Hi Guys - I have two of the ZP-80 units from Cullen. I went through Underwood HiFi (Wally) and they are great! One unit was set to a 48k output (my Spectral DAC will only take a 48k) and another unit set to a 96k outputfor my Peachtree Decco. The Decco is a great piece gear itself.
These are the mods:
The upgrade consists of installing a new custom Cullen Circuits designed pc board that contains:
1) A high end sample rate converter made by TI
2) A low jitter clock with less than .5ps jitter
3) A low noise power supply for the clock
4) A new micro processor
5) Input & output digital buffers.
6) New upgraded RCA output jacks are added.
I have not tried the analog outputs but direct head to head w/an unmodified ZP-80 gives you a much bigger less compressed sounding soundstage. Bass is much better and fuller and there is more "air" around all the instruments/vocals. It's well worth the cash.
These are the mods:
The upgrade consists of installing a new custom Cullen Circuits designed pc board that contains:
1) A high end sample rate converter made by TI
2) A low jitter clock with less than .5ps jitter
3) A low noise power supply for the clock
4) A new micro processor
5) Input & output digital buffers.
6) New upgraded RCA output jacks are added.
I have not tried the analog outputs but direct head to head w/an unmodified ZP-80 gives you a much bigger less compressed sounding soundstage. Bass is much better and fuller and there is more "air" around all the instruments/vocals. It's well worth the cash.