ACP+ Headphone Amp / Linestage

Guide under construction.

The body of the guide is 90% complete at this time.

A fantastic kit of parts available with all the components, hardware, fasteners and PSU.

Although some of the aesthetics of the parts do not match the photos in the guide, they are electrically and qualitatively a 1:1 match.

Photo 1 - Resistors

Photo 2 - Capacitors

Photo 3 - Semiconductors

Photo 1 - Jacks, switches, and Potentiometer. (Red are incorrect style to fit PCB , this photo will be updated)

Photo 2 - Example 24VDC power supply with 5.5x2.1mm plug.

Large - Groundplane attachment bolts Small - Mosfet attach bolts

Heatsinks and stick-on feet

Circuit PCB

Ground Plane board

Both are the same size

Note: If you plan on building this without a chassis (I.E., as shown...) you must use the ground plane.

Gather these components

Stuff PCB smallest to largest, resistors, then power jack,

Capacitors are polarized.

The Negative side is marked on the can

The positive lead is longer

The PCB has a "+" marked for the positive lead

Finish stuffing PSU capacitors and watch polarity.

Measure all resistors before inserting into the PCB. This greatly reduces errors during construction.

All smaller resistors are on a 0.5 inch lead spacing. A lead bender tool is recommended.

Remember, stuff resistors with the brown band to the right.

Stuff resistors with the slightly thicker brown band to the right.

Optocoupler has a dot at pin 1, this aligns with dot on PCB

Left side J112.

Right side LSJ74.

J74s in this circuit need to be matched.

The flat of the transistors aligns with the flat of the transistor mark on the silkscreen.

Q2, Q2 are a matched pair of LSJ74

Q3 is a J113 selected for Vp of 2.5v, +/- 1v

Bend legs down at point shown.

Thermal interface (pad or paste) not strictly required, but not a bad idea.

Mosfets do not need to be electrically isolated from the heatsinks.

Make sure heatsinks are aligned and do not touch each other.

A bit of tape will hold the jack completely flat on the PCB for soldering.

Photo 3 - Improper alignment. Make sure the jack is entirely flat on the PCB before soldering.

Maker sure potentiometer is flat on the PCB before soldering.

Make sure the switch is flat and flush with the PCB before soldering

Insert wisdom here.

Screw from bottom, spacer in-between, nut on top.

Place as shown