FireWire

Most DAC’s with a FireWire interface are pro-gear.
Few brands address the consumer market.

The TC Audio DICE chip is often used for the Firewire connection.

A lot of Firewire DACs use adaptive mode just like their USB counterparts.

Other than Metric Halo all the Firewire protocols work the same way adaptive does. That means any company using TC Electronics Firewire (From the Oxford set).
Only Metric Halo has an Async Firewire setup, everyone else is not.
J. Gordon Rankin

Mytek claims their Firewire interface is async.

Apogee Duet US$495.00

Two channels of professional-quality 24-bit/96kHz audio input and output
Two balanced XLR inputs, with selectable 48V phantom power on each input
Two unbalanced high impedance instrument inputs
One high-level stereo headphone output
Two unbalanced -10 dBV line outputs for powered speakers
Multi-function controller knob for volume and input gain control and assignable MIDI control
Multi-segment LED meters to display input or output levels
FireWire 400, compatible with Mac OS X Core Audio
Control functions built directly into Apple’s Logic Pro, Soundtrack Pro and GarageBand
Compatible with any Core Audio-compliant audio application
Apogee’s Maestro software for advanced control and low latency mixing
Dimensions: 4" W x 6.3" L x 1.5" H

The Duet2 is USB only.

KRK Ergo US$450.00

Firewire DAC with roomcorrection.

RoomPerfect ( Lyngdorf Audio) corrects up to 500 Hz

OSX and Win7 32/64 drivers

ASIO driver

Processing	400MHz Analog Devices Blackfin® DSP
RoomPerfect Algorithm Sample Rate	96KHz
Room Correction Frequencies	20-500Hz
Room correction Filter	1024 tap Finite Impulse Response
S/PDIF Input Operating Range	44.1 kHz to 96 kHz
S/PDIF conformity	IEC60958-3
Dynamic Range	96 dB system (component 118dB)
System THD+N	<0.025% using 0 dBFS input and 22-22kHz Band Pass Filter
Internal Sample Rates	44.1 kHz, 48 kHz, 88.2 kHz, 96 kHz
Maximum Microphone Input Level	-32 dBu
Maximum Line input Level	+19 dBu
Maximum Line Output Level	+19 dBu
Firewire Implementation	Dual 1394a (Firewire400) ports
Dimensions:	180mm (7") x 55mm (2.2") x 107mm (4.2")
Microphone Length:	197mm (7.75")
Weight:	610g (21.5 oz)
Power:	1394 Bus or External 12v
Operating Temperature Range:	40° F (4° C) to 110° F (43° C)

Review in Sound on Sound

Metric Halo Mobile I/O ULN-2 $1,695.00

2 Mic/Line/Instrument analog inputs on Neutrik Combo connectors
Balanced TRS analog sends and returns for analog inputs
2 analog outputs on balanced TRS connectors
24bit/96k converters on all channels
Headphone amp with front panel volume knob
Balanced stereo master control room monitor output with front panel volume control
AES-S/PDIF Digital I/O with selectable SRC
Onboard 80-bit multibus mixer for near-zero latency mixing and routing
4-pin XLR power port for compatibility with most location battery systems
9 front panel preset system/routing memories for stand-alone operation
FireWire Connectivity
Compact, light, and bus-powerable

Mytek Stereo192-DSD-DAC USD $1,695.00

Asynchronous USB2 with driver (Rigisystems )up to 192 kHz
Asynchronous Firewire 400/800 (TC Electronics)
Conversion: 32bit, PCM up to 192k, 64xDSD, 128xDSD.
Dynamic Range: 128dB (ESS Sabre chipset in 8 mono to 2 stereo config.) THD DAC: -110dB.
Digital Audio Inputs: SPDIF, AES/EBU, Toslink all up to 192k single wire.
(64xDSD and 128XDSD SDIF DSD interface on Mastering Version).
Clock: Internal Clock Generator (10ps jitter), Wordclock In and Out, or sync to incoming digital audio input with low jitter JET (tm) PLL.
Internal Async Hardware Upsampling- 16bit 44.1k etc. can be optionally upsampled prior to conversion to 192k/24bit with clock jitter eliminated.
Transparent, 1dB stepped programmable analog attenuator, separate for main out and headphones.

Various models including one with headphone and pre-amp function.

A tread on a forum including Michal from Mytek.

PrismSound Orpheus $4,495.00

ASIO and WDM drivers provided for Windows XP and VISTA
Directly compatible with CORE AUDIO on Mac OS X 10.4+ (Intel & PPC)
Eight "Prism Sound" premium-quality AD and DA channels
Concurrent operation of ADAT and switchable S/PDIF or AES3 ports

RME Fireface 400 $1299.00

Input AD: 6 x 1/4" TRS (4 x Line, 2 x Line/Instrument), 2 x XLR/TRS Combo connector (2 x Mic/Line), all servo-balanced.

Output DA: 6 x 1/4" TRS, servo-balanced, DC-coupled signal path. 1 x 1/4" TRS unbalanced

Input Digital: 1 x ADAT optical or SPDIF optical, SPDIF coaxial (AES/EBU compatible)

Output Digital: 1 x ADAT optical or SPDIF optical, SPDIF coaxial (AES/EBU compatible)

MIDI: 2 x MIDI I/O via breakout cable (4 x 5-pin DIN jacks), for 32 channels low jitter hi-speed MIDI

2 x FireWire 400

Dynamic range AD: 110 dB RMS unweighted, 113 dBA

THD AD: < -100 dB (< 0.001 %)

THD+N AD: < -98 dB (< 0.0012 %)

Crosstalk AD: > 110 dB

Dynamic range DA: 110 dB RMS unweighted, 113 dBA (unmuted)

THD DA: -100 dB (0.001 %)

THD+N DA: -96 dB (0.0015 %)

Crosstalk DA: > 110 dB

Input/Output level for 0 dBFS @ Hi Gain: +19 dBu

Input/Output level for 0 dBFS @ +4 dBu: +13 dBu

Input/Output level for 0 dBFS @ -10 dBV: +2 dBV

Sample rate internally: 32, 44.1, 48, 64, 88.2 kHz, 96 kHz, 128, 176.4, 192 kHz

Sample rate externally: 28 kHz - 200 kHz

Frequency response AD/DA, -0.1 dB: 5 Hz - 20.4 kHz (sf 44.1 kHz)

Frequency response AD/DA, -0.5 dB: 1 Hz - 43.3 kHz (sf 96 kHz)

Frequency response AD/DA, -1 dB: 1 Hz

Weiss DAC2 D/A Converter $3000.00

The DAC2 supports the following conversions:

FireWire to analog
AES/EBU to analog
FireWire to AES/EBU
AES/EBU to FireWire

Inputs: Digital Audio inputs on FireWire (two connectors), XLR, RCA and Toslink.

Outputs:

Stereo analog output on XLR and RCA.
Digital Audio output on FireWire, XLR and RCA.

Sampling Rates, Wordlength: 44.1, 48, 88.2, 96, 176.4, 192 kHz at up to 24 Bits.

Software: Drivers for Windows™ and OSX™ operating systems.

Weiss Minerva $5000.00

Another faceplate, another feet and you have the audiophile version of the DAC2

References

DICE - TC Applied Technologies

The Well-Tempered Computer