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marantz 18

  1. D

    Model 18 power transistors

    I have some questions regarding what power transistors to use and how clearly they need to be matched. One of the power resistors on the right side shorted and took the other one out. The R42 100 ohm resistor between them also burnt up. I bought 4 each On Semi MJ21193G and 94G to replace...
  2. cabsodyinblu

    Marantz 18 Wood Case

    Hello AK! First time posting on here, I’m wondering if anybody has the dimensions for the elusive B18-O or WC-9 case for the Marantz 18. These cases hardly pop up on the ‘bay so I figured I might as well try my hand at making one from scratch for my 18. Anybody got any leads? :music:
  3. BlackScholes

    Marantz 18 & 19 Receiver Restorations

    Edit: After 2+ years, I'm finally tackling these receivers. After restoring dozens of items out of my collection, I can say that I know a lot more now than I did two years ago so I'll be making updates to the below summary as well as additional posts to the thread. Before I regained my sanity, I...
  4. D

    New Transistor variability marantz 18

    I bought some new transistors for the model 18. They are the ones that precede the final audio power transistors. I got a batch of three NPN and five PNP because that’s how they were sold. There is a very large variation in the hfe values determined by my Peak semiconductor analyzer...
  5. D

    Marantz 18 Transistor

    I have a shorted Q14 power transistor. Can someone tell me the best place to get a matched Q13 and 14 set? Is there any place that would have the original motorolas? I got these transistor part numbers off another post. All I’ve seen online so far are some Mexico Motorola’s and unbranded...
  6. D

    Marantz 18 Scope

    I replaced the original 10uf 575v electrolytic cap in the scope circuit with a 10uf 630v solen pp film. Scope display was cleaner - easier to focus and brighter - but the alignment settings are way off. When I set the horizontal all the way left the dot only goes as far as the middle. Same...
  7. D

    Marantz 18 Bias

    When I turn on the receiver cold the bias reading goes up to 105 to 115mv on each side. It then slowly decreases to around the 80mv spec that it was set at, but only after an hour or so. Is this normal? Thanks!
  8. D

    Marantz 18 Help and Parts

    Hello, I’m new to the Marantz forum and need some help. I recently acquired a low serial number (1323) Marantz 18 that appears to be all original and works well. I cleaned the controls and checked the big electrolytic capacitors with a purple peak meter and all had very low ESR. It sounds...
  9. Randy B

    MARANTZ 18 on Craigslist

    Hi All, In my daily search for an 18, I found this. *NOT MINE* Sadly, too far of a drive. https://tulsa.craigslist.org/ele/d/broken-arrow-marantz-18-receiver/6871066311.html If somebody wants to pick it up and ship it, that'll be cool too - Thanks buddy! haha
  10. UncleBingo

    Marantz 18 Transistors

    Trying to source proper transistors for the driver and tone amplifier board for a Marantz 18. I've checked schematics and service manuals only to find proprietary Marantz part #'s (Grrr...) I even looked for an annotated schematic where someone perhaps wrote in some actual manufacturer...
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