Asher Guitars WD Music Products Amplified Parts Mod Kits DIY Nordstarnd Pickups Warmoth.com
Asher Guitars WD Music Products Amplified Parts Mod Kits DIY Nordstarnd Pickups Warmoth.com
Asher Guitars WD Music Products Amplified Parts Mod Kits DIY Nordstarnd Pickups Warmoth.com

6G2 build begun

Discussion in 'Shock Brother's DIY Amps' started by King Fan, Oct 21, 2017.

  1. Mongo Park

    Mongo Park Tele-Holic

    511
    Nov 28, 2010
    Winnipeg
    I can see your photo of how to test film caps for outside foil end. It looks straight forward, but anything else to it. Is it that the cap buzzes more in one position. This looks easier than building a tester.
    cheers Ron
     

  2. King Fan

    King Fan Friend of Leo's Ad Free Member

    Jan 1, 2013
    Salt Lake City
    Good question. You're right, it's a comparison, and it's easy.

    All through this thread, I shoulda been linking out to the other threads I've used in planning. I really owe a ton of TDPRI people for great info. Just lazy!

    The gang discussed outer foil tests recently in this thread. You might read upwards from the end -- several folks including @D'tar and @clintj clarify things nicely. For details on how to use the info, see this by Mr. Aiken.
     

  3. Mongo Park

    Mongo Park Tele-Holic

    511
    Nov 28, 2010
    Winnipeg
    Thanks man, something to mess with for the hand built MoJo
    Cheers Ron
     

  4. King Fan

    King Fan Friend of Leo's Ad Free Member

    Jan 1, 2013
    Salt Lake City
    Wired the rectifier socket. Then, comparing them to the red - white ones, I cut the red (630v) HV wires, capped with heat shrink, and ran 'em "out of the way" along with the other 42 wires heading southwest.

    6G2 - 1 (5).jpg

    For anyone keeping score at home, I'll attach below my PT wiring diagram.

    Then brought in the OT leads to pre-wire the power sockets.

    6G2 - 2 (2).jpg

    Finally, my total favorite, the 1-ohm resistors off the 6V6 cathodes with the wiring to the bias test points.

    6G2 - 3 (2).jpg
     

    Attached Files:


  5. keithb7

    keithb7 Friend of Leo's

    Age:
    46
    Jan 9, 2010
    Western Canada

  6. King Fan

    King Fan Friend of Leo's Ad Free Member

    Jan 1, 2013
    Salt Lake City
    Thanks, but it only looks braided there. Twists + parallax somehow. Just wait, though.
     

  7. King Fan

    King Fan Friend of Leo's Ad Free Member

    Jan 1, 2013
    Salt Lake City
    OK, let's catch up. Keith mentioned braiding. OK, here you go.

    IMG_5650.jpg

    I'm still using the nice tinned bus bar I got for my PR build.

    IMG_0061.jpg

    Let's get the tape labels off all those off-board leads...

    IMG_0068.jpg

    To finally test all the plate, grid, and cathode connections, we need the shielded leads from V1 pins 2 and 7.

    IMG_0069.jpg

    Today's Well Duh moment: If you don't turn up the volume pot, pin 7 shows continuity to ground, and you think you've melted the insulation between signal and shield.

    Finally, fly the heater wiring...

    IMG_0072.jpg

    Tomorrow: Final testing and, if the creek don't rise, power-up.
     

  8. jsnwhite619

    jsnwhite619 Tele-Afflicted Ad Free Member

    Sep 10, 2013
    Georgia
    Looking good!
     
    King Fan likes this.

  9. CoyotesGator

    CoyotesGator Tele-Meister

    309
    Jul 12, 2014
    Gulf Coast

  10. theprofessor

    theprofessor Friend of Leo's

    Aug 8, 2016
    Chattanooga, TN
    Is this the idea about braiding as tightly as possible? --- I know the signal wires should not parallel one another, since the parallel wire will pick up the signal of the other wire but in the opposite direction. That's why one tries to run them perpendicular to one another--to reduce the signal transfer from one to the other. But when wires must be run the same direction, they should be braided so as to reduce transfer? Or is the reason something altogether different?
     

  11. keithb7

    keithb7 Friend of Leo's

    Age:
    46
    Jan 9, 2010
    Western Canada
    I particularly like the circuit and bias boards. Matching. Nicely elevated. The ground bus is quite cool too. Laura Ingalls would most certainly approve that braiding. Very nice.

    Metal film resistors where it counts. Carbon comps where the guitar tones cruise. Sozo caps for some clout to the kidneys. Nice premeditated, methodical work here.

    Whats your call out rate amp Doctor? Very nice.
     
    King Fan likes this.

  12. theprofessor

    theprofessor Friend of Leo's

    Aug 8, 2016
    Chattanooga, TN
    Hey King Fan - Give me your version of the rationale around Sozo blue caps and the Mojo dijons. I'm not saying the be-all-and-end-all gospel. Just your take about why you used them. I know they're the talk of the town on some forums, but I don't know why. Just trying to learn...
     

  13. King Fan

    King Fan Friend of Leo's Ad Free Member

    Jan 1, 2013
    Salt Lake City
    Thanks, you all. This has been a fun build -- Keith can tell you I've been planning it about a year. But I'll wait until I have 'er singin' before I celebrate.

    Thanks, Keith. Hey, as you know, I've had plenty of time to plan! Your original and your build were my inspiration all the way.

