Good to see you're still building on your system, that's quite a list of equipment you have.
I sold my entire system except for the office system which consists of a couple MC60's, AR preamp, Lexicon CD, DIY Proac 5s.
My main system is Scratch built 300b monoblocks, DIY LDR preamp,modified Sono's w/synchromesh-Enlightened Audio Dac, Vinyl 1 phono, DIY turntable with graham phantom arm and dynavector XV1s. The DIY preamp switches between my 2 channel and Yamaha BDA1020 surround. The amp/preamp I built has a lot more synergy with my Khorns compared to the MX119/MC352 system I had. I spent good $$ on the best output transformers money could buy.
I decided to take on the challenge of designing and building a high voltage tube amplifier last year. To answer your question, I built two mirror image monoblocks(you can see it in the first image). The 300b amps I built 3 yrs ago were designed using tube cadd and a simple calculator. The new amps were designed using Spice simulations which saved me a lot of fine tuning. After assembling and testing I had to change the input caps to lower the voltage! I overlooked the fluctuating line voltage. An 8 volt spike in JEA line voltage put my secondary at 1280volts. I started out with 845's and 211 tubes but decided on the Russian gm-70's after shopping for NOS tubes. The Chinese versions were just not up to my standards and the gm70 was easier to drive than a 845. After 3 months of designing a circuit I spent another 3 months with parts selection and layout using autocadd. Landfall systems did a great job on cnc and made assembly much less painful. During the assembly I started some YouTube videos on microprocessor programming language. At first, it was like learning the Chinese language but started to take root after getting help from some forum members. I built a voltage divider network with opto isolation to monitor voltage and current on the gm70. This microprocessor will open the relays in milli seconds protecting my output transformer should a catastrophic failure occur. The processor also takes on the duties of soft starting the amp since the supply has about 9000joules of energy at 1200volts! I might try a couple other circuit changes that could improve on the sound. I'm not really fond of the IT coupling but it's the easiest way to handle grid current. Will try a current source and/or a plate choke-cap-grid choke.
These will be my winter amps since they put out some serious heat but will end up in a cabin in NC over the next few years as I'm looking to retire in 5 yrs.
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