Search results

  1. JRC75

    Question about driving multiple pairs of speakers - mismatched ohms

    Oops my bad, how did I get 8+6= 12.
  2. JRC75

    Question about driving multiple pairs of speakers - mismatched ohms

    Should not be a problem, just keep it out of clipping. A 6 and 8 in parallel gives 4 ohms. I haven't the amps specs as long as they can handle a 4 ohm load. I used to run my Citation on one set and the Marantz 1200 on the other set. Sounded great. You also need to make sure the phase is the...
  3. JRC75

    Anyone packed & shipped an HK Citation II amp?

    I wrap first in plastic bag. Then if I can get some foam they use in neon sign packaging. It has some give. Pack so it can't slide around. The foam protects it from impact damage. Make sure the foam stays in place Then for heavy equipment I cut card board to fit to the inside of box, or double...
  4. JRC75

    Replacement Scope Knobs?

    Or a self casting.
  5. JRC75

    KA-8100, 2SC1913, 2SA913 Q21-Q24

    Check AK "2sc1913 & 2sa1913 transistor substitute in a kenwood model eleven gx", There is more if you search web.
  6. JRC75

    This is what happens when you dip your stick(probe) where it doesn’t belong.

    Look at the bright side, it can always be worse.
  7. JRC75

    AU-719 Recap questions

    What I was taught late 60's, was if you went too much over operating voltage they may not stay properly formed. I don't know if this is so but I try to keep closer to the specified voltage of the originals. Anyone else care to share?
  8. JRC75

    Charred Filter Cap Terminal On KR-9600. What does that indicate?

    Usually means it has been arcing (poor connection) which heats up and causes problems. Replace them all.
  9. JRC75

    Replacing VU Meter Lamps Receiver

    I always spin the screws backward then when they drop in a bit go forward. I almost always catch the original path.
  10. JRC75

    Are these 3 or 6 capacitors?

    You may also want to check the old carbon resistors if you had not planned to replace them, they can drift way off value. Many restorers would replace these as well.
  11. JRC75

    Are these 3 or 6 capacitors?

    Looks like 3 caps. If 2 leads on each otherwise it would be 3 leads. I don't have the schematic. Doubling the capacitance puts extra stress on the rectifiers and power switch. Seems like many people do it without problems.
  12. JRC75

    Kenwood KA-8150 - left channel going out (?)

    Sounds to me like protect relay contact, try tapping on it not too hard just enough to vibrate the contacts.
  13. JRC75

    do you have buzzing too? Pioneer SX 990 / SX 2500 ..??

    The PS voltage out could have an AC componet on the DC which AC should not be there. I watched a Tube video where a guy used a signal tracer to find a bad componet in the power supply. Can't remember which one. This PS I think it was a zener generating the noise, been a long time ago. Try...
  14. JRC75

    do you have buzzing too? Pioneer SX 990 / SX 2500 ..??

    The DC voltages may be OK, but there could be AC ripple if you do not have an oscilloscope, you could try measuring with an AC multimeter. Also look at all the ground connections (do this first). You could also replace the electrolytics on the PS board, are they original?
  15. JRC75

    do you have buzzing too? Pioneer SX 990 / SX 2500 ..??

    Sorry I did not realize the clip was there... da. Sounds to me like a power supply problem. I noticed, looks like your amp was rebuilt. I wonder if any work was done to the power supply and I don't mean the supply for the power amp. The lower voltage supply, I don't have a schematic. If you...
  16. JRC75

    Specs / general info for an Allied 495

    For now I set it to 17mv across the emitter resistor. Later I will use a scope. Thought I Just posted this.
  17. JRC75

    Specs / general info for an Allied 495

    For now I set it to 17mv across the emitter resistor. Later I will use a scope.
  18. JRC75

    do you have buzzing too? Pioneer SX 990 / SX 2500 ..??

    I generally scrap it being careful not to gouge the PCB.
  19. JRC75

    do you have buzzing too? Pioneer SX 990 / SX 2500 ..??

    Maybe the trouble is from the pre amp / tone control. Have you tried disconnecting the pre amp out and main in? And then power up. Do not make or break these connections with unit on. If you still have buzzing trouble is in the main amp section. Wonder if you could have RFI interference? Your...
  20. JRC75

    Post a Picture of your Tape Deck - Decks

    Wonder if they have ever been lubed?
  21. JRC75

    do you have buzzing too? Pioneer SX 990 / SX 2500 ..??

    Not the one with the heat sink, a TO92 small transistor no heat sink. Between the heat sink and the c1061.
  22. JRC75

    do you have buzzing too? Pioneer SX 990 / SX 2500 ..??

    Check Audiokarma list of known problem transistors and replace those. If It's like mine, 2 on the driver board and more on the head amp unit. I checked Hifi Engine for a schematic for the sx2500 not there. I see a transistor left of the 2 - c1061 could be a c458. A noisy transistor may still...
  23. JRC75

    do you have buzzing too? Pioneer SX 990 / SX 2500 ..??

    Power supply maybe, I would rebuild the output driver board. I'm not sure what transistors this uses but the SX1500 uses 2sc458 which are known to be problematic.
  24. JRC75

    SX 737 left channel output reduced..control amplifier board?

    Could still be a switch, sometimes I push lightly on a tape monitor sw or move the selector sw a hair. Problems in a sw may be there and require more cleaning.
  25. JRC75

    do you have buzzing too? Pioneer SX 990 / SX 2500 ..??

    No it's not normal. I guess you tried it with AUX selected.
Back
Top Bottom