Audiophile USB to PCM

Can anyone list all or most of the current devices out there that convert USB to S/PDIF for connecting a computer to a DAC?

I am aware of the products by:

Red Wine Audio
Empirical Audio
U24 Waveterminal
M-Audio Transit (modded and unmodded)
Airport Express (modded and unmodded)

Others?

Others:

HagUSB, LessLoss, m-audio audiophile USB

Waveterminal is not current, not manuf. anymore.

Steve N.

I currently use FLAC+Foobar with M-Audio 192 Audiophile (PCI card and ASIO) feeding my Marantz AV Receiver thru SPDIF, but I want to go a step further and feed an external DAC thru the USB port and finally into my Aragon 18K pre-amp , Aragon 4004 MkII Dual-Mono power-amp and Mirage m-5si speakers.
So we have two problems, USB->SPDIF and choice of DAC.
I'll takle the USB->SPDIF now as DACs are a whole other matter, we (end users) have not many (credible!) options availabe and the price factor compplicates things.
LessLoss and HagUSB both cost about the same, but dont know much about LessLoss's product then we have a 30USD option from http://www.diykits.com.hk/dac.html (is it an option?!?) and finally the Emprirical Audio's products, of which I do not question the quality just the price, not that they are over-priced, just to me unfortunalty especially since I still have to buy a DAC (any comments on CIAudio's VDA2 http://www.ciaudio.com/vda2.html)
This leaves a huge price gap with only one contender the USB Freeway2, is it so clearly inferior to the other models?! what can I expect from it?

Go on Ebay and do a search for "USB to SPDIF Converter". There is one on there now for $35. Then go find an EAD DSP-7000 MKII DAC on the cheap and I think you will experience a life changing event for around $300.

The Sonos ZP80 has Optical and coax digital output for superior audio quality. I use it with Mark Levinson DAC, N32 Pre Amp and Wilson speakers. Not as good as vinyl but easy to play and quite good.