Phuncgnosis mods

[deadastronaut]

ha ha no worries...

cool, its nice to finally nail this mode lark after all these years!!!...

that R13 really kicks the response of the filter in to gear...without it its really weak when compared..(anything from 47k to 100k)

clip a resistor onto that 2.2n  and try it out...much better....


edit:  swapped out the 3904 for a 5088...squeel stopped..yay!!!...so far so good!.

[pinkjimiphoton]

i'll give it a shot when i get a chance!

[cab42]

I just found this thread and spent few moments updating the original vero layout with the down sweep mod:



I added the two components and a trace cut as well as moving the connection to the switch one row down.

Does it look OK?

In my build, I omitted the switch and the down sweep, but I'll give it a go. I don't think I have any 2N3904's left but I'll try some 2N5088's or BC549C's instead.

Carsten

[deadastronaut]

looks ok,  i tried various npn's, and i tried a few 3904's till i got one that worked,  sorry didn't measure the trannies hfe etc...

but that may or may not have been crucial..

[cab42]

looks ok,  i tried various npn's, and i tried a few 3904's till i got one that worked,  sorry didn't measure the trannies hfe etc...

but that may or may not have been crucial..

Thanks.

yesterday, I tried to make the circuit work. I had been using if for a long period, but it suddenly stopped working and has been lying in my box of abandoned effects in the hope of selfhealing.

I think i may have fried the TL072. I have sound on both the input pins (3 & 6) but none on the output pins, but the voltages looks OK.

Carsten

[cab42]

It has been a year since my last post and finally I took some time looking at my dead Phuncgnosis.

I just replaced the opamp and it quacked like a dream.

The only mod I had was replacing the 330K resistor with a 1M Pot as suggested by Mac in the original post and I had left out the down sweep.

I tried out a few of the changes suggested by Deadastronaut. First the down sweep. I used a 5088 and it worked right away. Well sort of, I expected something similar to Jimi's demo, but it's more like another up option.  When I hit the strings harder, it gives a higher sweep.

Next I added a socket for the up diode. I couldn't decide and as I had a three way slide switch, I wired it up as up-led, up-si or down. The difference between LED and Si is not big, though. Almost negligible really. 

that R13 really kicks the response of the filter in to gear...without it its really weak when compared..(anything from 47k to 100k)

clip a resistor onto that 2.2n  and try it out...much better....

This mod had the exact opposite effect on my curcuit. It killed all dynamics and it sounded like the speaker was wrapped in blankets. I used a 100K. Any idea why?

I also tried the release pot between D2 and D3. It works better than replacing the 330K with a pot.

Lastly I socketed the two 680pf caps and tried different values. I liked the original 680 pf and 1n best, but I can't decide. Another switch? I might even ditch the diode switch, stick with the Si up sweep diode and use the switch for the caps.

Regards

Carsten

[mac]

It has been a year since my last post

Why you took so long?
I was in Copenhagen last August, we could have talked about mods while drinking a beer or two   

mac

[Kipper4]

I'm fresh out of super bright greens.
Can i use a yellow super bright?
Thanks

[deadastronaut]

try it, probably fine..

[Kipper4]

What about the 470uf is it critical
i think the boggest i have is a 330uf?
thanks Rob
I've done a perf layout if anyone wants to see.

Edit ;I'm fibbing I have 1 x 470uf in a box of old stuff robbed from an old dvd player

[pinkjimiphoton]

470/330 whatever, should work.

color i don't think matters as much as long as it's not white, ultra or blue

yellow is pretty close i think

[Kipper4]

I'm getting loads of ripple/oscillation when in the (2n3904)down switch position.
and its not really sweeping. Help. (by sweeping i mean wah ing)
Are you guys using a Fuzz in front of it?
Currantly auditioning differant colour LEDs and BJTs.

[pinkjimiphoton]

i'll try and find mine later and see what it does. i don't think i used ultra brites, too brite and i don't think it will work as well sometimes.

[Kipper4]

i still have some trials re the leds and i found the problem now.
A back to front D1 . I did the layout wrong followed it and it wasnt until i double checked the orientation with the schemo that i found it.
Its qaucking now.
I'm gonna mess with it a bit more and now try some differant oppys and trannys.
tommorow
thanks Jimi. Let me know what you think when its in down mode can you really hear it qaucking the same?

[pinkjimiphoton]

yah it quacks going down but it sounds better going up. i think it's a psycho accoustic thing or something...

[Kipper4]

Thanks I hear ya brother.

[mac]

With another filter opamp tuned lower it could sound better.
Just a thouhgt.

mac

[Kipper4]

Please can you expand on that Mac. I'd love to see your ideas.
thanks
Rich

[mac]

Take a look at the Phozer II. It has two filter opamps.

If you look at the schematic in the first page, you can copy everything between R1 and R7, the upper opamp, and change C6 and C7 for 2n or so. The output goes to C8-R10.

BTW, R13 can put some DC at the guitar when used in  down mode. Check it.
I'd put C1 first, then R1. Or move the wire to R2-C1 junction.

mac

[Kipper4]

thanks mate i'll check that later and get back to you .
Also I'll check out the phozer