Smaller Footprint

Friends don't let friends buy obsolete clunky electronics.

Better futureproofing

Don't get trapped with old firmware! Because the metal lookup table is stored in the companion app, you'll get continuous updates with new coins and alloys.

Wider weight range

With the new 10-100kHz wide measurement spectrum, measure down to preivously unachievable thinness ⅒ oz gold coins.

Meet the Family

The DUO1 tests gold and silver alloys, as well as platinum and palladium, with the SigmaBoss™ companion app on your bluetooth-enabled phone. Just place the coin or bar on the sensor, and tap "test"!

The tiny AG1 tests 1oz+ 999 silver without the need for a phone - the green LED lights when the conductivity's right!

see how they work
The whole product range


For all stackers


Never has a sigma machine been so affordable

  • 10-100kHz sampling range
  • Continuous metal lookup table updates
  • Bluetooth interface for your phone
  • Detects iron, brass, copper, nickel, and other fakes.
  • Reads as small as ⅒ oz gold through plastic packaging!


For the silver lover


If you buy silver locally, the AG1 has your back

  • Up to 2.5mm testing depth
  • Verify Silver Eagles like a boss
  • Reads 1+ oz 999 silver through plastic packaging!
  • Detects iron, brass, copper, nickel, and other fakes.


Go big


For when the dude says he wants a "second opinion"

  • Never be caught out in a buying opportunity
  • Sleep easy knowing your stack is real
  • Both devices take the same 3×1.5V AA batteries
  • Mind-blowing price!

How do they work?

Sigma machines induce and measure currents in your bars and coins with an oscillating magnetic field. Each metal alloy has a distinctive conductivity and fake precious metals will get caught! This measurement technique requires a solid mass of metal for the currents to circulate, and thus is not applicable for jewelry such as necklaces and bracelets.

Do I need an app?

For the DUO1 model, keeping the "brains" on your phone allows you to get updated metal signatures when we test new alloys, and allows us to provide a friendly interface for a lower cost. And yes, the app is free - there's no charge for updates or any paywall for new services.

The AG1 model is self-contained, and has been pre-calibrated to only test against silver's conductivity value of 63MS/m. If the conductivity is right, the green LED lights up. Simple!

Why does it cost less than other sigma machines?

To keep costs down and pass the savings through to you, we house our state-of-the-art electronics in practical acrylic cases and we sell directly to customers. We focus on performance, functionality, and price, not on fashion. You get reliability and value for money.

How's shipping going to work?

$9.99 flat rate shipping worldwide for all orders. Ships from within the EU.

What's the timeline for availabiltiy?

Final prototypes for demo videos are presently being constructed. Both models will be available from March 2021 when the companion bluetooth app is uploaded to the app stores.


All hardware is guaranteed for 12 months against manufacturing and workmanship defects. As everything is manufactured using Just-In-Time techniques, if you're having a hardware problem or just want the latest firmware on your device, get in touch and we'll repair and have your device back to you quickly.

Why does it warn to use 3×1.5V AA batteries and keep away from heat?

It's a sensitive analog instrument, and the electrical properties of the sensor are affected by a change in temperature. Like all sigma machines, your device should be maintained at a constant temperature - and this means you shouldn't keep it warm in your pocket and then expect it to return a consistent reading as it cools down to room temperature.

The analog circuitry also expects at least 4.1V input voltage to avoid clipped waveworms - but don't worry; the battery light will not light if your batteries have been depleted below this voltage.

User manual?

Here you go.

Download The App Today!

You'll find the companion app for the DUO1 for Android in the Google Play store. You can also find the app on this site if you're comfortable downloading and installing it yourself.