Tube Amplifier

2A3 SET SRPP Loftin-White (Fi Primer 2A3)

image This handsome amplifier uses the 2A3 Tubes for its output.  Based on the Loftin White Amplifier, Brendon does not give much detail about the final design that he settled on.  However the specs are here and the pictures tell a story themselves.

The biggest lesson to be learned from this project is just how important a wiring scheme and also wiring types make the overall success of a Valve (or for that matter any audio project.

This article was origionally published on Brendon’s Geocities hosted site.  In the interests of preserving the article Brendon has kindly given permission to re-home it at Justblairs Audio and Electronics Pages.  Thanks again Brendon.

Read more: 2A3 SET SRPP Loftin-White (Fi Primer 2A3)


image In this article Brendon Lee Leads us through his build of a classic amplifier design, the Williamson 807.  Using anodised blue metalwork for the amplifier, Brendon certainly demonstrates an eye for detail.  Read on for all the juicy details on what is a visually stunning project.

This article is re-published with kind permission of Brendon Lee.  Originally hosted on Brendon’s Geocities site prior to the closure of Geocities hosting.

Read more: THE WILLIAMSON 807

211 SET Interstage Designed Monobloc Power Amp


This project was completed by Brendon in January 2004.  Brendon built a pair of monolock valve amplifiers using 211B+ Valves in its output stage.  This provides 20 watts of power to the speakers.

This project page gives photographs and descriptions to the main features of the amplifier build.  It was origionally published on Brendan’s web site hosted on Geocities.  Brendon has generously allowed the article to be re-published here in order to preserve it beyond the closure of Geocities free hostings.

Read more: 211 SET Interstage Designed Monobloc Power Amp

Dave Ewing’s 12AX7 Tube Guitar Amplifier

IMG_0129sIn this article Dave Ewing takes us through the build of his 50watt tube amplifier.  The amplifier itself is one designed for use as a Guitar amplifier, not the kind of audio projects normally featured on Justblairs Audio and Electronics Pages, however for anyone interested in building a Tube Amplifier the build process is essentially similar regardless whether it is to be used for playback or guitar amplification.

This article originally appeared on Dave’s own Geocities site, as you may be aware Yahoo has pulled the plug on Geocities hostings and many sites will be lost in the process.  Dave agreed to publish his articles here on order to preserve them for the DIY Audio community.  This article reads as a blog.

Read more: Dave Ewing’s 12AX7 Tube Guitar Amplifier

Dave Ewing's 300B Integrated stereo Amp


DCP_0333 I love the look and sound of valve amplifiers, I think it is only a matter of time before I build one for myself.  This example from Dave Ewing is no exception.  Using K&R 300BXLS tubes and matching transformers for the output stage, this amplifier not only sounds good, but is wonderfully crafted as well.

Dave Ewing completed this beautiful integrated stereo amplifier a few years ago.  This article was hosted previously on his Geocities site, however with the closure of Geocities Dave agreed to move it here to ensure that the project build article lived on.

Read more: Dave Ewing's 300B Integrated stereo Amp