At 06:42 PM 10/22/2004, wayne burdick wrote... >However, because of the problem with clipping at high signal levels, I >definitely don't recommend that anyone do this unless they're desperate for >more audio. The LM386 is a lower-power part and is also noisier than the >LM380, partly because of all that extra gain.
I was able to make both clip, but in both cases it was when the volume exceeded a comfortable level. The LM386 was putting out over 1/2 W when it did. I don't see where noise is characterized on the National datasheet, and nothing to indicate that the 380 has a better signal to noise ratio, which is what's really relevant. If more audio gain is needed to get useful volume, amplifying noise is unavoidable. The LM386 gain is adjustable, so if less than a 12 db boost is needed, that too is possible. It's reasonable to assume that a 386 configured for the same gain as a 380 would have comparable noise. I agree with your point that adding gain (or decreasing loss) earlier in the chain is preferred, and offered this as a solution for when that fails to achieve adequate volume, as it apparently has for some users. "Low power" is relative. I measured 4 VAC (p-p, ~500 mW ) on the 386 and 5 VAC (~850 mW) on the 380 at the onset of clipping, a relatively minor difference and inconsequential given that either level provides more than ample volume with the internal speaker. Going past clipping adds volume at the expense of distortion, but at the levels I observed it would only be useful for listening from across the room (or from the next room), where that may be a reasonable tradeoff. I doubt anyone who can make either clip is complaining about low volume. Mike _______________________________________________ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
