ROLAND: BeeBaa AF-100

I've posted layouts for a stripped-back version of the Roland BeeBaa, but never for the full BeeBaa.  So here it is.

The Roland BeeBaa has a couple of extra options, not generally found on fuzzes of the era, mainly the treble boost and tone control.  The switching swaps between a treble boost and a fuzz with two tone settings (notch filter or direct).  The fuzz feeds into a tone control, bypassing the treble boost.

I've listed 2N3904 for transistors, but you can use just about any silicon NPN -  for my ears, lower gain transistors sound better, but you might like something higher.   

MLCC capacitors have been used for 1uf and 10uf caps to save on space. 

Bi-colour LEDs have been included to keep track of the switching.  You could use single-colour LEDs using the standard method or no LEDs if you prefer (not recommended due to all the switching options).

Drop the last 4.7n cap on the right if you want more sizzle in the fuzz.

ROLAND BEEBAA AF-100 - VERO LAYOUT

ROLAND: Modded BeeBaa AF-100, Schematic

 

ROLAND: AF-60 BEE GEE

This one is interesting; it's a bit MXR Distortion + at the front and a Big Muff tone control at the back.  Here we have the Roland BeeGee - I have no idea where the name came from back then. That is an interesting choice from Roland.  

ROLAND AF-60 BEE GEE - VERO LAYOUT

ROLAND AF-60 BEE GEE - VERO LAYOUT, WITH GAIN MOD

Same again but with added gain control.  This allows the gain to be dialled back, as the stock setting is full fuzz on the original.

Probably best to use an old tin can single op-amp if you find one.  From my experience, the new op-amps just don't sound the same.  They don't sound bad, just different.  The newer op-amps are usually quieter and perform better in nearly every respect - which is why they were developed.  There's something about the poor performance of old op-amps that can bring a bit of extra character that I like (not enough to spend exorbitant amounts on NOS op-amps, though).

ROLAND: AD-50 Double Beat

Not one seen often in the wild -  this is the fuzz section from the Roland AD-50 fuzz wah.

ROLAND AD-50 DOUBLE BEAT - VERO LAYOUT

ROLAND: BeeBaa AF-100, Point to Point and Vero Layout (Modded)

This is a bare-bones Roland BeeBaa.  I built the full version and found that all I really used was the scooped fuzz sound - so this is just that.  Nothing but unadulterated vintage Japanese fuzz....    

I think this works best with low-gain transistors.  I made a version using weird KT315 Soviet BCE transistors, and it sounds mean.   If you want to take the simplicity a step further, just drop the Sustain control and run at full tilt all the time - you'll have a one-knob Japanese fuzz.  

There are also two great variations on the BeeBaa over on Dirtbox Layouts, which are well worth a look. The Stoner Bee and the Pink Goat.  Genuinely great layouts there - check it out if you haven't found Ander's site before (which seems unlikely).  

ROLAND BEEBAA AF-100 - MODDED VERO LAYOUT

AKA The Balmoral Electric Bee

Version 2, which is slightly more sensible in terms of spacing.

Now, if you want to mod it even more;

• Decrease the input cap to 100n to reduce bass - or you could get creative and sweep or switch between two caps for a thin-to-fat setting

• Reduce the 4.7n caps to increase treble - 1n on Q3 as an example 

• Bypass the notch filter completely by taking a feed from the 1u cap on the output of Q3 - which will be insanely loud by the way

• Remove a 10u cap to reduce gain (Q1 or Q2)

• Adjust the notch to your liking - use values from a Univox Super Fuzz as an example

ROLAND BEEBAA AF-100 - MODDED POINT-TO-POINT LAYOUT

ON THE SCOPE / FFT

Input signal: 440hz sine wave, approx 130mv TRMS

KT315 Soviet-era transistors

A distinct octave effect can be seen, and there's a lot of high-frequency content.  

Note:  The version on the analyser below has a 1nf capacitor instead of a 4.7nf capacitor on the last transistor before the output, resulting in higher frequencies.

The stripped-back BeeBaa has a lot of output, and an additional tone control could easily be added before the volume pot.

As a reference, this is roughly the difference between a 4.7n cap and the 1n cap on Q3 in LTspice (1n = more high-frequency content, which I tend to prefer)

This is it on LTspice, which is pretty similar to the scope results - always nice when the match (the light blue one is the output, the others are straight out of Q1, Q2 and Q3)

BRIDGED-T NOTCH FILTER

This is the notch filter produced in the modded Roland Bee Baa.  As mentioned above, this includes the response of Q1, Q2 and Q3, and then the notch in light blue.

SOVIET BEEBAA

Modified Roland BeeBaa with KT315 Soviet-era transistors (note: 1nf on last transistor). This was built using a slightly different layout to the one posted above, as the Soviet transistors are BCE, instead of CBE.  

I probably should have cleaned the edges of the vero up a bit more...  this was something I threw together without breadboarding, so I wasn't sure exactly how it would sound.  In the end, I'm very happy with it - just wish it was a neater build, but hey..   

SOVIET BEEBAA VERO LAYOUT

ROLAND BEEBAA AF-100 SCHEMATIC  

The stripped-down version removes the following;

- boost section and switching

- one filter option

- tone control