Why & How to Make the 845 Power Tube of Choice?

I currently have an 845 based custom system. My CD player has enough output to allow you to skip an expensive active pre-amp. If you have vinyl, I would go with a dedicated phono pre.

After spending a fortune to see if we could buy and modify a solid state based system that could equal tubes; We found several Nelson Pass designs that might satisfy someone like my friend who likes the convenience of solid state.

I am now a die hard tubee.

My current glass: 6SU7 X 2, 6SN7 X 2, 845 X 2.

But you need to go NOS except for the Chinese 845 metal plates. I prefer United Electronics, but a pair just traded on E-bay for $2,100.

Why 845s? They simple have the best combination of power, detail, and transparency.

I have my 845s putting out about 20 watts per channel, which more than adequately drive my 86db 4-ways using only first order cross-overs, but the wire and caps that I use are in the: If you have to ask; how much? you probably can't afford them category.

Simply put: He who dies with the most Euro Oil caps wins!

(Reference Audio Mods supplied mine).

The incredible wire: Features a flat 4-nines silver ribbon with two different natural silk dielectrics. The first embedded with oil injected at very high PSI levels. The second natural silk dielectric is embedded with a chemical designed to repel moisture.

My kinky interconnects use the same wire for the positive, but use a 6-nines stranded copper to the ground.

YOU MUST BUT EACH WIRE IN A SEPARATE SLEEVE. They should only meet at the RCA plugs. I admit it sounds weird, but just start moving the sleeves together and you will see how much signal you lose.

As for RCA jacks and plugs: The ones that look like crap and cost a fortune work best.

WARNING: I once had a custom CD player that was powered by about 300 pounds of boat batteries. The divorce was incredibly expensive, so I decided to have it catered. I had a catered wedding and this was a much happier occasion.

I agree with you about the awesome wonders of an 845-based SET, but not much else. To me the most important thing about an 845 design is the transformers. My custom-designed 845 monoblocks have trannies the size of a loaf of bread (well, almost) and can drive moderately sensitive speakers to very satisfying volumes in a huge room, with amazing delicacy, detail, and dynamics

But driving a CD player direct (no active preamp)? Certainly not mine (Raysonic 128), which sounds wimpy and blah without the preamp. As to internal wiring, mine is nothing special, probably straight from Radio Shack. But the amps are just outstanding and with the right tubes -- currently Mullard ECC31 inputs, new Genalex KT-77 drivers, and Shuguang Psvane (Pavane) 845s -- they sing like angels.

I'm not denying your experience (and with the obligatory YMMV, IMHO, etc.) just saying there's more than one way to get to SET nirvana. But you do need those 845s :-)
With 1250 volts on the plate I applaud your effort in designing and making an 845 based amp. Those voltages scare the crap out of me when it comes to DIY.
With SET transformers are very important to over all quality. I owned 4 845 amplifiers. They do sound good but output too much light and heat for my tastes. Heck with my 845 on and no lights its possible to read by the light of the 845 alone.
Regarding the light output of 845s, I resorted to sticking things on top of the transformers as light shields so that the tubes didn't blind me :-)

The metal plate 845s are the primary culprits here, in my experience.
You know I didn't think about a disco ball! As an aside part of the sound of an 845 is the turns ratio of the trans: eight to one I think.