Horizon Fitness 3.1 User manual

USER MANUAL FOR VERSION 3.1 AMPLIFIERS
APRIL 6th 2015
WWW.GARAGE1217.COM
Project
Horizon
Project
Horizon

Specifications
Tubes / Valves that can be used in Project Horizon (Many others too)
6V TUBES:
6922
7308
8223
6AQ8
6DJ8
6GU7
6CG7
6BQ7A
6H23
6H23N
6L12
6N11
6N23
6N1P
6N2P
6N6P
6N30P
B719
Cca
CV2492
CV2493
CV5358
E88CC
E89CC,
E188CC
E189CC
E288CC
ECC85
ECC88
ECC89
ECC188
ECC189
ECC288
ECC289
JAN 7308
6GM8
6N27P
ECC86
12V TUBES:
5751
5814
5814A
5963
6189
6201
6681
7025
7058
7729
6L13
12AD7
12AT7
12AU7
12AX7
12BH7(A)
12DF7
12DM7
12DT7
A2900
B152
B309
B329
B339
B749
CV0455
CV0491
CV0492
CV4024
E81CC
E82CC
E83CC
12V TUBES CONTINUED:
E181CC
E183CC
E283CC
E811CC
E812CC
E813CC
E2157
E2163
E2164
ECC81
ECC82
ECC83
ECC181
ECC182
ECC182
ECC801
ECC803
ECC803S
- Single ended OTL class-A output stage.
- Power consumption: 13W continuous, 19W peak.
- Power supply: 48VDC (0.55A cont, 0,8A peak)
- Input Resistance: 11kΩ / 31KΩ dependant on setting and module
- Input Sensitivity (6N23): 270mV (dependent on tube)
- Gain: 14 - 26dB (selectable and dependent on tube)
- Max Output voltage (no load): 14.1Vrms at 300Ω
- Output Resistance: Selectable 1.5, 35 or 120Ω
- Frequency Response: 10Hz – 160 KHz (-0.5dB) with 32Ω load
- Frequency Response: 4Hz – 400 KHz (-3dB) with 32Ω load
- Signal to Noise ratio: 91dBA (dependent on tube)
- Crosstalk: -88dB (dependent on tube)
- THD: > 0.013% (dependent on tube)
- Optimized for headphones 120-600Ω / Suitable for headphones 32-600Ω
OUTPUT
POWER
INTO:
16Ω
32Ω
64Ω
120Ω
300Ω
600Ω
OUTPUT RESISTANCE
1.5R 35R 120R
95mW
230mW
440mW
720mW
570mW
300mW
95mW
230mW
430mW
690mW
530mW
260mW
95mW
210mW
340mW
340mW
260mW
180mW

