NOT just another 5E3 build...

Discussion in 'Shock Brother's DIY Amps' started by charisjapan, May 8, 2012.

  1. charisjapan

    charisjapan Tele-Afflicted

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    Heater Wiring

    Ouch! Cramped fingers, hurts to type! Yes, I did heater wiring.

    Hackworth, as you suggested (or at least stated your own preference), I went the flat-to-chassis-up-under-the-lip routing. Actually, it went a lot better than my first build. Maybe practice does make better (not perfect yet). Getting real close to attaching those heavy hunks of iron, and trying to remember not to cover up where the bolts need to be. Also trying to envision where the tranny wires will go, so I leave a 'path' for them.

    Here's a few pics, but man, I hate the way cloth-covered wire looks after you mess with it a few times. All fluffy and frayed... Humphh!

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  2. charisjapan

    charisjapan Tele-Afflicted

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    Of course, as soon as I commit this statement to a public forum, I try a 'dry-mount' of the trannies... (sigh!) ...my MOSFET bolt is right under the O.T. Duhh!

    Fortunately, it just required one new hole, twisting the unit counter-clockwise. No need to change wiring. (phew!)

    A small amount of rationalization... I had to drill for a ground lug anyway. ;)
     
  3. andyfromdenver

    andyfromdenver Friend of Leo's

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    Those knobs look edible. Yum :)
     
  4. charisjapan

    charisjapan Tele-Afflicted

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    Caramel Knobs

    Hehe! More 'candy' pics. Getting a bit closer to the finish line...

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  5. andyfromdenver

    andyfromdenver Friend of Leo's

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    Looks sooo good! Ok, now I'm the one who should be sleeping :)
     
  6. charisjapan

    charisjapan Tele-Afflicted

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    Whoa!

    Well, I just wired up the Power Transformer like the Triode layout (because some of the wire colors don't match the Weber layout) and had a pair of orange wires 'left over.' I then checked the Classic Tone specs, and indeed it seems this P.T. has optional wiring. It says,

    "Like the original, it features the higher voltage secondary rating of 355-0-355V AC for the purist who wants the most accurate performing 5E3 power transformer but also features the addition of a lower, more conservative secondary voltage rating of 330-0-330V AC."​

    :oops:I don't know if I'm a 'purist' or not?! What would that mean in real world application?

    Which leads to the second BIG question, How do I wire one way or the other?

    The diagram states "Use RED-RED/YEL-RED for 710V, ORN-RED/YEL-ORN for 660V." I have already wired it using 2 RED and 2 YEL, what does that get me? How do these correlate to the pins on the 5Y3 rectifier, especially as it seems to be connecting 3 RED for the 710V?

    Sorry for the ignorance, but I can't make sense of this...

    Help!

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  7. tubeswell

    tubeswell Friend of Leo's

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    the reds make it 355-0-355, which with a 5Y3GT should get you about 395 B+, which is what a vintage amp designed for a 110V mains will give you in a 120V mains.

    the oranges make it 330-0-330, which gives about 366 B+ (with a 5Y3GT) which is a nice voltage and closer to the original 5E3 voltage in the 1950s. These amps sound better when the 6V6 plates are running about 340-360 IMHO.
     
  8. Telenut62

    Telenut62 Poster Extraordinaire

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    The Red/Yel is the centre tap/ground wire, leave it as is if you have it attached to a PT bolt, then depending on your mains supply you may want to try the lower 660V Orange wires to the rectifier. If so, then cap off the Red wires. Also now's a good time to read up on tube bias ;)
     
  9. alscort93

    alscort93 Tele-Meister

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    No comment :D :lol: :lol:
     
  10. charisjapan

    charisjapan Tele-Afflicted

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    tubeswell and Telenut, thanks!

    So a 'purist' is someone using a 50s amp at today's voltage, and a 'conservative' (like me!) is someone attempting to extrapolate what it probably sounded 'back then.' Add to that formula that I live in Japan, and this P.T. runs with 100V (actual 106~108V), and I guess I have to test and see what is actually measures.

    (See! I have been reading up on tube bias! ;))

    OK, I get it... hyphen trouble. Was :confused: about the language on the diagram. Add to that the difference in opinions about what is 'right' for a 5E3, and I guess it comes down to Empirical testing. When I finish the wiring, I will test the actual line voltage, secondary output, B+ and other voltages in red AND orange, and maybe even see what happens with the 100V vs 120V primary. Armed with those numbers I should be able to get this baby into shape.:D

    I have heard that 340~360V number before, so I'll shoot for something thereabouts. Again, thanks for the clarification.
     
