AudioQuest Diamond USB Cable

The AudioQuest Diamond USB is the brand's reference USB audio cable: solid conductors made of 100% Perfect-Surface Silver, carbon-based noise dissipation and an active 72-volt Dielectric-Bias System. It sits at the top of the range that starts with the Forest – and leaves nothing more open on the material side.

Why the Diamond?

Below this tier, silver is always just a percentage on copper. In the Diamond, the conductor consists entirely of Perfect-Surface Silver, a material with an especially smooth surface – exactly where a high-frequency USB signal travels almost exclusively anyway. Add to that Hard-Cell Foam as insulation, a carbon-based 3-layer Noise-Dissipation System, and the 72-volt DBS that keeps the insulation permanently polarised. The effect is unspectacular to describe yet unmistakable: less background noise, more body.

What you get

Available as A–B in 0.75, 1.5, 3 and 5 m, as well as A–C, A–Micro B 2.0, C–B and C–C in 0.75 and 1.5 m – each with the DBS module. Special lengths on request.

Who is the Diamond suited for – and who isn't it?

Plainly put: below a genuinely good DAC, the Diamond is the wrong place to invest – there, Carbon or Coffee practically get you the same result, and the remaining budget works harder in the source. Its justification lies in systems where every other position is already sorted and the USB run is the last open detail.

Our verdict

Not a gimmick, but the end of the line: the Diamond takes the last remaining unrest out of the digital feed. Whether your system plays in that league, we're happy to assess soberly with you – HD Zürisee in Wädenswil, 044 680 22 00, WhatsApp 076 534 22 00 (text only, no calls) or shop@hdzuerisee.ch.

Technical data

• Type: USB audio cable (USB 2.0), reference tier
• Conductors: solid-core, 100% Perfect-Surface Silver (PSS)
• Insulation: Hard-Cell Foam (nitrogen-injected foamed polyethylene)
• Noise dissipation: carbon-based 3-layer Noise-Dissipation System
• Dielectric bias: active 72V DBS (battery module on the cable)
• Connector contacts: silver-plated
• Connector variants: A–B, A–C, A–Micro B 2.0, C–B, C–C
• Lengths: A–B 0.75 / 1.5 / 3 / 5 m; other variants 0.75 and 1.5 m

Frequently asked questions

What's behind Perfect-Surface Silver?

A manufacturing process for especially smooth conductor surfaces. Because a high-frequency USB signal travels almost only along the surface, irregularities there act like small obstructions. In the Diamond, the conductor is 100% this silver, not just the plating – material-wise, there's simply nowhere further to go.

Does a cable change the transmitted bits?

No, and AudioQuest doesn't claim that either. The data arrives identical with any working USB cable. Differences come from noise that travels alongside the data line into the DAC and disturbs its analog section there. That's exactly what the Diamond works on, not the zeros and ones.

Which connector combinations does the Diamond come in?

As A–B, A–C, A–Micro B 2.0, C–B and C–C. The A–B version runs from 0.75 to 5 metres, the other variants we carry in 0.75 and 1.5 metres. That covers classic desktop DACs as well as modern devices with a USB-C jack. We can request special lengths.

When does the step from Coffee to Diamond pay off?

When the DAC, amplifier and speakers are already very finely resolving and the room plays along. Then the solid silver adds a bit more body and calm. In a system that's held back elsewhere, the money is better spent there – we'll tell you honestly where.

Why order the Diamond from HD Zürisee?

Because with a reference cable, we look at the system first and the cable second. Our practiced specialist team plans digital systems from source to speaker, takes care of warranty and DBS battery replacements, and is personally reachable in Wädenswil.

Goes well with

A reference cable wants a DAC of the same calibre – take a look at the DACs & D/A converters. All tiers of the range are under USB cables, the rest of the line-up in the AudioQuest world.