On Going Saga of 2325 re-cap and restore

Discussion in 'Marantz Audio' started by wurlyman, Apr 26, 2017.

  1. wurlyman

    wurlyman New Member

    Messages:
    49
    Location:
    Sacramento, CA
    Thanks,
    I have talked with Randy of irebuildmarantz but I ended up using Mouser and others and didn't order from him. He did say that after I finished the project if I wanted to drive it over to Santa Rosa one day he would realign the tuners for me. Nice guy.
     
  2. Trojan4Life

    Trojan4Life Active Member

    Messages:
    269
    That would be a nice little trip!
     
  3. wurlyman

    wurlyman New Member

    Messages:
    49
    Location:
    Sacramento, CA
    Hey guys,
    Mark Walker in N.C., AKA Blueglow Electronics just showed a new product in his latest video that lets you watch a circuit in action and on a virtual oscilloscope. I see all kinds of possibilities with it. I'm a visual learner and this looks great. Everycircuit.com
     
  4. Trojan4Life

    Trojan4Life Active Member

    Messages:
    269
    Cool! You can use it to troubleshoot.

    I might try it on the iPad at home.
     
  5. Trojan4Life

    Trojan4Life Active Member

    Messages:
    269
    Here's some good info regarding hFE and Vbe and a test method used if you don't have access to a curve tracer: http://audiokarma.org/forums/index.php?threads/ba-5000-rework.716307/page-4

    Start on post #67 to save some time. I found this advice to be very true regarding my differential amp pair:

    "There seems to be some consensus across many diy forums that Vbe at quiescent current is the best method of matching parallel outputs, and with the fact that I did not feel I could reliably measure Vbe at higher currents, this has been the primary value that I am comparing."
     
  6. wurlyman

    wurlyman New Member

    Messages:
    49
    Location:
    Sacramento, CA
    OK, I've rebuilt the P800 power supply after blowing C803. Replaced the H808 and 809 with Common cathode rectifiers MUR1620 plus C804, C806 and C811. Replaced transistors H803 thru H807 with KSC 2383 and matched the pairs, checked the 4148 diode at H812 and H801 and H802. Everything looks good. Waiting for my friend to come over for a test again. _DSC0285.JPG
     
  7. wurlyman

    wurlyman New Member

    Messages:
    49
    Location:
    Sacramento, CA
    Spent a very productive evening re-testing. The P800 power supply, PE01 tone and pre-amp and the right channel amp P700 are working fine. We even played it through a speaker, what a great feeling to hear it again after seven months and knowing that I did that! We set the DC voltage on the power supply to 35 volts and checked the 19 volt and 14 volt pins. They were within tolerance and that was with a 100 watt dim bulb. We will re-check it when the whole rig is completed.
    Left amp has no sound so we've pulled it out, found one broken wire which may have happened after we pulled it out. Did a little non-power testing of components including the differential pair and all diodes but haven't found the problem yet. I'm going to put some extensions on those wires that go from the output transistors to the jacks and take some of their tension off. Did about an hour's worth of HD videos of the process. All in all, it was a good night.
     
    Last edited: May 18, 2017 at 3:48 AM
    Hipocrates likes this.
  8. wurlyman

    wurlyman New Member

    Messages:
    49
    Location:
    Sacramento, CA
    Here's a follow up photo for those of you who wondered if the parchment paper instead of velum would work. I used it and blue LED fuse type lamps. The indicator lamps are still original. It looks great and I love it! _DSC0287.JPG
     
    Hipocrates likes this.

Share This Page