The Spud Kit

The Spud Kit is a complete two channel valve amplifier in kit form. Using a singled-ended pentode (6CL6 / 6197), the amp is capable of about 2 to 3 watts per channel into an 8 ohm load. The amplifier features a volume control and can be driven directly from a standard (2 volts or greater) line level output from your source.

Included with the kit are all parts necessary to build the amplifier, a schematic and a complete tutorial on CD ROM to assist new kit builders with this very simple project. The tutorial is geared towards the first time or inexperienced kit builder, but the project is fun for builders at all levels of experience. In addition to step-by-step instructions, the tutorial CD includes over 100 high resolution pictures of an actual Spud Kit being built.

Once built, this amplifier will be happiest when mated with a pair of high efficiency speakers such as the Hawthorne Audio Silver Iris line of products.  Many kit builders actually felt that the project was worth the price paid simply for the experience they gained and the pride they felt when they powered it up for the first time.  However, the surprisingly detailed and accurate sound offered by the Spud Kit is the real source of continuing satisfaction.  The Spud Kit excels at delivering the human voice in a clear and articulate manner.  Additionally, many listeners have commented on the expansive sound stage and impressive separation of instruments.

The Spud Kit debuted on the Hawthorne Audio forum and continues to enjoy support and regular discussion.  To read candid feedback on the sound of this kit, please visit


  • The Spud Kit is amazingly quiet with virtually no audible hum.  This is due, in part, to the rectified and filtered filament supply.
  • The 1st production Spud Kit was sent out on the road back in April, 2007.  The idea was to give Hawthorne Audio forum members the opportunity to audition the amp in their own homes and with their own associated equipment.  The feedback from this audition tour was (and continues to be) overwhelmingly positive.  See the forum for details.
  • The goal of the Spud Kit project was to provide an affordable tube amplifier kit that could be easily constructed by a first time builder and provide pretty good sound quality.  The kit has surpassed the original design goal and actually provides excellent sound quality.
  • In late 2010 a stock Spud was sent on the road again.  The 2010 Spud Tour finished up in January of 2011 and created enough buzz to warrant a 2011 Spud Tour.  This time, rather than sending the stock Spud on the road, a fully tweaked Spud will make the rounds.  Prepare to be impressed!

The Spud Kit is now available for most destinations worldwide.  Shipping options for domestic and international orders are available (please note that the shipping charge for international orders includes a world voltage compatible power transformer).  Although most kits are packaged and sent within days of your order being placed, please allow approximately two to four weeks for your kit to ship.  Check out the forum and the shopping cart for additional details on this kit.