Builder

Voigt Pipes
9 November 2012 at 10:56PM
The foot print without the board on the bottom, that added stability, turned out to be about 12" by 12". With the Radio Shack drivers I made adapters, but the wholes were for 8" Lowthers and Fostex drivers. I built these back in the late 1990's, before any software for Voigt pipes existed. Back then we worked by rules of thumb, 1/4 wave length was the pipe length, stuffing was trial and error, vent area was determined by how much you wanted to load the driver. Anything less than the area of the driver was not considered to load the driver, so the lower the Qts the smaller the vent/port could be.

Voigt Pipes
9 November 2012 at 10:51PM
All the dimensions are interior measurements. 73.75" is the entire length of the pipe, while 37.5" is the center from the bottom to the speaker.

A2 preamp.
9 November 2012 at 10:34PM
I keep forgetting stuff. The preamp has some output transformers per my own design like a power amplifier for speakers. This way I didn't have to use a large capacitor, and avoid capacitor coupling. Likewise it makes for a very very simple circuit, since I am biasing the tubes with LED's there are not resistors in the circuit. The input volume control is an opto-coupler volume control that also doubles as the grid leak for the control grid.

A2 preamp.
9 November 2012 at 10:31PM
Later I might post some information on the matching power amp. I came up with the idea after the preamp to use aluminum plates to mount the tubes on so that I could use the same chassis later for a different amp, with different tubes. This expands the use of the same style chassis.