Required Assembly Tools:
- Soldering iron, 25W minimum – Variable temp soldering station preferred with 1.5 – 2mm wide chisel tip
- .032 diameter 60/40 or 63/37 Tin/Lead solder is recommended. Lead free is difficult to work with and not recommended
- Magnifying glass (recommended but not required)
- Rubber Gloves (recommended but not required)
- 3M Green or Red Scotch Brite (recommended but not required)
- 3/32th Allen Key
- 5/64th Allen Key
- Flush cuts
- 90% Isopropyl alcohol (recommended but not required)
- Paper Towels (recommended but not required)
- Digital Multi Meter (DMM or DVOM)
WARNING:
Although Project Horizon runs at a generally safe 48VDC, Injury from improper assembly is quite possible. The main danger
comes from installing the polarized capacitors backwards as they can only be installed in one direction much like a battery
(more detail on capacitor installation comes later in this manual) If a capacitor is installed backwards, it may burst resulting
in burns or eye injury. If you are not experienced in electronics or electronic kit assembly, it would be wise to have an
experienced electronics person review your work before powering the unit on. Upon first power up, wear eye
protection and be wary of any burning smells or electrical noises such as loud pops or buzzes. If you followed this
installation guide properly and all components are in their proper places and were installed in their proper orientation, you
will soon be enjoying your amplifier without issue!
GARAGE1217.COM IS NOT RESPONSIBLE OR LIABLE FOR INJURY, PROPERTY LOSS OR DAMAGE AS THE RESULT OF ASSEMBLY OR USE OF THIS “DO IT YOURSELF” KIT. PROJECT
HORIZON IS CONSIDERED A HOBBY LEVEL PRODUCT. IT CONTAINS NO ELECTRICAL CERTIFICATIONS AND IS NOT ADVERTISED AS SUCH. USE AT YOUR OWN RISK.
Thank you for purchasing the Project Horizon Headphone Amplifier Kit. This kit requires minimal electronics and
soldering knowledge. The layout is easy to follow and setup is a snap! Please make sure to follow the instructions
outlined in this guide and you will be enjoying your amp in no time. First, lets go over the tools and items required
for your build which are as follows:
Before You Start Soldering:
Prep work needs to be done. Wash your hands thoroughly and dry. Put on the recommended rubber gloves and scrub down
the PCB (circuit board) on both the front and back side with 90% isopropyl alcohol to clean any residuals off of the board
from manufacturing. Once the board has been cleaned, set it on a dry paper towel out of the way. Try to use the rubber
gloves during the entire assembly process to keep oils off of the board and solder joints.
Heatsink Assembly Preperation:
Pre-assemble the heatsinks as shown below. The insulators and shoulder washers MUST be used appropriately and as
shown or a short will occur, damaging the amplifier. Do not over tighten the allen bolts. They should be tightened down
securely without crushing the insulating shoulder washer. Make sure the IRL510 and LM317 devices are pointing straight
down once secured. After each heatsink is completed, set it on its side so the leads that go into the PCB are not bent.
1/4" 4-40 ALLEN
BUTTON HEAD
SCREW
SHOULDER
WASHER
INSULATOR
IRL510 OR
LM317
4-40 HEX
NUT
IRL510 AND LM317DEVICES MUSTBE ATTACHED TO THE HEATSINK
IN THE FOLLOWING ORDER. FAILURE TO DO SO WILL RESULT IN
DAMAGE TO THE AMPLIFIER
HEATSINK
POSITION IRL510 AND LM317 DEVICES AS SHOWN
IRL510
LM317
IRL510
LM317

