6/17/2017
XKITZ XAMP-M2
4
RCA JACK
1
J2
B
12
AMPLIFIER CHIP
LM4766
1
U5
B
13
HEAT SINK
1
B
13
4-40 SCREW
1
B
13
4-40 LOCK NUT
1
B
13
NO COMPONENTS GO HERE
J3
14
Table 2.
Balanced Signal Input Upgrade Parts List
Pack
√
Device
Value
Marking
Qty
Reference
Designators
Bag
Install
Notes
Install
√
RESISTOR
10K, 0.1%
BRN-BLK-BLK-RED-VIO
3
R21,R22,R23
2
RESISTOR
20K, 0.1%
RED-BLK-BLK-RED-VIO
2
R20,R24
2
3.5MM TRS JACK
1
J1
12
Circuit Board Component Installation Notes:
1.
You will have extra 10K and 20K resistors after this step. These extras will be used in the next step.
2.
Install the 1% tolerance 10K and 20K resistors included in the standard kit ONLY if you’re running in
UN-BALANCED input signal mode. If you purchased the optional BALANCED mode upgrade, then
discard these 1% 10K and 20K resistors, and install the 0.1% tolerance 10K and 20K resistors
included in your BALANCED Mode Upgrade packet instead.
3.
Diodes are polarized devices; which means they won’t work if installed the wrong way around. A solid
bar on one end of the diode marks the cathode. The cathode goes in the square pad hole on the
PCB.
4.
Be sure to install these caps as close to the PCB as possible, especially C26 and C27, as they must fit
underneath the U5 LM4766 amplifier chip.
5.
To configure the Baffle Step Compensation circuit, install the appropriate cap value in C42. There are
3 possible cap values to install for C42, depending on your baffle size. See Table 3 below.
6.
Solder the 8 pin and 14 pin sockets into the PCB to hold the op amps. Align the notches on one end of
the sockets to the notches shown on the PCB silkscreen.
7.
Install the TL072 and TL074 op amp chips (or the OPA2227/OPA4227 chips if you’ve purchased this
upgrade) into the sockets. The op amp chips are polarized devices, installing them backward will
permanently damage the devices. Align the notch on one end of the op amp chips to the notches
shown on the PCB silkscreen. Be careful not to bend the leads on the op-amp chips when inserting
into the sockets.
8.
Install the 20 pin socket in the location on the board marked ‘XO MODULE’ (the row of resistors from
R57 at the top through R56 at the bottom). Install with the pin 1 notch toward ‘R57’ at the top of the
MODULE. Carefully insert the 20-pin component carrier into the 20-pin socket marked ‘XO MODULE’
with the chamfered corner matching that of the PCB pattern. Solder the 10 resistors included in the
XO component pack to the component carrier to configure your crossover frequency. Use the parts
placement diagram below and the instruction slip in your XO component pack to assemble the
Module. The 10 resistors are simply inserted across the component carrier and slipped into the two
horizontally adjacent, fork shaped pins. When you’ve double checked they’re all in the correct
locations, solder them in place. Cut the excess leads.
9.
Install the transistors and voltage regulator with their shapes matching the shapes on the PCB
silkscreen.
10.
Install the multi-turn trim-pots in the orientation shown on the PCB pattern.
11.
The electrolytic capacitors are polarized devices, be sure to install them the right way around. The
positive lead is longer than the negative lead. The positive lead goes in the square pad hole on the PCB.
Note that the polarity is also marked on the outer casing of the caps.
12.
Install the RCA jack in locations J2 ONLY if running in the stock UN-BALANCED mode. If you
purchased the optional BALANCED mode upgrade, then discard the RCA jack and install the 3.5mm
jack included in your upgrade packet in location J1 instead. Note that the PCB hole patterns for the
RCA jack and the 3.5mm jack overlap on the PCB. This is not a problem, since the RCA and 3.5mm
are used mutually exclusively.
13.
Install the amplifier chip. Attach the LM4766 to the heat sink loosely with the screw and nut. Insert
the assembly and solder the chip pins and the heat sink tabs. Tighten the screw to secure the chip to
the heat sink.
14.
Leave these locations empty. They are not required for this kit.