JohnA Posted July 11, 2004 Share Posted July 11, 2004 I just bought a Rat Shack SA-150 off of eBay for $23 delivered. It has a power output rating of 1.8 watts @ 1% THD. I will use it to power a pair of Auratone near-field monitors fed by my PC. 1.8 watts is not enough. I'd like 10 to 15 wpc. How can I replace the power section with a SS kit amp of that power range? Quote Link to comment Share on other sites More sharing options...
tpg Posted July 11, 2004 Share Posted July 11, 2004 This may totally not be what you are looking for... but I'll give it a go anyhoo... You might try a National Semiconductor LM3875 or something similar... Burr-Brown has similar devices... I can look them up and give you more info if you'd like to go this route... Anyway, build a low-power Gainclone out of one of these power integrated circuits... 1000uF resevoir caps, 2.2uF input caps, 22k resistor to ground, voltage gain of around 21.... and you could get even more power than 10-20W from it. It uses minimal parts... and they don't have to be high quality. Just 3 resistors (depending on the IC you use) and 3 caps... (per channel, of course). Of that seems intriguing... I can elaborate. I have built one, and they work quite well. Sound is very good despite the simplcity. Quote Link to comment Share on other sites More sharing options...
JohnA Posted July 12, 2004 Author Share Posted July 12, 2004 yeah, that's the ticket. My son has an SA-155 (black version) and I believe it uses ICs for output. It should be here in a couple of days, so I'll post more then. Quote Link to comment Share on other sites More sharing options...
djk Posted July 14, 2004 Share Posted July 14, 2004 Those 15W Tripath amps are $30 or less. http://db.audioasylum.com/cgi/m.mpl?forum=hug&n=70231&highlight=tripath+djk&r=&session= Quote Link to comment Share on other sites More sharing options...
michael hurd Posted July 14, 2004 Share Posted July 14, 2004 I don't believe it! I used to have one of those, donated by next oldest brother, after he left college. Mine was silver in color as well. I had the speakers from the old juliette system in my bedroom, connected to it, with the source being either a Sony sports walkman, or a hacked up blaster used for the tuner section only. Quote Link to comment Share on other sites More sharing options...
D-MAN Posted July 14, 2004 Share Posted July 14, 2004 The sight of that amp reminds me of a sea-story. Back in the 70's when I was in the Navy, our ship was going overseas on a WestPac tour for about 7 months. The guys in my division all chipped in a few bucks to get a stereo amp for the shop. I came to a little over $100 bucks. Well, we ended up getting one of these Rat-Shack 35w per channel integrateds and plugged a cassette deck into it and everyone agreed that it actually sounded pretty darn good. Later, the radar antenna cooling water drained (accidentally) out from the mast directly on the amp (while it was on) - they shut it off, and we vacuumed out the water and dried it out pretty good. We then plugged it in and it worked just fine! For the time and place, it was sure worth the money. DM Quote Link to comment Share on other sites More sharing options...
JohnA Posted July 14, 2004 Author Share Posted July 14, 2004 djk, Isn't the tripath a power amp? I'd rather have an integrated amp. Quote Link to comment Share on other sites More sharing options...
JohnA Posted July 15, 2004 Author Share Posted July 15, 2004 O.K., the output chip is an LA4440. The whole unit appears to run on +/- 15V before rectification. What does that become after it is rectified? Attached is some data that I partially understand. Quote Link to comment Share on other sites More sharing options...
JohnA Posted July 15, 2004 Author Share Posted July 15, 2004 More data http://forums.klipsch.com/idealbb/files/LA4440.pdf Quote Link to comment Share on other sites More sharing options...
JohnA Posted July 15, 2004 Author Share Posted July 15, 2004 ! Quote Link to comment Share on other sites More sharing options...
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