Fun little 5E3, sort of

Discussion in 'Shock Brother's DIY Amps' started by RottenTheCat, Feb 12, 2020.

  1. RottenTheCat

    RottenTheCat Tele-Holic

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    I've taken on a comission to build an amp that is based on the 5E3, but... of increased power, while keeping things more or less in line with the 5E3 tone as much as possible.

    Worked out using a Hammond 660vCT at 140ma for the power supply. And use a pair of coke bottle KT66's I've got here. Output... a Tremolux replacement. No choke. Switchable fixed or cathode bias. Gonna beef up the filtration just a little. Not much. I'm hoping the 140ish ma and KT66's will sag about as much as 90ma and 6V6's. We'll see. Which brings me to the rectifier... something tells me he's gonna like the sound of the 5Y3 - right before it blows. Dunno, maybe it'll hold up.

    Can't talk him out of a modern Jensen... sigh. Maybe it will offset the low end being a bit tighter than a Deluxe. C12N is his choice. I'd have gone with something else. Dunno what exactly, but I'm rather fond of oversized Celestions in tweeds, but that's just me. I guess its a personal thing, but I find the modern Jensens about as pleasing as a bad Tele bridge pickup....

    So, hoping to get about 35watts. Its going into a seafoam green wide panel cabinet with some nice small checker grille cloth.

    I'll post a few pics as it goes together. Probably this weekend I'll have time to get some serious work on it.
     
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  2. jimgchord

    jimgchord Tele-Afflicted

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    Sorry you cant nix the modern jensen
     
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  3. Wally

    Wally Telefied Ad Free Member

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    35 watts....Tremolux OT? Which Tremolux? I don’t think the tweed Tremolux OT will make that much. Are you planning on using the later Tremolux 4 ohm OT?
     
  4. robrob

    robrob Poster Extraordinaire Ad Free Member

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    The Fender Prolux would get you where you want to go. You could decrease its B+3 voltage dropping resistor to add voltage swing into the phase inverter to drive the big 6L6GC tubes harder to keep more of a 5E3 tone.
     
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  5. RottenTheCat

    RottenTheCat Tele-Holic

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    20200215_151322_resized.jpg 20200215_151454_resized.jpg 20200215_154842_resized.jpg 20200215_155001_resized.jpg 20200215_155323_resized.jpg

    Thanks Rob, but... transformers already here, so we march on. The Tremolux transformer is not such a bad item! My 2x10 combo Tremolux really sang. Of course that was blackface, and a combo.... etc etc. And, if you look at the way Fender did things, they stifled the low end on "piggyback" amps, probably because of the added low end response of the closed cabinets. I had to change the input to the PI in the Tremolux... but I digress.

    Just some odds n ends happening today, but thought some might be interested in the way I made my plate for grounding. Not to open up the can of worms.... let me just say, I prefer this method of ground. The copper comes from Hobby Lobby, cuts easily on a shear type (not rotary) paper cutter. I use a skinny UniBit to make the holes. The only hard one is the first, which I do with the plate out of the chassis. Then, a jack in that hole to hold things in place. Do the opposite end of the plate "in situ", and put a jack in that one (not the pot that will eventually end up there). Then the rest of the holes are made. The UniBit will self senter on the steel chassis hole, so once you have the first hole in the right place, and a jack to keep the plate in position, the rest of the holes are perfecto. I never use a pot to hold the plate, always afraid of a copper shaving getting into the pot.

    You folks probably looking at the less than stellar plating job from whoever is making MojoTone chassis. This is the first one I've gotten that had crap plating. Outer plating is fine, but there must have been some contamination inside, maybe a poor washing. Normally copper is laid down first, and it doesn't take much at all to get copper to stick to steel. Then nickel, then chrome. Something fubar'd, as the copper is there, but the nickel just didn't plate onto it in a few streaky areas. I scrubbed it back some, so flakes would be less likely to cause down the road issues. The cosmetics are good to go, so ... its ok.

    Back to that plate - what I do is fold the corners, and drill a few small holes in each folded spot. The fold makes the plate easy peasy to solder to. In the middle of the plate, first I drill the hole, then take scissors and fold the little strip up at 90 degrees or so. Again, makes soldering so easy. No need to break out the big 130w iron.

    A note on MojoTone Chassis. I've used quite a few Brand W chassis, and had really poor luck with the end caps, and/or the lettering. I've gotten them with soft, smeary lettering, and spot welds that just were not well done, crooked or snapped with the slightest pressure. Mojo has always been ok on the lettering for me, ditto with the integrity of the welding. This is a first as far as "defects" go, but like I said previously... its no big deal. Just a minor annoyance to clean up first.
     
  6. David Barnett

    David Barnett Doctor of Teleocity

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    Sounds like you've invented the 5E5 Pro...
     
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  7. RottenTheCat

    RottenTheCat Tele-Holic

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    Maybe so...

    20200215_171150_resized.jpg

    I want to share this with folks. The little tab. That's what I used previously on Bassman/Super/Pro/Bandmaster amp chassis. ITS NOT IN THE PLACE ITS GONNA END UP. I took this picture so you can see how it fits so nicely with the level of the chassis exterior. The (unseen) opposite bell of the transformer is centered in the chassis cut out, the attachment screws all lined up with the mounting holes. So, the stud parts you see are in the correct relationship with the chassis, and you can see the tab lines up perfecto. Lowes, bag of six is less than two bux. This amp has heavier than normal iron, so... I'm adding a tab. Also, on a Bassman/Super/Pro/Bandmaster, sometimes you need to stick washer between the tab and the cabinet, depending on the exact layout used when making the chassis. Its not a big deal.

