Yamaha DSP-E390

The DSP-E390 was a high-specification natural sound digital sound field processor that produced the rear and centre channels of a surround sound system. Manufactured by the Yamaha Corporation in Malaysia, it had amplified outputs for the rear and centre channels only. The rear channels were 15-watts each and the centre channel 60-watts. Given a stereo input, this processor was capable of resolving the signal into Dolby Pro Logic and Dolby Enhanced, surround sound. It also has 4 programs for digital sound field processing, and 3 centre channel modes consisting of normal, wide, and phantom. This amplifier also has remote control capability, and the volume knob is servo controlled connected by a dc motor. The amplifier usually comes in standard black or titanium silver colours.

Review

Digital sound field processors are very useful to audiophiles who use classic stereo amplifiers as their main system, and occasionally listen in surround sound. In this case, you simply feed the stereo signal to the DSP-E390 and it decodes it to produce the rear and centre channels. There is also an RCA output for a subwoofer, for which you will require a separate amplified subwoofer speaker.

The centre channel consists of the 2SA1694 and its complement 2SC4467 in a symmetrical push-pull configuration. These transistors have collector rating (Ic) of 8 A. The rear left, and rear right, channels consist of the NEC µPC1188H power amplifier integrated circuits. According to their documentation, they are capable of providing up to 20-watts output in an 8 ohm load, and require split voltage rails of ±22 V. These IC’s are easily replaceable and readily and cheaply available online.

These early amplifiers used discrete components in the decoding circuitry and therefore they sound better compared to some of the well-known DSPs that took over.

Price/eBay

The DSP-E390 is a very desirable audio processor and consequently it holds its value in the pre-used market. The price can vary depending upon the condition, and therefore one in mint condition, together with the remote control and original packaging can sell in the order of hundreds of pounds. However, a broken one with scratches and missing remote would be in the tens of pounds range. The audio power output ICs are still available and cheap making repairs cost-effective for anyone in the repair trade.

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