Empirical Audio Off-Ramp 4 USB format converter Specifications

Sidebar 1: Specifications

Description: USB-AES/EBU, -S/PDIF, or -I2S data format converter for use with PCs and Macs (driver software included). Drivers available for Windows 7/Vista, Windows XP/2003, Mac OS X 10.6 (Snow Leopard), Mac OS X 10.5 (Leopard), Mac OS X 10.4 (Tiger). Input: USB 2.0–compliant. Operates in asynchronous isochronous mode. Output: S/PDIF electrical on RCA jack, AES/EBU on XLR jack, I2S on RJ-45 jack. Sample rates supported: 32, 44.1, 48, 88.2, 96, 176.4, 192kHz. Input/output bit depth: 16 or 24. Power supply: 12V DC wall wart. Options: Monolith lithium-ion battery power supply, one or two higher-quality clock modules, Hynes voltage regulator on USB module, Canare 75 ohm BNC jack or NextGen connector.
Dimensions: Off-Ramp 4: 4.25" (108mm) W by 2.5" (65mm) H inc. feet by 7.25" (185mm) D inc. RCA jack. Monolith battery supply: 6.75" (172mm) W by 2.5" (65mm) H inc. feet by 6.6" (168mm) D. Approximate weights: 1 lb (0.5kg), Off-Ramp; 3 lbs (1.4kg), battery supply.
Finish: Black-anodized aluminum.
Serial Number Of Unit Reviewed: None found.
Price: $799. Options: Canare 75 ohm BNC output jack, $20; 5V I2S output capability, $50; Dual Turboclock, $700; Hynes regulator, $300; Monolith LI battery, $1199. Approximate number of dealers: Sold direct. Manufacturer: Empirical Audio, 13852 Bishops Cap, Black Butte Ranch, OR 97759. Tel: (541) 595-1001. Web: www.empiricalaudio.com.

Empirical Audio
13852 Bishops Cap
Black Butte Ranch, OR 97759
(541) 595-1001

VandyMan's picture



Very interesting review. I look forward to seeing a comparison to the Alpha USB. I thought it was too expensive for a USB converter ($1600), but it looks like a potential bargin compared to the Offramp 4. 

thestewman's picture


Did I miss something in your article ?

"Up to this point I'd been using a generic USB cable with the Off-Ramp. I now substituted the expensive AudioQuest Coffee cable ($295/1.5m). If I heard a difference, it was very small, but if I had to swear on J. Gordon Holt's unwritten autobiography, I'd say that the AQ continued in the same direction the improvement I'd heard with the battery supply."

 "I spent the rest of that day trying to measure the differences between these two USB cables. It proved as frustrating as a snipe hunt, though I did find a very slight difference in jitter between the AudioQuest and generic cables with the Transporter: The generic USB cable was better."


The Transporter does not have a USB input. 

John Atkinson's picture

The comparisons were between the premium and generic USB cables feeding the Off-Ramp 4, which in turn fed the Transporter via AES/EBU.

John Atkinson

Editor, Stereophile

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