output transistors

  1. Jon Weston

    MAC 1900 replace output transistors 132-080, 081

    Hello folks, Need help/advice. I finally got around to fixing the left channel output board on my MAC 1900 (serial:8X588, so no substitutions from notes 8-12 in service manual). The 132-081 transistor, one MJ15003, two BC416C epitaxial trans., And four carbon comp. resistors we're fried...
  2. E

    Luxman R-1050 Output Transistors Troubleshooting

    All, I have a Luxman R-1050 I'd really like to restore but it keeps giving me problems. A fuse blew on the right channel, which was then replaced with another fuse of the same rating, but that blew instantly and killed the output push/pull pair of the right channel (it turns out all 4 fuses had...
  3. jefferylhenr

    Luxman L100u and looking for the output transistor modern equivalents for replacements.

    I am restoring a broken Luxman L100u and looking for the output transistor modern equivalents for replacements. The research I have done indicates that: Use ONSEMI MJ21193 and 21194 for -2SC1079Y -2SA679Y . Same for the 2sd287 and 2sb539, use the MJ21193/94 does that make sense? Looking for...
  4. JB8

    PIONEER SX-440 Output Transistor Replacement?

    Hey all, I'll make this quick. Spent some time trying to sift through a bunch of threads to find this info but came up empty, so I'm putting up my white flag! What's a good replacement option for the 2SD226A? I'm getting some distortion at the speakers (mainly right side) but not through...
  5. J

    NAD 7150 replacement output transistors

    I need to replace the output transistors for my NAD 7150. The originals are Sanken 2sa1215 and 2sc2921. Anyone know what I can replace them with? Thanks for your help. Great forum. JG
  6. UrbaXter

    Output transistors for Marantz 250M

    Hi guys, I burned out the right channel output transistors of my 250M... :( According with the SM the right ones are SJ2519 and SJ2520, BUT, my unit has at the left channel, two pairs of A747A and C1116A, so my questions are: 1- We have today options available for the originals? 2- I found...
  7. H

    Pin out voltages on SX-1050 PA board output transistors

    This is rather embarrassing. I have rebuilt around 50 Pioneer SX-1050's, and have never had reason to check pin out voltages from the Power Amp board to the output transistors. Pins 21-24, then pins 25-28, then pins 29-32, and the last one pins 33-36. The voltages I am getting on this particular...
  8. B

    Pioneer SX-1280 Blowing Output Transistors

    Hello again everyone! First off, I'd just like to thank everyone for their input and suggestions on my other forum post! Your knowledge and expertise have helped me resurrect my 1280 from the dead. I've gone through about every board on this thing. Power supply board, protection board, pre-amps...
  9. automaat

    PIONEER SX1500-TD Dead Channel still blowing after output replace

    Hi everyone, I am a tech working in Canada. My focus is organs, synths, tape gear, etc... My weakness is Power Amps. I took this one on thinking it had a good output section and trouble in the front end. Turns out the left channel was blown. Fuse open. One output device shorted. I changed the...
  10. H

    Matching TO 3 output transistors. MJ15022

    Hi, looking for some advice please. I'm replacing output transistors in a Rotel RA913 and need to match them. My cheap transistor tester displays the following for the four transistors: B =62 Uf = 554mV B =72 Uf = 548mV B =62 Uf = 555mV B =58 Uf = 556mV Which number(s) should I be best...
  11. Captain581

    Do brand mismatched output transistors affect anything?

    I just purchased a gorgeous 2265B that admittedly look good - almost like new. Sounds good too, although maybe not quite as ear-friendly as my 2252B, which I just sold. Might be the BIAS, which I'll have tended to. I paid top price for this 2265B (too afraid to admit how much). I was told it...
  12. Keneye

    Pioneer SX-626 Heat sink on Transistors?

    Hi. Just saw a post about a guy pulling his 2SC793 power transistors and they were "dry". When I pulled mine to test, they had a mica insulator. No thermal paste. Should they also have thermal paste? All tested good but distorted left channel. Recapped board. Other transistors and trimmers are...
  13. MBuras

    Basket Case KA-7002 need some guidance

    I bought it cheap knowing it didn't have sound output. Didn't know until I got it that there were literally parts missing on the amp card and definite signs of being worked on. I've subbed in proper replacements where needed, making sure to check, recheck orientation and pinouts as needed. It...
  14. NickDeO

    KA-6160 Shorted. SOS!

    Hello AK, I’m working on a KA-6160 receiver that needed a few new caps in the power supply. In attempting to adjust the bias after properly installing the caps, it appears that at least one of the output transistors has shorted. Now, the DBT is fully lit and nothing powers on. The only fuse I...
  15. Ray122

    Pioneer SX-950 HELP!!!

    Hey everyone! In desperate need of some help here. I'm working on an SX950 for a friend, and for the life of me, I can't seem to keep the output transistors on the right channel from frying. I've gone through this a few times now and it's getting very frustrating. I had everything working just...
  16. Marantz 2270 - New Member - Total Novice But Want to Attempt "Restore" - Yay? or Nay?

    Marantz 2270 - New Member - Total Novice But Want to Attempt "Restore" - Yay? or Nay?

  17. Kingbleu

    Pioneer SX-1250 full restoration. Output transistors to replace or not to replace

    What are your thoughts about replacing the 8 output transistors on a Pioneer SX-1250 Q1, Q2, Q3, Q4, Q5, Q6, Q7, Q8 Original part numbers: Q1, Q2, Q5, Q6, 2SB600-R Q3, Q4, Q7, Q8, 2SD555-R Replace with Q1, Q2, Q5, Q6, 863-MJ21193G Q3, Q4, Q7, Q8, 863-MJ21194G I am getting ready for a fulI...
  18. camgilbert

    Sansui AU-6900 Woes .......

    Hello all, Long story short, I inherited a Sansui AU 6900 in a broken state, missing output transistors (3 of NPN's had been removed) Funny thing, this was to be my first major restore project, its the unit I started with and while I was waiting for parts and troubleshooting, I went on to...
  19. A

    Sony STR-2800 Two Blown Fuses

    Hi everyone. My Sony STR-2800 has blown two 4AT fuses (F803 & 804). I wasn't there to witness it, so it's hard to say how exactly it happened and whether someone maxed out the volume knob or something. It powers on, but there's no signal coming through the speakers and headphones outputs. A few...
  20. jdg123

    swaping new lamps for old

    I have been trying to make myself useful to the folks who post here because they have helped me out in so many ways with my restoration projects. I tried some picture posts but maybe Youtube is the ticket: For altering TO-3P onto a heat sink that once held TO-3. Specifically putting in...
  21. A

    AU-317 - bias problem causing blown outputs?

    Hi all I'm repairing a 317 that went pair shaped a few weeks ago. I'm learning as I go but I've got into new territory and I'd appreciate a little help narrowing the search for what might be the problem. I replaced output transistors TR17 and TR19 and driver transistor TR15. It now seems to...
  22. A

    AU-317 mkII troubleshooting - help appreciated

    If anyone has time to share some thoughts, it would be much appreciated. The 317 mkII stopped working. Cutting to the chase, I opened it up and did some checks. The following thread was most helpful...
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