My recollection is that the X32 was Wadia's attempt to produce a lower priced DAC than their multi-box 2000 and Digimaster 64, both of which used 64x oversampling vs. the X32's (you guessed it) 32x oversampling, in order to compete with the lower priced offerings at the time from Krell and Theta. I'm sure it dates back to the early 90s/late 80s. I think Harley reviewed it in Stereophile back then too.
Wadia X-32
On the advice of a friend I purchased a Wadia X-32. It does seem to take the edge of the CD sound in my system and I am very happy with the purchase. The seller said the unit was purchased new in 95. However, the serial number is XXXXXXXX-90, and the manual has a date of 1990. It leads me to believe the unit dates back to the 90's. Does anyone have any history on these units and what would be a it's expected "life span" -- Wadia says 20 years? If this unit is from the early 90's, I am shocked at how well it sounds IMHO, in my system compared to other state-of-the-art DACs (midfi - Parasound 2000, NAD 24/96 and Denon/Sony). Thanks for your help and time.