STP1-11 vs. NH35A: Which Movement?

Our debut watch, the Trieste, is offered with the choice of two automatic movements, the Swiss STP1-11 and Seiko (SII) NH35A. Both of these movements are reliable, but as our prices reflect, they are not made equally ($350 for NH35A Triestes, $500 for STP1-11 Triestes). Is the STP1-11 worth the $150 premium over the NH35A? That really depends on your needs and what you care about in a mechanical watch. In this post, we’ll take a closer look at the differences between the two movements and (hopefully) help out those who are having trouble deciding which one to get.

 
STP1-11 automatic movement

STP1-11 automatic movement

STP1-11 Technical Specifications

  • 26 jewels
  • 28,800 vph, 4Hz
  • 44 hour power reserve
  • Accuracy from factory: -0s ~ +15s / day
  • Hacking (stop seconds) and handwinding
  • Quickset date
 
NH35A automatic movement

NH35A automatic movement

NH35A Technical Specifications

  • 24 jewels
  • 21,600 vph, 3Hz
  • 42 hour power reserve
  • Accuracy from factory: -20s ~ +40s / day
  • Hacking (stop seconds) and handwinding
  • Quickset date

Decoration and Finishing

We’ll get the obvious difference out of the way first. The STP1-11 is exceptionally pleasing to look at, with perlage on the plates, gilt balance wheel and gears, and Geneva striping on the rhodium rotor. The entire movement is cleanly assembled and well-oiled, with precise etching and markings. On the other hand, the NH35A is quite the ugly duckling that has no decoration and isn’t finished to the same standard as the STP1-11.

 
STP1-11 (left) and NH35A (right)

STP1-11 (left) and NH35A (right)

 

Some of you may be thinking, “Hold up a sec! The Trieste doesn’t even have a clear caseback, so does it even matter how the movement looks?” My answer to that question is something I will be repeating throughout this post: it all depends on what you (the wearer) care about! For many watch enthusiasts (myself included), having a nice-looking movement matters, even if it’s obstructed by a solid caseback. By nature of this hobby, we are obsessive about the tiniest of details, especially those that are intangible or hidden from plain sight. Why do I care that my Seiko MM300 has an undecorated Grand Seiko movement in it? Because it’s really freakin’ cool, that’s why. And it’s the same deal with having a nicely decorated movement, whether it’s visible or not. I like knowing that there’s a beautiful mechanism ticking within my watch, but I also know that many people won’t care either. So again, it’s what you care about.

 
Closeup of the STP1-11, highlighting the perlage, gilt accents, and Geneva striped rotor Photo credit: Jguitron from Watchuseek (IG: @the_fourthwheel)

Closeup of the STP1-11, highlighting the perlage, gilt accents, and Geneva striped rotor
Photo credit: Jguitron from Watchuseek (IG: @the_fourthwheel)

 

Accuracy

The STP1-11 and NH35A are built to very different accuracy standards. NH35As are low-cost and produced in massive volumes. They are unadjusted from the factory and have a wide accuracy range of -20s to +40s a day. On the other hand, the STP1-11 is tested in five positions from the factory which lends to a much better accuracy range of 0s to +15s a day and highly consistent timekeeping in different positions.

Some of you may be thinking, “Hold up a sec! The Triestes are all regulated in-house and will keep good time regardless of the movement, so does any of this even matter?” My answer is: it depends on what you care about! For those who value accuracy, the STP1-11 is unquestionably the better movement to go for. Based on the countless number of Triestes I’ve regulated, STP1-11 movements almost always keep consistent time in different positions, and a lot of them don’t require any regulation at all since they’re so accurate out of the box. The NH35As on the other hand tend to be all over the place. For example, an NH35A-equipped watch may be +5s in the dial up position, but when you put it in the crown-down position, it will go to -20s. I have pulled a lot hairs trying to get some NH35A movements regulated to acceptable standards because their accuracy deviates so greatly in different positions. Unsurprisingly, there were a few NH35A movements we couldn’t even use simply because they were performing so poorly (low amplitude, wild beat error, impossible to regulate). If we didn’t check every movement that went into our watches, some customers would undoubtedly get crap ones, and we’re not about that.

We aim to regulate all of our STP1-11 movements to a standard of -5s to +5s a day in four different positions, which is very easy to achieve because the movement runs strongly from the factory. As for the NH35A movements, we aim to regulate them to a standard of -10s to +10s a day in four different positions.

 

Feel and Refinement

The STP1-11 feels more refined compared to the NH35A. The crown clicks more firmly into different positions, handwinding is much smoother (like butter), and setting the time feels a lot more precise. The NH35A doesn’t inspire the same confidence the STP1-11 does when operating the crown, but it is good nonetheless.

 
The crown action differs between the two movements

The crown action differs between the two movements

 

The date change is more instantaneous on the STP1-11. Whereas the NH35A slowly starts to change the date around two hours before midnight, the STP1-11 changes the date in a matter of ten minutes. I know Wes gets really bothered by the slow date-change on Seiko movements and he most likely isn’t the only one who feels that way. I, on the other hand, don’t really mind the slow date change. Again, it’s all about what you care about.

Last but not least, a big difference between the two movements is their frequency. The STP1-11 beats at 28,800 vph, while the NH35A beats at 21,600 vph. What this translates to is a smoother sweeping seconds hand on the STP models compared to the NH35A ones. Many people (myself included) value a higher beat-rate movement simply because it looks and feels more high-end. There are also many people who don’t care at all. Notice the recurring theme here?

 

Summary

You can’t go wrong with either of the movements. They are both reliable and easy to service (both now and in the future) and because we inspect and regulate them in-house, they will be performing well when you receive them. However, the two movements aren’t made equally, and I have outlined their differences below:

STP1-11:

  • Decorated beautifully

  • Highly accurate, more consistently accurate (less deviation) in different positions

  • Smoother handwinding, feels more precise when setting the time, better crown action

  • Quicker date change

  • Higher beat-rate, seconds hand sweeps smoother

  • Fully Swiss-made

NH35A:

  • Undecorated and unadjusted

  • Less accurate and accurate deviates more in different positions

  • Lighter handwinding feel, feels less precise when setting the time

  • Slower date change (takes around two hours for date to change)

  • Lower beat-rate, seconds hand doesn’t sweep as smoothly

  • Japanese movement, manufactured in Malaysia/Singapore