Germicon Compressor Parts List
v1.1 3/20/09
To view/order the partslist via Mouser click here.

Part	Value			Device					Mouser/SB Part Number

Resistors
(1/4watt :: Replace 291 in part number with 271 for metal film)
R1	4.7M									291-4.7M-RC (or 271-4.99M-RC metal film)
R2	82k									291-82k-RC
R3	470k									291-470k-RC
R4	470k									291-470M-RC
R5	2.4k 									291-2.4k-RC
R6	390k									291-390K-RC
R7	470k									291-470k-RC
R8	220k									291-220k-RC
R9	10k									291-10k-RC
R10	1.5k									291-1.5k-RC
R11	100k 									291-100k-RC
R12	LED									CHOICE (see notes)

Capacitors
(all values uF unless otherwise noted)
C1	.047			Poly Film					581-BQ014D0473K
C2	.047			Poly Film					581-BQ014D0473K
C3	.0022	 (2200pf)	Poly Film					581-BQ014D0222K
C4	4.7			Electrolytic				140-L35V4.7-RC
C5	4.7			Electrolytic				140-L35V4.7-RC
C6	4.7			Electrolytic				140-L35V4.7-RC
C7	4.7			Electrolytic				140-L35V4.7-RC

Diodes
D1	1N34A			Germanium Diode				526-1N34A

ICs
IC1	LM4558N		RC4558P					595-RC4558P

Transistors
(see notes for info on Transistor selection)
Q1	2N5457 or J201	TO92 Package				512-2N5457 or 512-J201_D74Z
Q2	J201 or 2N5457	TO92 Package				512-J201_D74Z or 512-2N5457

Potentiometers
GAIN		B10k		16mm Right Angle PCB Mount	Small Bear
VOL		B10k		16mm Right Angle PCB Mount	Small Bear

LED for ON/OFF display, 3PDT for on/off switching, 1 mono and 1 stereo 1/4" phono jack, 1 battery clip and/or 2.1mm plastic frame input jack, and a suitable enclosure.

Build Notes
1. R1 is the resistor to eliminate any box pop. You can pretty much use any value over 1M.  I selected 4.7M but feel free to choose any value you may already have or prefer. There is no 4.7M value in the 271 series so if you want a metal film here, the 271-4.99M-RC part is as close as Mouser has to 4.7M.

2. R12 is the current dropping resistor for the LED. If you're choosing a high brightness water clear LED like blue or green, I would suggest a value between 5k and 10k otherwise you'll drain the battery a bit more lighting up the entire room with your pedal. Something far less bright like a red diffused should be fine with something between 1k and 5k. The Mouser project docs include a 4.7k by default.  If you want to choose a different value when ordering, just type the value into the part number in the 291-X.Xk-RC format, and search for it.

3. Capacitor mounts on the board are designed to fit the caps whose parts are specified but most other common small footprint types should fit ok. I won't make any guarantees however... It's up to you to sort out which parts will or won't fit.  Poly Film caps are meant to be box types on a 5mm lead pitch and the electrolytics have enough space for a typical small 5mm around radial type.  The one in the parts list noted above and pictured in the docs is much smaller then that even.

4. The standard transistor choice for a stock Orange Squeezer build is a 2N5457 for Q1 and Q2. My preference is a 2N5457 for Q1 and a J201 for Q2. This creates a louder pedal with a bit less squishy tone. Using two J201s is cool too and makes the compressor compress less and boost even more. Two 2N5457 has a lot more compression and less of a volume boost.

5. The layout is designed so that the PCB conveniently mounts on top of the pots. You'll probably want to use some double sided 3M foam sticky tape on the backside if you don't use the PCB mount type and if you do, you may want to use some anyway just to make sure the case of the pot doesn't short to the PCB. You can turn a solder lug pot into a PCB mount as well by using some trimmings from your resistors. That's how I built the prototype.

6. The GAIN/COMP is sorta labeled backwards on the board... sorta. If you look at the schematic the GAIN control is essentially a volume control but in practice it effects the amount of compression and not the total volume. The COMP control is actually a bias adjustment for Q2. As an aside, this control was an internal trimpot in the original OS... turn it up and you get a really big volume boost. With two J201s or even 1 2N5457 and 1 J201 there's plenty of volume to get way past unity gain. In stock form its a bit tougher to get to that level. So anyway, they're kinda backwards of what they actually do because as I was looking at the schematic and routing the PCBs it made sense that the output volume control was the function changing the overall GAIN and so I labeled it that way on the board and it turned out to be backwards. Ultimately that doesn't matter at all since both controls use a 10k pot but its important that you understand this so you can label your pedal how you see fit.
 
7. The diode in an original is a 1N100 germanium. I use a 1N34A here (mounted upright for space considerations) as a substitute.  If you're into hunting down rare original and/or m@j@ parts then by all means...  and let me know if you find one. I'd love to hear if there's actually any noticeable difference.

8. PCB dimensions are 1 15/16" x 1 1/16" / 50mm x 27mm

For questions and/or troubleshooting help please post your question in the effects section at offsetguitars.com because if it doesn't work, its not my fault. Check your layout, check your soldering and ask for help.  :)

Thanks!