With tube rectification, you create a power supply filter with two or more capacitors separated by either a heavy duty resistor or a choke.  The value of the capacitors are between 10 and 50uf typically.  We presently use 47uf caps, which are the small ones in front of the large ones shown in the above picture.  The giant high voltage caps shown behind them are around 55 times larger and cost a small fortune.

Since the purpose of the power supply caps is to reduce the AC ripple effect and noise from the rectifier, having a simply giant capacitor fed by two super fast recovery 3 AMP diodes gives such superior filtering that you don't need, the resistor or choke, nor do you even need the second capacitor!  That means the output transformers are now directly connected to the raw current of the power transformer.  No more resistors to soften the dynamics, or chokes to eliminate hum are needed.
The noise and hash in the power grid that the VR tubes are filtering out, can not escape the black hole effect of such large caps.  Thus the power is ultra clean.

There really isn't anything more zen if you consider the simplicity of it.

The complexity was in evaluating and choosing the right caps.  Just because it's big don't mean it's all that good.  I wanted the best, so many long nights of reading through product datasheets, I found these and compared them to identical size German made Siemens and US made Mallary caps by installing them into the amplifier and listening to it.  I found these to be the best.  They are sure to last a long time because they are configured for 1000 volts and only see 510 volts.

Thanks Lon, that's the theory I was going by as well. In the past, I've not seen Steve overly excited about the stepped attenuators only saying they might be slightly better. I was curious if the difference might be bigger with *this* amp.

$150 would get me some Iso-Cups or tube dampers or what-not.