Interesting Looking Kit - Mojotone Studio 1

Discussion in 'Building the Classics' started by pedecamp, Dec 31, 2017.

  1. pedecamp

    pedecamp Well-Known Member

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    Has anybody seen this? Originally I was interested in the JVM1 but the clean channel was too clean to get any grit. This Mojotone is a 1 watt kit with 2 foot switchable channels, the clean channel can be dialed to get some grit in your tone and the dirty channel can be dialed any way you want. Price isn't bad either.

    http://www.mojotone.com/kits/MojotoneAmpKits_x/Mojotone-Studio-1-Kit

     
  2. Crunchifyable

    Crunchifyable Well-Known Member

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    Not bad. I'm always doubtful of 12__7s as a power tube but I've never had one with a true tube phase inverter.

    I think a single ended el84 probably sounds better, but that's my best hunch.

    I think mojo is too expensive but everything they sell commands a premium.

    If you like the JVM, that's a pretty easy circuit to copy, believe it or not.

    All it is is 3 triodes cascaded, and a switch between each triode to allow for 1, 2, or 3 triodes of gain. They route the tone stacks separately.

    The clean channel on the JVM is based on a fender blackface, so that's probably why you don't like it.

    Personally I'm going the complete custom route. I'm starting off with a plexi / 2204 hybrid, and can easily change it to a bright plexi + OWM. With a channel switch or separate inputs.
     
  3. MarshallDog

    MarshallDog Well-Known Member

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    Not familiar with this amp but sounds great and I can say MojoTone has top notch QC and great customer service. I am awaiting a Marshall 1X12 Blues Breaker clone combo cab from them. I would venture to guess anything they offer is top quality.
     
  4. stickyfinger

    stickyfinger Active Member

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    The shemati I have shows 3 gain stages with a cathode follower straight into to the 12bh7 power tube. Its a original circuit. Clean has it own circuit.

    It would be easy to change the circuit to soemthing more traditional but not showing a PI circuit for this type of valve made me decide to pass. I didn't want to do the research/engineering.

    Still very cheap and should be a killer practace amp if anyone is thinking about it
     
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  5. Crunchifyable

    Crunchifyable Well-Known Member

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    That's a shame about the PI. I learn a lot by reenginneering, but I guess the point of a kit is to build it by the book, simple and easy.

    My HT-5 is a letdown and the lack of a traditional phase inverter may be part of that. For all the hate the class 5 got, that single little bottle sounded pretty big.

    It's probably a cool amp to build. But with a different power amp.
     
  6. johan.b

    johan.b Well-Known Member

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    It's just self split output. Same principle as a regular long tailed pair by applied on the output tubes. . In such application it'll be slightly unsymetrical when driven into clipping thou.
    But on the other hand, with a "clean" channel, I'd assume they don't intend for the "power amp" to saturate and clip.
    ..it looks cool with that vintage marshall style head box thou.....
    J
     
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  7. pedecamp

    pedecamp Well-Known Member

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    The Marshall style head box is cool, I thought the power section was odd I never even heard of a 12BH7 tube but yeah since its a low volume 1 watt amp the power section is definitely not a big deal. My problem is I'm not a builder, a $550 kit plus pay someone to build it starts adding up unfortunately. To bad they don't sell them ready built for $550, I really like this amp I'd consider getting one.
     
  8. MarshallDog

    MarshallDog Well-Known Member

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    Maybe someone on this forum can build it for you for a low price???
     
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  9. pedecamp

    pedecamp Well-Known Member

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    Thats a nice idea! They do say its a 5hr build, should be easy for an enthusiast.
     
  10. Crunchifyable

    Crunchifyable Well-Known Member

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    My advice is to take your time and build your own if you want something that's not really on the market, or overpriced (vintage Marshalls, Fenders, supros, etc). Or just want to have a mod platform (with a turret board you can change things as often as you want.

    A number of amps use 12BH7s, 12au7s, as power tubes. Personally I am a little skeptical of them but hey...I own a Blackstar HT-5 that uses that amp and the power amp is a weak spot of the amp (but could also be the tiny OT).

    The power amp colors the sound...and I think I get better results with EL84 or a big bottle. But I'm a low volume, master volume, headroom kinda person. HT-5 is a thin amp...incapable of any real bass.

    Honestly $550 is a lot for this amp and a lot of that is a fancy chassis and output transformer, etc. For that price you can buy a brand new assembled low watt amp. But hey I get my parts from ebay, home depot, Mouser, and tayda.

    I'm building my first amp and it's a little hairy at times...but if you stare at a schematic or layout long enough you will get it. I think wiring a turret board is easier than wiring a guitar...the turret board actually holds everything in place.

    Tube amps are simple. Innovation, quite rare. Todays amps are not far removed from Leo Fenders...we just have added more switches, more controls, and voiced it for mids.
     
    Last edited: Jan 2, 2018
  11. stringer

    stringer New Member

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    20180321_095135.jpg Here's my studio one build.
     
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  12. pedecamp

    pedecamp Well-Known Member

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    So tell us about it.

    Unfortunately I've moved on from this, Marshall recently put out a DSL1 head for $299 ready to go if I decide I need a small tube amp.
     
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  13. stringer

    stringer New Member

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    Honestly
    Played with it through 4x12 cabinet loaded with 25 watt greenbacks
    Sounds ok. Nothing to go out and build one .
    I'e got other amps I prefer to use.
    I just wanted to build another amp kit .
     
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  14. stringer

    stringer New Member

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    Some pic of the guts..
    Please excuse the wiring color scheme..and sloppy build. 20171127_041535.jpg 20171127_041544.jpg 20171127_041554.jpg
     
  15. jensvonbustenskjol

    jensvonbustenskjol Active Member

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    Just bought myself a Fargen mini plex. I'm sorry mister fargen but I'm bringing my screwdriver and oscilloscope to the party... It's a wicked amp! I guts to know its secrets.... Muhahahaha
     
  16. stringer

    stringer New Member

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    Show us the guts pics
     
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  17. printer

    printer Member

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    I would want a phase inverter also. I would use a Mosfet split phase inverter with it. But then again, I like pentodes rather than a triode output.

    Here is an example of using a IRF820 as the PI. It gives you no gain as the Cathodyne circuit but it does not have the odd behaviors of the Cathodyne when overloaded. The circuit is just a Tweed inspired cathode biased amp that is reminiscent of the Fender Harvard/Vibrolux/Princeton without the tremolo and fixed bias.

    [​IMG]
     
    Last edited: Apr 20, 2018
  18. proxy

    proxy Active Member

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    How do you like MiniPlex?
    Is it the latest version?
     
  19. jensvonbustenskjol

    jensvonbustenskjol Active Member

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    It's not the latest,but it's the mkII at least. Sound wise I love it. Great overhead.

    I miss footswitch for changing style, and also send return loop could be nice. But it's retro all the way.

    I like it a lot. I'm not sure it's worth retail price. I got a great used deal.
     

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