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FAQ's
Pioneer, Teac, Tascam, Akai, Fostex, Kenwood, Sansui, Phase Linear, Marantz, McIntosh, Carver, SAE, HH Scott, Yamaha, JBL |
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Randall Reed Studios ▪ Motley, MN 56466 ▪ 218.575.2965 |
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All pictures that you see here on my web site are of the actual units I have for sale. Don't be fooled by outrageous watts per channel claims. These units here were rated in RMS power back when the govt made manufacturers rate their equipment in the same manner so that the customer would not be fooled. I remember in the early 70's seeing dinky amps at Schaak Electronics in Mpls saying they had 20,000 watts of power per channel! A lot of cheap stuff today is rated by whatever system a company wants to use. For example, peak-peak power will look 8 times the RMS power. Instantaneous power can be in the thousands of watts but is only attained for milli-seconds. Some class H amps used as instruments or club amps for example are rated over a 20-200mS time range so the ratings are somewhat misleading. RMS is continuous output power to the speakers and is the only power rating you should be concerned with. Most Class A and Class AB amps are rated this way. Class AB is the most common amplifier type from the 70's as it's the best compromise between low noise and high power. A few run Class A (cleanest) up to 10-30 watts and then switch to Class AB for the higher power. The ear usually can't tell the difference between these two types of amplifiers. I saw a cheap plastic stereo in one of the "Marts" recently rated at 300 wpc. Give me a break! Turns out it's RMS rating was under 10 wpc. I have a DJ amp that says right on the front "1000Watts". Not sure what-in-hell rating system they used but the literature rated it at 85 wpc RMS. Big difference eh? Also the total power input to the amp is not the actual power being used to drive the speakers. There's heat losses and other circuits inside the amp to drive. When you don't know the power output of the amplifier section, the Rule of Thumb on vintage amplifiers is to take 1/4 of the total power input and that's probably close to the RMS power per channel to the speakers. Some Sansui amps like the BA units will give total RMS power for both channels but this is rather rare. Another laugher is when people take the switched and unswitched outlet power in the back and say that's the power of the amp. All that does is connect either thru a switch/relay or directly to your AC power line. Has absolutely nothing to do with the power output of the amp. It's there as a convenience to hook up your other gear. |
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Copyright (c) 2001 - 2008, Randall Reed