LDA 43S_np DiY stereo audio amplifier kit assembly instructions

General assembly advice

- recommended unloaded power supply voltage (for 2x110W per 4 ohms power): +/- 42...44V

- recommended transformer (for 2x110W per 4 ohms power): 320VA transformer with 2x31...2x33VAC secondary voltage

Here's a possible positioning of the PCBs within a chassis with internal heatsink:

Assembly instructions of kit components

LDA172mc assembly instructions

PSMR101Sc assembly instructions

APBFa and APBMa assembly instructions

MIB12sc assembly instructions

List of connections between boards

PSMR101S is a stereo board while LDA172 and APBF/APBM are mono. Channel 1 connections on the PSMR101S are marked PROT1 and AOUT1. Channel 2 connections on the PSMR101S are marked PROT2 and AOUT2. Mark the two LDA172 boards "1" and "2". Do the same for the two ABPF/APBM boards. Always connect channel 1 to boards marked "1" and channel 2 to boards marked "2". Always connect boards marked "1" together and connect boards marked "2" together. Do not mix up connections between boards marked "1" with those marked "2".

PSMR101S - LDA172

PSMR101S

LDA172

Connection type

Remarks

J97/J98(+VCC)

J9(+VCC)

solder - solder

cable min. 0,5 mm2

J99/J102(PGND)

J13(PGND)

solder - solder

cable min. 0,35 mm2

J100/J103(ZGND)

J11(ZGND)

solder - solder

cable min. 0,35 mm2

J101/J104(GND)

J3(GND)

solder - solder

cable min. 0,25 mm2

J95/J96(-VCC)

J12(-VCC)

solder - solder

cable min. 0,5 mm2

J111(AOUT1)/ J109(AOUT2)

J10(AOUT)

solder - solder

cable min. 0,5 mm2

MIB12 - PSMR101S

MIB12

PSMR101S

Connection type

Remarks

J84/J85

J112(+12V)

solder - connector

cables min. 0,25 mm2

LDA172 - APBF/APBM

LDA172

APBF/APBM

Connection type

Remarks

+ER(J5/J7),‑ER(J6/J8)

J51(ERV)

solder - connector

observe +/‑ polarity;

see LDA172 assy instructions

PSMR101S - APBF/APBM

PSMR101S

APBF/APBM

Connection type

Remarks

J92(PROT1)/ J93(PROT2)

J53(PROT)

connector - connector

observe polarity when assembling connector

 

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