AX84 is staying put right here for the foreseeable future. Game on!

Account Info
Greetings, Guest.

Reset Password
Create New Account

Browser cookies are required for these functions.

This is our old projects area, and is provided for reference. If you're starting on a new build, please click on one of the other projects areas to your left

This project is undergoing maintenance. Some files may be missing or out of place while this is being completed.


The High-Octane takes the basic tube power amp of the P1 and adds a hi-gain preamp that rocks!


  • Hi-Gain 12ax7 Preamp
  • 6BQ5/EL84/SV83 Power Tube in Class-A Single Ended Configuration provides a surprisingly loud 5 watts or so of output power.
  • Cathode-follower driven Bass, Mid and Treble tone controls allow you to shape your sound. Alter the values of the components in the tone stack to tailor your sound.

This preamp works great with a variety of poweramps!

Although the Hi-Octane sounds fantastic and isn't THAT hard to build, it isn't recommended for first timers...
Note! The P1 Project page has some materials that may be useful to Hi-Octane builders as well, such as a theory document and a terminals trip drilling suggestion.

A Kit for this project is available... Please visit

Project Coordinator: Chris Hurley --- Skill Level: intermediate --- Status: Ready to Build.
Primary Documents:
•ADOBE ACROBAT DOCUMENT: Rev 05.11.23 (11/23/2005 of the P1, P1-eXtreme, Hi-Octane Build Guide : [download]
•ADOBE ACROBAT DOCUMENT: Rev 06.02.23 (02/23/2006) of the Hi-Octane Bill of Materials : [download]
•ADOBE ACROBAT DOCUMENT: Rev 06.02.23 (02/23/2006) of the Hi-Octane Schematic : [download]
•ZIP ARCHIVE: Rev 06.02.23 (02/23/2006) of the Hi-Octane templates and layouts : [download]
•ZIP ARCHIVE: This archive contains all of the primary documents for revision 05.11.23 of this project : [download]

Variation Schematics:
•SCHEMATIC: A variation on the Hi-Octane Poweramp by Chris Hill that shows how an EL34 can be used instead of the EL84 : [download]
•SCHEMATIC: A variation on the Hi-Octane Poweramp by Kurt Leniger that has a larger 6550 output stage : [download]
•SCHEMATIC: A variation on the Hi-Octane Poweramp by Kurt Leniger that has an octal socket in parallel with the EL84 : [download]
•SCHEMATIC: A variation on the Hi-Octane Preamp by Kurt Leniger that has several switches for tonal variation. : [download]
•SCHEMATIC: Ray Winkel's Ultra-High Octane variant featuring "Brutal Gain" and reverb : [download]
•SCHEMATIC: Rev 4 of the Hi-Octane Schem (for reference only- superceded by newer version) : [download]

•IMAGE: Chris' 10 Watt Self-Split Hi-Octane is small but fierce! :) : [download]
•IMAGE: Close-up 1 of EL84/6n1p Hi-Octane guts (Chris Hurley) : [download]
•IMAGE: Close-up 2 of EL84/6n1p Hi-Octane guts (Chris Hurley) : [download]
•IMAGE: Front of Chris' 10 Watt Self-Split Hi-Octane : [download]
•IMAGE: Ken Ritchie's Hi Octane pic : [download]
•IMAGE: Rear of Chris' 10 Watt Self-Split Hi-Octane : [download]
•IMAGE: Rockman69's Hi-Octane Amp Left View : [download]
•IMAGE: Rockman69's Hi-Octane Amp Right View : [download]
•IMAGE: Tom Scoville's sharp Hi-Octane. Check out those clean crisp lines! : [download]
•IMAGE: Tom Scoville's sharp Hi-Octane. closer look. : [download]
•MPEG AUDIO: 4/25/2 Clip of a new pre-built Hi-Octane by Chris Hurley : [download]
•MPEG AUDIO: Another silly 6n1p Hi-Octane from Chris. Not the best performance, but we do what we can. : [download]
•MPEG AUDIO: Brief layered sound clip of Hi-Octane Preamp and push-pull 6n1p power amp : [download]
•MPEG AUDIO: Chris' Self-Split EL34 High Octane converts to a 6L6 to save some filament current (change occurs after the feedback) : [download]
•MPEG AUDIO: One of Chris Hurley's High-Octane builds : [download]
•MPEG AUDIO: Yet another Hi-Octane Demo from Chris, with the 6n1p output stage (July 2001) : [download]
•ADOBE ACROBAT DOCUMENT: Brian James offers this switching preamp schem : [download]
•ADOBE ACROBAT DOCUMENT: Drilling layout for the Hi-Octane- Mark Searles took the photos of Chris's DMP build and drew this layout to show where to mount tranformers, sockets, etc... Makes building much easier. Can be adapted easily to the P1 or other small amps as well Although for the Heyboer transformers, this is easily adaptable to other iron. : [download]
•ZIP ARCHIVE: Pics and mpeg-4 audio/video clip of a recent Hi-Octane build by Chris Hurley : [download]

AX84® is a registered trademark of Doberman Music Products, LLC. AX84.COM content may not be reproduced without the express written consent of Doberman Music Products, LLC (
For information about using the AX84® trademark, project names and designs, click here
pg:oldprojects pg2: