AUDIOPHONICS LPA-S400ET Class D Stereo Amplifier Purifi 2x400W 4 Ohm

Two PURIFI 1ET400A modules

Each channel of the amplifier circuit uses its own PURIFI 1ET400A module. These high-performance Class D amplifier circuits each offer a very comfortable 200W at 8 Ohm while benefiting from the high efficiency of Class D amplifiers.

The 1ET400A modules embody a high gain loop greater than 75dB over the entire frequency band, providing high performance over the entire spectrum, surpassing any amplifier of any class.

Highly efficient in terms of Intermodulation Distortion Mode (IMD), these modules enable the LPA-S400ET to deliver a stereophonic image with high accuracy across the entire spectrum, providing even greater clarity during even the most complex musical works.

Harmonic distortion (THD) is kept extremely low at all power levels. This results in a lack of sound signature and the ability to reproduce all types of music without coloration.

The output noise is negligible, which allows deep silences and promotes the appearance of detail when listening at low volume levels.

The circuit benefits from a high rejection level (PSRR) that minimizes the impact of the power supply on audio performance.

The load-independent frequency response makes it possible to enjoy all the qualities of this amplification technology, even with the most difficult to drive speakers.

Low power consumption at rest and electromagnetic radiation (EMI). The high gain loop significantly relieves the workload of MOSFETs and allows them to operate under optimal operating conditions, reducing losses and EMI emissions.

The LPA-S400ET has its amplifier modules connected with a specially developed interface card for optimal integration.

Hypex Power Supply Module SMPS1200A400

The SMPS1200 switched-mode power supply is a very high efficiency model capable of developing a rated power of 1200 Watts in an extremely small footprint. It has been specifically designed and developed by Hypex to provide the 2x64V voltage required to operate the most demanding amplifier modules.

This low-noise quality power supply meets the power requirements of the amplifier modules in every respect. In addition, the amplifier modules themselves have an excellent ability to reject supply noise. This makes the LPA-S400ET extremely insensitive to mains imperfections and voltage/current fluctuations that can cause interference noise.

Audiophonics interface board

The 2 modules are driven in phase opposition, to cancel the "Power-Supply Pumping" effect. This allows a greater stability of the power supply, distributing alternately on each rail the calls of current and thus increasing its capacities.

We have opted for a 2-level voltage regulation, to optimise the power supply to the OPAs and the auxiliary voltage supplied to the modules.

One Texas Instrument LM4562 OPA per channel is used. These are very low distortion OPAs offering the highest transparency with a very low THD. They are mounted on a DIP8 socket, allowing their replacement if needed.

Gain of +7.2dB, i.e. a total of 20dB (default) - Maximum power reached with a signal of -4.2V RMS.

Gain of +12.5dB, i.e. a total of 25.3dB - Maximum power reached with a signal of -2.25V RMS.

Bypass: In this case, the signal passes directly from the inputs to the modules, allowing the lowest possible gain of 12.8dB. This mode can be interesting when using a strong preamplifier, capable of driving a 2 to 4K Ohm load and reaching a voltage of -10V RMS.

Connectivity

Designed for easy integration, the LPA-S400ET has a balanced (XLR) and unbalanced (RCA) stereo input. Bipolar switches allow easy switching between input sources and even allow independent channel control.

On the output side, BP-207 carbon / 24k Ø5.5mm gold / carbon insulated terminals provide an excellent connection to the loudspeakers.

