I got a crown dc300a amp that had one distort channel and one good one. In my "testing", I managed to cause "issues" to the good channel which now causes the main fuse to blow... :-( There is a thread in the audio section for that effort. I thought this thread would be more "general"... maybe about components / theory.
So after a long "sigh" and many days of contemplating and reading, I started back. Isolating the two banks of 5 output transistors on the 1 channel (4 2n5631 and one 2n3859a) that span +-60 v rails. I found a 2n5631 on each "side" shorted.
Reading various places, I found comments about matching "pairs" and matching in general, but I am not sure I understand what it means. Do the transistors (ie. 2n5631's) all have to match? vintage number? only a "pair" match? what is a "pair"? Another question is that the crown 3990 isn't readily available but some "mexico 2n5631" ones are... are these an OK replacement? or are they like some other "fake" units / semi-conductors that people find in the tv repair world?
Thanks for any guidance on this.... I hope I can eventually resurrect this poor unit.
So after a long "sigh" and many days of contemplating and reading, I started back. Isolating the two banks of 5 output transistors on the 1 channel (4 2n5631 and one 2n3859a) that span +-60 v rails. I found a 2n5631 on each "side" shorted.
Reading various places, I found comments about matching "pairs" and matching in general, but I am not sure I understand what it means. Do the transistors (ie. 2n5631's) all have to match? vintage number? only a "pair" match? what is a "pair"? Another question is that the crown 3990 isn't readily available but some "mexico 2n5631" ones are... are these an OK replacement? or are they like some other "fake" units / semi-conductors that people find in the tv repair world?
Thanks for any guidance on this.... I hope I can eventually resurrect this poor unit.
Comment