BAJA SLO MkII overdive pedal project 040218  [documentation]

Original effects with schematics, layouts and instructions, freely contributed by members or found in publications. Cannot be used for commercial purposes without the consent of the owners of the copyright.
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bajaman
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Post by bajaman »

Hi folks
Here is an updated version of my Baja SLO overdrive pedal - although the original design works very well, i wanted to get a bit closer to the individual gain stage's frequency and phase response characteristics and the only way I could see to do this, was to use four gain stages (not two as in the original BAJA SLO) matched to the actual four gain stage amplifier schematic :wink:
cheers
bajaman
Baja SLO MkII overdrive pedal 9v 030218.GIF
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287m
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Post by 287m »

here the perfman go
sadly, hard without jumper :)

great project series Baja :thumbsup
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slo-mkii-value.png
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FeVeR2112
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Post by FeVeR2112 »

287m wrote:here the perfman go
sadly, hard without jumper :)
I use 0 ohm resistors as jumpers... looks better.... :P

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bajaman
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Post by bajaman »

Here are the frequency and phase response graph comparisons - red is the Soldano SLO schematic and green is the pedal
cheers
bajaman
SLO MkII.gif
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HEAD
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Post by HEAD »

Hi,

finished mine today. Comes with a BM style tone control borrowed of the BSIAB II project. Made the low pass filter after the tc of the BSIAB switchable (that's the toggle switch). Love it. Simpler controls and yet pretty close to my Wampler triple wreck clone - though it sounds a bit raspier, which I like.

Cheers and happy holidays
Helge
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HEAD
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Post by HEAD »

Oh, and almost forgot to say thank you to bajaman and 287m who made it possible to have this wonderful pedal! Shame on me! Thank you so much guys!

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287m
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Post by 287m »

Hea, its beauty and beast :twisted:

so, because your nick is Head, you forced yourself to use chicken head knob too?

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roseblood11
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Post by roseblood11 »

Looks like an interesting version, please share schematics and layout!

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HEAD
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Post by HEAD »

Its just this design plus an added big muff style tone control with the BSIAB values (http://www.generalguitargadgets.com/pdf ... ab2_sc.pdf) and the low pass filters of the BSIAB design switchable. Since this tone control "eats" some volume I added a simple ehx lpb-1 after the tone control. Since this design has a lot of output I decided to to put the volume control before the tone control to not overdrive the transistor and hence get some nasty added distortion. Sounds complicated but is really simple in reality. I took this an redesigned the PCB to my taste: http://effectslayouts.blogspot.de/2017/ ... stack.html

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HEAD
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Post by HEAD »

287m wrote:Hea, its beauty and beast :twisted:

so, because your nick is Head, you forced yourself to use chicken head knob too?
To be super German here (which means no sense of humor :D): It did use chicken head knobs because a) I got them cheap from eBay and they are made for split shaft type pots which I used here and b) chicken head knobs somehow always evoke the impression of amps to me.

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Post by lmkv15 »

unterhalte dich mit Roseblood dich gleich auf Deutsch :-)

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HEAD
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Post by HEAD »

lmkv15 wrote:unterhalte dich mit Roseblood dich gleich auf Deutsch :-)
I know. Trotzdem, dieses Forum ist international und er sollte es verstanden haben. ;-)

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287m
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Post by 287m »

bump

an old friend want this, breadboarded with j201 (i think fake item). Sound good in front Joyo American. Time to redraw layout.

Baja, and anybody, any chance for tonestack? or where the best position to experiment?

Thank you

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Post by plush »

287m wrote: or where the best position to experiment?
Between clipping diodes and output buffer. Don't forget to decouple.

If any volume drop occurs, you can replace output buffer with a power booster.
Or add another gain stage to look like this: ->[clipping diodes]->[buffer/amplifier]->[tonestack]->[output buffer/amplifier]->[volume knob]

You can find classic soldano tonestack in gewgl.

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Post by Raumfisch2019 »

Thank you for this cool schematic. Just finished building it with my own PCB layout and really like it's sound!

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Post by roseblood11 »

I'm sooo lazy... I've been waiting for someone to post a veroboard layout for almost two years now... :-)

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Post by bajaman »

I revisited this pedal over the Christmas break and decided to add a tone stack on the output - I did change a few capacitor and resistor values, but essentially the circuit remains basically the same as the MkII version but with tone controls.
I used three small presets for the tone controls and built the tone stack on a small section of stripboard. I then attached it with double sided 3M insulating foam tape to the underside of the top of the enclosure and drilled three small holes in the base to allow adjustment of the three controls with a small flat blade screwdriver. I quickly found the "sweet spot" and once set, I felt that no further adjustment was necessary. Very pleased with this design and modification - here is the schematic - Happy New Year :D
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Baja SLO MkIII overdrive pedal 9v with tone controls 090120.GIF
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temol
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Post by temol »

Any plans for a new overdrive pedals? How about Mesa Boogie Mk 2 or Mk4? :)

T.

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Post by rcustoms »

temol wrote:Any plans for a new overdrive pedals? How about Mesa Boogie Mk 2 or Mk4? :)

T.
or splawn quick rod
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