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maybe I should buy one of Birgir's amplifiers so I can reuse the packaging as a bomb shelter

The Tsar has already spoken but since I just built a 400V KGSSHV using a similar PS (kgsshvpsminifinalstn9360) I can also share my experience. You can also referred to my earlier post #4321 which has the exact value of resistors I used based on availability at Mouser at the time. The formula to calculate the B+ is ((R29 + R5)/R6 + 1) x 10V (V out of the LT1021 voltage reference) and similar for the B- side of course. I also read that you should configure the pre-regulate Zener string to 50V above your desired voltage, in this case, 450V. In my case, I have been getting a very steady +408V/-406V output from my PSU. Hope this helps.

you want a transformer that has 360vac windings you change the 440k resistors to 390k

Apropos RSD 25 Best record Stores in Films (gallery - click to advance) http://www.telegraph.co.uk/culture/culturepicturegalleries/11528368/25-best-record-stores-in-films.html Some forgotten gems?

How do you hook the ladies? "Like this."

Pretty good thanks for asking. Still enjoy reading your posts Peter....;-) In very short I went from audio maniac to a more balanced state. Amicalement

I could suspend the very existence of disbelief and I would still expect the blind guy to run off the side of the building 4 seconds into that scene.

I've been playing with the servo in my KGST build. I had a couple of problems. First, at very high volumes, the servo would fail. I fixed that by moving away from the LT-1021-10 which requires about 1.3mA to run properly. I moved over to the LM4040-10 which wants about 150uA. I set it just a bit higher at 170uA. Problem solved Second, I have a small oscillation of about 100mV around 6.7MHz. This one has been a bit trickier for me. I figured I'd post the schematic here. This schematic has the updated cascaded current source, which is currently not on my board. The model runs fine. The schematic uses different values for the sand, but they are closely matched to the actual parts used. Here's where I'm at: The way it works is that I built a rough op amp (similar to the T2 batteries) which functions as an error amp to hold the input to Q1 at 10V (voltage divider via R9, R10, R13, R14 against R11) same as the input at Q2. It uses Q3/Q4 (I've used a single Darlington transistor) to create the proper current (about 20mA) to hold the output at 0V. This is similar in principle to the T2 servo, but need to push/pull in the opposite direction (why I used the error op amp approach). It works great (barring the oscillation) and holds the output within a volt or so from cold to fully warmed up. It is a simple average of the +/- legs. Since the oscillation is common mode, outside the audible range and relatively small, I can't hear it. Any thoughts would be appreciated.

Buy the one that will give you the FOV you prefer. Sharpness is a bourgeois concept.