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DIY tube amps?

Discussion in 'Amps and Cabs [BG]' started by Eric Cioe, Jan 4, 2006.


  1. Eric Cioe

    Eric Cioe

    Jun 4, 2001
    Missoula, MT
    I'm sort of interested in doing a low-power DIY tube amp during my Spring Break. Mainly, I'd be doing it to get experience, but it'd be nice if it provided a workable guitar (and/or bass) tone.

    Does anyone have any recommendations, especially low cost ones?
     
  2. patrickj

    patrickj

    Aug 13, 2001
    Baltimore, MD
  3. Passinwind

    Passinwind I Know Nothing Supporting Member

    +1

    Try http://www.firebottle.com/ampage/ as well.

    I'd stick with a guitar oriented one for starters. There are a lot more ready-to-go designs out there for guitar than for bass. I may post something about my latest DIY tube bass preamp soon here though.

    Best of luck, and have fun!
     
  4. A9X

    A9X

    Dec 27, 2003
    Sinny, Oztraya
    Make sure you learn about safety around high voltages before you start so that your first experience of tube amps isn't fatal. There's enough voltage in most to do you some damage. HV safety

    Now that the safety warning is out of the way, enjoy building your amp. I agree with the earlier suggestions of ax84 and diyaudio. There's an online tube resource thread here
    And this is the best written tutorial on the most common tube circuit type I've read.

    Enjoy. Tubes are great.
     
  5. doctec

    doctec

    Mar 22, 2005
    Beaverton, Oregon
    If you play bass and want to experiment with tubes, building a tube preamp is a good way to get started. It's simpler than building a complete amplifier, will cost less and -- coupled with a good power amp -- could be quite usable on stage.

    You should check out Kevin O'Conner's books:

    http://www.londonpower.com/books.htm

    In particular, "Tonnes of Tone" has very complete plans for building two different bass preamps. One is based on the Fender/Alembic design and the other is more like an Ampeg.

    I've used homebuilt preamps off and on for many years. Designing and playing through your own equipment allows you to put more of your "soul" into your music :)
     
  6. jvb

    jvb

    Jul 11, 2005
    Canberra, Australia
    Doctec, have you built either of the bass preamps in Tonnes of Tone? I don't have my copy of the book here, but does the Ampeg preamp have Baxandall type tone controls?

    regards,
    jvb

     
  7. Kelly Lee

    Kelly Lee Yeah, I'm a guy! Supporting Member

    Feb 17, 2004
    Marana, AZ, USA
    If you ever get really ambitious, check out Dogzilla. :D BTW, I haven't built it. I haven't the stones to try it yet!
     
  8. Eric Cioe

    Eric Cioe

    Jun 4, 2001
    Missoula, MT
    Dogzilla - Jesus. Huge. Reminds me of that 1k watt tube mono block that shows up on here from time to time (don't remember who had it).
     
  9. doctec

    doctec

    Mar 22, 2005
    Beaverton, Oregon
    Quote:
    Doctec, have you built either of the bass preamps in Tonnes of Tone? I don't have my copy of the book here, but does the Ampeg preamp have Baxandall type tone controls?
    ---------
    I've built several incarnations of the Fender style preamp and had good results. I just pulled out my copy of "Tonnes of Tone" this morning to make sure I remembered things correctly. The Ampeg style bass preamp has Baxandall controls and some local feedback with a "sensitivity" control to set the gain.

    This really is a good book for getting started with building and designing tube stuff for guitar and bass. There are chapters on how to physically put things together plus parts lists and pictoral drawings showing how to connect the parts -- in addition to the schematics and theory.
     
  10. jvb

    jvb

    Jul 11, 2005
    Canberra, Australia
    Just as background I've built quite a few valve/tube guitar amps, but since I've switched to bass I want to build a valve bass amp. I have a Leslie 147 (IIRC) 6550 based power amp to which I'll add a preamp, and change the power supply to use solid state rectification. The question is do I use Baxandall or Fender 3 tone stack? Got any ideas Doctec? Might have to try both :p
     
  11. doctec

    doctec

    Mar 22, 2005
    Beaverton, Oregon
    Might have to try both :)

    I've always liked the Fender tone stack. Just have to remember that the four pots (volume,treble,middle,bass) form an interactive passive network -- If you turn down the middle you have to turn up the volume to keep a constant level. I've got an old Ampeg B15 with Baxandall tone controls and it's ok, too, but I guess I've gotten used to the Fender design.

    Cool thing is once you have a chassis put together with point-to-point wiring, you can swap out Fender vs Baxandall tone stacks with a few minutes of soldering and see which one sounds/feels better to you!

    Adding a preamp to a Leslie amp sounds fun. Just be careful with the solid state rectifier -- Make sure you don't exceed the max voltage rating for the 6550s. As you probably know, tube rectifiers have quite a bit more voltage drop the SS ones.
     
  12. Passinwind

    Passinwind I Know Nothing Supporting Member

    My inclination would be Baxandall with a 6550 based amp, but that's just a sort of traditionalist view. I also have a lot more experience with the Fender stack, and tend to get better results with it. How about neither one though? :cool: If you haven't already, go to the Duncan Amps website, and download the Tone Stack Calculator applet. That'll give you a few more ideas. Maybe take a look at some old Gibson amp schematics too.

    I found something pretty cool and outside-the-box when I built my last tube preamp a few weeks ago. Unfortunately I can't talk about it right now though. :ninja: