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In case you are interested, the entire build is here: https://www.diyaudio.com/community/threads/the-midlife-crisis-my-833c-amp-build.232484/ Attached is a photo of the amps in action, driving my Infinity RSIIbs effortlessly.

I use series connected SiC Schottkys in my Midlife Crisis amps, 20 in a full wave bridge. Has worked flawlessly for more than 10 years now feeding a 2300V choke input LCLC supply. No balancing resistors, either, just small value caps across each diode. Attached is a photo of the rectifier board...

The front baffle design of the Omegas "baffles" me. Why not make it smooth instead of having the steps on the edges. Seems like that would cause a lot of diffraction effects...

I've found the standard Mundorf Supreme caps (not the silver or silver/gold) to be outstanding crossover caps for the money, and use them in my RSIIb's. No need to spend any more, IMO. There are a bit larger as they are actually two higher value caps in series in one wrapper.

I think what you call mylar is actually kapton.

PS: Here's what the external X-overs look like, for the woofers, low EMIMs and high EMIM. The tweeter circuits are on the opposite side of that central divider panel. Those 8 gauge inductors on the bottom are about 15lbs each... ;-)

You could always do what I did with my RSIIb's and pull the crossovers out of the speakers into separate boxes. Once I did that I could use massive components like 8 gauge air core inductors and foil/oil caps with no problem. Made it much easier to keep tweaking as well!

You mean like my monoblock room heaters? Very toasty, and the fans blow that nice warm air up the chimneys and out into my room. 24 degrees F this morning, perfect 833 weather!

Thanks to all for the Birthday wishes!

Good luck, and have fun!

Just saw this thread. I'm Magz over at DIYAudio. The S-833 OPTs I used for my 833 SETs sound great and have taken a 2.3kV B+ beating for 10 years now with no ill effects. You get what you pay for, I guess...and I did pay! ;-)

I like SiC Schottky diodes for cathode bias. About 0.86V per diode, small and easy to stack.

As much as I like my 2230 receiver, a good tube preamp is on another level entirely. You will hear things you didn't even know were in the recording. I strongly suggest browsing the 26 preamp thread for ideas. Of all the tube preamps I've heard, a good DHT sounds the best, with the 01A being #1...

I went all out on my preamp but a much simpler preamp would sound great, too. Here's mine which runs 26 or 01A Tubes, with VR tube regulation and tube rectification. I even built a DAC into it later:

You could build one. They are much easier to build than amps and you could use a cool old DHT tube like a 26 or 01A and have something better than commercial! Tons of info in this thread: https://www.diyaudio.com/community/threads/26-pre-amp.151421/

I used 4 Herbie's Giant fat gliders glued to the underside of each 2B to lift them off the floor. Makes them easy to move around but also tightens up the bass nicely. Not as OEM-looking as yours, though! https://herbiesaudiolab.com/products/giant-fat-glider

The balloon DHTs do require certain extra care to sound their best, such as insulation from vibration. Here's my solution - a high mass damped, double-layer, soft rubber mounted aluminum plate inside the preamp/DAC. The LCLC power supplies are in a second chassis. Volume controls are...

For me, neither octal nor miniature do the trick. After playing with them all, the old balloon 4-pin DHTs are IMO the best sounding small signal tubes of all. With a proper current-regulated filament supply (Rod Coleman reg, for example) and stout LCLC VR tube regulated plate supply, they have...

Test tone has never failed me in dozens of refoams of all size drivers. Cutting off the dust cap just seems so invasive...

Here's a picture Monolith Magnetics sent me of one of my OPTs under construction, before potting. That's an ECC83 tube next to it for reference.

Plate voltage is 2.3kV, running at 160mA. Output transformers are Monolith Magnetics S-833, with amorphous double-C cores and Teflon interwinding insulation. Each OPT weighs about 62lbs. All the measurements are in the thread linked above, as well as schematics and LTSpice and PSUD2 simulations.

The Midlife Crisis amps took me almost a year to complete, and are still going strong. They drive my big Infinity RSIIb speakers effortlessly. PS: I bought a red sports car anyway, a 2019 Challenger Hellcat, 717HP, 6-speed manual. Drove it for 3 years and sold it...the amps are a longer...

I removed all the fuses from my RSIIbs. Never had a problem since.

Thanks, everyone!