19 May 2008

KT77 Push-Pull DIY Tube Amplifier

Bruce has followed up his OddWatt tube amplifier project (a EL84/6BQ5 Push-Pull Tube Amp) with the Oddwatt 225 (a KT77 SIPP (Push-Pull) Tube Amplifier). The Oddwatt 225 is a scalable tube amplifier which will work with any octal tubes that share the base layout of a 6L6GC.

KT77 DIY Vacuum Tube Amp
The driver stage uses 6SL7 tubes in a SRPP topology which feed the KT77 self-inverting push-pull (SIPP) output stage operating in Class A Ultra Linear (UL) mode. The constant current source (CCS) uses an LM317 regulator.

DIY KT77 Tube Amplifier
I was most impressed with the performance of the design. The SRPP and Push-Pull outpout stage combine to produce a very low noise floor. Distortion was measured to be less than 1/2% at 12W. The design can be scaled for use with other tubes by simply adjusting voltage and cathode current. My understanding is that KT88 versions of this design are in the process of being built.

For complete information about this project, see the Oddwatt 225 project page -
DIY KT77 SIPP (Push-Pull) Tube Amplifier.

Related DIY Tube Amplifier Projects:

What's Playing:
Joni Mitchell - Carey

1 comment:

  1. Bruce

    I know I have said this before but a great looking build. I know you have other projects under your belt and looking forward to all of them. Thanks for highlighting the valve component boards to me. I have a stack and look forward to many happy builds.