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Data for the low-voltage hybrid headphone amp (AudioXpress 11/02)

PLEASE READ - Commercial usage of information on this site:

I consider all the information that I post here to be in the public domain.  So, you can use it however you want, for commercial or non-commercial use.

That said, I would appreciate it if you at least let me know if you are going to use any of the circuits or especially PCB Gerber files to make commercial products, or to sell bare PCB's.  

There are some cases where products are being sold not only with my permission, but active involvement.  The "Millett Hybrid" effort and others at HeadFi are examples (and excellent models of how the DIY community should work, in my opinion).  There are other cases where I have asked vendors to sell PCB's as a service to hobbyists.  And there are other cases where companies are manufacturing and selling PCB's, chassis, etc. without contacting me at all.

In ALL of these cases, I make no profit from any of the sales.  Zero, zip, nada.  I have a normal "day job" that pays the bills, this is strictly a hobby with me.  So please do not expect me to provide the level of technical support that you might expect when buying a product.  I try and help, but it sometimes takes me days - even weeks if I'm traveling for work - to respond.

Thanks for your indulgence in reading this!

The evolution continues!  The "Millett Max" has arrived... details are here.

Here's what the MAX PCB looks like:


A group at Head-Fi has taken the design and enhanced it, making it more of a high-end, "tweakable" design.   Great work guys!  This is how DIY audio SHOULD work...

There's full details of this project on this DIYForums site .   Cool!

Here's what the new PCB looks like:

You can also download the Gerber files of this version of the board (169k ZIP file) from my site.

Here's the original...

Thanks to AudioXpress and Ed Dell, the full magazine article is now available for download!

"Build A Low-Voltage Tube Hybrid Headphone/Line Amp (612kB PDF file)

This page contains files to download that relate to the article about building a low-voltage hybrid headphone amplifier that I wrote for AudioXpress issue 11, 2001.  This is a great project for the newcomer to tubes, since it's easy to build, and safe - it runs on 24V DC power!


The following files are available for download:


PDF file (176k)


ZIP file with Eagle CAD .SCH and .BRD (48k)

ZIP file containing Gerber files to build PCB's (163k)

TIFF file of PCB layout (25k)

TIFF file of top copper (25k)

TIFF file of bottom copper (25k)


Bill of materials:


PDF file (4k) or Excel spreadsheet (18k)