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  1. ddrjboo

    NAD 2400 output transistors fried substitute recommendations???

    A final list of bad transistors with potential replacements is: (2) SA1516 Q422 and Q424 Replace with 2SA1943-O(Q) (2) SC3907 Q421 and Q422 Replace with 2SC5200-O(Q) (1) SC3467 Q417 Replace with 2N5551 ???? (1) SA970 Q416...
  2. ddrjboo

    NAD 2400 output transistors fried substitute recommendations???

    This NAD 2400 amplifier was bridged and connected improperly to the speaker, and the result was the destruction of the (5) transistors circled in the picture. The damaged transistors are (2) 2SA1516, (2) 2SC3907, and (1) 2SC3423. I have posted a wanted ad on Bartertown for the transistors, but...
  3. ddrjboo

    anyone in virginia?

    Welcome to Suffolk! I have just moved to Kingsport TN. @Wolverine is definitely a great resource for bargain hunting in the Tidewater area and for knowledge on audio equipment, and he has been a great friend to me. We met a few years back when we kept bumping into each other at estate sales. As...
  4. ddrjboo

    Considering an external phono preamp...advice?

    I received my Pyxi phono preamp from SOTA this past Wednesday. I believe it is a better phono stage than the one in my Rogue RP-1 preamp. The Pyxi seems to provide better detail and less hum than the RP-1. The Pyxi definitely provides more gain for my relatively low output MC cartridge. My only...
  5. ddrjboo

    Pair of Adcom GFA-565 amps with hum and DC output

    @Wolverine I figure you may already be following this thread, but wanted to make sure you got this new information.
  6. ddrjboo

    Sansui 5000X phono section problem

    Thanks for the suggestions. Yes, the issue also occurs when using the Tape Monitors. :( I'll give recleaning the controls a try.
  7. ddrjboo

    Sansui 5000X phono section problem

    After going over the equalizer amp way too many times, I found that the yellow wire running from the left channel "P" connection on the equalizer amp to the selector switch had become disconnected. After reconnecting the wire, the phono section is working correctly. Now the issue is that when...
  8. ddrjboo

    Sansui 5000X phono section problem

    I think I tried what was suggested in the previous post (see photo). I used 68K resistors between positive and ground since that is what is in the schematic. No real difference in the sound, i.e., distorted sound in the left channel, much less volume from the right channel and distorted. I...
  9. ddrjboo

    Sansui 5000X phono section problem

    So I have noticed that the discrepancy in resistance values in the previous post only occur when the source selector switch is connected to either Phono 1 or Phono 2. Might there be a problem somewhere in the selector switch causing this issue? Taking that thing apart looks like a can of worms.:(
  10. ddrjboo

    Sansui 5000X phono section problem

    I replaced all the transistors in the equalizer amp with KSC1845s again. Now I would describe the sound when playing through the phono section as: Left channel loud and distorted, Right channel sounds much quieter, but distorted, almost like it is only playing crossover sound from the left...
  11. ddrjboo

    Sansui 5000X phono section problem

    Yes, the original SC458s are installed for TR601/602 It looks to me like the SC632A 71s are installed correctly for TR603/604 (see photo). It's hard to see, but the emitter is at the top of TR603 on the left side of the board. SC632A 81's are installed for TR605f/606
  12. ddrjboo

    Sansui 5000X phono section problem

    After @Leestereo talked about the feedback loop, I took a good look at the Equalizer circuit and discovered that I had installed C601 and C602 in C613 and C614's slots, and vice versa. I corrected the issue, and then went a little crazy replacing resistors on the board (see picture). I also...
  13. ddrjboo

    Sansui 5000X phono section problem

    I am confident the issue is not with the source turntable/cartridge, and have also tested the phono input with other sources. I am, however, not sure that there isn't a problem somewhere else (e.g. F-1350 Tone/Mic) that only causes issues for the phono inputs???? I am truly a novice when it...
  14. ddrjboo

    Sansui 5000X phono section problem

    I worked on: F-1036 Equalizer Amp (all the transistors are KSC1845 FTAs, and Base and collector were crossed to insert into TR 605 and 606) F-1350 Tone, Mic F-1042 Diode Stack F-6013 Driver amp F-1127 Ripple Filter I replaced the coupling caps and the main filter caps. Also replaced the output...
  15. ddrjboo

    Sansui 5000X phono section problem

    I am working on a Sansui 5000X for an AK friend. The receiver had a blown left channel when I started working on it. I used the following thread to recap, change transistors, output transistors, etc: https://www.audiokarma.org/forums/index.php?threads/5000x-recap.934300/#post-14213225 Now the...
  16. ddrjboo

    Sony STR-VX5 power supply problems

    After having the NJW21194 on back order from Mouser for 4 months, I got a message from them saying the status was "will advise". That doesn't sound good. Any info on alternatives from anyone would be appreciated.
  17. ddrjboo

    Foo Fighters drummer Taylor Hawkins dies at 50

    I have been able to see the FF in concert twice. It really seemed like they enjoyed what the were doing, and didn't want to leave the stage at the end of the show. In Richmond, VA, they played over 3 hours, and that was without an encore. When the show was over, I think the audience was as...
  18. ddrjboo

    Pair of Adcom GFA-565 amps with hum and DC output

    Oddly, the input PCB in the second amp doesn't appear to have any of the corrosion issues of the first amplifier, however, it still emits a low hum (lower than the first amp) and it reads about 1 V DC across the speaker outputs. All the ECs on the board have been replaced by someone earlier...
  19. ddrjboo

    Pair of Adcom GFA-565 amps with hum and DC output

    None of the brown Elna caps are left in the amps. They were replaced during the previous service. Taking a look at the input board, there was some minor corrosion on the solder side of the PCB where the ECs were. Per the link in Post #4, Pin 6 of IC101 should read between -6 and 6V. It read...
  20. ddrjboo

    Pair of Adcom GFA-565 amps with hum and DC output

    I've just read through the link and it is full of great information. Thanks @TPettenati ! After I've looked at the board again, I'll report anything I find.
  21. ddrjboo

    Pair of Adcom GFA-565 amps with hum and DC output

    The ECs on the input board look okay with no bulging or leakage, and they look to have been replaced fairly recently. I can remove them and test them if they are a likely culprit, but I'm thinking not.
  22. ddrjboo

    Pair of Adcom GFA-565 amps with hum and DC output

    I have a couple of Adcom GFA-565 amps that I am looking at for another AKer. At the same time, the two amps began exhibiting the same problem of putting out a hum through the connected speakers. Several things were tried to rule out speaker cables, the preamp, ground loops, etc. The hum does...
  23. ddrjboo

    Sansui B-77 fixable? (Doesn’t look too good...)

    I had similar issues with a B-77, but on the other channel. I ended up replacing transistors Q1, and Q5 through Q11 on both channels, and some resistors, and now all is good. I'm sorry my note-taking is so bad, or I'd give you the subs I used. While this is in no way one of Sansui's better...
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