How To Build A Fur Face

Transcription

How To Build A Fur Face
How To Build A Fur Face
By Steve Daniels, President, Small Bear Electronics LLC
What Is The Fur Face?
The Fur Face is a clone of the Fuzz Face. It uses inexpensive, easily-obtainable silicon
transistors, but it includes provision for properly matching the devices to ensure smooth
clipping. It also has many features that were lacking in the original pedal, like a DC
power jack, true-bypass switching, a tone stack and an in-use LED.
This manual contains complete instructions for building the pedal, and it is written to
guide people who have never built a pedal before. (Experienced hobbyists note: You can
skip sections as you need to.) I don't presume that you know any electronics, but you do
need some skill with hand tools and I don't cover in here how to solder; more about these
issues in the next section. That said, much of the information and many of the techniques
shown here are applicable to building lots of other pedals, and even other electronic
devices.
I know that you'll enjoy building--and playing through!--the Fur Face. While I've done
my best to make these instructions complete, I'm available by E- mail if you have
questions, problems or suggestions.
Yours In Good Music,
Small Bear Electronics LLC
123 Seventh Avenue # 156
Brooklyn, NY 11215
Http://www.smallbearelec.com
Smallbearelec@ix.netcom.com
Can I Really Build It Myself?
Yes, IF:
•
You can follow directions.
• You are comfortable with using basic hand tools.
•
You can solder well.
The kit includes a precision-drilled enclosure that reduces the tooling needed by more
than 90%. I will show you in this manual, step-by-step, the assembly, painting and decalapplication procedures that I used. If you have never soldered before, you may need to
check out some how-to information on-line about that, and maybe practice a little before
tackling this kit. Which brings me to:
What Tools And Materials Will I Need?
You don’t need a drill. However, installing the battery drawer is much easier if you have
a Dremel, or similar, rotary tool, or have access to one that you can borrow. You will also
need:
A 25- to 35-watt soldering iron, rosin-core solder, cleaning sponge and de-soldering
braid.
NB: Yes, a Radio Shack iron will do, if the tip is relatively new and well-tinned. The big
problem with very inexpensive irons is that the tips aren’t properly clad and so corrode
quickly.
Small screwdriver
Small chain-nose plier and side-cutter
Small locking- grip ("Vise-grip") plier
X-acto or similar knife
Self- locking tweezers or other "third hand"
A small round file and small flat file
A pointed steel "pick" or scratch awl
A Sharpie Marker
The case is drilled, but not painted, so you will need materials for finishing—
carborundum paper, spray primer, spray enamel and Acetone. Sealing the decal (included
in the kit) requires a clear, spray lacquer like Krylon. You will also need some epoxy
cement for attaching mounting studs and the battery drawer to the enclosure.
• Identify The Components
5% Tolerance Carbon Film Resistors
The values are in Ohms. The first two colored bands define the base number. The third
band is the number of zeroes to add, and the gold fourth band indicates 5% tolerance.
Value
How Many?
1,000,000 ohm or 1 Megohm
(Brown, Black, Green, Gold)
1
1
0 + 5 zeros
33,000 ohm (or 33 K ohm)
(Orange, Orange, Orange, Gold)
1
330 ohm
(Orange, Orange, Brown, Gold)
1
100,000 (or 100 K ohm)
(Brown, Black, Yellow, Gold)
1
8,200 ohm (or 8.2 K ohm)
(Gray, Red, Red, Gold)
May vary with the transistors supplied. See text
1
2,200 ohm (or 2.2 K ohm)
(Red, Red, Red, Gold)
1
6,800 ohm (or 6.8 K ohm)
(Blue, Gray, Red, Gold)
2
3,900 ohm (or 3.9 K ohm)
(Orange, White, Red, Gold)
1
100,000,000 or 100 Megohm
(Brown, Black, Violet, Gold)
1
Potentiometers
This style has pins that solder directly to the PC board.
