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schematic for kt88 power amp

Discussion in 'Amps and Cabs [BG]' started by roflol, Sep 14, 2008.

  1. looking to build my own amp and intending to use 4 kt88s struggling to find a good schematic for it though so any help would be apprieciated!
  2. Try looking for a schematic for an early Sunn 2000S. They used four KT88's. The later 2000S amps switched to 6550's. The Sunn 200S used two KT88's.

    Hope this helps you out some...

  3. 6550s are pretty much just the america equivelent of kt88s right? thanks for the help!
  4. elros


    Apr 24, 2004
    Proprietor, Helland Musikk Teknologi
    Have you built tube stuff before?
  5. aye its mainly just been low voltage stuff though and i've built alot of pedals. i'm doing a course on this kind of stuff next month so i've just been working out what i'm going to go for when i build myself a gig volume head.
  6. Here is what I built.

    I put this 70's era Hiwatt Pre-amp


    and mated it to this Sound City power supply and power amp section, which is very close to the Hiwatt 4xkt88 power amp.


    I did it this way because I already had the Sound City amp and just wanted to change the pre-amp. I completely rebuilt the power amp though so it's new except for the transformers.

    This combo sounds so amazing for bass it's almost hard to describe. It's like a hi-fi solid state amp combined with a bad ass tube amp. It can do perfect crystal clear cleans and gets a little dirty when you crank the gain up

    Good luck and have fun.
    Be careful of the high voltage, you need some serious juice to get 200 watts out of 4xKT88's. Mine has a plate voltage of 730V
  7. dijon43


    Oct 1, 2008
    The Ampeg V4 which came with 7027 tubes can also be used with 6550/KT88's. I used a V4 output transformer as a replacement for one that had burned out in an old Plush amp.
  8. Bassmec


    May 9, 2008
    Ipswich UK
    Proprietor Springvale Studios
    Heater current is a consideration I think we should look at.
    also the KT 88's are different to 6550's and require different output transformer impedance for best matching.
    Its hard to make a Hiwatt DR 201 4 X KT88 clone for less money or any better than Webber, maybe if you started with an old Simms Watts, Carlesbro or Sound City 200 you would save alot if the transformers and coke where OK but what's your time and burnt fingers worth even if you don't get across the plate voltage.:D
  9. Mojo-Man


    Feb 11, 2003
    I'm having Craig Collins of Collins Amplifiers.
    Make me a "tube" head and cab.
    I will run two KT88's.
    Wattage will be around 84-100 watts.
    Should be done in a few weeks?

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