Fender '68 Custom Princeton Reverb R34 location?

Discussion in 'Amp Tech Center' started by deadbeat son, Aug 20, 2015.

  1. caspersvapors

    caspersvapors Tele-Meister

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    I imagine it only exists on the Custom channel
     
  2. robrob

    robrob Poster Extraordinaire Ad Free Member

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    You are correct.
     
  3. caspersvapors

    caspersvapors Tele-Meister

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    I finally got around to doing the 18k resistor mod and it makes a huge difference. I didnt experience any thinning of the sound, just better control of the bass and a lower plateau. The amp is way more clear and tight now.

    For any other noobs attempting it, a piece of advice: you cant simply remove the resistor and call it a day, there needs to be a connection at r34. If you simply remove the resistor altogether the bass response is actually worse...I know because I did this lol

    So either jumper the resistor or solder in a wire in its place
     
  4. deadbeat son

    deadbeat son Tele-Afflicted

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    I did not. I originally jumped the 18k resistor and didn't care for it.

    Did you parallel an additional 18k, or simply jumper the existing resistor?
     
  5. caspersvapors

    caspersvapors Tele-Meister

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    The resistor is removed and a jumper wire is in its place.

    18k mod + RCA 12ax7a in v1 + eminence blue frame = killer tone
     
  6. jjang1993

    jjang1993 TDPRI Member

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    Hey everyone, I hate to bring this thread back up, but I'm considering getting a used 68' Princeton Reissue. How much bass does that jumper wire mod take out? Like if you could put a number to it, would it be -2 or -3 with the bass at zero after the mod? My jazz box has a lot of low end with my Vintage Sound 35sc (35watt single channel PTP wired Deluxe Reverb circuit in a Princeton cab) I have the bass at 0, pretty much all the time, I can't remember the last time I actually used the bass knob. Amazing amp, but at 42 pounds, not amazing to carry, and a double bills south of 2k, doesn't put my heart at ease to use a handcart on rough pavement. What 10" speaker will have the least amount of bass response?
     
  7. wanderin kind

    wanderin kind Tele-Meister

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    try a 10K in there and see what you think, or use a jumper so you do not lift pads off the fragile pc board,

    and don't let it get too hot, there is a non reset thermal fused burried deep in the pwr xfmr that will nail you for 100 bucks>

    https://groupdiy.com/index.php?topic=69973.0
     
  8. deadbeat son

    deadbeat son Tele-Afflicted

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    From what I recall, after jumping R34, you would need to turn your bass up to 4 or 5 to get the same sound as 0 on the stock amp. Why are you interested in the 68? A 65 PRRI wouldn’t need this mod.

    Good luck with your search!
     
  9. Wally

    Wally Telefied Ad Free Member

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    With that handwired circuit, a good tech can do a lot more to customize that Vintage Sound amp to your needs.
     
  10. jjang1993

    jjang1993 TDPRI Member

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    The vintage sound isn't the issue besides the weight. I rarely have issues of it being too boomy. The mid knob can help control the bass too. It's kind of like a 65' Twin but cut in half lol. It's funny how I find you can get tighter, less boomy bass, and a more usable bass knob with a Twin when compared to a Princeton Reveeb.

    Upon looking on the web some more, it seems the 65' reissue princeton is about the same price as the '68 one. Maybe $100 more at the most. The 68' apparently has less clean headroom too, so I'll probably keep my eyes peeled for a used 65' reissue on Craigslist or Offerup.
     
  11. wanderin kind

    wanderin kind Tele-Meister

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    you can jumper both channels, so maybe they wanted one channel different so that you could set up on channel for one sound and blend that with a different sound, kind of like a Sunn Beta Bass/Lead, or not.
     
  12. deadbeat son

    deadbeat son Tele-Afflicted

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    There aren't 2 channels in a Princeton. What amp are you referring to?
     
  13. wanderin kind

    wanderin kind Tele-Meister

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    dang, my mind is gone. sorry about that, thinkin of 68 deluxe reverb,
     
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  14. deadbeat son

    deadbeat son Tele-Afflicted

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    No worries, I was just confused.
     
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