Quantity
1K Reverse Audio
20K W
50K Audio
1
1
1
Marked
C1K
W20K
A50K
Capacitors
Metallized Polyester Film (Have no polarity)
150 pf.
.01 mf. (microfarad or µf.)
.022 mf.
.039 mf.
.47 mf.
Quantity
1
Marked
151
1
1
1
1
103
223
393
474
Radial Electrolytic (These are polarized; the black band marks the negative side.)
Quantity
2.2 mf.
47 mf.
1
1
Axial Electrolytic (Also polarized; the grooved side is positive.)
Quantity
22 mf.
1
Transistors
Two of the transistors come in a plastic case called TO-92 style. The flat side of the case will be
oriented according to the photo of the PC board. The designations of the leads are shown for
reference.
Quantity
2N4123
MPSA14
1
1
Leads Left-To-Right
Emitter, Base, Collector
Emitter, Base, Collector
The 2N2222A transistor is in a metal TO-18
case, and the legend on the PC board indicates
where the tab on the case must be positioned.
Diodes
The band on the case indicates how they should be oriented on the PC board.
Quantity
1N5818
1N4732
1
1
LED
The longer lead marks the positive side.
Jacks
DC Power
Stomp Switch
Transistor Sockets
Single-In-Line Socket
Other Items
9-Volt Battery Snap
Enclosure
Battery Drawer
Rubber Feet
PC Board
Mounting Hardware
Knobs
Decal
Hookup Wire
If you have all the parts and materials, the first construction step is adding mounting studs
for the PC board.
Securing The PC Board To The Enclosure
There are a number of ways to do this and a variety of hardware arrangements that will
work. The PC board- mounted potentiometers in this design provide major support for the
board, but for “belt-and-suspenders” stability we’ll attach a couple of metal studs to the
floor of the enclosure.
Each potentiometer has a metal “anti-rotation” tab that should be removed by snapping
off with a side-cutter. Remove the nuts and washers and install the pots temporarily in
their appropriate holes in the board. No soldering yet!
A 4-40 screw, two flat washers and a threaded stud go in each of the two holes at the
bottom of the pic. The washers are there as shims to precisely set the height of the board.
Secure the studs finger-tight.
Set the board in place in the enclosure, and install the nuts and washers on the pots
finger-tight.
Using a steel pick or awl, scratch on the enclosure the outline of where the studs will sit.
Remove the board assembly. With a small piece of 220-grit sandpaper or carborundum
paper, scrub the area that you marked for each stud so that it’s shiny. As long as you
clean the area where the marks are, it’s no problem if you go a little outside.
Using Q-Tips wetted with Acetone, carefully clean up the sanded areas. Swab each stud
similarly.
Mix a small volume of J-B Weld or similar epoxy cement and use a toothpick or icecream stick to apply a small amount to the bottom and sides of each stud. You don’t have
to use much right now; you’ll be able to add more later once the positions of the studs are
set.
Carefully, slip the board into place and secure by installing the nut and washer on the
middle potentiometer finger-tight. It is OK to use your stick to spread the epoxy a little
now that the studs are in position. Give the cement a few hours to cure.
When the epoxy has fully cured, remove the screws. Mix a small batch and beef up the
areas around the sides of the studs. Then mix one more batch and cement the washers to
the PC board as shown. A toothpick makes a good tool for applying a small amount of
cement all around the holes. Then use a clean toothpick for positioning and centering the
washers. When the epoxy holding the first two washers has set, mix a little more and
cement a second washer on top of the first on each side.
Mounting The Battery Drawer
Note: If, after reading this section, you decide that installing the battery drawer is more
tooling than you want to do, ask us to exchange the tooled back-plate for a blank one. We
will send you that with a spring- type battery clip that can be attached with epoxy.
The battery drawer has flanges on each end that will snap into place, but they need to be
cut down slightly to accommodate the thickness of the enclosure. The best tool for doing
this is a Dremel handpiece with a cutoff wheel, though I have managed it with a flat
needle file. If you use the Dremel, remember that abrasive cutoff wheels are both very
useful, and inherently dangerous! In normal use, they throw off particles of metal
and abrasive. When they break, and they do, the pieces fly like bullets. You MUST
wear eye protection and a dust mask when using them.
