Phuncgnosis mods on the BB

[Ben Lyman]

I bread boarded Tim E's Phuncgnosis and it sounds pretty good. Then of course I started searching threads and came across Rob's (Deadastronaut) mods here:
http://www.diystompboxes.com/smfforum/index.php?topic=49246.msg877226#msg877226

Right now it's somewhere in between Tim's and Rob's. I really like the green LED mod, there is a noticeable improvement.
Rob's 100K R13 makes the effect sound great with a distortion pedal but I didn't like it as much for clean funky playing.
R13 also had a big impact of the "reverse mode" when I tried with and without.
I noticed some mention of the reverse switch not working even though it sounded great in Rob's demo. At first it didn't work for me either but after trying a few different caps I got it to sound great with a 1000uF cap.

Here's the thing though, I had it working in reverse mode, then turned everything off and went away for a couple hours. When I got back, no more reverse mode, regular "quacky" forward mode still works. I checked and rechecked everything, tried a few more experiments, went back to the way it was but nothing would get that cool reverse wah back again. Then for no apparent reason it started working again. Did the 1000uF cap need to charge up for a long time or something?

Here's where it's at now, sounding pretty good but a lot of background noise, not any screeching but more of a dull hissing.

[Ben Lyman]

I may have figured it out. Need to do some more testing but I think a DPDT switch is in order for the UP/DOWN switch. It seems the 2n3904 collector wants to be grounded when not in use. I am guessing maybe the alternative is to strum constantly for 45 minutes every time you throw the switch 
Still hoping all the noise is just normal BB stuff.

Here's the new plan:

[thermionix]

What are you using to whip up schematics like that?  Must be some program.  I could spend hours with MS Paint and it wouldn't come out that good, lol.  Can you do tube circuits too?

[Ben Lyman]

Well, that didn't solve the problem. This cap+backwards transistor gadget is weird. The grounded collector works but only if the cap has already been fully charged or something.
If I leave the power off for a while and come back the cap needs to be used for a long time before the reverse wah can take effect.
If I grab a new cap off the bench, it usually works right away.
If I pop the cap across the power rails (plus to minus 9v) and put it back, it's no good again until I ground the collector, then bam it's working again.
I'm confused.. how can I make it so it will be reliable and consistent?

What are you using to whip up schematics like that?  Must be some program.  I could spend hours with MS Paint and it wouldn't come out that good, lol.  Can you do tube circuits too?

I'm pretty sure you can do anything with this, it's a free site called schematics.com
I created an account and I think I might have had to download a free bit of software to go with it.
If you save your projects on their site, I guess they are free for the world to see, so some people mightn't dig that.
I usually just take a screen shot of my creations and save them on my desktop as an image.

[thermionix]

Cool, thanks, I'll look into that!  Don't mind if people can see my stuff, I'm certainly not one to come up with anything new in this field.

[Kipper4]

IIRC I had trouble with this mod too. All that was a long time ago.
I hope you get it sorted Ben. Did you pm D.Astro.?

[duck_arse]

ben, the voltages! measure the voltage across the 1000uF cap, when working and when not, and then throw a big resistor across it, like 4M7 or something. [I have no idea how or why that transistor works.]

your R13 would be setting the offset for the audio and the rectifier - what was the value changed from?

[Ben Lyman]

ben, the voltages! measure the voltage across the 1000uF cap, when working and when not, and then throw a big resistor across it, like 4M7 or something. [I have no idea how or why that transistor works.]

your R13 would be setting the offset for the audio and the rectifier - what was the value changed from?

Ok, thanks duck! I'll get on that asap.
As for R13, do you mean mine or Rob's? It gets a little confusing when I make my own schematic and it doesn't match up to the originals exactly. Anyway, my R13 is the same as Rob's R12, never changed that voltage divider to set the Vb.

Rob's R13 is not in my schematic at all, it goes across his 2n2 cap and I like the effect it has in that it accentuates the wah wah sound but it also adds a little bit of distortion so it sounds great with an OD/dist pedal but not ideal for clean funky rhythm guitar.

IIRC I had trouble with this mod too. All that was a long time ago.
I hope you get it sorted Ben. Did you pm D.Astro.?

Rich, after reading through all the threads, I discovered that he has since departed ways with the original pedal and was not able to offer any help to the people who couldn't make the up/down work properly... although, I was kinda hoping he would see this thread and have some ideas to share 

Cool, thanks, I'll look into that!  Don't mind if people can see my stuff, I'm certainly not one to come up with anything new in this field.