Proper soldering is key to a quality final product. If you are new to soldering, here are some
basic guidelines to follow. It would be wise to buy a copper project board and a few cheap
resistors or other components to practice with before starting this project.
Soldering and Solder Joints:
- For best results and maximum conductivity of any component, Wipe each lead down using Scotch Bright. Only one
or two passes are required, making sure all of the surface has been cleaned. This removes oxidation or any other build up
on the metal that has accumulated over time. Once cleaned, it is a good idea the further clean the wire leads with 90%
isopropyl alcohol. Make sure all alcohol has evaporated prior to soldering as alcohol is VERY FLAMMABLE.
- Do not use to much or to little solder on each joint. See images below to get an idea of what you should be looking for
- The idea is to heat the pad and the component wire lead quickly and efficiently so that solder flows to each equally.
Wetting the tip of your iron with a very small amount of solder will aid in quickly heating up the pad and wire lead.
- Having to heat the component for long periods of time, especially capacitors is not a good thing. When soldering
capacitors, heat them only long enough to ensure a quality joint and let the unit cool down for a few minutes before
soldering the other side (especially on small capacitors)
- The solder joint should look bright and metallic. A dull or dark gray looking joint is referred to as a
“cold solder joint” Cold solder joints may not pose a problem initially, but can show up later in the amps life.
- After every solder joint, make sure to clean the flux off your soldering iron tip with a wet sponge that should be
provided with your soldering iron kit.
SOLDER
PAD
PCB
CUTAWAY WIRE
LEAD
PROPER SOLDER JOINT:
- Solder is bright and shiny. It is curved
smoothly starting at the edge of the solder
pad until it reaches the lead from the
component
- Solder should fill the via and flow through
the board slightly. It is ok to add solder to
the top side of the board, however it is not
required
CUTAWAY OF A VIA AND SOLDER PAD
PRIOR TO SOLDERING:
IMPROPER SOLDER JOINT:
- A large blob of solder, often dull in color is
not desired. The solder may not flow into
the via hole and cause a poor connection
or failure later in the amplifiers life.
VIA / HOLE
Bottom Chassis Prep / Final Chassis Assembly:
ASSEMBLE EACH OF THE 4 RUBBERFEET AS
SHOWN, ATTACHING EACH FOOT TO THE GRAY
SMOKEDACRYLICBOTTOM CHASSIS
THUMB SCREW
STANDOFF
PCB
GRAY ACRYLICBOTTOM
CLEAR ACRYLIC TOP
- ONCE THE PCB HAS BEEN ASSEMBLED,
SET IT ONTO THE FOUR THREADS
STICKING OUT OF THE BOTTOMGRAY
ACRYLICCHASSIS THAT YOU
PREVIOUSLY ASSEMBLED.
- THREAD ON EACHOF THE FOUR HEX
STANDOFFS ONTO THE THREADS THAT
ARE NOW PROTRUDING THROUGHTHE
PCB, SECURINGTHE PCB TO THE GRAY
ACRYLICCHASSIS BOTTOM. PROCEED
TO POWER ON THE UNIT (AS DESCRIBED
ON PAGE 2, WEARING EYE PROTECTION
ANDATA SAFE DISTANCE IN CASE OF A
MISTAKE IN ASSEMBLY)
- ONCE THE AMPLIFIERS FUNCTIONALITY
HAS BEEN TESTED ANDTHE UNIT HAS
HADA CHANCE TOFULLY WARM UP FOR
30 MINUTES, SET THE BIAS AS
DESCRIBEDLATER INTHIS MANUAL
BEFORE PLACING THE TOP CLEAR
ACRYLICCOVER IN PLACE
THREADED SPACER
RUBBERFOOT
NYLON WASHER
4-40 BUTTON CAP SCREW
GRAY ACRYLICBOTTOM
TOP OF PCB TOP OF PCBTOP OF PCB
THREADED SPACER

Project Horizon Operation Guide:
Normal Operation and Notes:
- Plug in the amplifier and then the power supply (in that order). Make sure the tube, headphone jack and input RCA’s are
secure. Once the amplifier is turned to the ON position, the front red LED (closest to the volume knob and headphone jack)
will illuminate red for approximately 1 minute. This indicates the protection circuit is active while the tube is warming up.
It may take several minutes for the tube to fully warm up depending on the tube type used
- When the protection circuit activates and de-activates, a slight click may occur
- When the power switch is turned on and the amplifier is plugged in, the red power LED at the back of the amplifier will
illuminate
- Depending on the tube type chosen and the sensitivity of headphones used, background noise (hiss) may be present.
Choosing a higher output impedance setting, or a lower gain tube can generally eliminate any background noise with
sensitive headphones. This does not mean a high gain tube cannot be used in our designs. Selecting a higher output
resistance or lower input gain setting will reduce noise with higher gain tubes. We advise you experiment with several
tubes to find out what you like best
- Some channel imbalance below 9 o’clock on the volume potentiometer is normal. We recommend you adjust your source
output levels and use Project Horizon with a volume setting of 9 o’clock or greater
- If input capacitors are bypassed, you will hear a scratching sound when adjusting the volume potentiometer
- Some faint scratch when turning the volpot is normal. This does not indicate a bad volpot – just a micro amount of DC that
is present with certain tubes. This type of scratch is generally only heard with no music playing / rotating the volpot
- Cell phones, radio frequency devices or cheap SMPS power supplies in close proximity to Project Horizon may create
noise that is audible when listening to music (generally clicks or digital noises) Amplifiers with exposed / visible tubes are
susceptible to these types of noises.
- Clean your Project Horizon with a microfiber cloth and plastic cleaner (dusting with a microfiber cloth is generally all that is
required). Compressed air is also great option for dust.
- Project Horizon can supply 500 – 600mA of heater current to the chosen tube. High current draw tubes such as a 6n6p or
6n30p cannot be used unless a Supercharger module is fitted
- Hot swapping tubes is not recommended (swapping tubes while the amplifier is on). Even though it does not cause
technical errors or malfunctions it could damage headphones rated for 1W or less.

