Audio Research Ref-1 vs sp10 mkII preamp

The sp10 mk2 is so good you cannot belive the magic of the project given to the audio community by the late Mr Johnson.
Needless to say, heavy mods are required: ps changed from electrolytics to full polyprops, this mod requires lifting of the entire ps chassis.
All capacitors in the conrol unit changed with Vcaps teflon reference, or V oil, pf values to audionote, volume pot changed tkd stepped top model, all resistors changed with vichay nudes/caddoks tfts/mills/kiwames..power cord changed to Vandenhul, plug from Chris Venhaus, rca females wbt, internal wiring vandenhul mcs 1000 doubled.
Photocouplers entirely bypassed, meaning you must switch the preamp on before the power amps and wait circa 4 minutes.Transistor amps not recommended......
hear to belive...ooops forgot..all tube sockets changed, fitted with siemens and telefunken NOS.
All soldering wonder solder signature.
Only active parts in the preamp are on off switch and volume control.
Cheers, its pure heaven....cartridge output must be no less then 1.6, no covers, two paps vents.

EAT cool dampers are a must, especially on v1 v2 v9 v10
I was very lucky in the late 80s, bought a truck load of telefunkens and Siemens in holland for cheap; at the time everyone was wasting time going digital.
I enjoy zero noise, 0 microphonics today.
I do admit its a set up extremely hard to manage and achieve for the everyday audiophile. Every single solder joint has been taken care of, and in critical areas hard wiring is a must.
It took me over 20 years to get it right.
You also need a dedicated power supply in the house, feeding itself directly from the entry mains (Vandenhul cable carrying the current).
Similar story goes for my power amps (d115mk2 one per channel vertical biamp). All caps changed, internal wiring, additional outboard power caps, wbt connectors, gain attenuators bypassed (the ones in the back)all GE power tubes and driver.