Expert Review: Scientific Anglers Amplitude Smooth Trout Fly Line

Published on 10/07/2022 · 7 min readThis review is my honest opinion of the fly line, which I purchased with my own money in June of 2022.
Andrew Grandemange, Fly Fishing Expert
By Fly Fishing Expert Andrew Grandemange

All photos courtesy of Andrew Grandemange

About this Review: This review is my honest opinion of the fly line, which I purchased with my own money in June of 2022.

My take

My preferred fly line for dry fly fishing for trout is the 5wt weight-forward Scientific Anglers Amplitude Smooth Trout. The majority of my fishing is done on rivers for trout, and whenever possible, I tie on a dry fly in hopes of catching a fish feeding on the surface. This true-to-weight fly line has an elongated front taper that helps to present dry flies delicately to picky fish. This line is perfect for many of the tailwaters where I fish.

About the line

  • Model: Scientific Anglers Amplitude Smooth Trout
  • Weight: WF2F, WF3F, WF4F, WF5F, WF6F, WF7F
  • Fly line taper: Weight-forward
  • Core: Braided multifilament
  • Ideal Temp Range (ºF): Moderate to cold climates
  • Loops: Welded loops at both ends
  • Total Length: 90ft
  • Line Profile:

About me

  • Preferred fishing style(s): Dry fly, nymphing, streamers
  • Experience: 20 years of fishing

Test conditions

  • When I bought this: June 2022
  • Rod and Reel Paired with Line: Douglas Sky G 9’ 5wt and Orvis Mirage LT II reel
  • Days tested: 20 days with the current outfit, but I have used this line taper for years
  • Waters I’ve used it on: Rivers
  • Species targeted with rod: Trout
  • Fly Size: 8–18

How it performs

Casting Ease

What I was looking for

I was in the market for a 5wt weight-forward floating fly line to pair with my new Douglas Sky G 9’ 5wt. I knew this rod would primarily be used for dry fly and nymph fishing, so I wanted a line with a taper designed to meet those specific needs.

Of note, one of the lines Douglas recommends for the Sky G rod is the Scientific Anglers Infinity taper. I already have a reel spooled with this line and use it on days when I need a line that is more versatile.

Why I chose this gear

I chose the Scientific Anglers Amplitude Smooth Trout line for a few reasons. First, I’ve used SA’s trout taper for years in both the Mastery series and Amplitude series, so I knew what to expect with this line. I also really like the taper for dry fly fishing because it’s true-to-weight and the elongated front taper aids in delicate fly presentations. Since it would be used primarily on days when I plan to only fish dry flies and nymphs, this taper is perfect. The other line I considered was the Scientific Anglers Amplitude Textured Trout line. I am not a huge fan of textured line, even though it floats better than smooth line because of the noise it makes when being stripped through the guides. So, I decided to stick with the smooth line.

Douglas Sky G with Orvis Mirage LT reel, spooled with Scientific Anglers Amplitude Smooth Trout line

What I love about it

  • Performance: The SA Amplitude Smooth Trout line performs well with the rod I was using. The tri-color line helps to gauge casting distance, and the front taper really helps turn over a longer tippet with a dry fly softly on the water surface.
  • Quality: SA’s Amplitude series is their premium series of fly lines. It has welded loops on both ends, which make it easy to attach the line to the backing and leader. It has their AST+ dry-slick additive built in throughout the line, which improves shooting ability resulting in longer casts with less effort. The line also floats better than other brands of lines I’ve fished as well as SA’s other series of lines, excluding the textured version of the Amplitude series. A nice added feature is the line ID that is printed on the end line, making it easy to quickly identify which line is spooled on a reel.
  • Versatility: Even though this line is designed to cast dry flies and nymphs, it can be used for casting medium to small streamers. I’ve used it to cast lightly weighted streamers on short leaders, and it’s worked decently. However, I prefer SA’s Infinity taper if I plan to fish all three types of flies during an outing on the water or a dedicated streamer line if I only plan to fish streamers.
  • Durability: The AST+ dry-slick additive of the Amplitude Smooth Trout fly line not only improves casting, but it also makes this line very durable. This line has outlasted many other brands of line I’ve tried. Those lines start to show signs of cracking after a season whereas this line still looks brand new.
  • Use Case: As mentioned a couple of times before, this line is designed for casting dry flies and nymphs in cold to moderate temperature water. I’ve fished those flies in the summer months here in Utah as well as the dead of winter, and the line fishes as expected.

Issues I’ve encountered

  • Weight: This line is true-to-weight. It works really well with the Douglas Sky G rod. However, I’ve also fished that rod with the Scientific Anglers Amplitude Infinity taper, which is a half-size heavier, and it loads a little better. It’s not a big enough difference that I would recommend one line over the other based solely on how the rod loaded.
  • Aesthetics: The line is tri-colored, which is great for gauging casting distance. However, I wish Scientific Anglers provided other color options like their camo color scheme. I’m not a big fan of the celestial blue running line or the grayish blue heron color of the front taper.

Scientific Anglers Fly Line with Line ID

Favorite moment with this gear

I’ve used this line for years and have caught a lot of fish using it, but using this line with the Douglas Sky G rod and Orvis Mirage LT reel was new to me. I purchased the rod and reel at the beginning of the summer and have enjoyed fishing this setup. My favorite moment, as described in my review of the Orvis Mirage LT reel, was that first catch. It involved a brown trout eating a dry fly that was well presented in a pocket of water near the bank. Not only did I get to hear the pleasant sound of a reel as the line was pulled out, but it really showed how well this line can present dry flies.

Value for the money vs. other options

The Scientific Anglers Amplitude fly line is priced at around $100, and I will happily spend that amount when it’s time to replace it. This line has Scientific Anglers AST+ dry-slick technology to improve castability, welded loops at both ends for quick connections to backing and leader, an improved dry tip that floats higher than a standard fly line, and the line ID for quick identification of the line when spooled. Many of these options are not included in the lower-priced lines offered by Scientific Anglers. For example, the next step down for this line is the Scientific Anglers’ Mastery Trout line, which costs around $80. This line has the same taper, line ID, and dual-welded loops as the Amplitude Smooth Trout line but features the older AST dry-slick technology and not AST+. The AST+ is 50% slicker than the old AST technology, so it can cast farther, float higher, shed dirt and grime easier, and last longer. The trout taper in the Frequency series by Scientific Anglers, which is priced at a little over $50, only has the AST technology and a single-welded loop. When looking at other comparable brands, the RIO Premier Technical Trout, priced at about $100, has a similar taper and their own version of line slickness technology. It presents a dry fly really well, but I have found that the line wears out quicker than the Scientific Anglers line.

Final verdict

The Scientific Anglers Amplitude Trout Smooth fly line is a must-have line for anglers that plan to fish dry flies and want a high-quality line. The taper is perfect for dry fly fishing, and the technologies built into the line make it superior to other lines on the market.

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