I found it very difficult at first and it took me a long time to figure out the quirks but I've learned how to use about 5% of it's features in order to create my schematics

[GibsonGM]

What are you using to whip up schematics like that?  Must be some program.  I could spend hours with MS Paint and it wouldn't come out that good, lol.  Can you do tube circuits too?

A lot of people download "Fritzing" (free) and use that to make nice-looking schematics...same program they use on the Arduino project sites.

[Ben Lyman]

When I turned it on this morn, 1000uF reads .37v and doesn't work.
10 minutes later it reads .75v and there is a subtle wah effect.
15 minutes, a little better sounding, .85v.
after a long time, finally sounding great and holding *sort of* steady at 1.25v

I have been experimenting with Tim E's original reverse mode with the 3 LEDs:
original with 3 red diffused, not much effect.
3 clear whites, some improvement.
3 superbrite green or red, no effect.
3 superbrite blue, the best sound so far, much better than diffused reds but still not as good as Rob's "transcaptor" thing-a-ma-jig (when it works at all)

A lot of people download "Fritzing" (free) and use that to make nice-looking schematics...same program they use on the Arduino project sites.

Thanks, I'll have to check that one out, I like free

[Ben Lyman]

Here's the latest experiment in trying to get the reverse mode to charge up quicker. It functions just fine like this and the Qbase + 1000uF are holding steady at about 1.44v
I need to shut it down for a while and wait to see what happens next time I fire it up.


Well, it just passed the first test; I put the DMM on the Qbase & 1000uF, flipped on the power and watched the volts rise steadily from .05v right up to 1.38v.
It took about 90 seconds but that is acceptable since it will begin charging as soon as a guitar cable is plugged into the input jack.

The real test comes tomorrow morning after it sits all night; if it charges right up after that, it should be good to go (I hope)   

[Ben Lyman]

Here's the full BB layout at the moment. 3 pots and a switch, lots of controls, lots of good sounds

R18 1K2 needs to be bigger, works good with about 10K

[Ben Lyman]

Success! Fired it up this morning and watched the volts rise steadily, just as I hoped. It did take almost 90 seconds but I was auto-wah-ing in reverse.
What do you guys think of the extra knobs? In addition to R1 input sensitivity I have those other two.
Not sure how to describe them, maybe R6 is sort of a release and/or attack speed?
Maybe R17 is a range control?

Not much of a demo here, it's more of a like, "Hey guys, watch me try to figure this out" video:

[duck_arse]

that last bit was funny. I guess that's the mark of a working autowah. it sounds pretty good.

[Ben Lyman]

that last bit was funny. I guess that's the mark of a working autowah. it sounds pretty good.

Thanks Duck, which last bit?
And thanks for suggesting I check the volts on my cap, that's what gave me the idea to set a divider on it to bring it up from a cold start.

[cab42]

I just watched the video. Your phuncgnosis sounds great!

I have modded my own phuncgnosis beyond repair, and I want to start all over on breadboard.

The first incarnation of my effect had intensity and release pots just like yours, but I ended up ditching the intensity pot and changing the release pot to DA's version. I never got the reverse wah to Sound good and I want to try your approach.

[Ben Lyman]

I tried DA's release pot too, it works great, sounds great, I like it. The only reason I went back to the 1M at input was because I have seen so many envelope filters designed that way, so it seems pretty safe and I was a little concerned how different types of guitar pickups would react to the circuit. One thing I remember about an old DOD I used to have, was that every guitar needed a different sensitivity setting on that pedal.

Hey, speaking of DOD, have you ever noticed how similar Tim E's Phuncgnosis is to the DOD 400? Except for the vactrols, almost the same maybe?

[thermionix]

One thing I remember about an old DOD I used to have, was that every guitar needed a different sensitivity setting on that pedal.

FX-25?  I had one of those not long ago, and it seemed like every time I plugged the SAME guitar into it, it needed a different sensitivity setting.

[Ben Lyman]

FX-25? 

Yup, that was it!

"Make your big toe shoot up in your boot!"
---Little Richard talking about Jimi, right?

[thermionix]

"Make your big toe shoot up in your boot!"
---Little Richard talking about Jimi, right?

You blew my cover, man!  Now I'm gonna have to change it.  (Like I wouldn't have anyway)