Skreddy Pig Mine

KindaFuzzy · Post by **KindaFuzzy** » 03 Oct 2011, 01:17

OK, here's a long distance trace from photos only. A friend borrowed one of these and sent some pics and confirmed values for me. the schematic isn't pretty, but I'm sure it's accurate.

KindaFuzzy · Post by **KindaFuzzy** » 08 Oct 2011, 03:40

Minor update, sustain is 100kb, volume is 100ka, and tone is 50kb.

culturejam · Post by **culturejam** » 08 Oct 2011, 04:00

Fuzzy, you rock.

tschrama · Post by **tschrama** » 08 Oct 2011, 18:56

Heee, thats great, big thasnk!

tschrama · Post by **tschrama** » 10 Oct 2011, 09:27

Could it be that the cap across the gain pot is 10nF (not 1nF)?

I couldn't spot the 200R cathode resistor, but I do think I can spot two 8K2 resistors.. are you sure there is a 8K2 before the 4th trannie?

Grtzz,
Thijs

KindaFuzzy · Post by **KindaFuzzy** » 11 Oct 2011, 23:07

I put all the pics I was sent in an album here: http://www.flickr.com/photos/35422385@N ... 873291422/

The cap across the gain is marked 102 for sure, the 200r is actually a pair of 100r resistors tied together at the top, they're over on the far side. I'll have to double check the 8.2k, but I'm pretty sure it's there.

tschrama · Post by **tschrama** » 12 Oct 2011, 09:14

Thanks for the explanation m8! I am going to breadboard it today.

grtz,
Thijs

okgb · Post by **okgb** » 12 Oct 2011, 15:15

Quick turnaround , nice work !
I can't keep up with even trying all the things to see if i Like them
but it's great to see & learn from the circuits , thanks

Skreddy · Post by **Skreddy** » 14 Oct 2011, 00:27

The good thing about this circuit variation is you can get a softer, creamier tone out of transistors that are otherwise fairly sharp and even a bit harsh sounding. It's actually a bit of work to design something that'll take modern, off-the-shelf, high-gain silicon BJTs and get a passable "vintagey" Big Muff sound. This design is tuned towards a strong midrange and good articulation, though; not wall-of-fuzz.

Those 1uf electro caps inline with the clipping diodes (mind your polarity, BTW) are the most important component of the "creaminess" factor. The 10uf input also helps of course, as do the .22 coupling caps between stages 2 and 3. Use ceramic disc caps where you need to soften the treble, which also helps add creaminess.

PokeyPete · Post by **PokeyPete** » 14 Oct 2011, 02:47

Looking at the given schematic and the photos, the number of resistors is different. I count about 25
in the photo (counting the 200R as one), and 23 resistors on the schematic. I see what appears to be
100R resistors in the photos that are not accounted for in the schematic.

Skreddy, thank you for your comments and explanations. Over and over you have shown you support
of this forum, and I, for one, would like to express my gratitude for your positive attitude and generous
assistance. Thank you!

KindaFuzzy, you've done an outstanding job if all you had to work from was component side photos!
But, I feel it may only be 98% complete. Maybe Skreddy will be kind enough to verify the schematic
or fill in missing pieces.

tschrama · Post by **tschrama** » 14 Oct 2011, 06:30

the extra 100R can be a series resistor for the Powersupply. I think spotted four 16K resistors.. huh

KindaFuzzy · Post by **KindaFuzzy** » 14 Oct 2011, 11:17

tschrama wrote:the extra 100R can be a series resistor for the Powersupply. I think spotted four 16K resistors.. huh

I think you're right, and there was a 10k that went to the LED I think, but left it out because the circuit was more important. So that would account for all 25, good eye, I wasn't that thorough.

Skreddy · Post by **Skreddy** » 15 Oct 2011, 07:01

One more thing: I use the classic BMP collector-resistor values in the Pig Mine.

Q1=18k
Q2=10k
Q3=18k
Q4=10k

Not 16k.

But some people do like using 15k all around. Whatever you like best.

Skreddy · Post by **Skreddy** » 15 Oct 2011, 21:46

KindaFuzzy wrote:Minor update, sustain is 100kb, volume is 100ka, and tone is 50kb.

If I made a Pig Mine with a 50k tone pot, that was a mistake.

50k is nice for when you want a more subtle tone control, where there's a bit of bleedthrough at both ends; a softer, less focused effect.
I use 100k on the Pig Mine and anywhere else I want a more aggressive, focused tone control.

KindaFuzzy · Post by **KindaFuzzy** » 15 Oct 2011, 22:07

50k for sure.

Skreddy · Post by **Skreddy** » 15 Oct 2011, 22:20

KindaFuzzy wrote:

50k for sure.

Yep. Interesting variation (it happens). Not my normal spec, though. Both are good choices, but like I said; 50k is more gentle, subtle, and unfocused. 100k is my preference in this circuit.

Skreddy · Post by **Skreddy** » 15 Oct 2011, 22:51

Oh; want me to replace your 50k with a 100k? Email me if so.

KindaFuzzy · Post by **KindaFuzzy** » 16 Oct 2011, 01:36

I'll let my friend know, it's his and he's over in Iowa. Thanks for the offer.

tschrama · Post by **tschrama** » 17 Oct 2011, 09:12

tschrama wrote:Thanks for the explanation m8! I am going to breadboard it today.

grtz,
Thijs

I got sidetracked... bought myself a Skreddy Lunar Module, ... and it's awsome

.. such a balanced unit, great versatility too, keep me playing more than soldering... no hype, it is really really nice.. comparing with my Dano CF-1: more sustain, more woody sounding, more buttery, more-focus, more articulation, more versatility...Skreddy must have *great* ears to cook up such a recipie.. i think like it better than my diy-pinked-mayo which skreddy help me build.

Anyways, the diy-pig-mine on half done on pref board.... I'll report back when I got tink to test it...

Thanks Skredyy for joining in!

.. but I still think I can see four 16K resistor. i dont get it

KindaFuzzy · Post by **KindaFuzzy** » 17 Oct 2011, 11:13

tschrama wrote: .. but I still think I can see four 16K resistor. i dont get it

They kind of look like brown blue orange in the pic, but I think it must just be the color setting of the camera making the grey look blue. I'd trust the man that built it if he says it's 18k/10k/18k/10k for the collectors.

Skreddy Pig Mine [traced]