Phuncgnosis mods

[mac]

I breadboarded the phuncgnosis env filter. It worked nice from the start, but I added some mods:
1) I found that replacing the only 330K resistor with a 1M log pot I could have more control over the wet/dry 1M lin pot at the input.
2) changing the down sweep led with a silicon diode (or 3 to keep the same volume) alters the deepness and freq response of the filter. In this case the pot I mentioned in the previous mod should be a 100k log.
I plan to use a 2PDT switch to swap between diodes and pots.
3) the 2.2n cap at the input has a great impact over the filter so I tried different caps from 1n to 4.7n with nice results. I used a rotary switch to change caps.
4) I tweaked the 0.1u and 1u caps to gnd, ie I reduced them a little by 1/10 or less. But I prefer the original values.

I hope someone found this helpul



mac

[Flaconsius]

Great Info, dude!
I´m thinkin´of makin´this effect soon, and your data is very helpful.
Cheers.

[deadastronaut]

heres a mod for the 'down' sweep.  (amonst others ive done on breadboard)...schemo later ok.

anyway it works much better than the leds.

up=1n4148

down= 2n3904.

its a little weird and probably unorthadox, but hey , it works....''however i do get squeel in this mode when using distortion...but i'll see if i can tame that.''.( which i did with leds btw)

9v to emitter....yes emitter.

base to a 470uf to ground  (use up those big caps.. )

collector to switch.....

i got rid of the 1M Pot altogether, i have 56k as input---100nf etc etc...

5.6M instead of 5M/ 2X1nf for filter...instead of 680pf's....(note: i like these for my side project)

in between D1/D3  i put a 2.2uf with a 1M pot instead of the 100nf,  this gives 'release' time adjust as well as 'intensity'.....wahhhhhh...(when turned down its a stuck wah)...

D2 super bright green led... 470n on out. (keeps it in line with bypassed tone thickness...

back later when i sort the squeel....if i can.....sounds lovely opening up now..great for leads, really has expression now.....

a very dodgy quality clip, but you get the idea........at last a down sweep yayyyyyyyyy......still tweaking it though.


https://dl.dropbox.com/u/7464107/phuncdown1.mp3

[Mark Hammer]

Sounds nice.  You need to make one for Steve Hillage!

[deadastronaut]

cheers mark, funny you should say that...thats exactly the sound i'm after...green etc...fish rising....etc etc...

i intend to put this with a sort of synthy brass fuzz when off bias just to get that fuller envelope, but have it optional too......and call it the ''ohm riff''

heres a clip with a mixture of the up/down modes...


https://dl.dropbox.com/u/7464107/phuncmixedmodesupdown.mp3

[deadastronaut]

ok, drew up a scheme,  i can't seem to get rid of squeel on down mode when using distortion after though....hmmmm...

any suggestions?....apart from sod off..

[mac]

Bien!
I have to try your mods.

in between D1/D3  i put a 2.2uf with a 1M pot instead of the 100nf,  this gives 'release' time adjust as well as 'intensity'.....wahhhhhh...(when turned down its a stuck wah)...

Please check C3 and the release pot in your schem.

mac

[deadastronaut]

ok, gotcha!...i'll sort it.


DONE..

[pinkjimiphoton]

rob...



i know what i'll be doing soon.

is this the updated schem bro?

can't wait to try it...cheers!

[deadastronaut]

@jimi:  yeah its updated,  but still getting squeel on ''down'' with distortion though......hmmmmmm...that needs to be sorted.

i have it on breadboard!..

[mac]

iirc, the squeel problem could be the 1n4148 lower forward voltage. Try adding a small resistor in series with the diode or transistor, or a 1kb pot to find the smallest value that stops squeel. This will reduce a bit the gain of the opamp at the peak freq.

ref: see colorsound inductorless wha

mac

[pinkjimiphoton]

thanks brothers,
i may have a go at updating the one i built a year or so ago...it's a great envelope, but down? there's a down? i wasted a footswitch on that?? lol..

be curious to see what i encounter, i'm becoming more and more amazed that anything i ever built in the beginning even works at all.