Assembly Guide
ADJUSTABLE INPUT GAIN
JUMPERS
LED ON/OFF
INPUT CAPACITOR BYPASS
OUTPUT RESISTANCE
JUMPERS
RCA INPUT
LED COLOR CHANGING
TRIMMERS
POWER
JACK
POWER
SWITCH
¼” - 6.3MM
HEADPHONEJACK
PROTECTION CIRCUIT LED
WHEN THE AMPLIFIER IS TURNED ON,
THIS LED WILL LIGHT FOR
APPROXIMATLEY 1 MINUTE INDICATING
THE PROTECTION CIRCUIT IS ACTIVE
WHILE THE TUBE WARMS UP
VOLUME
POTENTIOMETER
LED BIAS ADJUSTMENT
6V / 12V SELECTABLE
JUMPER (HEATER VOLTAGE)
LED PROVIDES LOW NOISE
REFERENCE VOLTAGE FOR
ANODE CURRENT SOURCES
R-CHANNEL L-CHANNEL
RCA LINE OUT
R-CHANNEL L-CHANNEL
Project
Horizon
Project
Horizon

STEP 1: POPULATE ALL SMALL COMPONENTS ON THE BOARD SUCH AS RESISTOS, RIGHT ANGLE JUMPERS,
DIODES AND SMALL CAPACITORS. THROUGHOUT YOUR BUILD, ALWAYS INSTALL THE SMALLER PARTS FIRST,
WORKING YOUR WAY UP TO THE LARGER COMPONENTS
NOTCH ON THE RGB LED
(ORIENTATION MARKING)
MUST FACE THE WHITE
MARKING ON THE PCB AS
SHOWN
FLAT SPOT OR THE
SHORT LEAD ONRED LED
(INDICATES NEGATIVE
SIDE OF LED) MUST FACE
TUBE SOCKET AS SHOWN
PAY CLOSE ATTENTION
TO THE GRAY BAND ON
EACH DIODE AS THEY ARE
DIRECTIONAL
FLAT SPOT OR THE
SHORT LEAD ON RED LED
(INDICATES NEGATIVE
SIDE OF LED) MUST FACE
EXACTLY AS SHOWN
PAY CLOSE ATTENTION TO
THE BLACK BAND ON EACH
OF THESE FOUR DIODES AS
THEY ARE DIRECTIONAL

STEP 2: POPULATE ALL MID SIZE COMPONENTS SUCH AS RCA’S,
POWER COMPONENTS, SMALL CAPACITORS, TUBE SOCKET,
RELAY, TRIMMERS AND SO FORTH
POLARIZED CAPACITORS MUST BE INSTALLED IN THE
CORRECT DIRECTION (WILL HAVE A STRIPE DOWN THE SIDE
DESIGNATING POLARITY) INSTALL THIS STRIPE FACING THE
FLAT SPOT ON THE CAPACITOR OUTLINE ON THE BOARD
CORRECTCORRECT INCORRECTINCORRECT
PLEASE NOTE: CENTER
PIN OF DC SOCKET IS
POSITIVE / 48VDC+
INPUT CAPACITORS ARE
NON-POLAR MEANING
THEY HAVE NO STRIPE
AND CAN BE INSTALLED
IN EITHER DIRECTION

VOLPOT GROUNDING
GROUNDING THE VOLUME POTENTIOMETER IS REQUIRED AS
WITHOUT IT, THE AMPLIFIER MAY BE SUBJECTEDTO NOISE /
INTERFERENCE.
THE IMAGES AREOF THE PREVIOUS GENERATION SUNRISE,
HOWEVER THE GROUNDING PRINCIPAL IS EXACTLY THE SAME.
FIRST, INSERT AWIRE LEAD INTO THE RIGHT SIDE VIA NEXT TO THE
VOLPOT AND SOLDER IN PLACE.
WRAP THE WIRE LEAD AROUND THETHREADED PORTION OF THE
VOLPOT AS SHOWN.
PUT ON WASHER AND NUTINCLUDED IN THE KIT. ONCE TIGHT, THE
VOLUME KNOB MAY BE INSTALLED.

