My Weekend Project:

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by Chrome Dinette, Jan 19, 2008.

  1. Chrome Dinette

    Chrome Dinette Member

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    [​IMG]
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    The guts are still empty, I will wire it up tomorrow. The power and output transformers came from my old Acoustic G60T. The smaller xfmr is not a choke, but will be doing dc for the preamp heaters. I will eventually put a cage on this so it can be safely transported.

    The circuit is going to be more or less tweed fender style, but with a pentode(5654 or 6ak5, probably) on one channel. Two volumes, one tone. Also, since I only ever plug in one guitar, I see no reason to put 2 or 4 input jacks on an amp. Half of a 12ax7 will end up unused. I may poke the bias pot out the top and put tip jacks on the back.
     
  2. Kappy

    Kappy Member

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    Is that the micro-nanette? ;)

    Looks cool. I'd be interested to hear how it sounds.
     
  3. IIIBOOMERIII

    IIIBOOMERIII Member

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  4. hasserl

    hasserl Member

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    Hey, check out my version of a 5E3X2 here: http://www.thegearpage.net/board/showthread.php?t=321553&highlight=5e3x2

    I used a 6AU6 for one channel, the other channel is one half of a 12AX7, the rest is a modified 5E3 circuit setup with four 6V6's for power. This turned out extremely well, a major a$$ kickin amp, it will eat a 5E3's lunch and go toe to toe with my 5E5A Pro any day of the week, any time of the day. It is my current favorite amp and it's getting a lot of work lately. I've had it out to two blues jams and one rock gig since I finished it, and it's performed excellently. It's definitely more rock than blues though, it gets with the program, like a hot rodded 57 Chevy with a big block stuffed under the hood.

    Let me know if you want help with the design or working out any bugs.
     
  5. 52ftbuddha

    52ftbuddha Member

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    I dont know which I like more the crazy surface it is on or the turquoise transformers. Very cool looking.

    rob
     
  6. Chrome Dinette

    Chrome Dinette Member

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    Nice looking amp. This is more or less my second amp with the same design. I made the first for a friend of mine, but it was all 12ax7's, with el34's for output.
     
  7. Chrome Dinette

    Chrome Dinette Member

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    Believe it or not they are totally day-glo green. My camera does weird things with some colors.

    I never did get this done today, probably will finish sometime tomorrow. I will never try to build a 50 watt amp in this size chassis ever again. I was hoping to have this toally neat looking inside but I keep running out of places to put things.

    Oh well, hopefully it will sound good. Later in the week I am building an amp in a 17"x10" chassis with some old transformers from a Sound City 50.
     
  8. Chrome Dinette

    Chrome Dinette Member

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    The pentode socket in this will accept a wide variety of pentodes. I like the sound of 6au6's( and I have a bunch) but they seem more prone to microphonics than 6ak5's or 5654's.
     
  9. Chrome Dinette

    Chrome Dinette Member

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    The surface is a coffee table my wife bought at a flea market a couple of years ago. It is made of sliced up rocks and crushed glass sealed in epoxy or something.
     
  10. hasserl

    hasserl Member

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    Yeah, I went thru quite a few that were microphonic. But when you get a good one it sounds great. I've got a stash of them now, and I keep an eye out for more.
     
  11. donnyjaguar

    donnyjaguar Member

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    Nice! I like it. You have the placement of the transformers correct - good on you.

    Note on digital cameras. If yours is like my two Canons, they work great but in Automatic mode the colour balance will be fooled by bright colours, like fluorescent greens and oranges. The resultant pictures will be skewed. The way around it is to put it in Manual mode and select the appropriate colour balance from the menu. That way it'll come out better. I discovered this while photographing my kids in one of these bouncy castles. Once I forced the camera to "bright sunlight" the pictures turned out perfectly. Otherwise they looked like sick aliens!
     
  12. Chrome Dinette

    Chrome Dinette Member

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    So I finished this. So far so good, though I won't really know how it is until I go to practice later. The two channels sound different, as expected, and the single tone control seems to be usable. It's pretty quiet when not playing, probably partly due to the dc filaments.
     
  13. Chrome Dinette

    Chrome Dinette Member

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    [​IMG]


    The color is slightly closer, but my camera is not as adjustable as I had thought.
     
  14. Chrome Dinette

    Chrome Dinette Member

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    After playing this loud at my practice space, I decided this needed some negative feedback and I ended up putting a presence control on the rear panel.

    Then I built this:[​IMG]
     
  15. Chrome Dinette

    Chrome Dinette Member

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    That is sort of a Marshall2204/Sunn Model T hybrid. The tube on the right is a 5840, a subminiature pentode that I shock mounted. Initial results are promising, but I need to take it to my practice place, where I can crank it.
     
  16. phantasm

    phantasm Member

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    Awesome!

    Nice stuff Dave, can't wait to hear it!
     
  17. Chrome Dinette

    Chrome Dinette Member

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    So, I went to my practice space to crank these up and I am surprised at how good they both sound. I may need to make a minor tweak to the smaller one, it is a little flabbier than I would like on the low notes, but it works way better than I had hoped. I will have to look at the power supply filtering and maybe the coupling cap values.

    I am going to have to try the bigger amp at a full band practice and see if it can cut it, but I really like it. It is more of a vintage sound than I would usually have, so it doesn't really do modern metal chug, but the single notes are out of this world and are way thicker than with my Deliverance. In fact, I beginning to wonder if there is something wrong with my Deliverance.
     

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