The Marantz PM-15S1 is a high-performance integrated stereo amplifier featuring advanced HDAM (Hyper Dynamic Amplifier Module) technology, toroidal transformer power supply, gold-plated connectors, MM/MC phono input, multiple analog inputs, preamp outputs, and headphone output. This service manual provides comprehensive technical information for qualified service technicians, including schematics, alignment procedures, parts lists, and troubleshooting guidelines.
Complete electrical and mechanical specifications for the PM-15S1 integrated amplifier.
| Parameter | Specification |
|---|---|
| Power Output | 85W + 85W (8Ω, 20Hz-20kHz, 0.05% THD) |
| Frequency Response | 5Hz-100kHz (+0/-3dB) |
| Total Harmonic Distortion | 0.005% (1kHz, 8Ω) |
| Input Sensitivity | 200mV (LINE), 2.5mV (MM), 0.2mV (MC) |
| Signal-to-Noise Ratio | 100dB (LINE), 85dB (MM), 74dB (MC) |
| Damping Factor | 100 (8Ω, 1kHz) |
| Power Consumption | 280W (maximum) |
| Dimensions | 440 x 156 x 427mm (W x H x D) |
| Weight | 18.5kg |
| Power Supply | Toroidal transformer with separate windings |
System block diagram showing signal flow and major functional blocks.
WARNING! High voltages present - discharge power supply capacitors before servicing.
Detailed circuit analysis of major sections.
CAUTION! Use only specified replacement components to maintain performance.
Access service mode via front panel controls. Required test equipment: oscilloscope, audio generator, distortion analyzer, DMM.
DC Offset Adjustment: VR801/VR802 for left/right channels (target: 0mV ±5mV)
Bias Current Adjustment: VR803/VR804 (target: 15mA ±2mA)
Phono Gain Adjustment: VR101 (MM), VR102 (MC) using 1kHz test signal
Protection Circuit Test: Verify relay timing and fault detection
Reference voltage measurements at key test points (all measurements relative to chassis ground).
| Test Point | Voltage (DC) | Description |
|---|---|---|
| TP+ | +45V ±2V | Positive rail voltage |
| TP- | -45V ±2V | Negative rail voltage |
| TP A | +15V ±0.5V | Regulated positive supply |
| TP B | -15V ±0.5V | Regulated negative supply |
| TP C | 0V ±5mV | Output DC offset |
| TP D | +5V ±0.2V | Logic supply voltage |
Critical replacement components with manufacturer part numbers.
Tip: Always replace output transistors in complementary pairs.
Complete printed circuit board layouts for all boards.
WARNING! Observe correct component orientation and soldering techniques.
| Symptom | Possible Cause | Corrective Action |
|---|---|---|
| No power | Fuse, power switch, transformer | Check main fuse F801; verify transformer primary continuity |
| Protection mode | DC offset, short circuit | Measure output DC; check output transistors |
| Distortion | Bias current, damaged transistors | Adjust bias current; test output devices |
| Hum/buzz | Grounding, filter capacitors | Check ground connections; test main filter caps |
| No phono signal | Phono stage, selector switch | Verify phono power supplies; clean selector contacts |
Reset: Power cycle unit; check protection circuit operation.
This equipment contains lethal voltages. Always disconnect AC power before servicing. Use isolation transformer when testing live circuits. Discharge large capacitors before handling.
CAUTION! High temperatures on heat sinks - allow cooling before servicing.
Marantz PM-15S1 uses proprietary HDAM modules - do not attempt component-level repair of these modules. Always use genuine Marantz replacement parts. Record all adjustments made during service. Final performance verification required after repairs.
Service Support: Contact authorized Marantz service centers for technical assistance and genuine parts.