Mad Bean Pedals Afterlife 2020 User manual

Afterlife2020
FX TYPE: Compressor
Based on the John Hollis Flatline
Enclosure Size: 1590A
“Softie” compatibility: none
© 2020 madbeanpedals
Overview
The Afterlife compressor is based on the John Hollis Flatline. It is a low-parts count, optical
compressor that will add excellent sustain and compression to your guitar tone. A simple op-amp gain
stage at the signal input sets the compression amount. The dynamic level of the input is processed
through IC1B where the signal is then rectied to drive an LED. The LED is the “engine” that drives
the photocell in parallel with R3 which dynamically changes the overall gain of IC1A. The end result
is that your guitar signal is compressed so that the overall dynamic level is evened out, thus creating
sustain. The release of the compression is determined by the value of C3.
Controls
• VOL - Total Output.
• SUS - Compression level.
More info about the John Hollis circuits: http://www.hollis.co.uk/john/circuits.html
Terms of Use: You are free to use purchased Afterlife2020 circuit boards for both DIY and small commercial operations. You may not
offer Afterlife2020 PCBs for resale or as part of a “kit” in a commercial fashion. Peer to peer re-sale is ne, though.
Technical assistance for your build(s) is available via the madbeanpedals forum. Please go there rather than emailing me for
assistance on builds. This is because (1) I’m not always available to respond via email in a timely and continuous manner, and (2)
posting technical problems and solutions in the forum creates a record from which other members may benet.

Parts Afterlife2020
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Don’t forget to break apart the two
PCBs before you start building!

Values Afterlife2020
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Traces Afterlife2020
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B.O.M. Afterlife2020
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Resistors Caps Diodes
R1 10M C1 1n D1 - D4 1n34a
R2 10M C2 1uF D5 1N5817
R3 220k C3 100uF IC
R4 10k C4 100uF IC1 TL072
R5 10k C5 10uF Optical
R6 330R C6 100n OPTO NSL32-R3
R7 47k Pots
R8 10k SUS 100kB
R9 10k VOL 100kA
R10 4k7
R11 1k

Shopping List Afterlife2020
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Value QTY Type Rating
330R 1 Metal / Carbon Film 1/4W
1k 1 Metal / Carbon Film 1/4W
4k7 1 Metal / Carbon Film 1/4W
10k 4Metal / Carbon Film 1/4W
47k 1 Metal / Carbon Film 1/4W
220k 1 Metal / Carbon Film 1/4W
10M 2 Metal / Carbon Film 1/4W
1n 1 Film 16v min.
100n 1 Film 16v min.
1uF 1 Low Prole Electrolytic 16v min.
10uF 1 Low Prole Electrolytic 16v min.
100uF 2 Low Prole Electrolytic 16v min.
1n34a 4 or, BAT46
1N5817 1
TL072 1
NSL32-R3 1or, VTL5C3
100kA 1 PCB Mount 9mm
100kB 1 PCB Mount 9mm

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Parts Guide Afterlife2020
NSL32-R3:
http://www.smallbear-electronics.mybigcommerce.com/photocoupler-silonex-nsl-32sr3/
1n34a:
http://www.smallbear-electronics.mybigcommerce.com/diode-nos-germanium/
You can also use BAT46 in place of 1n34a:
http://smallbear-electronics.mybigcommerce.com/diode-schottky-bat46/
Low prole Electrolytic caps:
http://smallbear-electronics.mybigcommerce.com/electrolytic-radial-low-prole-16v-1-f-100-f/
9mm PC Mount pots:
http://smallbear-electronics.mybigcommerce.com/alpha-single-gang-9mm-pc-mount/
Thinline DC Jack:
http://smallbear-electronics.mybigcommerce.com/dc-power-jack-all-plastic-unswitched-2-1-mm/
Enclosed Mono:
http://smallbear-electronics.mybigcommerce.com/1-4-in-mono-enclosed-jack/
http://smallbear-electronics.mybigcommerce.com/1-4-in-mono-enclosed-switchcraft-111x/
Lumberg Mono:
http://smallbear-electronics.mybigcommerce.com/lumberg-1-4-compact-shrouded-mono-jack/

Notes Afterlife2020
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The Afterlife2020 has been updated to conform to the newer style of 1590A layouts I’ve done in the
past year. The circuit is mostly the same with these exceptions:
• SUS pot changed from 100kA to 100kB. With a 100kA the tail end of the control (highest
compression) comes on very suddenly. The linear pot spreads the control out a bit more. Either
taper is ne but I tried a 100kB this time and ended up preferring it.
• I made the default optical device the NSL32-R3. IMO, this gives even more compression than
the previous part, the VTL5C3. And, it is cheaper. However, the pads for the VTL part are still
available on the PCB. I do not recommend “rolling your own” optical device with an LED/LDR for
this circuit. It does not produce as much compression.
• I added R11 to try and tame the switch pop on this effect. Unfortunately, the circuit will pop and
there doesn’t seem to be an easy way around it. My guess is it is due to the envelope detection
circuit. Any mechanical pop at the input gets detected by the envelope which causes a sudden
level change due to the LDR reacting.
Additional Notes
The Afterlife is a bright sounding compressor due to its incredibly high input impedance. If you prefer
a more neutral tone, you can tame the brightness by changing the circuit input. Change R1 and R2
to 1M and C1 to 47n. However, I found that this does impact the total amount of compression in the
circuit (it dampens the maximum sustain). I’ve tried it both ways and I prefer it stock.
As I mentioned in the Shopping List, you can use BAT46 in place of the 1n34a. They work equally as
well and can be cheaper. Keep your germanium didoes for your overdrives!
R7 impacts the overall sensitivity of the envelope. Higher values will increase the envelope output but
I do nd 47k to be the best balance.
Build Tip (optional)
Before soldering your optical device into the PCB, hook everything up to your testing rig. Insert an
LED loose into either the “A” (anode) and “K” (cathode) pads or the + and - pads below it (they are
connected to one another). Play some notes and watch the LED light up. This let’s you know the
effect is working correctly and will give you an idea of the attack and release times of the compressor.
You don’t need to connect to an amp to do this test.

Wiring Diagram Afterlife2020
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Make sure you solder your 9mm pots to the top of the daughter PCB. For
reference, the bottom side of the PCB says “reversed” under each pot.

1590A Drill Guide Afterlife2020
Note: Drill Guides are approximate and may require tweaking depending on the types of jacks, switches and pots you use.
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• This template will work for either mono enclosed jacks or the “Lumberg”
style.
• It uses the “Thinline” style DC Jack.
• It also shows the 3PDT02 bypass PCB but this is not required. If you are
wiring straight to a 3PDT you can use the same LED location on the right
side or choose a different spot.