    To be honest, I shoulda done this before I built the PR. That's a lot more amp -- more sectors, more RCA jacks, more tubes, more of everything. In many ways this should have been boring -- like a dumbed-down PR -- so I tried switching things up: Dale resistors, elevated epoxy boards, etc. But most of all I wanted to avoid several of the bigger mistakes and hassles I had with the PR build. It is a pure joy now, but it had me swearing and sweating at various points.

    Thanks, Prof. You're right, keeping wires paired or bundled is a way to try to cancel out as much EMF as possible when wires travel together. AFAIK, though, braiding is just a vanity version of twisting. I don't know that it has any advantage. Leo twisted stuff; modern twisted-pair cables are still a big deal. Braiding? One of the fun parts of building your own amp is to do stuff that's personalized, just cuz you can. You'll notice I go right back to twisting on the inside of the chassis.

    Oh, no, you pushed the big red 'capacitor' button. :D Stand back and cover your ears.

    You know as much about amps as I do or more. I don't think for a moment there's a right answer on caps, or that it matters as much as we all like to think. There's a huge school of folks who say 'caps is caps -- they all sound the same.' Lots of boutique builders use ODs, Doug Hoffman builds amazing amps using Xicons, etc. AFAIK, Dijons are a great cap -- some evidence suggests they may actually be as close to the fabled blue molded Ajax as any cap out there. OTOH, Sozos are 'blue' and they cost more. So they *might* be a tiny bit better. Maybe. Perhaps. Does blue and bucks mean they're like Ajax? Probably not, but it doesn't cost a fortune to pretend.

    Except, stay with me here, vintage 6G2s are absolutely full of blue molded caps -- they musta been cheap in the early '60s. I counted one that had I think 9 blue beauties in there, including every cap on the board. But by the time the PR took over, Leo was sticking all sorts of other caps -- like ceramic disks -- on the board instead. But he kept blue molded handing signal off V1 and going into the 6V6s. (OK, OK, he kept 'em as death caps too, not exactly a temple of signal handling.)

    Those caps in the middle of the board? They don't much handle signal -- they mostly vary the bias to make trem -- so no need to spend money there.

    Besides, and this is just me. Pale yellow all the way across the whole board would look boring. Like braiding, blue caps on both ends just make me smile. It's my amp. I can do it just for fun, for looks, for a laugh. There's karma in making your own choices.
     
    Last edited: Oct 31, 2017
    D'tar and jsnwhite619 like this.

  14. D'tar

    D'tar Tele-Holic

    946
    Jan 11, 2013
    WNY
    That looks fantastic King Fan. The braid is a nice touch. Everything shows how thought out the whole process has been for you. I have similar thoughts on capacitors. We can read all the hype and debunk material on line but we have to ultimately make our own decisions, and we'll never know if we don't try! Well done. Hope to hear it!?
     
    King Fan likes this.

  15. keithb7

    keithb7 Friend of Leo's

    Age:
    46
    Jan 9, 2010
    Western Canada
    It’s tomorrow. Did the creek rise? ;)

    Anxious up here waiting for an update on flowing electrons. Oh, and the glamour shot. Fully assembled! Can’t hardly wait to see this beauty.

    Sorry...Take your time, but hurry up.
     
    robrob and King Fan like this.

  16. FenderLover

    FenderLover Friend of Leo's

    Jun 11, 2009
    Minnesota
    Nice job King. I might be a little worried over the center conductor on your flying coax leads flexing and cracking due to the weight of the cable over time. Maybe tie wrap them down to limit their movement, but that's up to you.

    You should also make a plexi-glass cabinet top so we can keep looking at it. :)
     
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  17. robrob

    robrob Poster Extraordinaire Ad Free Member

    Dec 29, 2012
    United States
    That really is a fantastic looking amp. Come on, quit dragging your feet and tell us how glorious she sounds.
     
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  18. theprofessor

    theprofessor Friend of Leo's

    Aug 8, 2016
    Chattanooga, TN
    Hey King Fan! Yeah, she's purty! I look forward to hearing your report on how she sounds!

    While I'm here, I'll ask: what is the purpose of the runs of silicon on the filter capacitors? Does that help keep them from moving around or something?
     
    King Fan likes this.

  19. King Fan

    King Fan Friend of Leo's Ad Free Member

    Jan 1, 2013
    Salt Lake City
    I see this done on Alessandro handwires and other amps -- I was worried the caps might not be stable between those two little terminal strips. But a) I think they actually woulda been and b) it's really hard to goop on a nice clear smooth glob like the pros do. :)
     

  20. King Fan

    King Fan Friend of Leo's Ad Free Member

    Jan 1, 2013
    Salt Lake City
    While we wait, here's a big shoutout to the amazing guy who built my cab.

    Who does T-nuts on their handles *and* really really even, smooth, shiny, uniform shielding on the underside of the top?

    6G2 - 2 (3).jpg

    Who fits the baffle with wonderful, sturdy, flush nutserts (is that a word, at least once you're out of high school?) instead of speaker studs? Just *try* to tear your new cone on those beauties. And no deep-well sockets needed, either. Say, what cone do you think is in that basket?

    6G2 - 3 (3).jpg

    OK, if you've ordered from him, you probably know. If not, let me suggest you should.

    6G2 - 1 (6).jpg

    Peter Mather custom built this for my chassis size and a few other little changes I asked about. He was awesome to work with. The pine is super clear and every join, all the Tolex, and the baffle and grill cloth are *perfect.* No affiliation, just a newfound loyalty.
     
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