Miller Maxstar 150 TIG STL Welder Review

When it comes to reliable welding equipment Miller is one of the best names in the business.  They make all of their equipment right here in the U.S.A. using only top quality components. And all of their products are backed by an incredible support team.

The Maxstar 150 STL TIG welder is one of their better known welding products.  It took first place in our best TIG welder competition.  Let's take a look at it's capabilities to see how it stacks up against it's competitors.

It is on the more expensive side for welders in this category, but you'll find no more reliable product (or company) than Miller.  They set the standard in welders, plasma cutters, and more.

Miller Maxstar 150 STL TIG Welder Review

The Miller 150 STL is one of the most versatile TIG welders currently on the market.  It offers both TIG and stick welding capabilities as well as a number of features that make it highly portable. 

It weighs in at just under 14lbs, has a handy carry strap, and even has a multi-voltage plug for quickly switching between 120V and 240V power sources.

Key Specifications


Input Power

Amperage Range

Rated Welding Output


115 VAC, 15 A

5–100 A

100A @14.0VDC, 100% duty cycle

115 VAC, 20 A

5–150 A

100A @14.0VDC, 100% duty cycle, 150A @16.0VDC, 30% duty cycle

230 VAC

5–150 A

100A @ 14VDC, 100% duty cycle, 150A @16VDC 30% duty cycle


115 VAC, 15 A

20 –70 A

70A @22.8VDC 100% duty cycle

115 VAC, 20 A

20–100 A

70A @22.8VDC 100% duty cycle, 100A @24.0VDC 35% duty cycle

230 VAC

20–150 A

100A @24.0VDC 100% duty cycle, 150A @26.0VDC 30% duty cycle

TIG Functionality

For TIG welding applications it's amperage range is between 5-150A.  It offers a 100% duty cycle at 100A and a 30% duty cycle at 150A. Millers Lite-Arc technology allows for TIG arc initiation without the use of high frequency.

Notable Features

In addition to the lightweight design and inverter power source the Maxstar 150 is loaded with useful features.

  • MVP (multi-voltage plug) for use with 115V or 230V outlets
  • Fan-On-Demand cooling system kicks on only when necessary, reducing dust and debris intake into the unit
  • auto-line technology circuit for connecting to 115 or 230 VAC
  • Adaptive hot start allows for positive arc starts without sticking
  • remote control for amperage control
  • Lift-arc technology allows for TIG arc initiation without using high frequency
  • Pros
  • CONs
  • At 13.7lbs it's lightweight and very portable
  • Easily switch between 115V and 230V with MVP plug
  • Excellent thermal protection and fan-on-demand to extend usable life
  • PFC offers excellent performance on 120V, prevents breakers tripping
  • Very user friendly

Final Verdict

For lightweight TIG welding the Miller Maxstar 150 STL is a great machine.  At lower amperage it's got a great duty cycle, though it drops significantly at higher outputs.  If you need a TIG welder that is both reliable and portable this one is tough to beat. 

About the Author Jason Thompson

Jason is a work from home dad who has a passion for DIY projects, yard work, and SEC Football. His background is IT, but he's always fancied himself as a part-time ship welder, landscaper, and short order cook. During the week he can be found on his laptop 10 hours-a-day, but on the weekends he escapes to the local DIY Cave to play with REAL toys.  You can also find him on Facebook, Twitter, and can contact him via email.