Bixonic Expandora

[bigmufffuzzwizz]

This is a fuzz/od my buddy has been asking me to build for him now for awhile. I'd personally like one for myself too. It has the extra setting via an interal DIP switch. There's also a few different versions. This video seemed to show most of the settings. Check it out, what do you guy think?

http://www.youtube.com/watch?v=Bm9Zq-Cps3w&feature=related

[jkokura]

I'm interested in the Expandora too. I'll put some work on this I think.

I first got interested in it because Stuart Townsend used a pair on his board back in the late 90's with Delerious.

Jacob

[cjkbug]

I've had a couple of these over the years. they are really great. sold em both in a pinch but I always keep an eye out for a good deal on one. lots of great sounds available and it's billy gibbons favorite dirtbox. I'd be into building one.

[juansolo]

Got some schems for these, can't remember where I found 'em, but I stuck 'em in my repository* to check out later.









*which is just my personal stash of schems, it's not meant for public use (as it'd piss people off copyright-wise), but after torchy pulling all his veros and others dissapearing into the ether, when I find something interesting, I drop it into there. The only reason it's visible to the world is so I can access it when I'm not at home.

[bigmufffuzzwizz]

Great! I'm glad there's others interested. The 2nd schem you have juansolo seems very do-able.
On a side note, you have some great looking pedals!!!

[jkokura]

yeah Juan, that seems to be the best schem out there.

From the looks of it, it seems to be a complicated Rat. I'm going to work on getting the schem into Eagle this week, but the hardest part may be that it requires 3 IC's AND an opto as well. The original seemed to use an SMD part for that, so subbing one in will take some research for through hole parts available commonly at smallbear and such. We'll see how it goes, but I really doubt I'll be able to get this into a 125B the way I like.

Jacob

[juansolo]

Great! I'm glad there's others interested. The 2nd schem you have juansolo seems very do-able.
On a side note, you have some great looking pedals!!!

Cheers dude

[sgmezei]

+1
I'm interested too. I have never seen one of these in person but always remembered the name from a Billy Gibbons interview. And he is awesome.

[jkokura]

Hey everyone.

So I put some effort and work into this one this weekend off and on. I have bad news. I don't think I can do a useable layout for this project. The board would have to be quite big, and the routing quite complicated unfortunately. If it were a double sided board, it might be doable in even a 125B, but boy is this thing crazy! I have the schem file I can upload for Eagle if anyone else wants to try. I'm going to revisit this during the week to see if I can do it, but my usual style of layout may not be doable.

Jacob

[pandadandan]

Hey everyone.

So I put some effort and work into this one this weekend off and on. I have bad news. I don't think I can do a useable layout for this project. The board would have to be quite big, and the routing quite complicated unfortunately. If it were a double sided board, it might be doable in even a 125B, but boy is this thing crazy! I have the schem file I can upload for Eagle if anyone else wants to try. I'm going to revisit this during the week to see if I can do it, but my usual style of layout may not be doable.

Jacob

Thanks for trying man!

I've loved the Expandora ever since I head it on At The Drive-In's One Armed Scissor.  I remember it having a vague Rat-esque setup.  It uses an LM308, right? 

[jkokura]

a pair of LM308's, a Dual Op Amp, and an LED/LDR as well (Vactrol). It's just a little bit complicated. I'm gonna try again though, there's a layout out there so obviously it's possible. I just got a little discouraged because it's of above average complexity. Might be possible still, but I weigh it to be unlikely.

Jacob

[bigmufffuzzwizz]

I asked Harald Sabro if he'd give it a try and he put it on his vero request list. Another person asked for it too so I think he's gonna give it a look over but there's something like 25 projects in front of it like the mutron bi phase!!

[pandadandan]

PCB layout
http://freestompboxes.org/viewtopic.php?f=7&t=2949&p=141785&hilit=expandora#p91578

[Effectsiation]

Just wanted to BUMP this one!  Would love to see this as a complete project!

There's a layout for this on Aron's Gallery, but it seems like everyone is getting hung up on a suitable/replacement Photo-FET for this project. The Sharp PC419 (or at least the one SmallBear carries) is apparently SMD, causing some problems. There seems to just be general confusion about how a Photo-FET works compared to our standard Vactrol/LDR. From what I've read the Photo-FET would respond differently (more quickly) than a LDR. Most Photo-FETs look like ICs and typically have 6 pins (therefore not fitting in Vactrol spots: Designs that take 4 pins, for the Photo Cell Resistor/LED).

[bigmufffuzzwizz]

I too would like to give my hand at one but I've got a lot to finish before 

Harold recently put up a layout based on a thread at FSB. It looks like he replaced the photo-fet. It's unverified but maybe you wanna try?
http://www.sabrotone.com/?p=1215