Sony STR-DE400

The STR-DE400 is a high-spec Multi Channel AV Receiver (Digital Audio/Video Control Centre) manufactured by the Sony Corporation in 2006. It is a Digital Cinema Sound / Discrete 5.1-Channel Amplifier with Dolby Digital Pro Logic II, Digital Theatre System (DTS), and Radio Data System (RDS). This particular amplifier has Digital Cinema Auto Calibration (DCAC) technology that ensures perfect sound level of each speaker in a surround sound system. It comes with ECM-AC2 microphone for the DCAC auto calibration feature, and requires the RM-AAU006 remote control for use in conjunction with it. The full specifications for model versions covering all the countries are in the manual.

Review

It was a wonderful piece of electronic engineering from the Sony Corporation, and today highly sought after due to the clean minimalistic look and great sound. The audio power output circuitry uses the famous MN2488 and MP1620 complementary pair of transistors, driven by the STK350-530 IC. The transistors are by the Sanken Corporation, with collector current rating (Ic) of 10 A, producing a very punchy loud sound. With a good pair of loudspeakers, this amplifier is very loud making its presence heard.

In earlier surround sound systems, Sony introduced a programming method for setting the sound field whereby each speaker produced white noise and the listener, sitting at the centre, had to adjust the volume setting so that all the speakers had the same perceived loudness. Unfortunately, this method relies on the user having perfect hearing in the first place. With the STR-DE400, they offer DCAC, which is a system that automatically calibrates the sound field by detecting the white noise through the ECM-AC2 microphone.

Factory Reset

To fully reset the amplifier to the condition it was when from the factory, there is a reset procedure you can try. The reset procedure will delete all preset settings.

Pressing PRESET TUNING – and DIMMER buttons simultaneously, then press the Power button to turn ON the receiver.

When "FACTORY" appears on the display, let go of the buttons.

Intermittent Protect Error

Some of these amplifiers suffered from dry solder joints involving the current sense resistors. These resistors usually get hot and over many years develop dry joints resulting in the "PROTECT" error showing. The solution is usually to have a qualified electronic engineer remove the old solder and re-solder use some fresh new solder and flux.

Price/eBay

These are often for sale on eBay and the price can vary depending upon condition. This is a lovely looking amplifier with great sound, and having DCAC technology makes it very desirable. A unit in mint condition together with the manual and box can sell for over one hundred pounds and more. A scratched one without the remote would be around fifty pounds. A burnt one would be in the ten pounds mark for a hobbyist project. Although the audio power output transistors are cheap, you have to take the amplifier apart to get to the underside of the main board, making it a time consuming repair.

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