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NAD - DIY Hiwatt DR201

Discussion in 'Amps and Cabs [BG]' started by bb5000, Jul 20, 2012.


  1. bb5000

    bb5000

    May 30, 2006
    Sundsvall, Sweden
    It's finally done, I started this DiY project early this year, a Hiwatt DR201 build based on the 6xEL34 version an the Mid-70s preamp. Some extra features are individual bias adjustment pots, built in volt meter to make bias adjustment easier, flyback voltage diodes.
    The transformers come from TubeAmpDoctor in Germany and are DR201 replacement models.
    The preamp was tweaked into a mix between the DR405 and Mid 70s preamp with some adjustment for bass, no major changes though.

    a nice amp for both clean and crunchy bass & guitar, imo

    a few pics of the build progress, i ordered a blank chassis from a metal shop and did the rest myself:

    P0004821.

    P0004831.

    P0004828.


    P0004830.

    P0004789.

    Kabinett_5.

    P0004805.

    bild.

    P0004812.
     
  2. oerk

    oerk

    Oct 16, 2009
    Bavaria
    Wow, what a clean build! Nicely done!

    I can only imagine what amount of work goes into a project like this one.
     
  3. super nice!!
     
  4. webelo

    webelo

    Jun 7, 2011
    Douglas, MA
    Wow! That is a beautifully clean build. Did you build this just from a schematic?
     
  5. JMac- Wiskerface Designs

    JMac- Wiskerface Designs Terror headcase dude

    Jul 8, 2009
    Atlanta, GA
    Wow, awesome work! "Live at Leeds" on tap!


    Your amp has given Me a serious case of chub...
     
  6. bb5000

    bb5000

    May 30, 2006
    Sundsvall, Sweden
    Yes, I looked into the schematics at www.hiwatt.org and added a few things. Here's my modified version:

    Schema_Mid70_s_preamp_20120703.

    The goal was to be able to use 6xEL34 or 4xKT88 so that's why I use 100K grid leak resistors in the output stage instead of the 220K that's normally used for the 6xEL34.
     
  7. webelo

    webelo

    Jun 7, 2011
    Douglas, MA
    I'm super impressed. I wish I knew how to take something from a schematic to actuality. I can totally read a layout and can solder if you tell me where to put stuff, but any schematic more complex than a bass wiring schem, and I'm lost.
     
  8. jumbodbassman

    jumbodbassman Supporting Member

    Dec 28, 2009
    Stuck in traffic -NY & CT
    Born Again Tubey
    AWESOME build
     
  9. Chef

    Chef Moderator Staff Member Supporting Member

    May 23, 2004
    Columbia MO
    Staff Reviewer; Bass Gear Magazine
    Well Done Sir!
     
  10. bb5000

    bb5000

    May 30, 2006
    Sundsvall, Sweden

    Well, I also created a layout, that's a must for me too. There were some preamp layouts on hiwatt.org and photos, but I had to make some modifications to make room for the extras:

    DR201_ver_8_Mid70_s_preamp_mod_20120703.
     
  11. bassfran

    bassfran

    Mar 1, 2012
    Chicago
    Endorsing artist: Lakland basses
    Killer build- how about some soundclips?
     
  12. Jared Lash

    Jared Lash Born under punches Supporting Member

    Aug 21, 2006
    Northern California
    Amazing. Great job!
     
  13. Mr. Foxen

    Mr. Foxen Commercial User

    Jul 24, 2009
    Bristol, UK
    Amp tinkerer at Ampstack
    OK to rob this for a Sound City 120PA I wanna convert?
     
  14. bb5000

    bb5000

    May 30, 2006
    Sundsvall, Sweden
    Sure, I hope that it's readable. I use Microsoft Visio and the connections moves around when you move a component so you should double-check it against the schematics.
     
  15. Corey Y

    Corey Y Guest

    Jun 3, 2010
    Wow, nice work, really clean build. How's it sound?
     
  16. bb5000

    bb5000

    May 30, 2006
    Sundsvall, Sweden
    Like a Hiwatt :) I've only played it at home so far, but it seems versatile, loud'n clean or loud'n dirty. There's lots of low end available but the original preamp has also a boost from ~3600 Hz and up. I toned that down a bit, there's still tons of treble left if you want to use it for guitar and play power chords the Pete Townsend way.
     

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