Everything You Need to Know About Quad-Pulse Watches

1. Origins & Innovation: Where the VH31 Came From

All Redwood Quad-Pulse watches are equipped with Seiko’s VH31 quartz movement. Introduced in 2015, the VH31 belongs to a family of high-beat “Sweep Second Quartz” movements aiming to blend the smooth charm of mechanical watches with the precision and convenience of quartz.

2. How It Works: The Tech Behind the Sweep

• 4-Hertz Beat Frequency: Unlike standard quartz that ticks once per second, the VH31’s second hand “pulses” four times per second (2 Hz, or 14,400 vph), delivering a fluid, mechanical-like motion.
• Enhanced Torque: It generates around 0.30 μN·m of torque—nearly 400% more than typical quartz calibers—ensuring its sweep remains smooth even under heavy hand load.
• Precision Timing: With accuracy rated at ±15 seconds/month, this movement keeps time within about ±3 minutes per year—impressive at any price point.
• Durable & Practical: It uses a common SR920SW battery (lasting approximately two years), and even includes a hacking-seconds feature for precise time setting.

3. Why We Call It “Quad-Pulse”

Understanding Beat Frequencies: Quartz vs Mechanical vs Quad-Pulse

The name "Quad-Pulse" reflects the four-beat-per-second rhythm of the sweeping second hand—offering a blend of mechanical elegance and quartz-level reliability. It serves as a standout feature for our watches, emphasizing precision, smooth motion, and technical flair.

a. Standard Quartz Ticking

Conventional quartz movements tick once per second—resulting in a distinct, noticeable jump of the second hand every time.

b. Mechanical “Sweep”

Mechanical movements operate at frequencies like 2.5–4 Hz (18,000–28,800 vph), translating into 5 to 8 small beats per second. This gives the illusion of a smooth sweeping second hand, though it’s actually multiple very fast ticks.

c. Quad-Pulse: A Hybrid Sweep

The Redwood Quad-Pulse watches elevate the experience with 4 pulses per second. This delivers a smoother sweep, bridging the gap between quartz precision and mechanical elegance.

Quick Beat Frequency Comparison

Movement Type	Frequency	Seconds Hand Behavior
Standard Quartz	1 tick/sec	Distinct jumping motion
Mechanical	4–8 beats/sec	Smooth sweeping motion
Quad-Pulse	4 pulses/sec	Fluid, refined sweep

This side-by-side comparison underscores how the Quad-Pulse watches provide the charm of a mechanical sweep with the precision and reliability of quartz technology.

Final Thoughts: The VH31 in Your Watch Collection

At Redwood, our mission is to blend heritage designs with modern technology and everyday practicality. The Quad-Pulse watches embody that perfectly: They honour mechanical aesthetics while prioritizing accuracy, convenience, and reliability.