freestompboxes.org

Can't say i'm crazy about most of the amp sounds , but he doe's manage
to use the cae boost overdrive without it sounding horrible ,
Anyone know what the pork Loin pedal is based on [ or basic design ] ?

http://www.jimdunlop.com/blog/?p=3572&u ... dium=email

Has anyone had a chance to trace one of these yet? I'm curious to see what's going on inside these, and there don't seem to be any threads where someone attempted to trace it quite yet.

Thanks!

Here's the schematic i've traced from my own unit. Component numbering on the circuit board is a bit odd.


Guts (sorry for not using attachment, will upload the zipped file soon) :











I can take another picture of my PL if needed. Hi-res photo will be sent via e-mail.
First post here, hope to contribute more in the future.


.

Topics merged.

Congratulations on your reversing, looks like a pretty bitchy unit to trace! Thanks for this nice contribution to the forum...

Awesome!!

Me thinks the clean path should have more or less the same 3 transistor stage configuration both before and after the filter section.

The stages are just arranged differently superficially. They are the same except that, as drawn, R30 (equivalent to R13) is shorted. That's probably an error.

WhiteKeyHole wrote:The stages are just arranged differently superficially. They are the same except that, as drawn, R30 (equivalent to R13) is shorted. That's probably an error.

that was my thinking. for whatever reason, stage 2 was easier to interpret in my head.

it looks like the PN2484 is a general purpose transistor and could probably be replaced by anything common like the 2n5088/9

oops, sorry for making a new thread on this particular subject, i wasnt sure that this newer way huge belong to the boutique section (not in a bad way)

dont know how the first stage come up in a different arrangement on the drawing process
i'll check it again and see if there's any error in the scheme (probably R30 as said).

i don't think R30 is wrong, but the junction with C26 and R28 should NOT connect to 9v

Scheme updated.
The first and the second clean stage is identical, except the value of C1 and C32 between B-E.
Vref junction is around +3V.

Any idea how to make this a bit brighter sounding on the OD side ?. It cuts highs even when fully CW.
I also found that the Presence control doesnt do much.

EDIT : Input and output capacitor shown as electrolytic caps on the scheme. However they're film caps in the actual board.

Thanks a lot!!!, I've looking for this for a long time, I love the Pork Loin!!.

Lower R12 and the tone control will open up a little bit more.

Lower C11 might make it brighter as well. I'm not sure it it would make the presence control better though.

Great work! I don't suppose you have a fat sandwich as well?

coldcraft wrote:Lower C11 might make it brighter as well. I'm not sure it it would make the presence control better though.

Great work! I don't suppose you have a fat sandwich as well?

I dont have it. Tried one in a music store, can't dial a good tone out of it (probably have to mess with the internal trimmers).
I'm working on my Swollen Pickle MKII though, parts value is nearly the same as described in the particular thread, except that they have 4 extra pots that really do a lot as opposed to my PL. A great Muff variant (without that annoying hummmmmm like the original one i used to have)

Sweetalk wrote:Thanks a lot!!!, I've looking for this for a long time, I love the Pork Loin!!.

Lower R12 and the tone control will open up a little bit more.

TGP crowd says it nails "that Klon tone".
The clean part really blends well with the drive signal (better mix compared to sparkle drive).

And thanks for the suggestions. Will report back soon

definitely a good basis for some big modifications. I'm working on a tweaked up one now. Going for some more interesting Overdrive character. I'd like to see the input buffer become an OpAmp, and if it was inverting, we could drop the one at the output. Thoughts?

early.memoirs wrote:

earlymemoirs - pork loin.jpg

Scheme updated.
The first and the second clean stage is identical, except the value of C1 and C32 between B-E.
Vref junction is around +3V.

Any idea how to make this a bit brighter sounding on the OD side ?. It cuts highs even when fully CW.
I also found that the Presence control doesnt do much.

EDIT : Input and output capacitor shown as electrolytic caps on the scheme. However they're film caps in the actual board.

try making c11 smaller. that cap is dumping lots of highs to ground.

I am amazed at the mileage they got out of 22k resistors.

early.memoirs wrote:

earlymemoirs - pork loin.jpg

Scheme updated.
The first and the second clean stage is identical, except the value of C1 and C32 between B-E.
Vref junction is around +3V.

Any idea how to make this a bit brighter sounding on the OD side ?. It cuts highs even when fully CW.
I also found that the Presence control doesnt do much.

EDIT : Input and output capacitor shown as electrolytic caps on the scheme. However they're film caps in the actual board.

Really ALL 22k resistors?

actually no. looking back at the pictures, its definitely not all 22k. we need to get the values.