G'day,
Getting around to hopefully fix my yamaha a-500 amp and need some help. After reading some diy articles, I believe the output transistors for one side are gone (continuity between all three legs). Having some trouble sourcing parts, certainly OEM, but also suitable replacement. The output transistors are marked C3284 3D P and A1303 3D P. Pic attached...
Much appreciated for help and guidance... this is my first go at fixing an amp and would sure love to hear it sing again. Also appreciate advice for low cost amp clean up
Cheers. Al
Ottawa, Canada
Getting around to hopefully fix my yamaha a-500 amp and need some help. After reading some diy articles, I believe the output transistors for one side are gone (continuity between all three legs). Having some trouble sourcing parts, certainly OEM, but also suitable replacement. The output transistors are marked C3284 3D P and A1303 3D P. Pic attached...
Much appreciated for help and guidance... this is my first go at fixing an amp and would sure love to hear it sing again. Also appreciate advice for low cost amp clean up
Cheers. Al
Ottawa, Canada
Attachments
ok, have been looking on and off for few days, and of course didn't find anything til I post the question...
I think...
a1303 = NTE2306
C3284 = NTE2305
sound right? local or CDN suppliers. thanks
I think...
a1303 = NTE2306
C3284 = NTE2305
sound right? local or CDN suppliers. thanks
I would watch out with nte, i've heard they buy in and relabel all kinds of parts that dont match the "equavlient" part in any way.
Instead i think MJL3281 and MJL1302 or MJL4281 ans MJL4302 should be the best modern substitutes, provided the slightly larger TO-264 package will fit on the heatsink.
Instead i think MJL3281 and MJL1302 or MJL4281 ans MJL4302 should be the best modern substitutes, provided the slightly larger TO-264 package will fit on the heatsink.
Thanks for the heads up. What's the difference between your two recommendations? Having choices are good, but I'm not sure what to make of one over the other.
On a side note, I've got a Fisher CA-550 that's been sitting around for a dog's age. I'd love to bring it back to life. The stk8280ii power amp chip was replaced years ago, but I have no means to test IC chips. powers up, but won't go out of protect mode. Anyways, was looking at NTE replacement (so thanks again), but maybe I'll save those thoughts for another post.
Cheers.
On a side note, I've got a Fisher CA-550 that's been sitting around for a dog's age. I'd love to bring it back to life. The stk8280ii power amp chip was replaced years ago, but I have no means to test IC chips. powers up, but won't go out of protect mode. Anyways, was looking at NTE replacement (so thanks again), but maybe I'll save those thoughts for another post.
Cheers.
Never buy anything marked NTE. The moment you do, it'll catch fire. Literally.
Not quite literally, though.
Not quite literally, though.
They are Sanken 2SC3284 and 2SA1303. Modern equivalent is probably Sanken 2SC3519 and 2SA1386
You could probably also use Onsemi NJW0281G/NJW0302G or Fairchild FJA4313/FJA4213 - however these have higher Cob and lower fT than the sankens, which may require compensation to be adjusted.
As for suppliers, stick to the big ones like Digikey, Mouser, Farnell (im assuming youre from the US here). Forget eBay as you will almost certainly get counterfeit parts. Forget NTE too.
You could probably also use Onsemi NJW0281G/NJW0302G or Fairchild FJA4313/FJA4213 - however these have higher Cob and lower fT than the sankens, which may require compensation to be adjusted.
As for suppliers, stick to the big ones like Digikey, Mouser, Farnell (im assuming youre from the US here). Forget eBay as you will almost certainly get counterfeit parts. Forget NTE too.
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