OK, I've dropped the price down almost in half from my original price, now just a bit under parts cost. This has two variable outs, folks, so you can run one set to your headphone amp of choice and one to your regular amp(or biamp, as I did).
I have built a few vacuum tube components over the years and I consider this
to be one of the two best I have done(the other will be up for sale about 10 minutes after this
). It is a circuit I got from Tube Asylum stalwart Eli Duttman for a 12B4a linestage. As you can see from the photos it is ultra simple on the outside and built like a tank on the inside. The circuit incorporates 3 separate power transformers(1 power and two filament transformers) and 3 different chokes. I used the best components I could afford; Elma switch(a swiss made work of art), Alps volume, mahogany faceplate with solid aluminum control knobs, ceramic sockets, Schottky diodes, Solen and Sprague atom caps in the power supply, handmade teflon and copper terminal strips, mills resistors, and Bottlehead constant current source for each tube. The linestage has six! inputs and two outputs which I used for bi-amplifying. The output caps are a paralleled group of Sprague orange drop, Auricap, Sprague paper in oil and Solen poly to make up the required 3.3uf. I had ordered a pair of nice Russian mil spec pio caps but when I received them they were the size of a toilet paper roll and wouldn't fit! I built the linestage on a sub-chassis which fits into the aluminum enclosure and took extra care to shield the input jacks and cabling from any stray fields. In short I built this to the absolute best of my ability. So, you ask yourself, why do I want to sell it? I have read much over the last few years trying to find a tube based linestage that would be the ultimate and everything I read pointed toward the 12B4a as the tube to beat. Unfortunately in any batch of 10 12b4a's you will be lucky to find two that are well matched. I have 7 of them and currently do not have two that match(I will include these if you want, but I don't know why you would). I have used the preamp for the last 2 months with one set that were close enough that I could make up for the difference with level controls, but one of the tubes went noisy. Anyway, if you have a bucket of 12B4a's and a tube tester this is the deal for you. I am looking for $475 shipped and paypal'd in the Conus, but I am open to reasonable offers. A few pics...
withdrawn
