The ZKITs use the same proprietary output and power transformers that are used in all Decware products.  You can gather a wealth of information about them by looking over the design notes for various amplifiers and looking over the articles on the web site.  There is at least one dedicated specifically to our output transformers.

I would be happy to answer any specific questions here.

Steve

For 120 Volt operation of the world voltage transformer you connect the black wire and white wire together - That's your LINE.  Then connect the black wire with white stripe to the brown wire - That's you NEUTRAL.

The brown wire with the white stripe and the pink wire will be unused and should be capped off.

We decided recently to upgrade the ZSP1 preamp kit with the world voltage transformer and I forgot to update the schematic, sorry.

Steve

Okay, I broke out my electronics book and now understand the grounding scheme.  

However, I'm still unsure about R7 and R8 on my ZSP1 kit...I read 7.12 volts ac when I apply power to the transformer.  I calculated R7 value to be 48 ohms, based on the transformer amperage being listed as 150 mA.  Does this sound correct?  I can't measure the current since I don't have a current clamp.  Am I making a big to-do about nothing, not knowing if 7 heater volts will lessen tube life versus 6 volts?  What is one volt difference among friends?  Is 150 ma the current value for the Transformer?

Okay, my ZSP1 kit has been operating for a few weeks and guess what??

It sounds better and better as time goes by!!  I'll admit it sounded somewhat harsh or sharp, especially male voices, but now, it sounds very liquid and smooth, great bass.  I guess it wasn't broken in?  Not sure what happens during break in period, but whatever happened made it sound better!

Dan