STEP 3: POPULATE ALL LARGE SIZE COMPONENTS SUCH AS LARGE CAPACITORS, HEATSINK ASSEMBLIES
AND EXTENDED JUMPER
USE THE EXTENDED
3 PIN HEADER IN
THIS LOCATION VS A
SHORT 3 PIN HEADER
IRL510
LM317HV
PAY ATTENTION TO THE POSITION OF THE IRL510 AND LM317'S ATTACHEDTO THE
HEATSINKS! THE IRL510'S SHOULD BE TO THE REAR / LM317'S TO THE FRONT OF
THE AMPLIFIER. THIS IS THE #1 OOPS BY DIY BUILDERS ON THIS DESIGN
LM317HV

COMPLETED HORIZON 3.1 LAYOUT AND PHOTO:

EXTREME HEAT WARNING:
Project Horizon runs in Class A operation generating high temperatures on the heatsink assemblies. Never touch
the heatsink assemblies or tube during operation or severe burns may occur. Temperatures in excess of 70C / 158F
are common in these areas.
ONLY OPERATE THE AMPLIFIER IN A WELL VENTILIATED AREA!
NEVER COVER THE AMPLIFIER OR OPERATE IN A CLOSED OR CONFINED SPACE SUCH AS A CABINET!
See areas of caution below highlighted in red.
Input Line-Out
High-R
Mid-R
Low-R
High-R
Mid-R
Low-R
High-R
Mid-R
Low-R
High-R
Mid-R
Low-R
6V 12V
Bias High
Bias Low
Off
R/C
l/C
R-Bias
l-Bias
Version III
S/N: 0000
Project
Horizon
Project
Horizon
Input Line-Out
High-R
Mid-R
Low-R
High-R
Mid-R
Low-R
6V 12V
Bias High
Bias Low
Off
R/C
l/C
R-Bias
l-Bias
Version III
S/N: 0000
Project
Horizon
Input Line-Out
High-R
Mid-R
Low-R
High-R
Mid-R
Low-R
6V 12V
Bias High
Bias Low
Off
R/C
l/C
R-Bias
l-Bias
Version III
S/N: 0000
Project
Horizon

Easy Set Bias Adjustment
Easy set bias makes adjusting tube bias quick and easy. You can access the channel selector for the Easy Set Bias from
the outside of the chassis without having to take off the top cover. Dial in the bias by turning the blue trimmers clockwise if
bias for the channel is low or counter-clockwise if the bias for the channel is high. Rotate trimmer until both LED’s turn off.
To set, make sure to turn off any music source playing into the amp and turn the volume down to its lowest setting
BOTTOM LED GLOWING =
BIAS VOLTAGE LOW TOP LED BRIGHT = BIAS VOLTAGE HIGH BOTH LEDS OFF = CORRECT BIAS VOLTAGE
ROTATE TRIMMER
CLOCKWISETO RAISE
BIAS VOLTAGE
ROTATE TRIMMER
COUNTERCLOCKWISE TO
LOWER BIAS VOLTAGE
ROTATE TRIMMER
CLOCKWISETO RAISE
BIAS VOLTAGE
ROTATE TRIMMER
COUNTERCLOCKWISE TO
LOWER BIAS VOLTAGE
BIAS TEST OFF – LEAVE
SETTING IN THIS
POSITION AT ALL TIMES
UNLESS TESTING BIAS
RIGHT CHANNEL BIAS
TEST SETTING LEFT CHANNEL BIAS TEST SETTING
HOW TO SET BIAS USING THE EASY SET BIAS FEATURE