The front and rear sides have ridges that are meant to keep the drawer in position
horizontally. Grind down the two in the front using a small file or a Dremel grinding
wheel.
Press the drawer part way into place and use a Sharpie to mark the positions of the ridges.
Then grind notches for them with a needle file or Dremel cutter. A little at a time is best,
because you want to make room for the ridges without letting the notches show past the
outside edge of the drawer on top.
This picture shows the result. The drawer is in straight, and the cutout does not show.
There is some play up and down, but we will be able to cure that during final assembly
with a couple drops of epoxy.
Remove the battery drawer for now by squeezing the locking tabs inward and pushing the
assembly out; we are ready to paint the enc losure and apply the decal.
Painting and Decorating
If you are not comfortable with painting the enclosure yourself, you might want to ask the
assistance of someone who has this kind of experience…maybe an art student, or
someone who has done auto body paint—it is actually a similar process.
The first job is to smooth and polish the surface of the enclosure by wet-sanding with
progressively finer grits of Carborundum paper. Grits up to 2000 are available on my
Stock List, or most hardware stores carry up to 600. You can make a sanding block by
stapling Carborundum paper to a small block of soft wood, or get a commercial sanding
block like the one shown in the pics. It accepts a standard-size sheet, fits an average hand
easily and doesn’t need staples to grip the material.
Set yourself up as shown with a small tray of water and 220 grit paper in the block. This
process is hell on hands, so I keep a box of disposable rubber surgical gloves in the Cave.
Wet both the paper and the surface of the box. Sand each surface of the enclosure,
working back-and- forth, in the long direction—Don’t scour. Dunk the box every so often
to keep it wet.
As the abrasive begins to really smooth the surface, it will start to feel a little slippery.
Periodically, give the box a thorough washing and dry it to check your progress.
There will still be fine scratches at 220 grit; you want to get All the larger scratches out
and have an even finish all over. At some point, take a small piece of the 220 grit paper in
your hands and go over the whole surface evenly, but pay special attention to the rounded
edges and corners.
When you are satisfied with the finish at 220 grit, refill your tray with clean water, charge
your block with 400 grit material, and repeat the whole process. Continue through 600
grit. In my experience, a 600- grit finish will do nicely for putting down a primer and then
a coat of spray enamel.
Repeat the sanding process on the cover of the enclosure
A suggestion: There is nothing worse than having to sand out a ding, especially after you
have put several hours into creating a nice finish. Whenever you are moving around the
shop with your piece, do so slowly, and be aware of where you are going.
Before you prime or paint, clean the pieces as if they were going into an operating room.
Wash them Very thoroughly with running water and do a careful wipe with a soft cloth
wetted with Acetone. Acetone is flammable! Follow the precautions on the can!
Getting primer and paint to adhere to metal can seem like a black art. It can be done in a
home shop if you are very careful about preparing the surface and avoiding dust and
humidity. Apply a light coat of a self-etching primer (from an auto- or marine-supply
store), following the directions on the can, and let the pieces dry overnight. Here’s the
enclosure after priming and before painting. I have it propped up on a “lazy-susan” that I
bought for a few bucks in a hardware store—lets me rotate the piece easily without
touching. I keep a hair dryer around the shop; before applying paint, I play it over the
surface for a minute or two at medium heat. In my experience, warming the surface helps
prevent voids.
Some references recommend baking the piece (in a toaster oven) for about an hour at 150
to 170 degrees. In my experience, this is optional.
Repeat the cleaning, priming and painting process on the cover of the enclosure.
The decal that comes with your kit was printed on an ordinary inkjet printer to “waterslide-release” decal stock and then sprayed with clear lacquer to protect the image. Cut
the decal to size with a sharp scissor. Set up a small dish with some warm water. Place
the decal in the water, and hold it under gently with your fingers. Within a minute, you
will start to feel the decal film slide away from its backing. At that point, remove the
decal from the water, position it on the surface of the box, and carefully slide the backing
paper out from under the decal film.
