Torchy BMP layout and Tonepad Schem irregularities??

[solarplexus]

http://www.indyguitarist.com/torchy/Distortion_Overdrive/EH%20Big%20Muff%20Pi/BMP.gif

I've built my Big Muff with this layout and I didn't the bassy sound of it.  I saw on Tonepad different versions and mods of the "Triangular" or "Green Russian" versions but the part numbers from Torchy's layout and the schems aren't all matching.  Not that they are actually suposed to... but if they used the BMP schem, shouldn't they be the same ??

I'm trying to match the parts so modding would be easier to figure out.

Also, there is an additional R22 in the Tonepad schem that is not in Torchy's layout, and there is a resistor in Torchy's layout that has no identification (K7 to K9, right between R21 and R13).

Here's what I found so far :

Torchy's Layout            Tonepad Schem
R8                               R10
R13                             R15
R15                             R16
R16                             R17
R17                             R18
R18                             R20
R20                             R21
R21                             R22

The caps all seem in the right position/part number...

Any help figuring these part numbers would be appreciated... and what about the X resistor in Torchy's layout ??

Matt

[wampcat1]

what's the url to the tonepad schem?

Thanks,
Brian

[solarplexus]

http://www.tonepad.com/getFile.asp?id=94

[spudulike]

Isnt the mystery resistor superfluous ? On the torchy layout its in parallel with R15 (100R from e to gnd). Could be he moved R15 away from the tranny but the original position wasnt removed ?

Have you asked torchy about it ?

[nightingale]

There are many versions of the BMP circuit.
Last week I built each muff from the tonepad PDF back to back 3 nights in a row from start to finish. Each circuit has a different character.
Check out this link to the "big muff versions page": http://www.pisotones.com/BigMuffPi/psst/BMP_versions.htm

hope this helps,
ry

[solarplexus]

But does the parts number in the layout matches the part numbers in the tonepad schems ? ?

If yes, it would mean I only have to change the values

[Barcode80]

torchy's layout likely does not match any of the project pages. he probably drew it from whatever schem or trace he had which may not match exactly to any tonepad or ggg project. further, his layouts are all considered build-at-your-own-risk and aren't verified or supported by him. they were posted by wampcat and have an understood unwritten disclaimer that some tweaking is necessary on some. it would take less time to make your own layout than to try to decipher his against another project his has no connection to.

[col]

I built one from Torchys BM layout and it didn't sound right. I have spent hours trying to de-bug it and I'm sure there's no errors but all the ones I did to my own layout have sounded fine. There was a double of one resisistor from what I remember but even with that removed it wasn't right. I much prefer the triangle muff/3 knob foxy lady with no electolytic caps. All the photos of early muffs show a full ceramic cap complement and I suspect that that makes the difference. Maybe Torchys layout with all 100n caps would sound better, I dunno! Some people think the modern isuue sounds better. It also makes a massive difference what transistors you use even if the hfe is nominally the same. I like BC184C and BC549C. I have tried allsorts with the same gains but they do sound different. That is the great thing about DIY, modify it 'till it's what you want. Don't be satisfied with what other people tell you is the right way to do something.

[solarplexus]

Well I built the layout and it's too bassy and muffled... so if I look at the parts value and the schem I guess there are some parts that aren't quite fit.  I'll still try to find which part on the schem is which... then the layout could be verified and modded as pleased.

Anyway, thanks for your help/suggestions.

Matt

[solarplexus]

Ok I rechecked the schematic on tonepad and the layout from torchy.

Seems to me that R13 on the schem (which goes to ground) is missing on torchy's layout.  The part number is there but it's not the right place/value.

Here's what I found :

R8 schem = R10 layout
R10 schem = R8 layout
R13 schem = missing on layout
R15 schem = R13 layout
R16 schem = R15 layout
R17 schem = R16 layout
R18 schem = R17 layout
R20 schem = R18 layout
R21 schem = R20 layout
R22 schem = R21 layout

Could anyone help me verify this ??  It would be greatly appreciated!

Thanks,

Matt

[solarplexus]

Could anyone please help me with this ??

pretty pretty plz ??