Supra USB 2.0 A to B 1m

Supra USB 2.0 A to B Cable, 1 m

A DAC, a printer, an audio interface or a streamer very often connects to the computer via a square type B USB plug. This Supra cable links this type of device to a standard USB A port, over one metre, inside an ice blue jacket. It is made in Sweden by Jenving Technology, in Ljungskile, with the same construction as the brand’s entire USB 2.0 range. This range runs from 70 cm to 15 m.

An A plug on the computer side, a square B plug on the device side

The division of roles is the same as for any A to B cable. The flat type A plug goes on the device that controls the link: computer, hub, music server or streamer with a USB output. The squarer B plug goes on the peripheral, most often a digital-to-analogue converter (DAC), a printer, a turntable with USB output or a MIDI controller. The signal travels in both directions, as the USB standard specifies. The connectors bear the Supra name and their housings are overmoulded onto the jacket. Repeated plugging and unplugging therefore pulls on the moulding rather than directly on the solder joints.

Nineteen tinned copper strands per conductor

Each conductor combines 19 strands 0.127 mm in diameter, giving a cross-section of 0.24 mm² (AWG 23). The copper is oxygen-free (OFC) and then coated with a thin layer of tin, which protects it from oxidation over the years and makes soldering to the connectors easier. At 72 Ω per kilometre, the resistance of one conductor over one metre is 0.072 Ω, a value with no consequence for either the 5 V line or the data. The multiple strands give the cable moderate flexibility. It is not a thin cord you can wrap around two fingers, but it bends easily behind a desk or a hi-fi cabinet.

Individually shielded twisted pairs

USB data travels over a pair of twisted conductors, and their characteristic impedance is 90 Ω, the value set by the USB 2.0 standard. Respecting this value limits signal reflections at the ends of the cable. These reflections distort the pulse edges at 480 Mbit/s. At Supra, each pair has its own aluminised PET foil shield. The data line thus remains isolated from external interference and from the power line that shares the same jacket. The capacitance of 52 pF per metre and a velocity factor of 0.66 (the signal travels through the cable at 66% of the speed of light) are the two other parameters that determine how the cable transmits pulses. Over one metre, the propagation delay is about 5 nanoseconds.

Between a computer and a DAC

During audio playback, the computer sends music to the DAC in isochronous mode: packets are sent at regular intervals and a damaged packet is not resent. Most recent DACs operate in asynchronous mode, meaning their own clock times the conversion. The cable’s role is therefore to deliver each packet intact, without adding interference. Bandwidth is never an issue: a 24-bit, 192 kHz stereo stream takes up less than 10 Mbit/s of the 480 Mbit/s available in USB 2.0 Hi-Speed. However, the cable does not correct a noisy 5 V supply on the computer side. It passes through the cable like any other current. If a USB-powered DAC hums or hisses, the place to look is the power supply and grounding rather than the cable.

One metre in the catalogue, up to fifteen as an option

The one-metre version is enough to connect a laptop to a DAC sitting next to it, or a streamer to a converter in the same cabinet. The range is also available in 0.7, 2, 3, 4, 5, 6, 8, 10, 12 and 15 m. The longer lengths exceed the 5 m usually accepted for a passive USB 2.0 USB cable, and Supra guarantees them with no signal degradation. Other lengths are made to order. The PVC jacket is just over 7 mm in diameter and bears the marking “SUPRA USB 2.0 > Made in Sweden” along with a length marker.

Frequently asked questions

Can it be plugged into a USB 3.0 port or a computer equipped only with USB-C?

An A plug fits without any problem into a USB 3.0 or 3.1 port, which remains compatible with USB 2.0. The link then runs at USB 2.0, which poses no limitation for a DAC or a printer. For a computer with only USB-C, you need a USB-C adapter to female USB A.

Can this cable power a DAC that has no power supply of its own?

Yes, it carries the 5 V line like any USB cable. The available power depends on the computer’s port: 500 mA on a standard USB 2.0 port and 900 mA on a USB 3.0 port. A DAC or headphone amplifier that requires more must have its own power supply.

Is there a direction to observe when connecting it?

The plugs only fit one way: the A into the computer or hub, the B into the peripheral. The cable itself is not directional.

Can a USB hub be placed between the computer and the DAC?

Yes. The Supra cable then connects the hub to the DAC, and the hub is connected to the computer by another cable. For audio playback, it is better to use a hub powered by a mains adapter and to avoid having the DAC share a hub already occupied by hard drives or a webcam. These devices draw on both the power supply and the bandwidth.

Is the cable available in a colour other than ice blue?

Ice blue is the standard colour for the entire Supra USB 2.0 range. Jenving makes other colours to order.

What other plugs does the Supra USB 2.0 range offer?

The same cable is available with a Mini B plug, for certain recorders and older devices, and with a Micro B plug, found on portable DACs and compact headphone amplifiers. It is also available as a male A to female A extension. These models all have the same conductors, the same shielding and the same impedance.

Technical Specifications

General Specifications

• Type: USB 2.0 high-speed
• Signal direction: bidirectional
• Length: 1 m

Connectivity

• Connectors: USB A male to USB B male
• Number of conductors: 19
• Conductor diameter: 0.127 mm

Performance

• Transfer rate: 480 Mbit/s
• Velocity factor: 0.66 × C

Electrical Characteristics

• Resistance: 72 Ω/km
• Capacitance: 52 pF/m
• Impedance: 90 Ω

Physical Characteristics

• Aluminized PET shielding
• Outer diameter: 7.5 mm