More “Mostly” Mojotone 5e3, version 2! (The Yellow Jupiter build)

Discussion in 'Shock Brother's DIY Amps' started by BobSmith, Jun 17, 2019.

  1. King Fan

    King Fan Poster Extraordinaire

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    Great job!!!
     
  2. BobSmith

    BobSmith Tele-Meister

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    It’s not quite as close as the pictures seem to indicate, but one of the layout points is to position the board so that the tube socket comes between the 2 caps where there is more space.
     
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  3. BobSmith

    BobSmith Tele-Meister

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    Last couple of days work work was busy, so no time for fun work. I had a chance to wire up the ground bus bar (with exception of the actual grounding of the bar which will come from an input jack), pots, and bright cap.
     

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  4. BobSmith

    BobSmith Tele-Meister

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    Annnnnd...input jacks are in. Star washers behind each jack. Bus bar ground to Normal 1 channel jack.

    Now just need to add a power connection and mains ground to chassis lug. Will be tomorrow’s work.
     

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  5. BobSmith

    BobSmith Tele-Meister

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    Finally finished up everything. I took my time and slowly brought up on the variac in stages as I added more tubes. I checked all the voltages and let everything settle for about an hour plugged into my dummy load. Too late yesterday to make any sound (very unappreciative neighbors), so today I got a chance to crank it up, and play thru my 63 reissue tele.

    Whoa.

    I haven’t done the AB yet, but damn this came out right and everything you’d expect is there. It’s exactly the same as the previous one save for yellow Jupiter’s over red. Seems brighter and richer. I think I may like it better than my other one. But that still remains to be proven. I’ll have to think about how to do a test. I wish I had a head switcher so I could put it all thru the same speaker and flip between them.

    I’ll post some voltages when I get a chance. Meanwhile here are some gut shots from the bench and installed in the cab next to “Red”. Please excuse the crappy chassis. We can blame Mojotone tone for the accelerated relicing.
     

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  6. SacDAve

    SacDAve Poster Extraordinaire Silver Supporter

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    Looks great
     
  7. King Fan

    King Fan Poster Extraordinaire

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    Bob, awesome. You have a one in a million chance to compare (and record) the red-yellow thing. My buddy has some illicit way to use an ABY pedal to swap heads, but what would it take to do it right?


    Sent from my iPad using Tapatalk
     
  8. BobSmith

    BobSmith Tele-Meister

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    I can’t imagine how to make this work with just an ABY switch. I think it’s really hard to maintain a load on the idle head. I’d hate to blow something up :)

    I’m looking at getting a Radial tonebone headbone switcher. They retail for $250, but can go for around 150... that’s the way to do it. I have an itch trigger finger to hit buy, but I think I’ll wait a bit to see if I can get an even better deal (ebay history shows them going for 100!)
     
  9. Robear

    Robear TDPRI Member Ad Free Member

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    Just a gorgeous build. Congratulations! A lot to aspire to on my next build.
     
  10. BobSmith

    BobSmith Tele-Meister

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    Here are my voltage readings...

    I broke down and got a Radial Headbone VT. Only proper way to do a test “head to head”. When it gets here I’ll be hooking them up to several of my speakers including stock fenders (Jensen and Eminence) as well as a Celestion Heritage G12H and of course an alnico Blue. I’ll also run it thru my Weber Mass attenuator. Can’t wait for the showdown!

    If you don’t know the Headbone, it’s another fantastic creation from those wizards in Canada.
     

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  11. BobSmith

    BobSmith Tele-Meister

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    Ok, so my Radial Headbone came in. Sweet device!

    Red Vs Yellow Jupiter
    I’ve dialed in the same settings on the red and yellow builds and been playing with it for about a week. I tested thru a Celestion blue speaker (had planed for others too, but an thing called time vanished) but ran thru a bunch of different guitars including the big ones: my CS 63 tele (reissue 63 Pups, what I play 90% of the time), a strat (abby wound pups), les paul std (brustbucker pro pups), and es-335 (classic 57 pups). I had my dB meter on too (was hovering around 100-104dB, loud, but no peeps from neighbors). You can see the my settings that I used for humbucker guitars. For single coils I turned up volume 2 to noon for more girth. Volume 1 (about 3) and tone (about 9-10) were the same.

    I had a VERY hard time telling between the amps. I think they both sound great and could (and did) play they for hours. I could almost say they were identical, but maybe, just maybe the yellow had a bit of extra sizzle (like presence) that I found quite pleasing. The Red sounded a bit warmer and darker. I didn’t hear the difference so much plugged straight in, but when I kicked on my compressor (Origin Effects Cali76 compact deluxe), that area of frequency seemed to go down a bit with the red Jupiter amp.

    I found this a bit surprising because I was expecting the yellow to be the darker of the two based on the YouTube video of a guy AB’ing them. That kinda leads me to believe, it may not be the caps themselves accounting for difference. Who knows... but these amps are otherwise identical (Mercury trannys, wired exactly the same way). I did used slightly more NOS Allen Bradley resistors in the yellow (let’s not go there, shall we?) and I did use a ohmite 250ohm instead of the xicon 270ohm for the power tube cathode resistor. Doubt that had any impact. Probably there are some small variances in component values. But not a huge difference. That’s for sure.

    One thing I was a bit surprised by was how damn good the les Paul sounded thru the 5e3. (I don’t pull my les paul out very often). I was under the impression that humbuckers could be a bit muddy and bassy sounding. I found that to be the case with my 335 (Classic 57s), where the neck pickup was not doing well on chords, almost sounded dull (granted my 335 is a bit on the warmer side). But the les Paul was a different story and was fantastic on almost any setting, great crunch, lead tone, dynamics and sustained so well. One of the reasons I almost always use a compressor on my fenders is to boost sustain, but on the les Paul, the compressor wasn’t needed at all...hmmm I might be picking up that guitar a bit more for messing around!

    I was gonna do a recording (and still might, depending on free time), sorry, and stay tuned. If I do something I want it to be meaningful, and since I didn’t have too much to report here I think the results will be disappointing for you.

    So next build will be yellow??? Anyone out there surprised?
     

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