Speakerplans.com Homepage
Forum Home Forum Home > General > Amp Forum
  New Posts New Posts RSS Feed - newman amp
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

newman amp

 Post Reply Post Reply
Author
Message
full speed View Drop Down
Registered User
Registered User
Avatar

Joined: 20 January 2010
Status: Offline
Points: 206
Post Options Post Options   Thanks (0) Thanks(0)   Quote full speed Quote  Post ReplyReply Direct Link To This Post Topic: newman amp
    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 informationIMG_20201014_073311.pdf
Back to Top
full speed View Drop Down
Registered User
Registered User
Avatar

Joined: 20 January 2010
Status: Offline
Points: 206
Post Options Post Options   Thanks (0) Thanks(0)   Quote full speed Quote  Post ReplyReply Direct Link To This Post 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.
Back to Top
Earplug View Drop Down
Old Croc
Old Croc


Joined: 03 January 2012
Location: Europe
Status: Offline
Points: 6165
Post Options Post Options   Thanks (0) Thanks(0)   Quote Earplug Quote  Post ReplyReply Direct Link To This Post 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?



Earplugs Are For Wimps!
Back to Top
jbl_man View Drop Down
Moderator Group
Moderator Group
Avatar

Joined: 12 January 2005
Location: London.
Status: Offline
Points: 10825
Post Options Post Options   Thanks (0) Thanks(0)   Quote jbl_man Quote  Post ReplyReply Direct Link To This Post 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? 
Be seeing you.
Back to Top
Earplug View Drop Down
Old Croc
Old Croc


Joined: 03 January 2012
Location: Europe
Status: Offline
Points: 6165
Post Options Post Options   Thanks (0) Thanks(0)   Quote Earplug Quote  Post ReplyReply Direct Link To This Post 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:-


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


Earplugs Are For Wimps!
Back to Top
full speed View Drop Down
Registered User
Registered User
Avatar

Joined: 20 January 2010
Status: Offline
Points: 206
Post Options Post Options   Thanks (0) Thanks(0)   Quote full speed Quote  Post ReplyReply Direct Link To This Post 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..
Back to Top
full speed View Drop Down
Registered User
Registered User
Avatar

Joined: 20 January 2010
Status: Offline
Points: 206
Post Options Post Options   Thanks (0) Thanks(0)   Quote full speed Quote  Post ReplyReply Direct Link To This Post Posted: 15 October 2020 at 4:25pm
here the image from inside
Back to Top
BJtheDJ View Drop Down
Young Croc
Young Croc
Avatar

Joined: 28 November 2012
Location: Bristol
Status: Offline
Points: 687
Post Options Post Options   Thanks (0) Thanks(0)   Quote BJtheDJ Quote  Post ReplyReply Direct Link To This Post Posted: 15 October 2020 at 4:43pm
Only users lose drugs
Back to Top
jbl_man View Drop Down
Moderator Group
Moderator Group
Avatar

Joined: 12 January 2005
Location: London.
Status: Offline
Points: 10825
Post Options Post Options   Thanks (0) Thanks(0)   Quote jbl_man Quote  Post ReplyReply Direct Link To This Post 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.
Be seeing you.
Back to Top
full speed View Drop Down
Registered User
Registered User
Avatar

Joined: 20 January 2010
Status: Offline
Points: 206
Post Options Post Options   Thanks (0) Thanks(0)   Quote full speed Quote  Post ReplyReply Direct Link To This Post 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..
Back to Top
 Post Reply Post Reply
  Share Topic   

Forum Jump Forum Permissions View Drop Down

Forum Software by Web Wiz Forums® version 12.03
Copyright ©2001-2019 Web Wiz Ltd.

This page was generated in 0.062 seconds.