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Re: New Member with Vintage PA Question [message #17349 is a reply to message #17346]

Wed, 08 August 2012 13:06

stevem
Messages: 4733
Registered: June 2004
Location: NY

Senior Member

Hello and welcome!
The K300 head is rated to output its full 150 watts of clean power into a 4 ohm load, so when used for PA with two cabinets they should be 8 ohms each, which 95% of all pa cabs are.

The two cabinets that you use should be rated for 100 watts of power, but in all liklyhood even PA cabs rated for 50 watts should hold up for vocal rehersal in a basement or garage.

With any Solid State amp you can always use it to power a higher impeadance speaker, like 16 ohms for example, but you should never go lower than the 4 ohm rating for the K300.Every time you double the impeadance that the amp is driving you will get about 1/3 less output wattage, so going from powering a 4 ohm load ( by way of two 8 ohm cabinets) and having the full 150 watts of clean power to a 8 ohm load you end up with only some 85 watts of clean power.
Back in the era when these amps where made they rated amps at their peak power output, hence the K300 model name.
Today amps are rated at there RMS power output.
In short, your Fender speakers will work just fine, but there bass/low end responce will be a bit on the light side with only a 10" driver for lows.
The K300s monitor output needs to be put to a power amp first to drive any monitor speakers.

[Updated on: Wed, 08 August 2012 13:08]

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