While the film is wet, you have some control of its exact position. Position the face of the
decal so that it is square and centered, and press the sides downward. Blot the three
surfaces firmly and thoroughly with a paper towel. You want to squeeze out All of the
water and get rid of air bubbles. When done, let the decal set for several ho urs. To protect
the design, spray with clear Krylon or automotive clear coat. Spray a very light first coat,
and give that a couple of minutes to get tacky before putting down additional coats.
Apply a coat of clear Krylon to the cover of the enclosure.
With an X-acto knife, carefully trim away the remains of the decal film that covered the
holes for the pots, stomp switch, LED and jacks.
Install the battery drawer on the cover and secure it in place with a few beads of epoxy
cement.
The enclosure is finished, and you are ready to assemble the PC board
Stuffing The Board
That’s what we call the process of mounting components on the printed circuit board (PC
board) and soldering them in place. While the order in which the parts are mounted won’t
affect the audible result, it’s convenient to mount small parts first and finish with the
pots. Heat up and tin your soldering iron, wet your cleaning sponge and let's begin,
starting with the resistors. Find resistor R1 (1 Meg = Brown, Black, Green, Gold)
Using a chain-nose plier, grab one lead of the resistor about 1/16” from the body. Bend
the resistor lead sharply downward at right angles to the body of the component. Then do
the same with the other lead:
Look for the silkscreened legend “R1” on the PC Board, and insert the resistor into the
appropriate holes. (Resistors have no polarity and can go in either way.) While holding
the resistor in place, cut off all but about 3/32” of the leads and bend flush to the board.
Solder in place. Bending the ends of the resistor leads flush to the board is very important
in this build, because the solder side of the board mounts directly over the cans of the
potentiometers; keeping the lead profile low will avoid short circuits.
The next four resistors, R2, R3, R4 and R5 are the ones that set the bias of the transistors.
Getting a Fuzz Face to sound “right” is a matter setting the values of these resistors
appropriately for the gains of the transistors. This is pretty easy with silicon devices,
because the gain of a particular type number will be fairly consistent across a lot. We sort
and match parts so that only one resistor, R4, needs to be selected specifically. The
devices you receive with the kit will indicate the required value, and it will be bagged
with the transistors. The values and color codes of the bias resistors are:
R2 (33K = Orange, Orange, Orange, Gold)
R3 (330 Ohms = Orange, Orange, Brown, Gold)
R4 (Per Device – Nominally 8.2K, Typical Range 3.3K to 10K)
R5 (100K = Brown, Black, Brown, Gold)
We guarantee correct biasing using the resistor values specified and the transistors
supplied with the kit. For the spec, see Tweaking Performance and FAQs at the end of
this manual. We know that many builders will want to adjust this to taste, so the kit
includes a 5-pin length of single- in-line socket material. This allows plugging in any
desired resistor for R4.
If you are using germanium devices, you may need sockets for the other three bias
resistors. To cut single- in-line socket material to length, score about a dozen times in the
groove between the pins with an X-acto or similar knife and then snap off at the score
line. Then remove each of the middle pins by holding a soldering to the bottom of the pin
and pressing gently till the pin falls out.
The rest of the resistors are:
R7 (2.2K = Brown, Gray, Yellow, Gold)
R8 (6.8K = Blue, Gray, Red, Gold)
R10 (6.8K = Blue, Gray, Red, Gold)
R12 (100 Meg = Brown, Black, Violet, Gold)
R13 (3.9K = Orange, White, Red, Gold)
All of these can be soldered in permanently.
Here is the board with all of the resistors soldered in except for R4, which is replaced
with a length of single- in- line socket material.
