The DAC on the Mark IV is a Burr Brown PCM2705 (USB and DAC). I'm not sure of the opamp.
The Hippo HIfi Bloat for comparison uses the PCM2707 chip for USB combined with the PCM1794 DAC, but for $229.
I'm not sure how much of a difference this will make in sound quality out of the USB port which is 16bit. Both seem to use USB 1.1 from what I can tell.
I'm new to DAC technology. So I'm learning as I go. Dave at HotAudio has been great in answering my questions.
Other Mark IV Specs :
THD+N when driving a 16-W load is 0.03% at 1 kHz
THD+N when driving a 32-W load is 0.02% at 1 kHz
THD+N when driving a 10-kW loads is 0.005% at 1 kHz
Thermal and Short-Circuit Protection
Sampling Rate: 32, 44.1, 48 kHz
Has 3.5mm Stereo Headphone Output Jack on front
Left and Right Gold plated RCA line level outputs to drive power amplifiers, receivers.
Dimensions: 65mm by 65mm by 30mm ( 2.5 inches by 2.5 inches by 1 inch )
Weight: Approximately 100 grams
Extremely Low Jitter