    When removing the screw on the transformer.... mind the shellac stuff. Brush it off the exposed portions of the stud. Go slow, back the nuts off the screw carefully, pull the screw out (don't fubar the plastic insulator sleeve), slide the tab over the screw (I use a little star washer between the screw and the tab too). Put it all back together.
     
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  8. jman72

    jman72 Tele-Afflicted

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    I have a C12N in my 5e3, and I think it sounds great.
     
  9. RottenTheCat

    RottenTheCat Tele-Holic

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    And that is one modern Jensen that I've not actually played with. So maybe it'll do. Its his choice. What are they? 50 watt rated?
     
  10. muchxs

    muchxs Doctor of Teleocity

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    Couple things you may want to consider:

    Last time I tried to use "Coke bottle" style 6L6Gs on a 5E3 chassis they bumped heads. The socket spacing is too close together.

    KT66s will use 3 amps of your filament current.

    A 5AR4 was, is and always will be a perfect match for KT66s.

    Bogen used a 5Y3 with 6L6Gs in an old P.A. amp. I've seen a lot of old amps. A single 5Y3 with a pair of 6L6s is exceedingly uncommon.
     
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  11. RottenTheCat

    RottenTheCat Tele-Holic

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    Good call on the envelopes. I'll check it out.
     
  12. Uncle Daddy

    Uncle Daddy Tele-Afflicted

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    That bracket needs a captive nut on the inside. My Tweed Super uses a similar one, and it's a royal PITA getting the nut in place whilst feeding the bolt through from the top.

    Fortunately I have tiny paws. I should have trained as a dentist.
     
  13. RottenTheCat

    RottenTheCat Tele-Holic

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    May I humbly suggest, for your tight spaced needs....

    https://www.harborfreight.com/6-pc-fine-point-tweezer-set-93598.html

    They're absolutely useless for yankin out a nose or ear hair, unless you rework the tips so the ends actually touch, but for holding a nut, or fishing a wire, they're alright.

    Only a small evolutionary step up the quality chain are Pakistani made "long reach, bent nose" hemostat. I get 'em at the flea market in Okeechobee when I decide to make it out to civilization. Apparently a lot of stoners out there - looking for chic roachclips (or retrievers, for when the string breaks). At any rate, I sift thru and find a good set, and they multitask as "oh crap, that just fell into the Sporty's crankcase" when doing a top end, or holding that nut you speak of, or keepin my fingers out of the spray when applying KalGuard coatings.
     
  14. Esquier

    Esquier TDPRI Member

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    For an extra support bracket, I made them up from aluminum "angle iron" type stock. I'm about out of the stuff and don't know where to source some more from. It projects almost two inches back from the chassis, and the screw is under the handle area of the cabinet. Sorry, no pics, I'm picture challenged...
     
  15. RottenTheCat

    RottenTheCat Tele-Holic

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    I like that idea, making the handle screw do double duty.

    Have had no time to work on amp building... hopefully... maybe... tomorrow. Worked 11 hour days already this week. If what I did "worked" for the customer, I'll know in the morning. If it didn't work, no amp work till next Saturday.
     
  16. RottenTheCat

    RottenTheCat Tele-Holic

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    Oh sorry, I missed your post. Blackface Tremolux. Its a 4 ohm job, and so is speaker.
     
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  17. The Ballzz

    The Ballzz Tele-Afflicted

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    I'm guessing you mean this sort of thing?

    image.png

    Or These?

    image.png image.png

    Just Askin'
    Gene
     
  18. RottenTheCat

    RottenTheCat Tele-Holic

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    If its that much of a pain in the butt... jeeze... loosen the screw, let the nut back off a bit. JB-Weld the nut to the L-bracket and tighten the screw. That should hold 'er in place. Just don't use so much JB-Weld that you glue the screw to the nut!
     
  19. RottenTheCat

    RottenTheCat Tele-Holic

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    Well, I wasted time screwing around with the cabinet covering that Mojotone didn't quite do their usual "el perfecto supreme" job on. I swear, they must have been breaking in a squad of left handed scheffleras to work on cabinets.... 20200222_214941.jpg Anyway, I was able to complete the board this evening. There's a few leads to attach. Usually, I'll flying lead the jacks, and bring them down to the board, rather than other way around. There's the ground wires to prep and attach... but its all pretty much done.

    Still need to finish up the copper plate, with the folds and holes for the ground connections, that makes a mess, so I'll do it outside tomorrow.

    20200222_215311_HDR.jpg
    I thought y'all might get a kick out of my screen protector. I had this custom made by a plastics place out in California. They're still laughing at me, because... the plexiglass panel is to keep cat piss off the screen. Yah, CAT PISS. Whenever they sneak into my work area, they just can't resist marking - male or female alike. Two flat screens later, I knew something had to be done. I don't like to dig holes, so dispatching the cats was out. This keeps the screen operable, and a little GlassPlus cleans up the spray. I cannot use the words in this forum that I'd generally use when describing how I feel about this... but they're the YL's kritters, I'm more or less deballed about doing a thing with 'em, other than puttin' up.
     
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  20. Mr Ridesglide

    Mr Ridesglide Friend of Leo's Silver Supporter

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    Do you have a photo of the rear of board?
     
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