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Transistor Substitutions

I am gathering the transistors I need to rebuild the 2325 PH01 Buffer Board. I have KSC1845FTA to replace the (4) 2SC1345D,E. I have KSC2383YTA to replace the (2) 2SC1318Q,R, but cannot find a replacement on any list for the (4) 2SC720R,S at HH05,06,07,08. Can anyone help? Thanks
 
dustidean said:
I am gathering the transistors I need to rebuild the 2325 PH01 Buffer Board. I have KSC1845FTA to replace the (4) 2SC1345D,E. I have KSC2383YTA to replace the (2) 2SC1318Q,R, but cannot find a replacement on any list for the (4) 2SC720R,S at HH05,06,07,08. Can anyone help? Thanks
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I'm not convinced that any of those need to be replaced. Are you sure it's not 2SA720? 2SC720 is a 500MHz RF transistor.
 
Thanks for responding. When you say, "any of those", are you referring to all (10) transistors on the PH01, or the (4) 2SC720 transistors. The first (6) are on the "10 Worst" list, so I thought they should be changed out. And to your question about 2SA720 or 2SC720-I don't know! I don't have it apart yet, but the SM says there are (4) 2SC720 on PH01. I know the manuals sometimes are in error but have not seen any info regarding this situation.
 
dustidean said:
Thanks for responding. When you say, "any of those", are you referring to all (10) transistors on the PH01, or the (4) 2SC720 transistors. The first (6) are on the "10 Worst" list, so I thought they should be changed out. And to your question about 2SA720 or 2SC720-I don't know! I don't have it apart yet, but the SM says there are (4) 2SC720 on PH01. I know the manuals sometimes are in error but have not seen any info regarding this situation.
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2SC1318 is only problematic, IME, in hot running Pioneer power supplies where it wasn't derated enough to last 50 years. C1345 is a pretty good high gain, low noise transistor that I generally only replace if faulty. I consider changing A720 to be optional if not faulty. If you don't need the voltage capability, KSB1116A is a good choice. For higher voltage applications, KSA1013 gets the nod. 1116A has more gain, 1013 has higher voltage and dissipation capacity.
 
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Moderator note: the conversation about transistor substitutions for Pioneer M-22 and Harmon Kardon A402 have been moved to their own thread.

Transistor Substitutions in Pioneer M-22 and Harman Kardon A402

There is a hard transistor 2SA898: Pc 1W, Vcb 150v, Vce 120v, Veb 5v, ic 0.05A, Tj 175°C, ft 100 MHz, hfe 150 Found some: 2SB1109: Pc 10W, Vcb 160v, Vce 160v, Veb 5v, ic 0.1A, Tj 175°C, ft 140 MHz, hfe 60 2SA1220A: Pc 20W, Vcb 160v, Vce 160v, Veb 5v, ic 1.2A, Tj 150°C, ft 160 MHz, hfe 150 (or...
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JoseHH said:
Ciao!
The choice of the part to use depends on the location in the circuit. I would be more inclined to use a KSD1616A which is closer to the 2SC1417, but not a perfect macth.
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Thanks for the reply
And in the power section of a Marantz 1090,
I thought the KSD2383 would be fine.
 
I need to replace Q 5 ( 2SC1451 ) on a Pioneer SX-636 power amp ass'y AWH-034 .
I have KSC2690AY will that work or is there something better ? Thanks for any help
 
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