I love my PS Audio Direct Stream with Red Cloud :)

Metrum is r2r, but there's FPGA processing:
http://www.the-ear.net/review-hardware/metrum-acoustics-adagio-dacpreamplifier

"New to the Adagio are Transient DAC Two modules, a further development of the Transient and FPGA architecture used in the Pavane DAC. Inside each module are two 16-bit R2R ladder converters and one FPGA. When a 16 to 24 bit signal enters the module it is split into two sections by the FPGA. The upper bits are passed directly to one of the R2R converters, while the lower bits are raised to the highest level before they reach the second R2R converter. This increase in level is done so as to use the highest voltage on the ladder resistors, moving away from the relativel noisy, low level signal part that exists in all types of converter. Before the output stage the signal level of the second converter needs to be adjusted to the correct level and combined with the original upper part to create the correct output signal. Metrum manipulates the least significant bits (LSB) because lower level irregularities occur, non-linearity arises and digital noise becomes part of the analogue signal with lower level signals. These modules reduce noise by -145dB or more. This might sound simple but it took years to write the algorithms for the FPGA and to develop the Transient DAC Two R2R converters."

Not to stray too off topic though, PS Audio dacs are great, was just wondering what other dacs use fpga processing.

I honestly felt the ps audio ds dac was soft in the bass, it also lacked some detail. When I pulled off the cover I found a pair of  m6 lamination edcor transformers doing, the current to voltage conversion, I would think. The difficulty with using a m6 lamination in a low level signal application is the core is has higher  hysteresis loss than nickel and is far less sensitive to small signals. Just because a dac has a FPGA doesn't make it a great dac. The analog section plays a key roll in sound reproduction. The Schiit Yaggasil was far superior in my system IE bass, information, sound stage width. Then I went to a gustard x20 pro which is an amazing dac. Tight bass, massive sound stage, all sorts of subtle detail. The output stage is filled with the evil op amps etc. 
Now I am running an audio gd 2 and the gustard x20 pro. The audio gd has a warmer sound but they are very close sonically over all.

FYI I have 4 systems in my house and I found basically the same result in 3 of the systems. My fourth system is av.

As someone who is in the clothing business,  my technical knowledge of some of the things mentioned above is pretty limited.  that said,   i have been into and enjoying good home high end audio since the mid seventies. I have a system that is 100% PS Audio and think they are a fantastic company with fantastic products.  Is there better out there?  Probably but i do not stray as i am happily married.  When a company has designers like Paul McGowan,   Ted Smith,  BHK,  etc.  then that is pretty impressive.  Add great customer service and built and serviced in the US,  plus the free upgrades like Red Cloud (which i thought was a nice improvement over Huron) and they are #1 in my book.   And they have great sounding products which is why we are all here.