ARCHIVED FORUM -- March 2012 to February 2022READ ONLY FORUM
This is the second Archived Forum which was active between 1st March 2012 and 23rd February 2022
Finally got round to repairing/refurbishing a BM4400 I've had for years, mainly so I can pair it with a BG8000 or BG4000 to paly my old vinyl.
Replaced all of the electrolytics, including the awkward ones under the switch, and have replaced the transistors and rectifiers in the 15V supply. Just getting round to replacing output components, thanks to a crispy bias resistor, when I noticed that the output transistors are TIP141 and TIP145, not 146's. I know they're lower voltage than the 146 but they seem to be factory fitted, with the exception of one which doesn't have the coil solder method. I'll replace the lot with 142/147 and replace the BD135 with BD169s, which should work o.k.
The question is: has anyone ever seen a BM4400 with that complement of output trannies? Perhaps a short stock day in the factory?
Also, thanks to all the guys who have posted those lovely informative posts about their work on resurrecting the best amp B and O ever made. They are invaluable and full of excellent tips.
AndyF: ...I noticed that the output transistors are TIP141 and TIP145, not 146's.... The question is: has anyone ever seen a BM4400 with that complement of output trannies?
...I noticed that the output transistors are TIP141 and TIP145, not 146's....
The question is: has anyone ever seen a BM4400 with that complement of output trannies?
Yes.
Martin
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