Hi
I am the 'in famous boss'

John keeps refering to. The amp we took to Steve's house was a triode connected EL-34 SET. At that time, it was being driven by 717A - a mushroom shaped pentode. The amp has gone to quite a few changes in the power supply and now uses a 6E5P [an octal variant of 76] as the driver. The gain is ok because I also built a pentode linestage based on 6AK5, similar in style to Yamamoto CA-03L for my friend.
For John, I decided to go with 6CB5A, an idea I got from Thomas Mayer, who is an awesome builder. He has a blog that makes for awesome reading. The link is --
VinylSavor
The driver is a German post pentode C3m, again I got the idea to use this from Yamamoto San, who uses it in his 300B amp, which has awesome photo shots and reviews over at six moons website. The driver is pentode configured and uses IXYS 10M45S in conjunction with low noise renesas zeners to give a rock solid 100V at the screen of C3m. The key to pentode drivers is all in the screen regulation. C3m is an unsual beast, in that it has a 20V filament voltage. Since I am getting a customer made power transformer for John's amp, I can get away, 'cause I will spec all the necessary secondary voltages.
The power supply for his amp will be a choke input supply, and the input choke is a 15H/200mA Hashimoto choke built for choke input supply. I have used these chokes in my other preamps and amps, they are built like a tank, and have the necessary shielding etc. Only issue is they are not cheap

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6CB5A is an indirectly heated triode, so one can get away with AC.
The output transformers are Magnequest MQ FSO-30. These are heavy duty beasts, and I built a 300B amp for my boss using these transformers, and they sound good!!
The coupling cap is Duelund Alexzendar PIO's. I am currently using them in my office amp which is a 45 SET, nice smooth sound.
This is an integrated amp, 'cause with a pentode driver, you can getaway with a 2 stage amp without the need for a linestage if your inputs are CD players, or phono preamps. The volume control and selector comes from gold point a bay area based setup. I use Gold point on all my builds.
One thing is for sure, this is going to be a heavy beast
My own setup is all DHT, my preamp is a parafeed EML 30 linestage, and my amps are low powered 845 monoblocks [8W]. The driver is a 46 DHT connected usign Slagle's IT. The o/p transformers are MQ 5K transformers. The input stepup is a Hashimoto 10K. The philosophy behind is following Sakuma San's approach of a all DHT [Directly Heated Triode] system.
The link to Sakuma San is
Direct Heating makes it for an interesting reading, and there is a youtube video interview in japanese, and int hat interview he plays some of his amps, damn! they sound good even on you tube..
My preamp/amp pictures with the circuits are published at jacmusic website, if you click into customer projects and look for 'sridhar.ganti'.
The only caveat, I can deliver this to John early next year, as I have couple of friend's orders in queue, and I myself want to build a 801A driving a 45 monoblock using Hashimoto 5K output transformer I have on hand, plus it is a full time job managing John
sridhar