[pinkjimiphoton]

hey guys,
i "retrofitted" the phuncgnosis i vero'd a year or so ago...

all i did was lift the connection for the "down" mode and make a little daughterboard with a 470u cap and a 2n3904 like rob has in his schematic.
i can't seem to get it to sweep down...or so i thought. it doesn't sweep down, really, but what it does do is work backwards from the normal..

the lighter you play, the more treble... i thought it was gonna be the DIRECTION of the sweep. so it kinda thru me a little.

i tried adding a 100u/1n400X power filter.. and blew the chip AND the 3904. i'm wondering if maybe it would be better to go with 100u instead of 470, and maybe use the 470 on the b+ instead. near as i can figure, it did the same thing that killed my rebote;
by having a bigger cap after the initial one across the power rails, the bigger cap takes longer to discharge.. so when you turn it off, it feeds voltage back thru the circuit.
or something. i don't completely understand it.

i have zero squeal with fuzz before or after, seems to work great...thanks guys, cheers!

[deadastronaut]

so you got it working with no squeel then?....cool.

2 caps across power rails?.....is that it?...


is the rest of your circuit 'standard scheme'' then?....


by 'down' i meant backwards...erm...sort of..

[pinkjimiphoton]

bone stock vero layout from the gallery, other than a  47k resistor added for switch pop (as per the vero).



i lifted the switch return on the right side, and added a daughter board with just a 470u cap and a 3904  connected as per your schem, rob.

i tied the 9v to the b+ rail, and the ground to the ground rail, and took the wire to the switch to the collector.

worked like a charm...it's weird...it's almost like a delayed filter sweep, as the cap charges...but ZERO squeal in my build.

used a 4558 for the OA.

[deadastronaut]

b+ rail ...do you mean VR?...(voltage divider)


glad it worked for ya!....i'm still getting massive squeel, on 'down' mode though, no matter what i try....

[pinkjimiphoton]

the schematic shows the emitter of the 3904 going to v+, not vr.

so that's what i did. it indeed works, and properly! the 3904 can handle the juice fine, it works now. here's a stupid pedal trick.
excuse my lame, white, non-groove bass playing. 

that's a mexi fender fretless jazz full blast into the phuncgnosis with the one mod (and the 47k pull down as in the vero above) into the Sterno Face Fuzz i'm giving away in the turkey day shootout into my ruby, into a 3.5 inch 8r speaker.

it's cool!!

but i may trade it off for an old sekova (seiwa) analog delay. in that case, i'll do a proper layout.

rob, try putting v+ to the emitter of q1. bet ya it works. it's cool, it's a backwards envelope...not backwards in the way it sounds, but the way your attack controls it now.

before in up mode, you hit it harder, the higher the sweep.
down mode didn't do sh*t, frankly.

now, down mode works great...the softer you play, the higher the sweep...play balls and it drops into a bloody perfect pocket with a touch of compression.

so...if you made a mistake on the schem (i magnified it to be sure, yah, it shows as 9v+), well, i just verified that it works for ya. try it, and see if you still get the squeal.

[deadastronaut]

nice one jimi...


yeah the schemo is correct...  v+ to emmiter etc.....i just wondered what b+ was...i guess battery!!!!

anyway, i have it wired as per schemo, it may be the other mods causing it...R13 might be the supect!..hmmm....

i think i'll stick it back to original values for now and see if it sorts that out....i added R13 as it gives a better responsive  up/down' so it'll be a shame to lose that....anyhooooo....

cheers man, 

[pinkjimiphoton]

like i said, this is what i did, and how it's connected... and it absolutely works.

will try to get a proper vero together in a couple days if i get a chance.

well done, Rob and Mac..cheers, mates!!

[pinkjimiphoton]

i'm an old tube amp guy, back in the way back, the positive voltage was all called "b+" cuz everything ran on batteries...sorry bro.