D*A*M - Meathead  [traced]

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

Owkey, really love this pedal, very nice fuzz, pictures of the perfboard:

https://s70.photobucket.com/albums/i94/ ... 0Meathead/

Pot: 500k Lin

Left to right:

Elco 1: 47u
Film cap: 10nk 400
R1: 18k
Trans1: T2n3904
R2: 120k
R3, vertical: 819 ohm
R4: 4,7k
Trans2: BC182L
Tant blue: 471
R5: 1k
Elco2: What i Can read : 021 ko (1nF?)
Film cap2: 22nk 400
Tant blue2: 47

box is an Bimbox n°5003-13

enjoi and thanks to this amazing forum!

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The Rotagilla
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Post by The Rotagilla »

Nice, thanks! :applause:
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analogguru
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Post by analogguru »

enjoi and thanks to this amazing forum!
:hmmm: Am I right that you want to see now the

D*A*M - Meathead schematic

enjoy,
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RnFR
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Post by RnFR »

alright! i heard this thing was really cool. i think i'll put it on the breadboard tonight. thanks!:applause:
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Greg
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Post by Greg »

It is a great sounding Fuzz...
Many thanks to Stefcuypers and to AnalogGuru... :thumbsup
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briggs
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Post by briggs »

Wow! Great work all round. Looks like one of those standard "all out all of the time" fuzzes. Doe it react well to guitar volume alterations I wonder?
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stefcuypers
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Post by stefcuypers »

nice and fast analogGuru! thanks, did someone allready made a pcb layout?

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Post by bajaman »

YAFF :wink:
surely you do not need a PCB for this - Yet Another Fuzz Face :slap:
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RnFR
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Post by RnFR »

ha! i guess one should actually take a good look at the schem before commenting! :oops: :lol:
supposed to be a nice one tho!
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Post by bajaman »

well at least it is silicon - so should sound the same and work consistantly well :wink:
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MoreCowbell
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Post by MoreCowbell »

this is the older 1 knob silicon version...i'm not sure if Dave has changed the 1 knob version since this one was made a couple years ago.

there is also a "deluxe" version with fuzz, filter, and volume controls.

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Post by MoreCowbell »

BTW... .01u seems "too small" for the input cap. I didn't look at the pictures, but .1u seems to make more sense.

Maybe I should look at the pictures first , before making that statement... :slap:

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Post by seniorLoco »

MoreCowbell wrote:BTW... .01u seems "too small" for the input cap. I didn't look at the pictures, but .1u seems to make more sense.

Maybe I should look at the pictures first , before making that statement... :slap:
Yup... no meat with .01uf ??? :mrgreen:
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lynessmy
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Post by lynessmy »

Any mojo factor from the cap? would it sound differently if normal MYLAR FILM or MULTI DIP were used?

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Post by JHS »

The green caps soften the sound a lot, yielding in a rounder fatter tone. With other caps the Meatball will have sound more harsh, clearer and with more treble.

Those green caps are crap for hifi stuff but IMHO they are really good in a simple fuzz circuit. I wouldn't call this Mojo, hype or whatever, they only sound different compared to other types.

JHS

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Post by bajaman »

I wouldn't call this Mojo, hype or whatever, they only sound different compared to other types.
Agreed - less top end = smoother sound and less fizz :wink:
I like the sound of the old Crowther Hot Cake when compared to the current version his wife is building.
It had a crappy (for hifi) 741 op amp - the new one has a TL071.
AND - even Paul knows the sonic benefits of those crappy mylar capacitors - he has always used them - still does.
cheers
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Post by lynessmy »

stefcuypers wrote:nice and fast analogGuru! thanks, did someone allready made a pcb layout?
Redrawn Schematics to generate the layout .
Image

Component Layer
Image

Trace Layer
Image


Size of board is 38mm Wide x 28mm Height. (shrink to about 25%)

Layout is not yet tested but all connection matched the redrawn schemetics.
Man...this i red hot...fresh from the oven...i don't even put it up on my blog yet....

1M pull down resistor is not in the schematic shared by analoguru. It was added for just in case.
103 input cap was said to have "NO MEAT". I put an optional 102 / 104 in the layout.
Additional pads added to cater different pitch sized for 470p cap.
Ignore the tant mark for the 47p cap.
Diode are 1n400X.
Sq pad for POT is the first lug.
Sq pad for E-Cap denote positive terminal. :hmmm: As usual...

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lynessmy
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Post by lynessmy »

I build this yesterday with positive result but the design is not very tweakable.
The pot i labeled as DRIK :slap: typo there....Should be DIRT as in the schematic...is not more than a volume knob.
I will replace 1k resistor with a pot to see what can i get.

:secret: that make it like the Si NPN fuzz face..... :lol:

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Post by stefcuypers »

Thanks lynessmy for the pcb layout and comments! Very nice blog also! keep up the good work!

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Post by JHS »

The Meathead is a typical Si-FF/TB clone, maybe with a somewhat refined sound with a bit more gain and bite, nothing more. The sound depends more or less on the gain of the used trannies and the type.

I have a program that calculates the nominal gain for the trannies in a FF or RM in a circuit with user defined values but I'm short on time to make such al calculation. With my experience I guess both trannies have app. 150-180 hfe.
Higher or lower hfe won't match the collector Rs and the feedback R.

JHS

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