[Amps] Acoustic Noise Comparison

[Jerry Kaidor]

Hello,

   Still playing with my "new" Alpha 78.  I had noticed that the fan was a
bit loud for my taste, and thought I'd put a measurement on it.  So I
dug out my old Radio Shack sound meter and measured.  At my operating
position,
about 2 feet from the amplifier, I get 58db ( C weighted ).

  To compare, I pulled out the 30L-1.  From two feet away, it was below the
most sensitive scale of the meter.  At *least* 10dB below the Alpha.  I
was able to get the same reading as the Alpha by positioning the sound
meter about 2 inches above the 30L1, pointing the meter straight at the
fan.

   I just ordered a new blower for the Alpha.  I believe they also supply
new packing with that.  If it's not any quieter, I will investigate a
2-speed arrangement.  This would be easy to prototype up with the old
fan out of the case.

                                   - Jerry Kaidor, KF6VB