Phuncgnosis: so close!

[gnarlyguitarist6]

I just finished up my phuncgnosis build today, which is my second attempt because I messed up the first time beyond repair.  The down sweep works perfectly, but I have a couple small problems.  The up sweep seems much less pronounced, and I have horrible switch pop when switching between the up and down sweeps ( those are the two LED sections, rite?)  I know some people have asked similar questions and a few have said that not much can be done about the up-sweep being less pronounced, but can changing the LED's make a difference?  I used red LED's from small bear, should I try radio shack LED's instead?  Or is there something else I can do?  Also, how can I fix the switch pop on the SPDT (up/down sweep) switch?  I saw someone else had asked this but never got an answer, I dont think.  For anyone willing to help me, let me know if you want me to measure the voltages from the IC (a TL072).  Thanks in advance.

[cab42]

If you look at this layout: http://aronnelson.com/gallery/Cab42s-layouts/phunc_on_v1_0, you can see an optional 47K resistor from pin 7 of the IC to ground.

It was suggestested by petemoore and jmusser. I don't how well it works, though, as I have omitted the switch in my build and uses only the down sweep

Regards

Carsten

[markm]

To my limited knowledge of this circuit, my understanding is that the upsweep is much less weaker than the downsweep.
My understanding is that is just the way it is. 

[gnarlyguitarist6]

Carsten - I actually like your idea of not using the switch, having only the down sweep would be fine for me.  But im really new at this, so could you tell me what else I would have to change/ move around to get rid of the switch?  I used Tatems layout, though, at http://www.diystompboxes.com/smfforum/index.php?topic=48455.0.  I appreciate the help.  Thanks.

[cab42]

The switch creates a connection from the middle pole to on of the outer poles. Therefore the switch can be replaced with a jumper.

In Tatems layout it would be a jumper from b29 to e29 in order to get a fixed down sweep or from a29 to e29 to get a fixed up sweep.

Have you seem Mac's ideas for mods? http://www.diystompboxes.com/smfforum/index.php?topic=49246.0

I have only tried the first, replacing the 300K with a 1M pot. It works OK.

Regards

Carsten

[oldrocker]

I added a stomp switch to toggle the up and down envelope.   The up sweep is a little slow in response but I think it works very well.  The frequency response is on the high side but not bad.  The circuit looks easy to build but it takes a little effort to get it right.  I ended up using those small yellow LED's from Radio Shack and a 5532 to get it to sound like I wanted.
http://www.logmonster.com/images/full/?pic=phunc3n_1187620654-422-15333.jpg
http://www.logmonster.com/images/full/?pic=phunc1n_1187701026-422-15332.jpg