A friend recently lent me his Bent Audio TAP-X, which I really liked. He shipped it to my office, so I figured why not replace my little tube pre in my office system before bringing it home. Well it was pretty amazing in my little work system (Lindemann 24/192 USB DAC, tube pre, Mackie MR5 monitors), enough so that since I had a few spare bux, I ordered a set of the 28 tap autoformers from
Dave Slagle and a 24 position switch from China and both arrived this past week.
Sitting in the shop Friday night I was trying to figure out what I would use for a case, I didn't need anything fancy since it was just for work and I really didn't want to spend any more. I had planned on using a small DAC chassis a friend gave me but it was not quite tall enough.
Then I spied an old Musical Fidelity X-10D, which was a tube buffer one put after a CD player. I was given this some years ago and recently came across it in a box, it was in the shop for testing as I was going to put it on eBay. Well, a light came on and a little measuring said that it was big enough and wouldn't look too bad.
So I finished wiring it up before lunch today, after some testing to verify it all worked as expected I installed it in my main system. It was as quiet as could be even though I have bal to SE adapters on the ends of the cables to the amps. With the ATSAH NC (Hypex NC1200 based) amps there is zero noise with my ear in the drivers, this with 105dB sensitive Beyma AMT's.
This is rather messy but eminently suitable for my office and perhaps the best thing that could be done with the old MF X-CAN.
I have named it Medusa because that is a lot of wire... I need to find a smaller knob but this one is very vintage. I used a chunk of PCB to mount the transformers, slides right into the can. A few minutes with the drill press for bore a 9mm hole in the front plate and three more for the screw mounting bolts took care of that. I did have to drill some new holes for the RCA jacks, the originals were too close together for standard jacks. The hardest part was the switch has a 5mm shaft and the knob is 1/4". Turns out that 1/4" copper tubing is about 4.8mm inside, so a little reaming with a #8 drill bit fixed it right up. I also slit the tubing to allow it to snug down a little better. Best ~$500 I've spent on a preamp without a doubt.
Of course the worse part is wiring but it wasn't hard, just tedious and much checking is required. I used enameled magnet wire. The RCA's are rhodium over copper, no brass.
mike
