Non-Trem AB763 Layout for PR Chassis

Discussion in 'Shock Brother's DIY Amps' started by Phrygian77, Mar 7, 2017.

  1. Phrygian77

    Phrygian77 Tele-Afflicted

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    This is my work-in-progress layout for a non-tremolo AB763 circuit in a Princeton Reverb chassis. So far, I haven't been able to find anything like this, so I decided to make my own.
     

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    Last edited: Mar 7, 2017
  2. robrob

    robrob Poster Extraordinaire Ad Free Member

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    So you're going to keep the reverb?
     
  3. Phrygian77

    Phrygian77 Tele-Afflicted

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    Yes. I just want to give up the tremolo for a long tail pair. Did I imply something else in another post?

    I just realized that posting a PNG was a bad idea. I can pretty much convert it to any format, including SVG. Is there anything I can attach here that would look better, or do I need to link to another site.
     
  4. Phrygian77

    Phrygian77 Tele-Afflicted

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    I changed the attached file to PDF.
     
  5. FenderLover

    FenderLover Poster Extraordinaire

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    Looks pretty good. Just throwing it out there, a lot of folks love the spring reverb and is sometimes the reason for building an amp in the first place, but....an FX loop is a lot easier, and you can plug anything you want into it. Just sayin'.
     
  6. jhundt

    jhundt Doctor of Teleocity

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    are you using a multi-section cap can?
    which transformers are you planning to use?

    and have you checked that the 3 resistors shown on the left edge of the board will actually fit in that space?
     
    Last edited: Mar 10, 2017
  7. Phrygian77

    Phrygian77 Tele-Afflicted

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    The JJ 40-20-20-20 can cap is cheap and it fits the Mojo/Zachmdhunter chassis, so that's what I'm planning to use. Basically, my build will be a single channel Vibrolux (ironically) without the tremolo. I'm going to extended the PT cutout in the chassis, and use a Tremolux/Vibrolux transformer (ClassicTone 40-18041). I'm going to put a 90ma choke where the PR OT normally mounts. The OT will either be a Bassman or Vibrolux/Tremolux/Pro type mounted on the preamp side of the chassis. My control layout will be Volume, Treble, Middle, Bass, Dwell, and Mix.

    I won't be using the 1K in my build since I'm using a choke. The drawing is to scale and the components are sized based on components that I would use. Those dropping resistors, for example, were based on Vishay PR03 & PR02 metal films (the others are 10mm x 3.5mm). Considering that I wanted to created a layout that anyone could use, I guess that could be an issue.
     
  8. FenderLover

    FenderLover Poster Extraordinaire

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    Maybe not an issue, I've done that too. You can leave the eyelets in-line, but stagger the resistor bodies left-right-left, if you get what I mean.
     
  9. jhundt

    jhundt Doctor of Teleocity

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    it's a very interesting build. I have a much-modified Princeton Reverb II that I built with the same inspiration - the single-channel Vibrolux. The original PRII had too many unnecessary gimmicks for me.

    are you not concerned about the location of the output transformer? I thought that the OT should be kept away from lower level signal leads... but then I have never tried it on that side so I don't really know.
     
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  10. jhundt

    jhundt Doctor of Teleocity

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    oh, by the way - my PRII has a Presence control similar to the design used on a 5f6a. It adds some really nice sparkle.
     
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  11. Phrygian77

    Phrygian77 Tele-Afflicted

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    I started a thread a while back about modifing the PRII to give it more of a blaceface voice. You and I had a fairly lengthy conversation about it. I love my modded PRII. It's my main gigging amp. I also have a Rivera Super Champ, mostly unmodified, that I gigged with for years. I retired it from gigging though after I aquired the PRII. The SC is full of NOS tubes, including a RCA 6C10.

    I always thought that was a no no also, but it's been done before. I was inspired by this video.

     
    Last edited: Mar 11, 2017
  12. jhundt

    jhundt Doctor of Teleocity

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    oh yeah, I remember... I just looked back at that thread.

    pretty cool video here, I see he runs all the wires outside of the chassis to avoid the problems.
     
  13. Diverted

    Diverted Tele-Meister

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    Phrygian77, how did the build work out? I have also been wanting to build a single channel AB763 with reverb but no tremolo. I saw Rob Robinette's Blackvibe, which is close but still has two channels. Before I start this I want to be aware of any pitfalls or issues, so I'm very interested in your build! Do you have an updated schematic and/or layout?

    Thanks,

    Ted
     
  14. robrob

    robrob Poster Extraordinaire Ad Free Member

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    The Blackvibe is a single channel amp with two inputs, a high and a low. I do have a layout at the bottom of the Blackvibe page of an AB763 with the tremolo deleted. I had several people request it.

    [​IMG]
     
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  15. Diverted

    Diverted Tele-Meister

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    Your layouts are so clear and easy to read. Thanks for posting them.
     
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