ZM1040 Nixie Clock

New clock accuracy upgrade!

The original circuit used an oscillator with a frequency stability of 30ppm, and this could vary with temperature and age. At this tolerance level, the clock could be off by minutes per month. Even with the variable capacitor and fine-tuning, it can be challenging to calibrate the clock given the fluctuations in temperature. Integrating with GPS and other time-accuracy designs were considered but ultimately limited the ability to keep things simple.

Crystal oscillators have come a long way in the past 20 years. After some prototyping, there is now an upgrade circuit which replaces the existing microcontroller and utlizes a new crystal oscillator that has a frequency stability of 50ppb (yes that's 50 parts per billion!). This translates to a clock accuracy level +/- a few seconds per year, without the need of a bulky GPS integration or external signal. We're confident you'll be impressed by the accuracy of the clock after this upgrade. Along with the upgrade the assembly code was optimized to fix some minor errata from the previous design since this is now based off a newer MCU.

Only a small batch of these upgrade circuits have been made and once they're gone, there won't be any more made. The cost may seem high but consider that the crystal part itself costs over $100 given the high-grade of accuracy. The installation is simple and straightforward and only requires swapping the existing microcontroller with the new plug-in board. There's a photo of the prototype on the right. If you're interested, you can purchase one using the button below.

ZM1040 Clock Upgrade
Price: $399.95

The ZM1040 clocks are sold out. Sorry.

This is a limited edition run of a professionally-made nixie clock that can utilize the beautiful Philips ZM1040 tubes. A small number of these clocks have been made by a collector who wishes to share the beauty of these tubes with the world. If you like orange, glowing digits in retro-style tubes, you won't find a more attractive clock anywhere.

The circuit board was designed by a perfectionist with an eye for simplicity and elegance. The majority of the circuit is comprised of high quality, surface-mount components with only two through-hole ICs. The clock utilizes a microcontroller for its time-keeping with a crystal oscillator which can be adjusted using an on-board potentiometer to improve accuracy. The clock software also features cross-fading so that you can watch the digits slowly fade from one to the next for a really cool effect.

Setting the time involves the simple operation of two buttons at the rear of the clock. 24-hour or 12-hour display is selectable via a jumper on the circuit board.

The clock is encased in a sturdy, custom-made plexi-glass cabinet, which displays the inner circuitry for all to see. The tubes are socketed in 84 individual steel socket pins, providing a nice retro finish.

The power is drawn from an ordinary 12V DC wall adapter. A 110V version is supplied with the clock and a 220V version is available.

The clock includes all of the following:

  • Nixie clock in plexi-glass cabinet
  • 110V/12V AC/DC wall adapater
  • Instruction manual
  • 6 ZM1040 or similar tubes (currently using Z566 tubes)

  • The clock case measures 8.5 inches wide, 3.5 inches deep and 4.5 inches tall. The ZM1040 tubes included measure over 2.5 inches from end-to-end and the digits are over 1.25 inches tall! The life-expectancy of these tubes is estimated to be 10 years.

    Your order will be shipped the next day and will be delivered by USPS Priority Mail. All sales are final. 30-day warranty for repairs. Please contact for other questions.

    Read some of the comments.

    I got it the other day and I absolutely LOVE it! It is so incredible, I have been looking for a Nixie tube clock like this one for years! Thanks!

    Seth K.


    Just a note to let you know that I received the Nixie Clock today.

    This will make a nice addition to my Nixie collection. The cross fading is very unique.

    The clock is gorgeous! It is the most professionally constructed clock that I have seen.

    Mike S.

    It's here! And it is amazing. I have been staring at it for more than 3 hours now.

    Dave S.

    I did receive the clock on Thursday and am very pleased. The build quality is very nice, the layout of the board is super. It's beautiful to look at. You did a very nice job!!

    Brian B.

    I got it yesterday!

    Its beautiful!

    My co-workers were very impressed by this bit of nastalgia!

    Is your clock going out of production soon? I'm considering buying one as a birthday present for a friend.

    Thank you very much for this clock!

    David H.

    One word

    fantastic !!!!!

    thanks again

    Dave B.


    I just received the clock little before,and am very pleased with it.

    Thank you so much.

    Thanks again!


    Yasuhiro O.