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newman amp

Printed From: Speakerplans.com
Category: General
Forum Name: Amp Forum
Forum Description: The 'Stopping Jake Fielder moaning constantly' forum description...
URL: https://forum.speakerplans.com/forum_posts.asp?TID=105790
Printed Date: 24 November 2020 at 4:04am
Software Version: Web Wiz Forums 12.03 - http://www.webwizforums.com


Topic: newman amp
Posted By: full speed
Subject: newman amp
Date Posted: 14 October 2020 at 5:50am
hi guys.any help for this transistor please..it is from old crx newman amp where i can found this or can i replace with something similar?no labels written on chip only think you can read is half the words operational aplifier.thank you for any information uploads/7353/IMG_20201014_073311.pdf" rel="nofollow - IMG_20201014_073311.pdf



Replies:
Posted By: full speed
Date Posted: 14 October 2020 at 5:12pm
no opinion here what kind of transistor is that? nobody have seen similar on epoxy resin? one chanel is broke and needs to repaired.


Posted By: Earplug
Date Posted: 15 October 2020 at 9:53am
Manufacturers will often erase numbers - or encase components in resin to stop copying, etc. You really need to try contact them to find out. Or post some more photos of where the thing comes from in the circuit, but without more info, it can only be a bit of speculation.

And searching for Newman amplifier comes up empty. Where does it come from?





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Earplugs Are For Wimps!


Posted By: jbl_man
Date Posted: 15 October 2020 at 1:09pm
Yup,looks like two transistors, side by side, encased in potting compound. If it's dead, you could try gently chipping the resin off,and see what they actually are? 

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Be seeing you.


Posted By: Earplug
Date Posted: 15 October 2020 at 4:13pm
Or - if there is a working channel, you could take some measurements and try deduce what those are. The voltages around the pins will tell you a lot - and then pop into a tester, eg:-

https://www.ebay.com/itm/LCR-T4-LCR-T5-ATmega328-Digital-Transistor-Tester-12864-LCD-Capacity-Meter/401232204698?hash=item5d6b4d939a:g:0yUAAOSwEzxYOE4a" rel="nofollow - https://www.ebay.com/itm/LCR-T4-LCR-T5-ATmega328-Digital-Transistor-Tester-12864-LCD-Capacity-Meter/401232204698?hash=item5d6b4d939a:g:0yUAAOSwEzxYOE4a

See what it tells you, ie BJT - or Mosfet, NPN, PNP, etc.




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Earplugs Are For Wimps!


Posted By: full speed
Date Posted: 15 October 2020 at 4:18pm
thanks for answers..nothing can t found about this amps on net..i check the transistors like your advise..


Posted By: full speed
Date Posted: 15 October 2020 at 4:25pm
here the image from inside


Posted By: BJtheDJ
Date Posted: 15 October 2020 at 4:43pm
Only references that I can find to Newman amps are these on AliBaba :

http://guide.alibaba.com/t-shop/newman-bw-215-15-trolley-square-dance-outdoor-stereo-speakers-subwoofer-bass-sound_78682357.html" rel="nofollow - http://guide.alibaba.com/t-shop/newman-bw-215-15-trolley-square-dance-outdoor-stereo-speakers-subwoofer-bass-sound_78682357.html

http://guide.alibaba.com/t-shop/newman-kw-232-12-inch-trolley-speaker-power-amplifier-with-bluetooth-wireless-microphone-outdoor-square-dance-sound-loud_80450671.html" rel="nofollow - http://guide.alibaba.com/t-shop/newman-kw-232-12-inch-trolley-speaker-power-amplifier-with-bluetooth-wireless-microphone-outdoor-square-dance-sound-loud_80450671.html


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Only users lose drugs


Posted By: jbl_man
Date Posted: 16 October 2020 at 12:58pm
A quick look at the photo,i assume the outputs are mounted on the black heatsink bottom left, so the four mounted on the little silver heatsinks will be the drivers,and the 2 encapsulated ones are the pre-drivers. Looks like a BJT amp,not mosfet. As Earplug suggested above, take some voltage readings off the working one (all six pins), and then with a diode range meter ,to deduce if they are NPN or PNP.


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Be seeing you.


Posted By: full speed
Date Posted: 17 October 2020 at 2:49pm
found one 2N5551 is shorted..ordered and wait to replace..i measure carefuly of the circuit the others on resin and looks good..



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