As I am building a Zen 9 amplifier I thought I would devote a few posts here.
For details of the design go here: http://www.passdiy.com/
As with all these class A amps heatsinks are first and foremost so I started off by coming up with a chassis based on some Conrad Heatsinks I had at home.
These particular extrusions are rated a 0.25 degrees C per watt and will reach an operating temperature of about 50 degress C at an ambient room temperature of 25 degrees C. They are flanged and have an inset at the ends which neatly allows a plate of 3 mm aluminium to form the front panel. The overall heatsinks dimensions are 300 x 150 x 45 mm and form the sides of the chassis as can been seen from the image below.
The overall chassis external dimensions are 480mm x 300 mm x 150 mm.
The two smaller vertical finned heatsinks at the rear are used exclusively for the Power JFets
Using short sections of L angle and some 12 mm x 12 mm square rod I made some backets and used M4 bolts to secure everthing together.
I then milled out the holes for the mains IEC socket, mains power switch and RCA inputs and Speakon output sockets and the Blue Led for the front panel.
The Zen 9 amplifier design has it origin in the single stage Zen but uses a unique LU1014D Loveltech Power J Fet as the key gain device. (see article for details).
Four installments in the article discuss in depth the circuit theory and performance benefits. The amplifier has particular potential for high efficiency driver and horn devotee's give the amplifier has very low noise and distortion in class A operation.
When I complete the main pcb's I will post another image
Ian
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Originally Posted by Ian Mackenzie
. Leak TL12 has another verison of BBC,bigger and heavier,totally different transformer,as good as american made transformer.