JHS - Charlie Brown

General documentation, gut shot, schematic links, ongoing circuit tracing, deep thoughts ... all about boutique stompboxes.
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Boba7
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Post by Boba7 »

Ok, got it, the first SHO is actually an AMZ Mosfet Booser exactly as seen here: http://www.muzique.com/schem/mosfet.htm

It explains the 2x2.7k, the ceramic cap, the 2 electros, and the 150r is actually 10M.

The rest is strictly the dirt part of the Box of Rock (which is a mosfet BSIAB) with an added contour pot (thanks to AMZ)

The only resistor that's added is r26 (100k), above the contour pot. Dont know whats going on with that one.

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POTL
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Post by POTL »

Good day somebody have a circuit of this effect
I know that it is built on the basis of BSIAB but they have a different number of transistors and hence cascades
http://proguitarshop.com/media/catalog/ ... guts-c.jpg
I'm a little hung when he tried to pick up the resistor values :oops:
I think that this is very similar to zvex distortron :)

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POTL
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Post by POTL »

Really?
Nobody knows at this forum?

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phatt
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Post by phatt »

Google a resistor colour chart,, Good practice for you. :wink:
First 3 bands are value numbers,,
4th band is the multiplier,,
5th band is the tolerance.
Post your results to check your work. :thumbsup
Phil.

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POTL
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Post by POTL »

almost all resistors and symmetrical layout looks like I can not understand how to read from left to right or right to left

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phatt
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Post by phatt »

Yes it can be confusing and more so with 5 bands. :scratch:

Take R12 (top left next to C8) you read that one from left to right.

So,,, Brown (1), Black (0), Black (0), Yellow (4), Brown (1)
First 3 gives you 100 then Yellow is the multiplier which means you multiply 100 by 10,000,,,,or just add 4 zeros.
So R12 is 1Meg :thumbsup

Multipliers work thus;
Black= x1
Brown= x10
Red= x100
Orange= x1,000
Yellow=x10,000
etc;

5th band is Brown which =1 so it's a 1% tolerance.

If you read the bands backwards and it makes no sense then just read it the other way.
R1 (Top Center) might confuse you as the multiplier is Gold. :hmmm:
So grey, red and black reads 820 but the multiplier in this case is less than 1.
Gold means you multiply x .1 which gives you 82 Ohms,,,, or just take away one zero.
Hope it helps,,
Phil. :thumbsup

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POTL
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Post by POTL »

R1 82R
R2 61K9
R3 100K
R4 2K7
R6 10M
R7 1M
R10 2K7
R11 460K
R12 5K1
R13 1M
R14 1M
R15 180R
R16 5K1
R17 1M
R18 1M
R19 330R
R20 47K
R22 82K
R24 10K
R26 100K
R30 1K
Im right?

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J0K3RX
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Post by J0K3RX »

POTL wrote:R1 82R
R2 61K9
R3 100K
R4 2K7
R6 10M
R7 1M
R10 2K7
R11 460K
R12 5K1
R13 1M
R14 1M
R15 180R
R16 5K1
R17 1M
R18 1M
R19 330R
R20 47K
R22 82K
R24 10K
R26 100K
R30 1K
Im right?
Yeah, those look about right. I marked R4 as 1.7k but meant 2.7k.. mistake :roll: R2 and R11 I brought up to the more common values.
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charlie brown-res values.jpg

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Boba7
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Post by Boba7 »

Hey

I posted all the resistor values on the previous page!

Basically it's a Box of Rock without the boost part and with an AMZ Mosfet booster in place of the first stage of SHO, to avoid the crackle ok thing.

The only thing I can only guess is the role of the 100k above the contour pot. Looks like it's parallel to the pot to bring down its value (say 100k with a 100k resistor to make a 50k pot?)

Anyways, for something EXTREMELY close, just build this : http://tagboardeffects.blogspot.fr/2011 ... -vero.html

Replace the 100n that goes to Tone 3 with a 10n, and add a contour pot (a 25kb or 50kb that acts as a variable resistor between the 82k resistor in the center and ground)

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Boba7
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Post by Boba7 »

Only mistake you made is your 1.7k is a 2.7k

:)

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POTL
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Post by POTL »

Yesterday I compared the components of Charlie brown and the Bor and Distortron
Too many different components, jhs, will not depart from the original so much.
Maybe someone has one
And you can take a picture of the Board with both sides details, transistors (jfet or MOSFET)
Maybe try to traced the scheme

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POTL
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Post by POTL »

UP

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ThiagoFaraday
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Post by ThiagoFaraday »

Hello everyone!

so someone here knows the big difference about this version of charlie brown between the V4 with 3Q band. Im having issues trying to build this pedals. and angry charlie V3 same issues.

Here one Picture of charlie Brown V4.
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imgrc0068754851.jpg

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Post by POTL »

ThiagoFaraday wrote:Hello everyone!

so someone here knows the big difference about this version of charlie brown between the V4 with 3Q band. Im having issues trying to build this pedals. and angry charlie V3 same issues.

Here one Picture of charlie Brown V4.

tomorrow or the next day try to throw here the scheme of the previous version.
Although it seems to me that I will Frankenstein =)

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POTL
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Post by POTL »

I think is look like this
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CHARLIE BROWN.JPG

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Boba7
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Post by Boba7 »

I think the 100n in the tone section should be a 10n in the Charlie Brown (see the 10n in the middle of the pcb on the gut shot)

Also c6 is 22n, not 100n and c2 is 100n not 1n

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POTL
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Post by POTL »

Boba7 wrote:I think the 100n in the tone section should be a 10n in the Charlie Brown (see the 10n in the middle of the pcb on the gut shot)

Also c6 is 22n, not 100n and c2 is 100n not 1n
I can fix later, I was even more interested in the connection scheme - specific power filter and first stage

I joined zvex distortron with AMZ tonestack AMZ and booster, I want to understand everything if I did the right thing?
this is my first circuit

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Post by Boba7 »

Looks good to me!

It looks like there might be an additional 100nf parallel to the 47/100uf in the power section. Don't know.

And we don't know the tone pot value, though it might well be 25k.

I don't really understand this contour mod. It doesn't make a big difference in the eq curve. Replacing R19 with a low value and the tone pot with a bigger value would make more sense to me.

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Post by POTL »

Boba7 wrote:Looks good to me!

It looks like there might be an additional 100nf parallel to the 47/100uf in the power section. Don't know.

And we don't know the tone pot value, though it might well be 25k.

I don't really understand this contour mod. It doesn't make a big difference in the eq curve. Replacing R19 with a low value and the tone pot with a bigger value would make more sense to me.
EQ I took out of your post

Image

also possible option eq
http://www.madbeanpedals.com/EP/schemat ... nabout.gif

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Post by POTL »

Boba7 wrote:Looks good to me!

It looks like there might be an additional 100nf parallel to the 47/100uf in the power section. Don't know.

And we don't know the tone pot value, though it might well be 25k.

I don't really understand this contour mod. It doesn't make a big difference in the eq curve. Replacing R19 with a low value and the tone pot with a bigger value would make more sense to me.
you can share a link to the online or offline schemes emulator freeware software
I want to test before assembly

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