need a sub for an IC

Jim Karr · 3rd November 2005, 12:27 AM

I own a Crown DC-300A amplifier which I dearly love. I need help.

There is one and only one IC in the entire amp....a dual op-amp in the negative feedback loop....UA 739. I replaced it this spring because one channel began fading away in volume, and exhibited a hissy, weak signal.

I ordered a replacement from Crown, (only place I could find one) and they nailed me $18 for a 14-pin DIP chip.

Well, my amp must have an incorrect voltage, since the chip is apparently failing again. However, I can't find this chip anywhere in stock by a parts distributor. Many websites for chip importers list the number, but then you've got to buy hundreds or thousands of them.

MCM in Ohio showed that ECG725 was a sub, but it's no longer available.

Are there any other subs that you can suggest? HELP!!!!!!!!!!!!!!

jaycee · 3rd November 2005, 03:27 AM

http://pdf.alldatasheet.net/datashee...ILD/UA739.html

You could probably replace it with any dual opamp provided the replacement isn't too fast

Jim Karr · 3rd November 2005, 11:00 AM

This sounds wonderful........any suggestions as to which opamps would be appropriate?

(Thanks kindly for your response)

paulb · 3rd November 2005, 01:11 PM

A bit tricky - not too many dual opamps come in 14-pin DIP package.
I see it here:
http://www.americanmicrosemi.com
Check the datasheet from the previous post to figure out which one you need. I think plastic is probably ok.

Jim Karr · 3rd November 2005, 03:47 PM

As the legendary Harry Caray used to bellow,"Holy Cow!" 66 cents is a whole lot cheaper than 18 dollars from Crown! Thanks!

3rd November 2005, 12:27 AM	#1
Jim Karr diyAudio Member Join Date: May 2004 Location: Southwest Michigan	need a sub for an IC I own a Crown DC-300A amplifier which I dearly love. I need help. There is one and only one IC in the entire amp....a dual op-amp in the negative feedback loop....UA 739. I replaced it this spring because one channel began fading away in volume, and exhibited a hissy, weak signal. I ordered a replacement from Crown, (only place I could find one) and they nailed me $18 for a 14-pin DIP chip. Well, my amp must have an incorrect voltage, since the chip is apparently failing again. However, I can't find this chip anywhere in stock by a parts distributor. Many websites for chip importers list the number, but then you've got to buy hundreds or thousands of them. MCM in Ohio showed that ECG725 was a sub, but it's no longer available. Are there any other subs that you can suggest? HELP!!!!!!!!!!!!!! __________________ As for me and my household, we shall serve the Lord. Joshua

3rd November 2005, 11:00 AM	#3
Jim Karr diyAudio Member Join Date: May 2004 Location: Southwest Michigan	This sounds wonderful........any suggestions as to which opamps would be appropriate? (Thanks kindly for your response) __________________ As for me and my household, we shall serve the Lord. Joshua

3rd November 2005, 03:47 PM	#5
Jim Karr diyAudio Member Join Date: May 2004 Location: Southwest Michigan	As the legendary Harry Caray used to bellow,"Holy Cow!" 66 cents is a whole lot cheaper than 18 dollars from Crown! Thanks! __________________ As for me and my household, we shall serve the Lord. Joshua

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3rd November 2005, 03:27 AM	#2
jaycee diyAudio Member Join Date: Apr 2004 Location: Norwich, UK	http://pdf.alldatasheet.net/datashee...ILD/UA739.html You could probably replace it with any dual opamp provided the replacement isn't too fast

3rd November 2005, 01:11 PM	#4
paulb diyAudio Member Join Date: Jun 2001 Location: Calgary	A bit tricky - not too many dual opamps come in 14-pin DIP package. I see it here: http://www.americanmicrosemi.com Check the datasheet from the previous post to figure out which one you need. I think plastic is probably ok.

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