Capacitors come next. Start with C3, a 22 mf. electrolytic. This one is axial mount; the
side with the groove is positive and the arrow on the case points negative. Note its
position in the pic and be sure to insert it correctly. Press its body close to the board and
trim the leads down to about 3/32”. Bend the leads flush and solder. Follow with C1 and
C2. These are radial electrolytics, 47 mf. and 2.2 mf. respectively. The black band on the
side of the case marks negative and the silkscreened legend on the board marks positive.
The rest of the capacitors are polyester film types; they have no polarity. Take care to get
the right values in the right positions. The designations and the values are:
C4 – 150 pf. (Code 151)
C5 - .47 mf. (Code 474)
C6 - .01 mf. (Code 103)
C7 - .022 mf. (Code 223)
C8 - .039 mf. (Code 393)
Here’s a look at the board to this point:
OK, Diodes. D1 is for reverse-polarity protection, and the legend on the board will show
you which way to orient it. The bar side of D2 faces resistor R13.
Add transistor Q3. The legend on the board indicates which way the flat side of the case
should face.
Add transistors Q1 and Q2. If you are using the devices that come with the kit, transistor
sockets are not mandatory; silicon devices can tolerate normal soldering heat. Pay
careful attention to the orientation of the flat side of Q1 and the tab on the can of Q2.
Knowing that many people would want to try a variety of devices, I laid out the board so
that it can accommodate transistor sockets if you want to add them. When soldering the
sockets in place, take care to place them parallel to the board. A tip for doing this: Hold
the component in place with self- locking tweezers. Solder one pin in place, and then
check the orientation. If the socket isn’t parallel with the surface of the board, you can
now grip the board carefully in your fingers, re-heat the joint and hold the socket in its
proper orientation while the solder cools. Then solder the other pins.
Use a small piece of tape to hold the DC power jack in place. It must sit flush to the
board with its front edge parallel to the edge of the board. On the solder side, loop a small
piece of bare wire through the front contact and solder the contact to the trace of the
board. Clip the excess wire when done.
The contact immediately to the rear should be bent forward a little to avoid a possible
short later with the can of one of the pots. Then loop a small piece of bare wire through
the contact and solder the contact to its trace. The contact to the left will receive the
positive battery lead during final assembly, so leave it unsoldered for now.
Before soldering the pots in place, add the wires for the signal input to the board and
LED control; their pads are under the cans of the pots, and it would be hard to make the
connections later. The right-hand pic shows where we are.
Install the pots one at a time, taking care to get the right value in the right position. In the
left hand pic, R6, the C1K, is on the right and R9, W20K, in the center. Suggestions:
•
Be sure that the contacts are flush to the board, as the height of the contacts sets
the height of the board in the case during final assembly.
•
Insert an ice-cream stick or other support under the can of the pot to hold it
parallel to the board.
•
Don’t just solder the contact of the pot to the trace; use the soldering tweezers to
hold a short piece of bare wire in place as shown, and then solder. Now bend the
wire around to the back of the contact, bend again so that it follows the direction
of the PC board trace, and then solder again.
Why? These board- mounted pots make the final assembly and testing much
easier, but the contacts can be the source of some funky intermittent connections.
Installing this way prevents problems later. Use the same technique on the two
outside contacts of R9, and the left-side contact of R11.
Two jumper wires are needed on the top of the board. Loop a short piece of bare wire
around the center contact of the tone pot. Solder in place, make a right-angle bend in it,
and run it to the left-side contact of the level pot. Loop there and solder. The other jumper
wire runs from the pad in between R2 and R3 to a pad near the bottom of the board.
The next step is to set the vertical position of the LED in the enclosure.
You are at a delicate stage, because you have put a lot of work into finishing the case.
Slips, falls and mistakes with tools can ruin the finish and cause you grief, so stay
focused and work patiently. Set up a towel or soft cloth on your bench to protect the
face of the enclosure while you work.