  11. charisjapan

    charisjapan Tele-Afflicted

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    Haha!

    Y'know, I think we have to come up with a better term than 'mount.' :rolleyes:

    Attach? Bolt-on?

    And certainly no more 'dry-mount!' ;)

    Try-and-see? temporarily put in position? (even these can be racy!)
     
  12. andyfromdenver

    andyfromdenver Friend of Leo's

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    Lol
     
    Last edited: Jun 10, 2012
  13. charisjapan

    charisjapan Tele-Afflicted

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    Where was I? ... Oh, yeah, study tube bias. :oops:

    Decided to start wth 100V Primary and 330-0-330 secondary HV, so re-wired to ORN-RED/YEL-ORN. I left the REDs twisted and capped in case I want to go to 355-0-355. I wanted to leave the other primary options open, so I braided and capped those wires until I make some empirical measurements.

    Finished ground (I hope!), primary to PT lug, centers and 1st filter cap to chassis lug, rest of the board to input jacks via copper wire bus. All jacks and pots star-washer grounded.

    OT and VVR done. Used a micro-switch for 4/8 ohm speaker selection. My speaker is a 10" Weber Sig AlNiCo (and if it is anything like my Jensen P-8R, I'm gonna be a happy puppy!) I ordered the cab with both 10" and 12" baffles, so I can go full-size anytime.

    I plan on doing the fine-tooth-comb thing tomorrow, but if you catch anything wrong I'd appreciate a holler!

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  14. Telenut62

    Telenut62 Poster Extraordinaire

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    Did you fit the extra caps to go with the VVR? I bet it will squeal like a banshee without them :neutral:
     
  15. charisjapan

    charisjapan Tele-Afflicted

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    As you can see in the last picture, not yet. :( But I did take your advice to heart, studied about it in Dana's installation manual, and bought the caps. Those, and a "variety pack" of resistors are in my stash box for replacement and tweaks. I also got few different 12AX7s, an extra pair of matched 6V6s, and a 5Y3 for troubleshooting and future amps... I do believe I'm getting rather 'involved' with this amp thing! :eek:

    USPS Tracking finally decided to divulge information about my cab, and it's going through Chicago International now. That means (possibly) that I'll get it in about a week. :D
     
  16. Telenut62

    Telenut62 Poster Extraordinaire

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    Ah now your in the Bermuda triangle stage.....waiting for that arrival at your customs. Best forget the tracking website till next week ;)
     
  17. charisjapan

    charisjapan Tele-Afflicted

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    (Gasp!)

    I know what you mean. The package disappeared into 'Limbo' for almost a week, then suddenly...

    Arrived at Sort Facility - June 12, 2012, 8:28 pm

    Processed Through Sort Facility - June 12, 2012, 9:33 pm​

    That the package was 'processed' in 1'05" is scary! I suspect the next update to take at least 2 days...

    (note to self: DON'T check for a WEEK! :rolleyes: )
     
  18. Revv23

    Revv23 Friend of Leo's

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    With a variable b+ you can always just turn the vvr down a bit to get into the sweet spot.
     
  19. picknpluck

    picknpluck Tele-Meister

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    Did your decision to go this route have anything to do with the electrical system in Japan? Would have gone the same route Stateside?
     
  20. charisjapan

    charisjapan Tele-Afflicted

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    Revv23 - Yeah, that's the plan. I just don't want to have too much on tap. Kind of like a nuclear reactor's "105%" or a jet engine's "military power." I want the VVR to give me approximately 70% to 100% B+, with 90~100% the sweet spot, and a little bit extra for, well, FUN. :p

    picknpluck - Yes, on paper my present wiring should get me 365V or thereabouts. I'll just have to see if the Classic Tone PT was designed at a literal 100V or the actual 106~108V I measure at the outlet of my home. Either way, this should give me a little more voltage than the sweet spot, and the VVR will allow me to dial in exactly where I want to be. The other purpose of the VVR is to give me all that Tweed Goodness (distortion) with a little less volume. Rooms in Japan tend to be a lot smaller than other places, even our meeting room with seating for 80 is only 1,100 sq ft (100 sq m). :( As for what I would do Stateside, probably used the RED 120V wiring and still installed the VVR for sweet spot adjustment. I'm generally conservative, and want a Tweed Deluxe to sound like one. ;)
     
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