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transistor matching

  1. Carbsandcaps

    Really high hfe reading

    So I’m testing some germanium transistors I just got to try to get some matches. One of them read 239! Is there something wrong here or is this a super transistor? Also while we’re on it. How close should 2 transistor hfe numbers be to be considered matched?
  2. X

    2SC2071 / 2SA939 sub with KSC2690A-Y / 2SA1220A-Y ?

    Will these be a valid and ideal substitute for transistor matching ? this will be going in a Marantz 2500's Amp board. 2SC2071 / 2SA939 sub with KSC2690A-Y / 2SA1220A-Y ? thanks in advance ! :)
  3. S

    Yamaha CR-2020 Pre - C Transistor Matching

    What are the matching pairs that need to be changed out on the A and B boards if one (or more) transistor fails? I found a bad TR502 (2sc1213a - NPN) on board A and a bad TR504 (2sc1213a - NPN) on board B. I understand the transistors need to be replaced in PNP/NPN pairs. With that being...
    • SharkBait07
    • Thread
    • pre-c transistor matching yamaha yamaha cr-2020
    • Replies: 0
    • Forum: Yamaha
  4. dlucy

    dlucy’s guide to transistor testers and curve tracers

    There are a bunch of devices and DIY kits that help one understand “does this transistor work” and often reveal a few basic performance specs. Below is a listing of some of these devices you may be interested in, some of the information about each device, and, hopefully, a bunch of comments from...
    • dlucy
    • Thread
    • cheap component tester curve tracer transistor matching transistor tester
    • Replies: 64
    • Forum: Solid State
  5. Ric Harris

    I need to ID what this part is?

    The MPC70 21N6 & 21N4 are transistors? I have queried those numbers and haven't found anything. These have just 2 contacts wire rather three. Transistors and Semi Conductors must have values like caps but I just don't know what I'm see here. It's for a Rotel receiver that is basically toast as...
    • Ric Harris
    • Thread
    • transistor matching
    • Replies: 13
    • Forum: DIY
  6. R

    transistor matching in Kenwood KR-5030

    Hi, I just bought a Kenwood KR-5030 from a guy for cheap because it "didn't work". ( I'm new to amplifier repair/restoration, but I've been an electronic hobbyist on and off over the years.) So far I've fixed the power switch - a well known issue with this amp, cleaned the controls, and...
    • robthomp
    • Thread
    • kenwood kr-5030 transistor matching
    • Replies: 24
    • Forum: Solid State
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