and really went over the wiring.

I had never seen the fixed wah mod and will have to try it.

My favorite mod is the resonance mod Mark Hammer mentions here:
'http://www.diystompboxes.com/smfforum/index.php?topic=17057.0

I love to run a super-fuzz into the 440 and with the res pot, make it sound like a wounded seal. Yes, I'm easily amused...

[ke4unr]

Dan, thanks for the nice compliment! Yes, Slacker was very helpful.

I've been looking for and pondering a fixed wah effect. I happened to see the EF440 w/ Fixed Wah mod on BYOC's site just recently. It also happens that I've got some concert dates coming up that I can make good use of an envelope filter.

The fixed wah mod does sound good to my ears, but it isn't going to be a perfect match for a true wah %^&*ed where you prefer it. But, I still think it will be useful, and it takes up a lot less room on my live pedalboard where space is at a premium.

Thanks much for the link. I just read it, and will do so again. I want to fly this thing live a few times to see how it performs. Then I'll decide what, if any further mods it needs.

Btw, I socketed C6 & C7 (GGG schematic). The stock circuit calls for a pair of .022uf. Change them to larger caps and the frequency range is a little darker and has a bit more sweep. .033uf is suggested to start with. I tried them and they work as advertised, but so far have gone back to the .022uf. I'll experiment more as time allows.

"easily amused..." Hehe, yeah. I tried running mine with chorus & delay along with one of my distortions and boost going all at once. Was getting almost an E-Bow/violin type effect.

Thanks,
Ray K.

[slacker]

Looks really good

[ke4unr]

Ian, thanks for the compliment. And yet again I appreciate your detailed reply that helped me see the error of my ways.

Thanks,
Ray K.

[Mark Hammer]

Nice build.  I particularly like the toggle you used.  Very nice low profile that reduces risk of damage or accidental flicking.  Who makes them and where did you get it?

BTW, I had completely forgotten about that resonance mod.  Thanks for reminding me.

[ke4unr]

Mark, your compliment is much appreciated!

The short toggle switch came from our friend Steve at Small Bear. Here ya go: http://www.smallbearelec.com/Detail.bok?no=792

Ray K.

[Mark Hammer]

Mark, your compliment is much appreciated!

The short toggle switch came from our friend Steve at Small Bear. Here ya go: http://www.smallbearelec.com/Detail.bok?no=792

Ray K.

I should have noticed that, but somehow missed it.  Many thanks.