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Looking for a fairly simple but good quality amp schematic for a 50w 8ohm guitar speaker...

Discussion in 'Shock Brother's DIY Amps' started by EricW, Nov 16, 2017.

  1. EricW

    EricW NEW MEMBER!

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    I know very little about amps and i'm starting out with electronics but i'm determined to try.

    I'm looking for a solid state and preferably a clean amp whose circuit one can find online with all the basic knobs like tone, bass and volume. If it has more adjustments on the clean channel that's only a bonus. It should preferably sound decent enough (i know the speaker really isn't a very decent one) so the amp should preferably match the speaker or the wattage of the amps output could be a bit more due to it being a solid state.

    The speaker i have is a Celestion Rocket 50 (50W 8Ohm guitar speaker)

    I found this schematic in the link below (all rights goes to the owner/creator/website of origin. not sure how the plagiarism works on getting schematics online for personal use)

    http://el34world.com/charts/Schematics/files/peavey/peavey_basic50.pdf

    Problem is that this amp circuit might not sound good with an electric guitar as it is said to be a bass amp.
     
  2. nsmith01tx

    nsmith01tx Tele-Meister

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    Hi Eric,

    The "50 watt" designation just means it will handle up to 50 watts, it doesn't actually require a 50-watt amp. The key info is the "8-ohm" part. I think any amp with a 8-ohm output impedance should push this speaker just fine.

    See Rob Robinette's "How Amps Work" to learn more about this topic, there is information on that page about the Fender Champ 5F1 too, which is about as simple an amp as you'll find - and LOUD for it's small size. (They can be made with an output transformer for 8 ohms as well).

    Before you start such a project do a LOT of reading, and learn about what you're doing - the voltages in these amps can kill you. Also, look at kits - that will make it much easier to get it right the first time. You can follow the build logs on this forum to see how others do their projects and learn from their successes and failures before you start your own.

    Good luck!
     
  3. sds1

    sds1 Tele-Afflicted

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    That Peavey Basic 50 circuit is not what I'd call simple! You're probably looking for something with way less components than that.

    I caught that you're looking for solid state, but you'll find the most enthusiasm around here is for tube amps. Like @nsmith01tx mentions above, the 5F1 is a great example of a super simple amp. It's not solid state, but check it out anyhow so you know how simple an amp can be.
     
  4. tubeswell

    tubeswell Friend of Leo's

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  5. VintageSG

    VintageSG Friend of Leo's Ad Free Member

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    There are circuits out there for pre-amp and tone based around op-amps that will do for the front end. Scour Ebay and you may come up lucky. For the power stage, scour Ebay again. There are many kits for mono power stages. Some are based around venerable older designs such as the TDA20x0 output IC which will give between 10~30 Watts in to an 8 Ohm load, up to the TDA7293/4 which will push around 40~50 Watts in to 8 Ohms. There are also some very useful Class D modules to play with. Class D amps from Ebay generally sound OK up to the point of clipping. I've faffed about with a few.
    One thing to budget for though is the power supply transformer. Do not skimp here. The power supply can make or break a solid state amp. Go 50% over on the VA requirement and 1000uF ( minimum ) per Ampere + 1000uF for the smoothing. Bridge rectifier modules make life easy. Go at least an Ampere over the peak current draw. Preferably more. Transformers cost. A cheap, barely adequate transformer can ruin the sound of an amp, whether it be a solid state or valve. Inadequate smoothing likewise.
    For the Class D stuff, laptop type power supplies can work.
    If you do go down the kit of parts route, you can always replicate/adapt the schematic on Vero. Think modular. How about looking for a solid state 'amp sound in a pedal' type schematic and running that into a TDA2050a board?.
    Chassis wise, for solid state stuff, folded metal project boxes work well.
    Do you have an enclose/cabinet for the speaker?.
     
  6. jmp81sc

    jmp81sc Tele-Meister

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    I would start with a Ruby or Noisy cricket LM386 style amp. Learn how to solder, cheap, safe, learn how to read a schematic etc. Loud enough for home playing or jamming with a friend. Gateway drug to bigger and more complex pedals and amps.
     
  7. ChopSauce

    ChopSauce Tele-Meister

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    I have been subliminally suggested that the 5E3 sounds awesome through the Rocket 50 :cool:

    I know it doesn't match your (notably tone control) requirements, but this latter feature might be added on one of the two channels, if I remember well Rob Rob's website.

    Given all the information on that (5E3) build it should be even simpler than managing with LM386 bugs :D
    (I started building one of those and afterwards I don't feel it has been of much help with latter building my own tube amp.)

    Solid state, really?
     
    Last edited: Nov 17, 2017
  8. zook

    zook Friend of Leo's

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    I found an oar a couple days ago, so I'm building a boat...
     
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  9. nsmith01tx

    nsmith01tx Tele-Meister

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