Thinking of using these to replace my 2SD287C and 2SB539C output in my Pioneer SX-1050 AMP, anybody have suggestions? comments?![]()
They seem to be cheap and readily available here in Australia but I noticed the 4467 are only 8A collector. Would I be sacrificing power? I don't mind rewiring for this package. Thanks againWrong ...there is more parts that are closer to the originals ...It is very common in the forum that the only available option is 21193- as was in the past MJ15024
You need to look better
2SC4467-2SA1695 is much closer replacement by far easier to fit commonly available plus that these are easier load and much faster so after all you are going to have a bit better amplifier
Going to that type of change you need to scope the all thing since compensation might needs to be altered ( in most cases you will get away with it...)
there could more similar to those
Kind regards
Sakis
So you recommend these? They seem to be the only genuine article I can find to replace the old ones after being taken by Chinese knock offs before... Would the sonics be as good in your opinion? CheersYes, those are the correct transistors to use. And the only valid option available. They are drop-in replacements, but you have to replace all of them.
Anything else you use will be fake or unsuitable to the job.
You've been adviced to use NTE parts - never do this. Just google NTE transistors and you'll see the horror stories.
Thanks Ian, yes I know what you mean about Chinese fakes I bought replacements completely unaware of the market in fraud devices and promptly fried 4 of the original transistors because I mixed and matched original and fakes. Only needed 2 originally but now I only have 2 original ones left which work one channel fine at half power. I bought some b539 from a chap in America but they are not the C variety. Only difference I can see is Uce rating of 30 volts less which should be fine in this amp so really or I need is 287s to complete it or a complete set of comparatable units. I did a full recap of the protection circuit and the lytics in the power amp. Power rails ok so left the ps alone. Those 2sd1047 and b817 look a perfect replacement. And available from wes in oz. should I go and buy enough to match up pairs Ian? Much obliged. Might just get this working again soon!The SX1050 has 2 pairs of output transistors for 170W/4R rating so the SOA of 2SC4467 could be a bit small. You can buy alleged NOS and Chinese TO3 copies of Japanese types but what guarantees do you have? BTW, 2SC4468 looks closer in SOA to the 2SC287C but is probably harder to find. I'm inferring the PNP complements are included in comparisons.
2SD287C PDF Datasheet - NEC Corporation - Datasheets360.com
http://www.semicon.sanken-ele.co.jp/sk_content/2sc4468_ds_en.pdf
Whilst considering T03P package replacements, genuine spec. 2SD1047/B817 might be more suitable. KEC copies are close enough to original spec.
After 40 years, I assume this receiver has had at least 1 full re-cap. of electrolytics. If not, I would look at replacing all and certainly those in the output protection circuit, so at least that works correctly to protect the replacement transistors. NTE, BTW, has a bad rap in the US.
Cheers again Ian. I have requested manufacturer details from wes for these, let's see what happens. This is my first semiconductor amp repair and I never thought parts would be so hard to find! Have to go back to valve ampsYou are right Sakis, but I have been successful with several KEC pairs bought a few times in the last 2 years. I used them in a number of small PA amplifiers that get a hard life and fail a lot due to poor VI limiters. Their Ft is below the Sanyo spec. but that's not an issue here. Their plastic TO3P package is difficult to copy and the part number is not so familiar (KTD1047/KTB817) so perhaps fakers will be less successful in stealing their market.
KTD1047B_15 pdf, KTD1047B_15 description, KTD1047B_15 datasheets, KTD1047B_15 view ::: ALLDATASHEET :::
Thinking of using these to replace my 2SD287C and 2SB539C output in my Pioneer SX-1050 AMP, anybody have suggestions? comments?![]()