i have a black K250-1 sn#78526. it has 2 blue lights on the front, 1 is the power button and the other is for polarity (not sure what the purpose of that is). i would like to know its approximate age, wattage or any other info i can get.
Hi,
SN 78526 was made around the end of November, 1971.
Power output is 125 watts RMS at 4 ohms.
You can use speakers rated as low as 3 ohms with it.
The polarity switch is the same effect as unplugging the AC cord and plugging it back in reversed. If the amp hums more or if you are getting shocked, you should change the polarity switch setting.
For more info on the K250, search this site for "K250".
-Les S