Sony STR-DE845 Surround Receiver

I bought this receiver in 2002, and for that time it was fine for the price, I think around $400. However, I recently bought a Yamaha RX-v661 for $500, and I can't believe how superior this unit is to the Sony. The setup, the remote, features like pure direct and the ipod dock, and especially the sound make me think the sony was overpriced and not as good as the Yamaha.

I bought this receiver in 2001. It was hooked to an Infinity home theater speaker system, which has five small speaker and subwoofer. I only use <1/3 of the max volume at all the time. Just like many people commented here, it worked great... until last year.

First the center speaker quit and I heard clicking noise from the receiver. Such noise can only come from a relay. So I just switch it to 2-CH mode, since I did not have time to fix it. Then in last week, the receiver finally gave up. It stoped working either right after power-on or after working a several minutes. So I have to take it apart to do something. Here is what I found out. By the way, I am quite an experienced electrical engineer.

The Op-amps in the pre-amp stage were overheated. There are three of these NEC op-amp chips on the main board. They are black big chips mounted vertically. I touched the chips after power-on for 2-3 minutes. They are hot, feels about 55-60 degree C. This is with the cover open, no input signal, no speaker hook-up. Then I noticed some of the leads of the op-amps were de-soldered and the board was black around the chips(open the bottom cover, looking from the back side of the main circuit board). It takes ~160 degree C to soften solder. So the silicon in these chip must be above 180 degree C at that time!

Here is what I think happened. The designer did not give the op-amp chips enough heat sinking. So the chips over-heat. Not hot enough to fail immediately... robust NEC chip design! The solder points got soft when temperature got to ~160 degree C and hardened again when cooled down. After several years of execise, the solder joints became unstable, sometime touch sometimes not. This caused the protection functions to kick in. Then relays started to click on and off, folowed by shut off.

Here is how I fixed it. These op-amp chips have metal slug on back and screw holes for heat sink mounting. SONY did not put in any heat sinks for them. (Come on, it costs <$0.3!) So I resoldered the IC leads. Then I cut three pices of 30mm X 50mm X 0.8mm from a copper sheet, drilled screw holes. Then mounted the copper pieces to the back of the op-amp ICs. Some silicon greese or thermal pad between copper and IC will be very helpful. I used some phase-change material, if you know what it is.

After done that, I hooked up speakers and DVD players and turned it on for about one hour. It was fine. These op-amps are still hot, but should be cooler than before. Someday they may fail just because of running hot for too long. If they fail, I may buy replacement from ebay for $7 each.

Hope you find it helpful. Good luck!

This item has been thoroughly reviewed and the features have been well explained but I want to add one thing: Just like the Sony reciever I had before this one, the display begins to dim after about a year. Some of the LED's don't work at all now. As far as functionality and cost-effectiveness of the 845 are concerned though, you can't beat it!

I have purchased this receiver (Gold Chassis) for USD 470 in Kuala Lumpur back in 2000, and have been looking for a replacement since 2003 since Sony introduced their 6.1 and 7.1 receivers with higher fidelity built-in surround decoders.

The one thing that I didn't like about the receiver was its analog volume control, and I was looking forward to replace that feature with a digital dial along with a multitude of new built-in decoders like the Dolby Pro-Logic II.

To my surprise, non of the newer Sony receivers of the same price range can quite measure up to the DE845 in one important area: The Sound.

I'm sure anyone who owns a home cinema in their living room would've read somewhere that in order to achieve optimum directionality and for your surround system and for it to sound convincing and natural, you wil need identical speakers for all the full range channels (be your home theatre a 5.1 or a 7.1 system).

If you own a Sony receiver of the same price range / class as the STR-DE845 today, you will notice that the receiver's (parametric) equalizer controls only the tonal quality of the front left and right speakers. This feature works as long as you are only using the two front channels to listen to music. However, when multi-channel decoding is activated, you'll end up with the two front channels producing different sounds from the remaining channels. This completely defeats the purpose of using identical speakers for your surround system.

The only way to maintain optimum directionality is to set the equalizers to off. I'm sure anyone can imagine how most speakers sound without any equalization.

The STR-DE845 however, like most of its counterparts from the 2000 and 2001 line-up, is equipped with three sets of identical parametric equalizers that control all the main 5 channel outputs. Every channel can be adjusted to respond with the same tonal quality as the others when given the same signal.

Of late, only a few high end QS and ES receivers like the AV3000 and AV5000 are able to fully control the sound quality of each speakers. But let's face it, at the end of the day, your surround receiver is meant to produce sound and music, and you shouldn't have to punch a big hole in your wallet to do it.

By the way, after returning a few new Sony receivers, I've decided to keep my almost 5 year old STR-DE845. Although it is a little scratched and worn, it still roars like a beast and it works well with my new Sony satellite system SAVE-445H.

This receiver is just amazing! I went from the 445 to the 845, and I have to confess that I only changed because I bought a full set of five Cerwin Vegas, LS12's front, LS5's center and rear and an LW12 subwoofer, and I wanted a few more watts to get the most from the Cerwins, not entirely necessary really, because the 445 is no slouch in performance and still went very very loud, then I connected the 845, OH MY GOD! this receiver is a beast!! I put on a CD first, a jungle cd from the UK, I cranked it up and nearly had a cardiac arrest, it is breathtakingly powerful.

The controls were set flat "as always for music" using only the two main speakers, the bass treble and midrange blended really well, the low bass notes common in jungle music were deep and low, and kept good pace with the music, the treble sounded rich and clear. An audiophile "if there really is such a thing" would no doubt think the sound was just brute power with no class, besides you cant get a great sounding receiver for just a few hundred dollars right!!! wrong, you can, and this receiver if you are lucky enough to find one, would be a great place to start.

I found mine in mint condition, I have seen the new 875 and appreciate some of the changes sony have made, banana plugs, front panel hookup, great, but the remote, the front panel nahhhh dont like em! the 845 for looks and that awesome remote wins me over easily, and I intend keeping it for a long long time, just wish I could have found the silver version, WOW I really like those but you dont see that many of them around, hope this helped you.