PS Audio · amplification · House of Stereo
Current, control, and room to breathe.
The PMG S400 brings PS Audio’s current-based amplifier architecture to a stereo chassis. Its combination of Class A bias and substantial output capability is intended for a revealing two-channel system with demanding loudspeakers.
One stereo power amplifier. Choose your finish.
PMG S400 Stereo
A signal path built around current
PS Audio uses a current-based circuit with low feedback and generous Class A bias. Rather than treating rated wattage as the entire story, the design addresses the amplifier’s behavior as the signal changes and the speaker presents a complex load. It is a dedicated analog power amplifier: source selection and listening volume belong to your preamplifier.

PMG S400 Stereo
Power behind the performance
An actively regulated supply supports the audio circuitry. Both channels live in one enclosure, giving you a straightforward stereo installation without giving up balanced connectivity. Choose the S200 or S400 by considering speaker sensitivity, listening distance, and desired headroom. Leave ventilation space around the enclosure; high-bias amplification produces heat during normal use.

A closer look at the manufacturer’s measurements
This plot is supplied by PS Audio. Read the measurement conditions alongside the trace when comparing specifications; it is not an independent House of Stereo measurement.

Make it work in your system
Thoughtful setup makes the difference.
Begin with volume control
Connect a preamplifier or a correctly configured variable-output source. Start at a low level and use the input type suited to your system.
Give the amplifier room
Leave ventilation and cable clearance. Check speaker impedance and mains requirements in the manual before installation.
Match power to the room
Speaker sensitivity, listening distance, and playback level affect useful headroom. Ask House of Stereo to help compare an amplifier with your speakers.
The details that matter
Specifications
| Rated output into 8 Ω | 200 W per channel |
|---|---|
| Rated output into 4 Ω | 400 W per channel |
| Inputs | Balanced XLR and single-ended RCA |
| Gain | 26.2 dB |
| Input impedance | 100 kΩ RCA / 200 kΩ XLR |
| Frequency response | <10 Hz–80 kHz, ±0.25 dB |
| Dimensions with feet and binding posts | 17.5 W × 8.75 H × 16.75 D in |
| Weight | 57.2 lb |
| AC supply | Automatic 120/230 V, 50/60 Hz |
| Idle consumption | 190 W per chassis |
Ratings are manufacturer specifications. Check the linked manual for complete operating conditions, regional requirements, and installation instructions.
Before you choose
Common questions
Do I need a preamplifier?
Yes, you need a suitable source-selection and volume-control stage. This is a power amplifier, not an integrated amplifier.
Are speakers included?
No. This listing covers the amplifier package described above. Speakers and source components are separate.
Keep researching.
Read the manufacturer’s owner’s guide (PDF)
