My Transistors, original or copy? - Page 37 - diyAudio
Go Back   Home > Forums > Design & Build > Parts

Parts Where to get, and how to make the best bits. PCB's, caps, transformers, etc.

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 30th May 2011, 05:18 PM   #361
Banned
 
Join Date: Nov 2006
Location: Torpoint
If no-one answers within a few days the pictures become immaterial but point taken.
  Reply With Quote
Old 30th May 2011, 07:02 PM   #362
diyAudio Member
 
unclejed613's Avatar
 
Join Date: Dec 2006
they don't show any obvious signs of being fakes. is the printing inked or laser etched? it should be laser etched
__________________
Vintage Audio and Pro-Audio repair ampz(removethis)@sohonet.net
spammer trap: spammers must die
  Reply With Quote
Old 30th May 2011, 07:56 PM   #363
Banned
 
Join Date: Nov 2006
Location: Torpoint
How can you tell the difference ?
  Reply With Quote
Old 30th May 2011, 10:16 PM   #364
diyAudio Member
 
unclejed613's Avatar
 
Join Date: Dec 2006
laser etching goes into the surface, ink stays on the top of the surface. take a dab of heat sink grease and rub it into the lettering. if it goes into the letters and makes them show up better, it's etched. if it doesn't, they're printed.
__________________
Vintage Audio and Pro-Audio repair ampz(removethis)@sohonet.net
spammer trap: spammers must die
  Reply With Quote
Old 30th May 2011, 10:25 PM   #365
diyAudio Member
 
nigelwright7557's Avatar
 
Join Date: Apr 2008
Location: Carlisle, England
I wonder how often fake transistors have been blamed when the real problem was the design(er) ?
It takes a lot of money and know how to start up a fabrication unit.
Why bother if you cant sell your fakes easily ?
__________________
PCBCAD50 software. http://www.murtonpikesystems.co.uk
  Reply With Quote
Old 31st May 2011, 04:12 PM   #366
Banned
 
Join Date: Nov 2006
Location: Torpoint
Quote:
Originally Posted by unclejed613 View Post
laser etching goes into the surface, ink stays on the top of the surface. take a dab of heat sink grease and rub it into the lettering. if it goes into the letters and makes them show up better, it's etched. if it doesn't, they're printed.
The Heatsink Compound enhanced the engraving so I guess these stand a reasonable chance of being genuine.

I'll try loading one of them up to 15A and see if it can hold its own.
  Reply With Quote
Old 1st June 2011, 05:17 PM   #367
Banned
 
Join Date: Nov 2006
Location: Torpoint
I managed to get around to building six of the devices into my DIY-PASS Aleph 4 output stage having previously matched them.

Loading them up to 100mA each they seem OK. Next step will be to push them up to 4A.
  Reply With Quote
Old 4th June 2011, 01:14 PM   #368
Banned
 
Join Date: Nov 2006
Location: Torpoint
Under SOA test these seem original. God Bless Genuine E-Bay vendors.
  Reply With Quote
Old 15th June 2011, 06:30 AM   #369
diyAudio Member
 
meanman1964's Avatar
 
Join Date: Oct 2006
Location: Belgium the land of chocolate
I bought eight MJL4302A and eight MJL4281A trannies.
I measured them with a cap tester between E and C
Don't know if this is the right way and came out with the following result:

MJL4302A: 9,53
9.9
9,96
9.94
10,45
10,35
10,41
10,37

MJL4281A: 9,53
9,48
9,43
9,52
9,50
9,40
9,42
9,15
are those fake or not and what is the best way to find out please explane?
They all have the sign ON and the seller told me they are OnSemi

Last edited by meanman1964; 15th June 2011 at 06:34 AM.
  Reply With Quote
Old 15th June 2011, 06:44 AM   #370
diyAudio Member
 
tiefbassuebertr's Avatar
 
Join Date: Jul 2005
Location: D-55629 Schwarzerden
Quote:
Originally Posted by meanman1964 View Post
I bought eight MJL4302A and eight MJL4281A trannies.
are those fake or not and what is the best way to find out please explane?
They all have the sign ON and the seller told me they are OnSemi
check out this thread - especially post #22:
Possible fake Toshiba/Sanken transistors?
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
NTE transistors-->> Backwards from original case layout!! What the heck! 777funk Solid State 1 10th May 2009 02:49 AM
Need DVD copy software! Kyte_08 The Lounge 7 16th February 2008 01:48 PM
how to backup original cd as the same sound quality as original cd ctrn Music 3 16th May 2006 04:21 PM
Copy of Kore-Eda pre ? sinski Chip Amps 2 4th May 2006 12:03 PM


New To Site? Need Help?

All times are GMT. The time now is 12:46 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2