bFly-Audio Pure-Tube – Device Absorber for Tube Amplifiers

The bFly-Audio Pure-Tube is a device absorber tuned to the higher operating temperatures and the weight of tube amplifiers.

It is built on the same seven-layer MLA structure as the regular Pure, but is designed in material and load capacity so that it stays reliable in the long term even under heavy, warm-running tube equipment. You choose load capacity and height (17, 24 or 31 mm) directly here on the page.

Why the Pure-Tube?

Tube amplifiers bring two challenges that a normal absorber doesn't solve ideally: they are often heavier than solid-state units, and they get noticeably warmer in operation. The Pure-Tube is dimensioned for exactly this load profile, with the same seven damping layers of cork, Sorbothane and special rubber as the standard Pure.

What you hear

More calm in the background, cleaner imaging and fewer microphonic effects – tube amplifiers in particular, because of their sensitive electron tubes, react especially clearly to vibration from outside.

Who is the Pure-Tube for (and who isn't it for)?

Just right for tube preamps and power amps that noticeably benefit from decoupling. Straight talk: for solid-state units without tubes, the regular Pure is the more suitable choice and usually also the more sensible one price-wise – the Pure-Tube is specifically tuned to tube load profiles, not generally "the better" version.

Our verdict

Anyone who owns a tube amplifier and has ever seen how it reacts to a knock on the rack immediately understands why there is a dedicated variant here. Which size, height and mounting suit your device, we're happy to clarify with you at HD Zürisee in Wädenswil.

Technical data

• Type: Device absorber for tube amplifiers, MLA technology (Multi Layer Adjustment)
• Construction: 6 materials across 7 layers – cork with natural rubber, aluminum body, cork with natural rubber, Sorbothane with a parallel air chamber, special rubber, aluminum lid, gel cushion
• Diameter: 44 mm
• Height: selectable 17, 24 or 31 mm – selectable directly here on the page in the «Height & mounting» option (no effect on the sound, no price difference)
• Load capacity per absorber: Pure-Tube-0 up to 12 kg · Pure-Tube-1 up to 35 kg · Pure-Tube-2 up to 55 kg
• Mounting: without thread (freestanding, height 17, 24 or 31 mm freely selectable) or with M4, M5, M6 or M8 thread (CHF 30 surcharge per set, always at the designated 24 mm height) – all selectable directly here on the page
• Colors: Aluminum silver or black
• Manufacturer: bFly-Audio, Germany
• What's included: 4 absorbers in a case, in your chosen color, size, height or thread version

Frequently asked questions

What is the difference from the regular Pure?

Both work with the same seven-layer MLA structure, but the Pure-Tube is specifically tuned to the weight and heat generation of tube equipment. For solid-state amplifiers without tubes, the regular Pure is usually enough.

Which size suits my tube amplifier?

Again, the weight per contact point is decisive: Pure-Tube-0 carries up to 12 kg, Pure-Tube-1 up to 35 kg, Pure-Tube-2 up to 55 kg. Weigh your device and divide by the number of feet, then choose directly here on the page.

Which height should I choose: 17, 24 or 31 mm?

The manufacturer recommends placing the absorber directly under the device's base next to the original feet. Choose the height so that the original feet just barely hover – the device then rests exclusively on the absorbers. The height has no effect on the sound and none on the price. It's best to measure the height of your original feet; if in doubt, we're happy to advise you.

Can the Pure-Tube permanently withstand the heat of tubes?

Yes, that's exactly what it's built for – the choice of materials takes into account the higher operating temperatures that tube equipment generates in continuous use. A normal safety distance between tubes and housing still makes sense.

Can I also bolt the Pure-Tube in place?

Yes, in the «Height & mounting» option you choose between the free heights 17, 24, 31 mm and the threaded version M4, M5, M6 or M8 (CHF 30 surcharge per set). The threaded version is supplied at the designated 24 mm height.

Why buy the bFly-Audio Pure-Tube from HD Zürisee?

Tube amplifiers are sensitive devices for which decoupling is especially worthwhile – we advise you whether your model benefits from it and which size fits. Call, write, or reach us on WhatsApp, drawing on our practice in Wädenswil.

Goes well with

You'll find further absorbers for solid-state devices with the Pure, and more on the topic under decoupling and HiFi furniture.