[sdiy] magic hi-fi amps

metasonix at earthlink.net metasonix at earthlink.net
Mon Jun 24 03:16:11 CEST 2002

>That is, those audio visual surround sound decoder/amplifiers. There are
>hundreds of them. And they all claim to push out 100watts/rms on all
>5 (or in some cases 6, the sub woofer out as well) channels, yet they
>barely weigh 8kg. 
>(Onkyo, Denon, Marantz are all guilty I'm afraid).

You need to take the historical view. This kind of crude
salesmanship has been going on since high fidelity became
a mass market in the 1950s.

I have a Fisher ad from 1955. In it, they claimed their new
model 50-A amplifier produced 50 watts, or "100 watts peak!"
It used two triode-connected 1614s, which are metal-cased
6L6s. There is NO WAY IN HELL you can get more than 25 watts peak
out of those 2 tubes, even at the limit of their plate disspation!
Believe me....I've tested 50As on the bench. ALL of their published
specs were inflated.

Avery Fisher was famous for such ads. Consumer Reports magazine
wrote nasty editorials about him. Yet his company thrived;
he sold out to Sanyo for millions in 1974, and died filthy rich.
New York City named a major concert hall after him.

I had to fix a Philips surround receiver recently. 
It used LM1875 ICs for all 5 channels, 
which are each good for maybe 20 watts at best--
yet the packaging claimed "350 watts!!"

E. Barbour

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