M1s with the Ultimate upgrade. Yep, the preamp is a 3 box Aesthetix Calisto Signature with dual power supplies. I had a pic of it earlier in the thread. The Rankin piece is a Wavelength Crimson USB DAC re-tubed with old Cunningham globes and a Mullard rectifier. I've been running it in my headphone rig, but took it downstairs recently to try it in place of my older Audio Note. Yes indeed, the Sound Lab interface boxes are heavily reworked. I did it before Sound Lab offered interface upgrades beyond just the transformers and it actually helped provoke Sound Lab into offering cap and resistor upgrades of their own. I went a bit further than they did though. The caps in the interface were chosen after a shoot-out between the original Solens, Jensen copper PIOs, Teflons, various films and a pair of giant Swiss NOS paper and oil cans sourced from Audio Consulting in Switzerland. The Swiss NOS caps won. Imagine Jensen coppers with greater transparency and greater neutrality. The stock sand cast resistors were junked too in favor of wirewounds. The inductors are another story. The little half-fist sized factory upgrade items were replaced with custom wound models from Audio Consulting that weigh about 10 pounds a piece and are so large they have to be housed in small wooden boxes outside the interface box. They make Goertz and Madisounds sound broken in comparison....
Needless to say, this approach blows the factory upgrade parts away.
Nice Sanderman, Question or two what Sound labs do you own.....and are those preamps hiding under you gorgeous Rack... 1 more? what is the Gordan Rankin piece??? My good friend has the huge sound Labs that have been reworked by the factory in the back part(please excuse lack of my knowledge about this area) where the Transformers are and the power and speaker connectors go.....His system is one of the best I've heard, (that he himself owns)........I'm sure yours is right there.......OK one more ? Didn'tWolcott amplifiers make some huge V-8 shaped amp "Mono Blocks)???