IN-14, Z570M, or IN-8-2: Which Tube Should I Choose?
Quick comparison
| Tube | Character | Best for |
|---|---|---|
| IN-14 | Warm orange-red glow, classic gothic digit font, side-view | The default choice — widest stock, most "typical Nixie" look |
| Z570M / Z573M / Z574M | Taller digits, glow tint varies slightly by batch/origin | A more distinctive, slightly larger-looking display |
| IN-8-2 | Shorter, stockier digits, rounder font | Good value when it's more readily in stock than IN-14 |
All three are what we and most of the hobby call "medium tube" size — noticeably bigger than small clock tubes like the IN-2 or IN-12, but not as large as showpiece tubes like the IN-18. That's why the MNC6 and MNC6 V2 list all three as interchangeable tube-holder options rather than separate products: the board and driver electronics don't care which of the three you plug in.
IN-14 in detail
The IN-14 is the tube most people picture when they hear "Nixie clock." It's a Soviet-era side-view tube, originally made for industrial panel meters and lab equipment, with enough surplus stock still circulating that it remains the easiest of the three to source consistently. The digit font has the slightly angular, gothic look that's become the visual shorthand for the whole hobby. If you don't have a strong preference, this is the safe default — it's what most reference photos and demo videos of Nixie clocks are actually showing.
Z570M (Z573M / Z574M) in detail
The Z570M family runs taller than the IN-14, which makes the display read as a little larger and more substantial from across a room. Because these tubes came from a few different manufacturers and production runs, glow tint and exact digit shape can vary slightly between batches — part of the appeal for people who want a display that looks a bit different from the "default" IN-14 look, but it also means two Z570M-family tubes side by side won't always match perfectly if they came from different lots.
IN-8-2 in detail
The IN-8-2 is shorter and more compact than the IN-14, with a rounder, less angular digit shape. It's a common choice when IN-14 supply tightens up, since the underlying surplus pool is a different batch of old stock and doesn't compete for the same tubes. If budget and easy sourcing matter more to you than matching the "classic" look exactly, this is a solid option.
[Ian: this is the spot for the details only you'd actually know — current relative pricing/availability between the three, any batch of tubes that had a noticeably different glow colour, or a specific driver/voltage quirk you've had to compensate for with one family versus another. That kind of detail is what separates this page from a generic tube spec sheet.]
How to actually decide
- Want the classic, unmistakably-Nixie look, and the safest bet on stock? Choose IN-14.
- Want a taller, slightly more distinctive display and don't mind minor batch variation? Choose Z570M/Z573M/Z574M.
- Want a shorter, rounder digit, or IN-14 is temporarily hard to get? Choose IN-8-2.
- Not sure? All three use the same tube-holder mechanism on the MNC6 and MNC6 V2, so you can start with whichever is in stock and switch tube-holder boards later without touching the clock's main electronics.
All three tube families are available as tube-holder options on the MNC6 V2 6-Digit Nixie Clock and MNC6 6-Digit Nixie Clock. The Modular Nixie Clock and All-In-One Clock also support IN-14 and Z570M/Z573M/Z574M if you want swappable tubes on a different board format.