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CS50 PSU Parts

CS50 PSU Parts

2014-10-17 by bob@...

Got a bad supply in a CS50.

Power supply had broken free and trashed the innards, which have been repaired, but now I'm getting a high pitch whine under all the audio, and the sound in general is a bit lumpy.
Visible cyclic noise on the power lines. Seems to be the +/-15V lines. as it's still there if I remove the fuses for the other lines.
Have changed some bits in the PSU which has lessened the issue, but it's still there.

Anyway...I'm looking for replacements for the power transistors.

I can find a 2SA745s, but there don't seem to be any 2SD203s in circulation.

What are a good complimentary pair to use instead?

Anyone have a suggestions?

Of course I could be barking up the wrong tree and the problem may be elsewhere.







Re: [yamahacs80] CS50 PSU Parts

2014-10-17 by Rikard Latvala

Have you tried: http://www.littlediode.com ?

They usually can find just about everything you´re
looking for.

Best regards,
/RL

-----Originalmeddelande-----
Från: "bob@... [yamahacs80]" <yamahacs80@yahoogroups.com>
Till: yamahacs80@yahoogroups.com
Datum: 2014-10-17 13:07
Ämne: [yamahacs80] CS50 PSU Parts

     
Got a bad supply in a CS50.

Power supply had broken free and trashed the innards, which have been repaired, but now I'm getting a high pitch whine under all the audio, and the sound in general is a bit lumpy.
Visible cyclic noise on the power lines. Seems to be the +/-15V lines. as it's still there if I remove the fuses for the other lines.
Have changed some bits in the PSU which has lessened the issue, but it's still there.

Anyway...I'm looking for replacements for the power transistors.

I can find a 2SA745s, but there don't seem to be any 2SD203s in circulation.

What are a good complimentary pair to use instead?

Anyone have a suggestions?

Of course I could be barking up the wrong tree and the problem may be elsewhere.








 



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Re: [yamahacs80] CS50 PSU Parts

2014-10-17 by Bob Stewart

Doesn't have any, but have emailed him anyway.
Show quoted textHide quoted text

On Friday, October 17, 2014, 'Rikard Latvala' rikard.latvala@... [yamahacs80] <yamahacs80@yahoogroups.com> wrote:

Have you tried: http://www.littlediode.com ?

They usually can find just about everything you´re
looking for.

Best regards,
/RL
-----Originalmeddelande-----
Från: "bob@blzproductions.com [yamahacs80]" <yamahacs80@yahoogroups.com>
Till: yamahacs80@yahoogroups.com
Datum: 2014-10-17 13:07
Ämne: [yamahacs80] CS50 PSU Parts

Got a bad supply in a CS50.

Power supply had broken free and trashed the innards, which have been repaired, but now I'm getting a high pitch whine under all the audio, and the sound in general is a bit lumpy.
Visible cyclic noise on the power lines. Seems to be the +/-15V lines. as it's still there if I remove the fuses for the other lines.
Have changed some bits in the PSU which has lessened the issue, but it's still there.

Anyway...I'm looking for replacements for the power transistors.

I can find a 2SA745s, but there don't seem to be any 2SD203s in circulation.

What are a good complimentary pair to use instead?

Anyone have a suggestions?

Of course I could be barking up the wrong tree and the problem may be elsewhere.









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