I would be really interested in this "version", but I have only found a partial schematic on the internets and I am not very good at reconciling schemes unless they line up (ie C6 = C6)
Can't do all the buffering and I have a feeling it doesn't have a muff tonestack.
I can do the buffering off board. I was under the impression from the schematic I saw and guitarpcb.com that the g2 is a modified muff. Any suggestions on taming the muff to get a more of a dirty overdrive sound?
Here is the schematic I found. Look right below the creamy dreamer...http://www.bigmuffpage.com/Big_Muff_Pi_versions_schematics_part3.html
There is already a Madbean project for the G2 called the "Darkside," but I don't see any reason why you couldn't plug the G2 values into a Mudbunny. You'll need to be a little creative with the tonestack.
The emitter resistors set the gain for Q2 & 3. You'll notice the Q2 one is relatively high (680ohm) which reduces the gain at that stage substantially.
Use BC550s, ge diodes, the right coupling caps, modify that tone control and you'll be in the ballpark.
Here's how to compare the schems, you can see the the circuits follow the same route. I've got an arrow showing R2 on the kit rae schem, you just need to plug the right values in for the rest. Grab a pencil and list the part values against the Mudbunny part numbers. I've done the first few for you.
I've also done the tonestack, as you'll need to modify it. Omit the crossed parts and add the extra 100k resistor to ground somehow. One neat way to do it would be to put the 100k in the R18 position and jumper pins 1 &3 of the mid pot. Alternativly you could tack it on to lug 3 of the tone pot and run it to any ground connection. I'll often do this sort of thing on the back of the board to keep it looking neat.
(http://i190.photobucket.com/albums/z30/codtone/cornish_zpsbe019cb2.jpg)
are the way the clipping diodes drawn on the Schematic still able to work on the mudbunny board this is where i got stuck?
Yes, they're electrically identical. MBs schem is just better drawn. ;)
cool wish i could see that as easily. thanks for such quick response
No worries, do us a favour and post the parts list here when you're finished.
This is a cool little diagram from the Kit Rae site (http://www.kitrae.net/music/Images_Secret_Music_Page/BIG%20MUFF%20CIRCUIT%20GUIDE.pdf) too.
r1 1m c1 47n
r2 39k c2 1n
r3 100k c3 47n
r4 470k c4 47n
r5 680r c5 1n
r6 15k c6 220n
r7 1k c7 4.7uf*
r8 8.2k c8 1n
r9 100k c9 220n
r10 470k c10 TS
r11 680r c11 TS
r12 15k c12 220n
r13 8.2k c13 220n
r14 100k c14 PS
r15 470k c15 PS
r16 100r
r17 15k
r18 TS
r19 TS
r20 390k
r21 100k
r22 8.2k
r23 2.2k (note 22uf electo and 680r parallel to ground)
TS= tone stack PS = power supply
i still seem like the diodes are differnt this is the darkside? is it the shareing the nodes
Well, maybe someone else will confirm this then, but I maintain that the diodes are electrically the same , just drawn differently. They are Ge in the G2 though.
Good catch, I overlooked those extra resistors at the output. The 39k can just go across lugs 1 &3 of the output pot, the extra cap and resistor on Q4 will have to be flown.
I like where this is going.. might have another build for the ever growing Juansolo muff excel doc.
Quote from: GVC66 on December 21, 2013, 07:11:34 PM
Here is the schematic I found. Look right below the creamy dreamer...http://www.bigmuffpage.com/Big_Muff_Pi_versions_schematics_part3.html
Bwahahahaha... Juan can't get away from that site this month.
lol, indeed!
ok i have a mudbunny board all socketed spent this morning populating and this works. u used 1n270 diodes( i used bat 41 in my darkside build)
i did a pharoah tone stack and i gotta say sounds pretty good
used 100k pot for sus and vol also did not add the extra output resistors that are in the darkside schematic
i just wanted to see if it would be close
Wow, this thread took off like crazy... Well, while I was away, I tried several trannies and settled on bc550s ( I actually think guitarmaggedon suggested theses too ). Used 103 for coupling, 1n60p for diodes, and after some serious swapping on the input cap I settled on 683. I have not boxed it yet so I do not have a good way to compare to my dry (my test box is uber basic) but, I love this thing. I was going to surround it with a couple of Cornishish buffers but I am not sure it is necessary. I loved the demos out ere of the G2 and with this experimentation I think I have the spirit of it in a 1590b now. Very happy.
you have to put those extra component's on that last q4 (i attached at the junction of R23 on new black mudbunny)
it will make the increase gain/output volume
all said and done it is some what different then my darkside i dont know if the buffer changes how hard the trannies get hit or if the diode are clipping different
still nice sounding muff