Slip the LED into its holes on the board, but don’t solder yet. Pay attention to polarity;
the shorter lead should face R13, the 3.9K resistor. Set the board in place in the enclosure
and finger-tighten the hardware on the center (tone) pot. Screw the board gently down to
the studs. Push/maneuver the LED down so that it is in its hole with its flange flush to the
enclosure. Turn the case over carefully, and note how much the LED protrudes with the
flange bottomed. Decide how much you want the LED to protrude, and set this by putting
right-angle bends in the leads as shown in the right-hand pic. Disassemble, solder the
LED to its traces and clip the excess lead lengths.
OK, now for the final connections to the board:
•
•
•
•
A 6-inch lead to the middle contact of the level pot, soldered on the top of the
board. This is the green wire in the pic.
The battery snap is wired to the DC power jack. Be sure to wrap the positive lead
around the contact of the jack before soldering.
A 6-inch black lead from the pad below the negative battery snap lead.
A ground lead (also black in the pic, on the left).
The board is done and you are ready to assemble your pedal.
Final Assembly and Testing
Install the board in the enclosure with the nuts on the pots finger-tight and the screws
gently screwed down. Install the jacks and the stomp switch as shown, also with their
hardware finger-tight. Take care to get the mono and stereo jacks on their correct sides
and the beveled edges on the jacks where they belong.
Solder a black lead to the sleeve of the output jack. Run this to the sleeve of the input
jack, but don’t solder yet. Add the ground lead from the board to this connection, and
then solder.
Route the black lead from the DC power jack to the left and then downward. Solder to the
ring contact of the input jack.
Wiring the switch contacts invariably confuses a lot of people, so let’s do it “by the
numbers”:
When you have finished the wiring, install the recommended resistor value for R4.
Connect a battery, your guitar and an amplifier. Click the stomp switch…does the LED
go on and off? Try out the controls. If it sounds like a Fuzz Face,
CONGRATULATIONS!
Before you continue, connect a power supply and make sure that everything still works
with/without a battery.
Final steps: Secure hardware, screw knobs in place, attach rubber feet to the base. Slice
one in half with an X-acto knife to get the half- width pieces for the battery drawer end.
Troubleshooting
Time to break out the multimeter and figure out where the problems are. Here are the
measured transistor voltages in the build you see here:
Collector Base
Q1 1.56
.65
Q2 4.89
1.56
Emitter
0
.93
YMMV depending on transistor gains, but any serious differences are a sure indication
that something is not right. Here is an “X-Ray” view of the board:
Check everything against this layout and the pics. Use the continuity scale of your meter
to make sure that everything that should be connected really is. This being essentially a
Fuzz Face, there are myriads out there who have built it and can help you debug a build.
The Forum at diystompboxes.com is an amazing resource for this. If you bought the full
kit, I will help you debug by e- mail. Write to: smallbearelec@ix.netcom.com
Tweaking Performance And FAQs
As I noted earlier, we selected the value of R4 to put the voltage on the Collector of the
device we supply for Q2 at 4.5 volts +/- .25 volts. If you are using different devices or
just want to experiment, here is what to do. Set up the pedal as shown with a plug in the
input and battery or power supply connected. Ground the negative side of the meter.
Measure the voltage at the point shown. Raising the value of R4 will bring it down, and
vice-versa. When I first tested this example, R4 was 3.9K. Raising it to 4.3K brought the
voltage down to 4.6.
What If I Want A Higher/Lower Gain Device For Q1/Q2?
No problem! We supply a 2N4123 for Q1 and a 2N2222A for Q2 because these types are
available, known to work well and in the middle of the desirable gain buckets for the
Fuzz Face. But numerous other silicon devices that will work in your pedal are cheap and
readily available--maybe even at the local Radio Shack, or check the Small Bear Stock
List. Devices that I know other people have used are the 2N2369, 2N3440, 2N3904,
2N4401, BC108 and BD139.
I measured The Gains Of The Devices On My Multimeter. How Come They Are
Higher/Lower Than The Figures You Specified ?
The chip that runs your meter contains an algorithm to figure gain, and that may be
different from the “Bare Bones” calculation that we use. We measure the gains at room
temp with 9 volts collector to emitter and 9 microamps into the Base.