Manual Bias Setting Using a Multi Meter
- First, make sure no equipment such as headphones or other source device is plugged into the amplifier
- Turn the volume knob down counterclockwise (its lowest setting) and make sure the power is off
- Insert your tube of choice into the amplifier and make sure all proper jumper tabs have been placed according to your
tubes voltage and how you want to use the amplifier
- Set your Multi-Meter (DVOM or DMM) to voltage DC. Set the range for 20VDC. The Bias test points are large enough for
you to insert the probes of most DMM’s directly into the board so you do not have to hold the probes up. Make sure no
metal parts of your probe touch any other components on the amplifier as a short could occur.
- Turn on the amplifier and watch the voltage for around 30 seconds. If the voltage does not appear on screen, turn each of
the blue 25 turn trimmers 10 turns counterclockwise then re-check.
If it measures under 20, let the amp warm up for 15 minutes
- Once the amp is warmed up, measure each of the two positive bias points in real time while turning the adjustment screws.
(Counterclockwise will lower voltage, clockwise will raise voltage) Dial in each side to around 22VDC
- Plug your music source into the RCA jacks on the back side of the amplifier. First, only use a cheap set of headphones to
test the sound of the amp in case of any assembly issues. Once you are satisfied the amp is functioning properly, plug in
your favorite headphones and enjoy the amp! Re-check the bias every 30 minutes for the first few hours and make any
tweaks as needed. Please remember to disconnect headphones, source devices and turn the volume its lowest settings
prior to tweaking bias
Once bias measures stable, every few months or longer depending on how much you listen to the amp, it may need
its bias calibrated again. This is normal. Also every time you make a change such as changing tubes or changing
input capacitor jumpers, you will need to re-calibrate the bias
ROTATE TRIMMER
CLOCKWISE TO RAISE
BIAS VOLTAGE
ROTATE TRIMMER
COUNTERCLOCKWISE TO
LOWER BIAS VOLTAGE
22 VDC22 VDC

Project Horizon has several jumpers settings to customize the amp the way you would like it. Below gives you the
details on what these jumper settings do!
THE 6V / 12V JUMPER ALLOWS YOU TO USE BOTH 6 AND 12 VOLT TUBES. BEFORE POWERING ON YOUR
AMPLIFIER, YOU MUST MAKE SURE WHAT VOLTAGE YOUR TUBE RUNS AT AND SET IT ACCORDINGLY VIA
THE JUMPER. ATTACH THE JUMPER TAB TO THE CENTER PIN AND TO THE SIDE PIN CLOSEST TO THE
VOLTAGE YOU DESIRE (6v OR THE 12v SIDE)
(EXAMPLE OF 6V SETTING IN RED)
TO NOTE: IF IN DOUBT, SET THE AMP TO 12V. IF ONLY ONE CHANNEL WORKS, CHANGE IT TO THE 6V
SETTING. YOU CANNOT DAMAGE A TUBE IF SET TO THE WRONG VOLTAGE
INPUT CAPACITORS CAN BE BYPASSED PER YOUR
PREFERENCE. MANY VIEW THIS AS A PURIST
FUNCTION AS IT IS ONE LESS COMPONENT IN THE
SIGNAL PATH. WITH INPUT CAPS BYPASSED, YOU
MAY HEAR A SCRATCHY SOUND WHEN ADJUSTING
VOLUME. THIS WILL NOT DAMAGE YOUR
HEADPHONES OR YOUR AMPLIFIER. TO NOTE: YOU
MUST RE-BIAS THE AMPLIFIER AFTER MAKING A
CHANGE TO THIS SETTING
TC = THROUGH CAP (EXAMPLE SETTING IN RED)
BPC = BYPASS CAPACITOR
OUTPUT RESISTANCE IS CONFIGURABLE
BETWEEN 1.5, 35 and 120Ω. HIGHER OUTPUT
IMPEDANCE WILL HAVE A SLIGHT EFFECT ON
BASS AND TREBLE FREQUENCIES WHICH IS
ALSO DEPENDANT ON YOUR HEADPHONES
(EXAMPLE OF 120Ω SETTING IN RED)
INPUT GAIN JUMPERS

