Review: First Ascent Amplify Down 900

The First Ascent Amplify Down 900 is the ideal bag for hikers who plan on heading into South Africa’s mountainous wilderness areas during winter, such as the Cederberg, Drakensberg and Wolkberg ranges.

Key Information

Price (at time of writing): R4299
Weight: 1825g (with stuff sack)
Temperature rating: Comfort: -3°C
Filling: Goose down (RDS Certified) – 650 fill power

Specialising in Warmth

When you think of down sleeping bags in South Africa, the First Ascent Ice Breaker will most likely be one of the first bags you think of. It has made a name for itself as a sufficiently warm sleeping bag in almost all South African conditions, while being versatile enough for both hiking and “car camping” alike.

With the Amplify Down 900, First Ascent has foregone the “jack of all trades” approach of the Ice Breaker and focused on maximum heat retention.

Cosy and warm in a snow-covered landscape.

Design

The Amplify Down 900 has a mummy shape, which tapers quite aggressively down along the legs and footbox. This might seem uncomfortable to people who like to have some space to move, but it ensures minimal air volume inside the bag — less air to warm up means better heat efficiency.

The tapered mummy shape maximises warmth while minimising weight.

Unlike the Ice Breaker, it does not have a full-length zip but rather a ¾-length zip and shaped footbox — all in an attempt to maximise heat retention, since every zip is a potential point of heat loss.

Shaped footbox keeps your feet warm and comfortable.

The Amplify range gets its name from the elastic stitching method that allows the sleeping bag to expand width-wise, so it stretches and conforms to one’s body as you move in the night, reducing any restrictive feeling.

Features

First Ascent have ticked all the boxes with this sleeping bag for a comfortable night’s sleep in cold conditions:

Generous zip- and chest baffles to stop any cold air from creeping through the zip or in the gaps around one’s neck and chest as you move around.

Well-padded baffles help keep warmth where it belongs — inside the bag.

Elasticated drawstrings in the chest baffle and cowl let you cinch the bag around your face to minimise exposed skin and keep your head warm.

Internal storage pouch for a cellphone, power bank or camera batteries — essential in sub-zero temperatures where batteries drain quickly.

Handy internal pouch for keeping electronics warm overnight.

Anti-snag fabric along the inside of the zip reduces snagging on the thinner Microtex lining. It doesn’t eliminate snagging completely but does a decent job of keeping the lining out of the zipper.

Anti-snag fabric along the zip reduces catching and wear.

A stuff sack with compression straps is included, helping to compress the lofty down and save pack space. It also comes with a large mesh storage bag for long-term storage.

Temperature Rating

I’ve spent a few nights in this sleeping bag at temperatures between -2°C and -4°C, comfortably warm while wearing trousers, socks, a t-shirt, fleece and beanie. One night I crawled into my sleeping bag while still wearing my down jacket and eventually woke up sweating — the thermometer read -2°C. So there’s definitely a safety margin below the stated comfort rating of -3°C.

Tested in below-freezing temperatures — impressively warm throughout.

That said, First Ascent claims a “Transition” rating of -15°C and an “Extreme” rating of -20°C. I wasn’t able to test the bag in those conditions, but those are extreme ratings with narrow safety margins — use caution if venturing into those temperatures.

Cons

My main gripe with this sleeping bag is the shallow cowl (hood). For a bag designed for maximum warmth, the cowl feels a little out of character. It’s not a dealbreaker, but a deeper and more contoured cowl could improve comfort in frigid conditions without adding much weight.

The hood is slightly shallow for a winter-rated bag but still functional.

The other issue is the over-engineered velcro tab at the top of the zip. While intended to prevent accidental unzipping, the overlapping design makes it overly secure — a bit of a fiddle to open each morning. It’s also positioned inside the bag, which risks being scratchy.

Velcro zip tabs are secure — perhaps a little too secure.

These are minor issues but stand out in an otherwise excellent sleeping bag.

Conclusion

The First Ascent Amplify Down 900 is a great option for winter hikes in South Africa and abroad. The -3°C comfort rating feels accurate, and there’s enough margin for colder nights. I’ll happily recommend this bag.

This sleeping bag was provided by First Ascent for review purposes and can be purchased from their online store: https://www.firstascent.co.za/amplify-down-900-sleeping-bag

To learn more about choosing sleeping bags, check out this article: Sleeping Bags 101