Can I Use Germanium Devices?
Sure, with a couple of caveats. First, I purposely did this design with cheap, readily
available NPN silicon devices so tha t anyone could build it and it would play gracefully
on a board with other negative-ground pedals. No separate power supply is required.
NPN germanium is available, but a pair that hits reasonable gain buckets and is not too
leaky will cost considerable $$. It's not a conspiracy; for reasons stemming from what
was technically feasible in 1960s and ‘70s transistor factories, low- leakage NPN
germanium is relatively scarce. See my Stock List if you are interested. If you troll E-Bay
for devices, get some assurance from the seller that you will be able to return unsoldered
devices that are hissy or excessively leaky.
I do not recommend attempting to use PNP germanium for a negative-ground build, and I
will not offer technical support for such; too many reported problems with intractable
motorboating noise.
The other thing I suggest is using socket-pin material for all four bias resistors.
Germanium varies so much in gain and leakage, and is so temperature-sensitive, that you
may need more control than just adjusting one resistor will give you.
But I Only Have PNP Devices and Can’t Afford/Can’t Find NPN…
It is possible to do a positive- ground build using the Fur Face board. You have to reverse
All polarities and ignore the legends for the electrolytic caps, diodes and LED. The LED
driver transistor should be an MPSA64. If I can make time, I will actually do this build
and document it.
Can I Do Anything To Improve Temp Stability In An All-germanium build?
I don’t know of any perfect solution. A reverse-biased germanium diode from the Base of
Q1 to ground does help, and some people substitute a 10K pot or trimmer for R4.
What About Si/Ge Hybrids?
I have tried an NPN germanium device with a gain around 110 for Q2. I swapped it in
without even touching the bias and it worked well right off the rip. Nice mix of
germanium smooth clipping with a little extra “bite,” and more temp stable than straight
germanium.
What About Other Mods?
Rather than hack up a hand-made pedal, get a solderless breadboard and set up what you
want to try on there. Then, if you come up with something that you want to change,
you’ll know what you are doing.
Reference Information
Here is the schematic:
A parts list follows.
Quantity
Description
SBE Stock List
SKU
1
1
1
1
1
2
1
1
1
Resistors - All 1/4-watt 5% Carbon Film
1 Meg
330 ohms
Selected For R4
100K
33K
6.8K
2.2K
3.9K
100 Meg
1
1
1
Potentiometers and Trimmers
1K Reverse Audio
20K W
50K Audio
1
1
1
1
1
1
1
1
Capacitors
47 mf. 16 Volt Radial Electrolytic
2.2 mf. 16 Volt Radial Electrolytic
22 mf. 16 Volt Axial Electrolytic
150 pf. Polyester Film
.01 mf. 50 Volt Polyester Film
.022 mf. 50 Volt Polyester Film
.039 mf. 50 Vo lt Polyester Film
.47 mf. 50 Volt Polyester Film
1
1
1
1
1
1
Transistors and Diodes
2N2222A
2N4123
MPSA14
LED 5mm High-Brightness Red or Blue
1N5818
1N4732A
2000
2008
2025
2302
2215A
2211
Wire
Bare Tinned Copper Wire , #22 or #24
Insulated Pre -Bond Wire #24, Colors
0509
0508
Jacks, Fittings, Hardware
Mono Jack, Switchcraft #111
Stereo Jack, Switchcraft #112B
0603
0604
1
1
0900, 0901, etc.
1011
1011
1011
1404
1400
1100
1101B or 1150
1105
2
1
1
1
1
1
2
2
3
4
1
1
1
Transistor Sockets
5-Pin Single-In-Line Socket Strip
9-Volt Battery Snap
DC Power Jack
Battery Drawer
Stomp Switch
3/8” Tall 4-40 .187” O.D. Aluminum Studs
4-40 x ¼” Screws
Knobs
Rubber Feet
Printed Circuit Board
Enclosure
Decal
0707
0706
0619
0611C
0614A
0203
8007
8003
0825B or similar
0314