Project Horizon now features a selectable gain module which allows a quick change of input resistor values
combined with jumpers for a quick high/low setting adjustments
INPUT GAIN CAN BE CANGED +/-
USING THESE JUMPERS
USING THE DEFAULT RESISTOR
MODULE (20K RESISTORS) GAIN
OPTIONS ARE 14 OR 26dB
DEPENDING ON TUBE
DEFAULT QUICK
CHANGE RESISTOR
VALUES ARE 30K
Selecting custom resistor values to change input gain:
- Actual gain is tube dependant. For example, a 12AU7A will have far less gain than a 12AX7
- The high gain setting is fixed at 20dB (again variable depending on tube used – but is a good rule of thumb)
The low gain setting is defaulted at 14dB. However one may make or order custom modules to raise or lower the
LG / low gain jumper setting. Examples:
- 10K resistors will increase gain by +6dB (gain of 20)
- 15K resistors will increase gain by +3dB (gain of 17)
- 30K resistors (default value for the LG setting) 0dB change (gain of 14)
- 45K resistors will further decrease gain -3dB (gain of 11)
- 60K resistors will further decrease gain by -6dB (gain of 8)
These options are made available to help mate the amplifier with the widest selection of equipment possible

LED Light Color
Another feature of Project Horizon is an adjustable RGB (RED GREEN BLUE) LED under the tube.
RGB LED’s can produce almost any color desirable. Often manufacturers tie you into their specific
color scheme on their products. We feel it is important for you to choose the color you desire which can
set an enjoyable mood when listening to your music. Adjust the brightness and color by turning each of
the trimmers with a small jewelers screwdriver.
GREEN
RGB LED
BLUE RED
COLOR / BRIGHTNESS
ADJUSTMENT TRIMMERS

Project Horizon 3.1
Resistors
R1 = 100K SM X 1
R2 = 470K SM X 1
R3 = 10K SM X 3
R4 = 330K SM X 1
R5 = 330R SM X 2
R6 = 4K7 SM X 1
R7 = 120R LG X 2
R8 = 47R LG x 2
R9 = 2.2K LG X 2
R10 = 220R SM X 3
R11 = 100K LG X 2
R12 = 1K LG X 2
R13 = 100R SM X 2
R14 = 22K SM X 1
R15 = 470R LG X 2
R16 = 10R SM X 2
R17 = 10R SM X 4
R18 = 5.1K SM X 1
R19 = 510R SM X 1
R20 = 5.6K SM X 1
R21 = 220R LG X 2
R22 = 1K LG X 2
R23 = 1K SM X 2
OPT-1 = 1K SM X 1
Diodes
Z1 = C43 X 1
Z2 = C39 X 1
D1 = RED 3MM LED X 1
D2 = 1N4148 X 2
D3 = RGB SMD LED X 1
D4 = RED 3MM LED X 1
D5 = SB260 DIODE X 1
D6 = RED 3MM LED X 2
D7 = TO220 DIODE
Capacitors
C1 = 100nF X 6
C2 = 47uF X 1
C3 = 2200uF X 2
C4 = 1uF X 2
C5 = 470uF X 2
C6 = 100uF X 1
C7 = 10uF X 1
C8 = 4.7uF X 1
C9 = 69uF X 2
C10 = 100pF X 2
Transistors
Q1 = BC546 X 2
Q2 = BC556 X 3
Q3 = IRL510 X 2
Inductor
L1 = 100uH X 1
Regulators
IC1 = LM317HV X 2
IC2 = LM317HV X 2 (HEATSINKED)
DC-DC = SC OR RECOM MODULE X1
Jacks
J1 = HEADPHONE JACK X 1
J2 = TUBE SOCKET X 2
J3 = BLACK RCA JACK X 2
J4 = RED RCA JACK X 2
J5 = DC INPUT JACK X 1
A-M = ATTENUATION MODULE
Jumpers
JP1 = 4 PIN RIGHT ANGLE X 3
JP2 = 3 PIN STRAIGHT X 5
JP3 = 3 PIN EXTENDED HEADER X 1
Switches
SW1 = POWER SWITCH X 1
Potentiometers / Trimmers
P1 = 10K VOLUME POTENTIOMETER
P2 = 50K SINGLE TURN TRIMMER X3
P3 = 50K 25T VERTICAL TRIMMER X2
Relay
U1 = 48V RELAY