High-End Audio Products & Audio Equipment | PS Audio

PMG S400 Stereo

PMG S400 Stereo - Main image
$6799.32 $9999 In stock

Category: Amplifier

The S400 is the PMG Signature Series in stereo form. Two channels of 200 watts each into 8 ohms, doubling into 4, drawn from the same state-of-the-art active power supply that drives the M800. The same Class A bias of 50 watts per channel keeps both channels in the most linear region of operation for 99% of normal listening. The same bandwidth beyond 500 kHz, the same flat distortion across the audible band, the same strikingly low overall feedback.

A single chassis. A single power cord. Two channels of reference-quality amplification.

The S400 exists for the listener who wants the entire Signature Series experience without two boxes, two power cords, and two sets of cables on the floor. Nothing in the topology has been pared back. The chassis is the only thing that changed.

Designed by Darren Myers. Engineered into production by Bob Stadtherr. Hand built in Boulder, Colorado.

​

Before you pay

Check the method and total at checkout.

When it ships

Allow for processing time as well as the journey to you.

Standard Shipping: Handling (business days) 0–1; Transit (business days) 7–15.

Express Shipping: Handling (business days) 0–1; Transit (business days) 7–15.

View policy
If you need a refund

Keep your order number and contact the store to start.

Please contact us for the refund processing timeframe before returning an item.

View policy
Delivery costs

Review the cost for your destination and chosen service.

Standard Shipping · United States: $0.00

Express Shipping · United States: $3.99

View policy
Returning an item

Check the return conditions before sending anything back.

United States · Return window (days after delivery): 30. Return method: By mail. Return postage: Seller pays.

View policy

Customer Reviews (4.8 / 5 · 5 reviews)

Hazel ★★★★★

I’ve been using this S400 for a few days and the way it doubles power into 4 ohms really wakes up my speakers — the active power supply keeps everything tight and effortless

Michael ★★★★★

I swapped out a class AB amp for this and the difference in grip on my speakers is obvious — the bass stops and starts instead of lingering. The active power supply seems to be doing real work, because it barely warms up even after a couple hours at loud levels.

Sebastian ★★★★★

The extra headroom from 200 watts per channel completely changed how my towers handle big orchestral peaks — nothing sounds strained anymore. It runs cooler than I expected for something with an active power supply, even after a few hours.