Kenwood ka 701 in for service, bias 26mV???

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  • Опубліковано 4 гру 2024
  • this is a kenwood KA-701 , there a lot of talk in setting the bias, here's my findings...
    pls comment.
    #bias, #biasissues,#biasissues, #bias26mVisnotpossible,

КОМЕНТАРІ • 23

  • @craigm.9070
    @craigm.9070 Рік тому +1

    Really nice to see this amp in such great shape; a little tune up goes a long way. Pristine examples from the receiver/watt wars are getting hard to find out in the wild. They are performing in homes and listening rooms keeping the music alive. Thank you for your time!

  • @mdzacharias
    @mdzacharias Рік тому +9

    I think you're wrong about the bias bit. 54mV across .66 ohms yields about 80+ mA idle current. 26 mV across the pair of resistors equates to about 40 mA idle current. This is much more in the range to be expected for this class amp. Further, the higher bias on both channels would explain your higher current draw at the mains. I think the inability to adjust is caused by a problem elsewhere. I would ask if the amp seems to idle rather on the overly warm side at the heat sinks.

  • @mateoguillermo5571
    @mateoguillermo5571 Місяць тому

    I had the same problem. The precision bias-adjustment trim-pots and also the DC-offset adjustment trim pots tend to fail on this amp. They don't even work properly when cleaned. You have to replace all of them with new equivalent trim pots with the lowest possible tolerance (I used "Burns" brand) and both adjustments (bias at 26mV on each channel and DC-offset at "zero" mV on both channels) are done smoothly and easily as suggested in the service manual.

  • @robertgriffin7569
    @robertgriffin7569 2 дні тому

    Hey joe,
    Great layout at your bench/ workstation...nicely done service as well, and yes often times schematic's leave a little to be desired. They can be easily be misinterpretted, misprinted, etc..
    Good call.
    ✌️❤️😁.

  • @timcorner2821
    @timcorner2821 Рік тому

    Another fine session at your bench. Your right to use common sense when reading schematics and service manuals, as they often can be wrong. From what I have read, many companies make errors on their manuals. Apparently Marantz is famous for marking polarity wrong on the boards etc.... Anyway, I look forward to having my receiver next up on you bench. It should prove an interesting session for your viewers to see.

  • @jameswarren1831
    @jameswarren1831 Рік тому

    I'm really enjoying the ceramic screwdrivers for adjusting pots in a powered amplifier.

  • @robertwheeler4068
    @robertwheeler4068 10 місяців тому

    Nice work Joe!👍 I wouldn't mind finding one of these clean & serviced to own! I already have the Kenwood matching companion tuner to complement this amp!⚡

    • @VintageAudioFever
      @VintageAudioFever  9 місяців тому +1

      Yea.they are nice amp!!! If you keep your eyes open...one will pop up for you....
      Rare but there are some floating around.

  • @aeyb701
    @aeyb701 Рік тому

    I just came across your channel after watching audio repair videos for years, and subscribed.
    A fellow Maritimer? I pick up a PEI accent, I think. I could be way off.

    • @VintageAudioFever
      @VintageAudioFever  Рік тому

      welcome onboard, I am from the east coast yes...but not the island haha!

  • @stevefoster2700
    @stevefoster2700 9 місяців тому

    Thanks Joe, very interesting and great idea with the plastic straw over the screwdriver! Could you tell me what you were reading on the meter when testing the filter capacitors. I could see the probes but not the meter. Thanks again!

    • @stevefoster2700
      @stevefoster2700 9 місяців тому

      I see it now...the Capacitor Wizard.

  • @valerianpantsulia5137
    @valerianpantsulia5137 4 місяці тому

    Good video and cool explanation

  • @drdyna
    @drdyna 25 днів тому

    Man they knew how to make a good looking amp back then, just needs a couple of big meters :)

  • @mikeeygauthier2959
    @mikeeygauthier2959 Рік тому

    Highly recommend, a fuse upgrade to the synergistic purple!

    • @VintageAudioFever
      @VintageAudioFever  Рік тому

      ouffff! I'm not sure the customers would absorbed the high cost of these fuses...maybe you can elaborate on these fuses, I'm interested to hear your views on them.

    • @mikeeygauthier2959
      @mikeeygauthier2959 Рік тому +1

      @@VintageAudioFever OMG! I cannot express how impressive these fuses are. I have a modest system, comprising of a Cambridge Azur 851 N Preamp DAC, a pair of Focal Solo 6; I started by upgrading to ceramic fuses, then went to the synergistic orange fuses and then to the synergistic purple fuses. The increase in sound quality was unbelievable ! Pricey, I know, but the improvement in sound quality was well worth it. Of all the dollars that I’ve spent on this stuff, including IsoAcoustics, audience cabling-used of course), this was the most significant.

    • @VintageAudioFever
      @VintageAudioFever  Рік тому

      Ok....well it's good to know....and thanks for sharing

    • @robertgriffin7569
      @robertgriffin7569 2 дні тому

      @@mikeeygauthier2959
      Thank you for the info..

  • @michaelaue7411
    @michaelaue7411 Рік тому

    Haw close are the specifications at rated output

  • @liecharleandado3194
    @liecharleandado3194 10 місяців тому

    sir gud am, i have def. kenwood integ. amp, can i perform dc biasing for my ka990d without connecting output transistor, thnk you so much for your reply...