[R-390] R-390 600 ohm audio solution

[Drew P.]

wrote:

> There is at least one more alternative, That is to simply
> use one of the dozens of audio amplifiers on a chip, very 
> few components, very effecient, cheap, and distortion and 
> frequency response so good that I have nothing that could
> even start to measure it.   Mount it external or strip an
> old audio module and place it there. Collins designs have
> nearly always been more that a little lacking in audio 
> quality and  when combined with the distortions produced 
> by detectors, AVC systems, and even the transmiters, it
> seems that any improvement in the long chain would help.

The work has already been done for us, and the result is 
especially appealing to the scrounger.  Use a computer 
speaker of reasonably good quality.  I've had some of these
apart and have seen the internal stereo amplifier using 
the TO-220 -like LM XXXX series of audio amp chips, rated 
for 10 watts.

Drew