52 lb, 250 watt versas 20 lb, 500 watt receivers?

My dated Sansui 9090db receiver weights 52 lbs with a 6 inch square power transformer. It has power transitors on the back with big cooling fins and is rated at 250 watts at 8 ohms. The new surround sound receivers weigh much less (15 -20 Lbs)and boost 500 to 600 watts.

What is the new technolcgy used to allow this weight reduction? Would it be worth my while to trade considering surround sound is not a big deal to me?

Charlie

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Originally Posted by CharlieBee

My dated Sansui 9090db receiver weights 52 lbs with a 6 inch square power transformer. It has power transitors on the back with big cooling fins and is rated at 250 watts at 8 ohms. The new surround sound receivers weigh much less (15 -20 Lbs)and boost 500 to 600 watts.

What is the new technolcgy used to allow this weight reduction? Would it be worth my while to trade considering surround sound is not a big deal to me?

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Like statistics, it is easy to lie about watts. Your receiver likely adheres to the stringent RMS continuous full frequency range with all channels driven measurement. Sadly, many of the new HT receivers are falling back to the old IHF or dynamic power rating. Which means that for a split second with one channel operating, the amp might put out that much power. Many of the new lightweight receivers like the Panasonic XRs are digital amps. Theoretically, they do no rely as much upon brute delivery of current to operate. While the concept has been around for a while, there are more manufacturers using that approach. I have yet to hear one I really enjoy. That includes the Halcros which measure great but sound a bit sterile to me.

rw

What E-stat says is right.
The only thing I would add is that power supplies, transformers, etc, have become considerably lighter while maintaining or improving performance...so weights have dropped a bit. What's more, as efficiencies improved, they give off less heat, requiring less heatsinks and cooling fins, etc, shedding even more weight.
But not 25-30 lbs of weight...
When it comes to amplifiers, straight up amps, you most often get what you pay for.

Quote:

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Originally Posted by CharlieBee

My dated Sansui 9090db receiver weights 52 lbs with a 6 inch square power transformer. It has power transitors on the back with big cooling fins and is rated at 250 watts at 8 ohms. The new surround sound receivers weigh much less (15 -20 Lbs)and boost 500 to 600 watts.

What is the new technolcgy used to allow this weight reduction? Would it be worth my while to trade considering surround sound is not a big deal to me?

Charlie

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The thing to keep in mind with the older receivers like these Sansuis is that they were built to meet a much more stringent output rating standard. The FTC standard specifies that a mono or stereo amp must be rated with the output sustained with all channels driven for 30 seconds (?) using a full bandwidth test tone at 8 ohms impedance. A 250 watt/channel receiver is very powerful by any standard. But, as others have said, you don't look at how good a unit is based on its weight and wattage alone.

Surround receivers don't fall under this standard, so they can report all kinds of nonsensical output ratings. First thing to look at is whether or not the output is rated using an all-channels driven test, and also to look at the energy consumption on the back. Almost all multichannel receivers are rated with either one or two channels driven, NOT all of them at the same time. If these receivers say that they output 100 x 7 channels, that does NOT mean that their total output capability is 700 watts. It merely means that it can output 100 watts through any ONE channel at a time, not that it can do with all of them simultaneously.

As far as weight goes, the older receivers had a LOT more analog switches and dials that were all wired together. Newer multichannel receivers have fewer analog controls, and most of the processing is now done digitally, which only requires the weight of a few microchips. Another oft-overlooked source of heft on older receivers is the tuner. If your Sansui comes with an old analog tuner with the full length radio dial, those components alone can weigh several pounds. A friend of mine with a vintage Kenwood receiver had the tuner short out on that unit, so he took the receiver apart and pulled out all of the tuner components. After pulling out the tuner components, his receiver weighed about 8 lbs less than before.

If surround sound is not a big deal to you, then you're better off keeping that old Sansui. The reason to go to a multichannel receiver is if you want to move up to multichannel sound or want something with digital format decoding, video switching, and bass management for integrating a subwoofer.

I suppose the phrase "they dont build 'em like they used to" would apply here also.

Charlie,

Yep the big breakthrough in weight reduction is the use of BS instead of real specs - apparently it weighs less. :D

Your Sansui is considered a great receiver by the vintage guys, looking in the review section here it got a 4.85 out of 5 rating after 54 reviews. That's pretty good. If you read them you might find some good info.

So you've got options! Is the Sansui going to be better than a decent separates system? Unlikely IMO, but it's got a very good chance to outperform many, prolly most, HT receivers.

One issue with the older stuff is, sometimes they need maintenence. A quick look around shows two known issues with your Sansui - the Dolby switch fries, and having to tap the glass sometimes to get a light to work.

Not to slam it - I would use it - right now! And even if the pre goes haywire eventually you can use it for its' great amp.

Which if I was going the HT route is exactly what I'd do - get a HT rec'r with pre outs and see which amp section sounds better, then use the Sansui to take some heat off the HT rec'r, giving the center & rear channels more headroom while probably giving you better sound on the mains for 2 channel enjoyment. Heck I'd at least try it.

And you get a nice bonus - keeping the Sansui out to show off the good looks while having a stack of equipment to decorate your room. THIS is what Martha should be talking about :D !

Pete

A "nudie" pic of a Sansui 9090db:

And here's a link to a detailed spec sheet:

http://www.sansui.us/images/Manuals/9090DB_spec.JPG

Pete