When I first bought my Supratek Grange, I was a little concerned about what might happen if my preamp needed a little work, but Mick's website said he would forward schematic to tech, so that served to allay my fears...Wonderful preamp, and the most georgeous piece of equipment I have ever owned....
Well, the time came when I experienced a problem with the system, and I THOUGHT I had it narrowed down to the preamp, so I contacted Mick with questions, one of them being would he recommend anyone in California to take a look at my preamp. He said to contact Kevin Covi in the eastern U.S. I called him on the phone, and he spent an HOUR with me talking over my perceived problem, Supratek design philosophy, etc. Wow! Having been in audio for 25 years, this was quite a suprise that he spent so much time with me, and assured me he would troubleshoot my preamp, and make it right. He also volunteered to set up my preamp to use PX4, 45, AND 300B tubes. Well, long story short, he checked out my preamp, and it was fine. He changed the switches for the tubes, readjusted bias, gave it the once over...Perfecto....AND he turned it around within days, and charged me about 1/2 to 1/3 what any tech would charge (in my opinion). SO! Hope you don't have a problem with your Supratek, but if you do (or think you do) know that there are people like Mick and Kevin Covi who are dedicated to their product and high quality service...A+++