Hi, I'm new...oh, and I could use a hand.

Started by blues_mang, July 10, 2007, 11:31:38 PM

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blues_mang

Hey all! Newcomer, but long time lurker. Have learned a lot from the many knowledgeable people here. I've built over a dozen pedals, mainly with BYOC boards which was a fantastic start, but I'm beginning to branch off a bit. I recently built Jack Orman's MOSFET Boost and modded it with some of the diagrams I found here. So, it's time to come out of the shadows and into the limelight and say hello and to ask for some help.

I built an octave fuzz pedal from one of Keith's PCB's over at BYOC. He had incorporated an untested mod in which you could bypass the fuzz by bypassing the 2nd and 3rd transistor stages and a zero ohm resistor (jumper), giving you a clean octave. There is pads incorporated into the PCB for this, but I can't seem to get it to work and can't wrap my head around why what I've done so far isn't working. I've been waiting patiently for an answer from the forum over there, but haven't received one. Since it is a theoretical untested mod, he doesn't give much support for it. However, he is good at answering technical questions on getting your stock pedal to work. You're kind of on your own when it comes to mods, which I suppose is the way it should be. So, I'm posting a link to the thread with the schematic for his octafuzz (which is stickied on his website for anyone to see) and am wondering if anyone can tell where I can put the switch to bypass the fuzz and have a clean octave?

http://board.buildyourownclone.com/viewtopic.php?t=4508

Thanks.

-BB

If you ain't gots da blues in yo shoes, then you got a hole in ya soul.

Dan N

Sorry, I've never built an Octavia. On the PCB, what parts is the 0 ohm jumper connecting?

brett

Brett Robinson
Let a hundred flowers bloom, let a hundred schools of thought contend. (Mao Zedong)

Barcode80


bonkdav

ive heard of bypassing the transformer so that is only fuzz and no octave, but not bypassing the fuzz...sound neat. i wish i could help because that interests me too. hopefully someone has the answer.

rockgardenlove

Schem:
http://pic20.picturetrail.com/VOL83/511092/4336798/244821211.jpg

Layout:
http://pic20.picturetrail.com/VOL83/511092/4336798/244821926.jpg

I assume that little resistor would go in the "0" marked resistor pad.  Seems logical.  Can you tell us where each end of that jumper would end up?

Shouldn't be too hard after that.
When it doesn't work, does nothing happen, or what exactly?

Cheers!



blues_mang

The mod to switch out the fuzz is a DPDT which lifts the zero ohm resistor and C7 electro cap from what I can tell. When it is switched, I get no sound at all. Sort of like a mute switch.  :icon_lol:  I will open up the pedal tonight and trace where the zero ohm resistor connects. One other thing, the 2 unmarked pads next to the C8 cap are the pads that were built-in for this mod. The one directly next to C8 connect to the + side of the C7 electro and the other pad connect to the transformer. On the cap is wired to the pole of the DPDT and opposing lugs are wired to these pads.

-BB
If you ain't gots da blues in yo shoes, then you got a hole in ya soul.

blues_mang

#7
Okay, checked the PCB and traced out the zero ohm resistor. One side of it goes to a trace that connects to the leg of Q2 (2N5088) and the other side connects to a trace that runs to R2 (680K).

Here is what Keith said on the original post about the fuzz lift switch...

"This is a theoretical mod that I have not tried myself. The octavia is somewhat similar to the tonebender as far as the fuzz circuit goes. It's a 3 stage cascaded transistor fuzz. So this mod bypasses the 2nd and 3rd transistor stages leaving you with essentially nothing more than something that is very similar to an LPB w/ a gain knob which runs into the transformer for the octave effect."

Like I said, when I followed his diagram in this post
http://board.buildyourownclone.com/viewtopic.php?t=4230

and added the zero ohm resistor lift, it mutes the pedal completely.

Any help would be greatly appreciated. Here's a pic of the completed pedal by the way (with the non-working switch). The pedal design is based loosely off of Hendrix's album cover Axis: Bold as Love, hence the name of my pedal Octave: Bold as Fuzz.

If you ain't gots da blues in yo shoes, then you got a hole in ya soul.

blues_mang

Anyone or any other info. needed? I'd really like to get this one figured out. It's been driving me nuts for months. I'm sure it's something simple I'm overlooking, but I just can't wrap my head around it.
If you ain't gots da blues in yo shoes, then you got a hole in ya soul.