# Code Red: Take II



## Chuck D. Bones (Feb 9, 2020)

I posted my Code Red (Apple Fritter = Candy Apple Fuzz) in Build Reports a couple of weeks ago.  I was disappointed with how that pedal sounded. After a bit of tinkering, it now does something I like.
BEFORE:
TREBLE control did nothing, tone is always bright.
I could not find a setting I liked anywhere on the NATURE control.
AFTER:
At 10, TREBLE control gives the same bright tone as before.  At zero, the top end is down 5dB at 1KHz, down 12dB at 3KHz and down 18dB at 10KHz.  It's soft, but not dark.  The adjustment range is smooth.
I hijacked the front panel location for the old FUZZ control and installed a GAIN control in its place.  It adjusts the gain and distortion in the JFET stage.  It's also capable of controlling the bass & midrange content.
The NATURE control is now the FUZZ control.  It varies the gain over a 50dB range and gives a gated tone at the low end of rotation and a huge gain boost at the high end. 
With everything dimed, the overall gain is in excess of 80dB, which is more than most Big Muffs and on a par with the M I Audio Crunch Box (Angry Andy).  There is no shortage of sustain.
I did it with these three mods.  They can be done individually or in any combination.  They don't interact per se, but they do complement each other.
TREBLE MOD
I had posted a TREBLE mod before, it involved changing C11 & R18.  That worked OK, except the overall volume dropped 4dB when turning TREBLE down.  Not a big deal, but easily fixed.  Change the TREBLE control from B50K to B10K. Delete R17.  Change R18 to 1K and C11 to 22nF.  If you want it darker when the TREBLE is turned down, increase C11.  I also changed the VOLUME control from B50K to A50K to get a better sweep on the VOLUME control.
NATURE MOD
The NATURE mod completely changes the pedal.  Delete C9, Q4 and R13.  Change R14 to 270K.  Cut pin 1 of the NATURE pot short.  Add a 3.3K resistor between NATURE pin 1 and the pad on the board where pin 1 used to go.  Change R16 to 330R.  The knob that was called NATURE is now the FUZZ control.  It does most of what NATURE used to do to, only better. It controls the gain of the 2nd and 3rd stages and it varies the 3rd stage bias.  The tone is buzzy & gated when FUZZ is set to zero.  The gain and distortion are huge when FUZZ is dimed.  I mostly use FUZZ between 10:00 and 3:00.  I tried installing a trimpot to fine-tune Q3's bias across the range of the FUZZ control; it's visible in the inside pic.  I liked the sound best with it set to zero, so it's not included in this mod.  I changed C7 to 4.7uF to tighten up the bottom at high FUZZ settings.  If you want _maximum wool_, leave C7 at 22uF.  You might want to try different Ge transistors for Q3.  Higher hFE and/or higher leakage produce less gating.  I ended up using a medium hFE, low leakage 2N1308.  More hFE _does not_ result in more gain, it just changes the biasing.
GAIN MOD
This mod is the icing on the cake.  The original FUZZ control works pretty well as-is.  This mod varies the gain of the 1st stage and makes it possible to control the bass and mids going into the distortion stages.  The old FUZZ control has a 40dB adjustment range.  This mod reduces the adjustment range to 20dB.  You get the same gain as before when GAIN is dimed, you just can't turn it down as far.  Most of us wouldn't use the low end of the range anyway.  Not with this kind of pedal.
Delete R5, R7, C5 and the A50K FUZZ pot (I re-purposed the A50K as the VOLUME pot).  Install a 10K resistor where C5 used to be.  Connect the pin 2 and 3 pads (the two round pads) where the A50K FUZZ pot used to be. Using 2" stranded wires, connect a C10K (solder lug) pot where R5 used to be.  Pin 1 goes to the R5 pad nearest Q1 (GND).  Pin 3 goes to the R5 pad nearest Q3.  This new pot is the GAIN control.  There are three options for the GAIN mod and they each provide a different tonal palate.
Option 1 - Pre-Gain
If you want the GAIN control to vary the gain equally at all frequencies, connect pins 1 and 2 of the GAIN pot together.
Option 2 - Mid Boost
If you want the GAIN pot to act as a Mid Boost, install a 470nF Cap between pins 1 and 2 of the pot.  With this mod, the bass frequencies don't get boosted when you turn GAIN up, only the mids and some of the treble get boosted.  This is similar to the MID BOOST control on the Skreddy Hybrid Fuzz Driver.  If I could only pick one option, it would be this one. But read on...
Option 3 - Bass
If you want the GAIN pot to act as a Bass Boost/Cut, jumper pins 1 & 2 and connect a 470nF cap between pins 1 & 3.  With this mod, the treble and upper mids are always at max gain; the GAIN pot varies the bass & lower mids.  This is _similar_ to the BASS control on the Timmy, Pink Purple and a few other pedals.
Option 4 - Why not have all three?
This mod lets you switch between the three options above.  To implement this mod, you'll need a DPDT on-on-on toggle switch and you'll need to drill hole a in the enclosure for it.  I used Small Bear part number 0223G.  It's compact enough to fit comfortably under the board.  When set to the middle position, the switch internally connects the middle & bottom pins on the left side, the middle and top pins on the right side.  Make sure the switch you use does that.  Wire the switch per the close-up of the VOICE switch, shown below.  The black (GND) wire connects to pin 1 of the GAIN pot, the yellow wire to pin 2 and the blue wire to pin 3.  The 470nF film capacitor is mounted leads-up just below the switch.

Here are some pics:


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## Chuck D. Bones (Apr 20, 2020)

Mir9 said:


> Hello. What do you think of this guy's Candy Apple Fuzz questions?
> 
> 
> 
> ...



This is the schematic Mir9 references:




There may have been a few versions of the Candy-Apple produced by BJFe/Mad Professor.  That could explain the variety of schematics.  No way C2 is 100nF, that correction has to be wrong.  C6 electrolytic?  OK, I guess, but I'll stick with film there.  1K in series with C9 makes sense, otherwise the 2nd stage gain gets way too high when NATURE is dimed.  I tried that R14 change.  It turns this into a "normal" differential transistor octave.  The biasing is too hot for that to work well; there is a huge volume dip when the currents in VT3 & VT4 are balanced.  The TREBLE control definitely needed fixing.  Listen to the YouTube demos, the TREBLE control doesn't do anything there.  These mods are ok, but I like mine better.  Why R20 is there at all is baffling.  Just make R21 smaller.  My opinion is that this was an early design by BJ and was not all that successful.  It evolved into the Pink-Purple, which is one of BJ's finest designs.  Although my mods took the Candy Apple from "hate it" to "might use it sometimes" in my book, I have too many dirt pedals I like better.


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## Chuck D. Bones (Apr 20, 2020)

One more thing...
On FSB, Ch1 asks how VT4 gets biased on if R14 is grounded.  The answer is two-fold:
1) Ge transistors can be leakage biased.
2) VT2 can deliver a signal large enough to turn VT4 on during some of the positive portion of the waveform. 

Tonebenders do both of these things.


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## music6000 (Apr 22, 2020)

Chuck D. Bones said:


> I posted my Code Red (Apple Fritter = Candy Apple Fuzz) in Build Reports a couple of weeks ago.  I was disappointed with how that pedal sounded. After a bit of tinkering, it now does something I like.
> BEFORE:
> TREBLE control did nothing, tone is always bright.
> I could not find a setting I liked anywhere on the NATURE control.
> ...


That's not an LED, This is a LED!!!


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