Specifications
Product type	Power amplifier
Power	227W @ 8Ω, 1%THD 425W @ 4Ω, 1%THD 450W @ 2Ω, 1%THD
THD+N	0.0007% @ PO=1W, f=1kHz 0.00026% @ PO=10W, f=1kHz 0.00015% @ PO=100W, f=1kHz 0.0007% @ PO=1W, f=20Hz-20kHz 0.00029% @ PO=10W, f=20Hz-20kHz 0.00017% @ PO=100W, f=20Hz-20kHz
IMD (CCIF)	0.00025% @ PO=1W, f=18kHz+19kHz 0.00022% @ PO=10W, f=18kHz+19kHz 0.00027% @ PO=100W, f=18kHz+19kHz
IMD (DIM)	0.002% @ PO=1W, DIM30 0.002% @ PO=10W, DIM30 0.002% @ PO=100W, DIM30
Quiescent noise	11.5µV (A-Weighted)
Dynamic range	131dB @ 4Ω (A-Weighted)
SNR	131dB @ 4Ω (A-Weighted)
Frequency response	20Hz - 20kHz ±0.01dB @ RL=8Ω 20Hz - 20kHz ±0.01dB @ RL=4Ω 20Hz - 20kHz ±0.01dB @ RL=2Ω
Output impedance	Iout = 1A @ 0.07mΩ, 1kHz Iout = 1A @ < 0.65mΩ, 20Hz-20kHz
Input impedance	RCA : 47kΩ / XLR : 100kΩ Bypass : 2.2kΩ / 4.4kΩ

Specifications

Product type

Power amplifier

Power

227W @ 8Ω, 1%THD
425W @ 4Ω, 1%THD
450W @ 2Ω, 1%THD

THD+N

0.0007% @ PO=1W, f=1kHz
0.00026% @ PO=10W, f=1kHz
0.00015% @ PO=100W, f=1kHz
0.0007% @ PO=1W, f=20Hz-20kHz
0.00029% @ PO=10W, f=20Hz-20kHz
0.00017% @ PO=100W, f=20Hz-20kHz

IMD (CCIF)

0.00025% @ PO=1W, f=18kHz+19kHz
0.00022% @ PO=10W, f=18kHz+19kHz
0.00027% @ PO=100W, f=18kHz+19kHz

IMD (DIM)

0.002% @ PO=1W, DIM30
0.002% @ PO=10W, DIM30
0.002% @ PO=100W, DIM30

Quiescent noise

11.5µV (A-Weighted)

Dynamic range

131dB @ 4Ω (A-Weighted)

SNR

131dB @ 4Ω (A-Weighted)

Frequency response

20Hz - 20kHz ±0.01dB @ RL=8Ω
20Hz - 20kHz ±0.01dB @ RL=4Ω
20Hz - 20kHz ±0.01dB @ RL=2Ω

Output impedance

Iout = 1A @ 0.07mΩ, 1kHz
Iout = 1A @ < 0.65mΩ, 20Hz-20kHz

Input impedance

RCA : 47kΩ / XLR : 100kΩ
Bypass : 2.2kΩ / 4.4kΩ

General
Power supply	230V (110V on demand)
Dimensions (without connectors)	19 x 35.9 x 7.8cm
Weight	3.17kg
Housing material	Aluminium
Color	Black

General

Power supply

230V (110V on demand)

Dimensions (without connectors)

19 x 35.9 x 7.8cm

Weight

3.17kg

Housing material

Aluminium

Color

Black

Input	RCA
Input	XLR
Output	Speaker terminal
Color	Black
Material	Aluminium
Channel	Dual Mono
Accepts Banana Plugs	Yes
Light symbol	Yes
Class	Class D / T
Fuse holder	Yes
Input voltage (V)	230V AC
amplifier chip	Purifi 1ET400A
Power (max)	400W

Quality of the product 5 stars quality of the packaging no stars
Overall satisfied. The product is nicely build and the sound quality is super. However the product was put in a big carton box (not a product box) with a lot of random filling (carton, foam, plastic) it could easily have been damaged. No user manual or anything. The rubber absorbing rings for the feet (I almost throw them away with the filling) and power cord were thrown unwrapped and unprotected in the box. Just a little more attention to the wrapping and packaging would increase the excitement and trust over the product enormously. But again once connected and listening to the Music all worries and concerns are soon forgotten and the happy feeling remains.

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