The cheapest tone upgrade you'll make all year – stock up on multi-pack guitar strings from just $4.99 in Amazon's Big Deal Days sale

As one of the original acoustic guitar manufacturers, Martin Guitars knows a thing or two about acoustics. Their own strings are excellent quality, and this multipack deal is incredibly cheap. You can grab these for just $4.99 per pack, making them an absolute steal in the Big Deal Days sale.

Ernie Ball’s Earthwood acoustic offering also has a nice discount in the Big Deal Days sale. Working out at $5.74 per pack, these are amongst the cheapest acoustic strings you’ll find right now.

Ernie Ball Paradigm strings sit somewhere between a coated set and a non-coated set. The technical term is treated, where coating is applied during the manufacturing process rather than after it. It makes them feel and sound more like a non-coated set, and right now you can bag them for just $9.99 each.

If you prefer a non-coated acoustic guitar string, this is the deal for you. This 5-pack of D’Addario EJ26 acoustic guitar strings works out at just $6.39 per pack, which is incredibly cheap as far as acoustic strings go.

When it comes to acoustic guitar strings, shelf life matters even more, as acoustics are so reliant on natural tone. While old electric strings get covered up by an amp, pedals, and pickups coloring the tone, there’s no hiding place when it comes to acoustic. These Elixir Nanoweb acoustic string sets are available for just $12.74 in this multipack deal over at Amazon.

I've been testing electric guitar strings recently for our buying guides, and while I won't reveal the exact results here, I can tell you that the D'Addario NYXL scored very highly indeed. Over at Amazon, you can bag a three-pack of them with 20% off. That's $9.06 per pack.

If you want long-lasting tone, Elixirs are the gold standard. They may be more expensive than non-coated strings, but they stay fresher for much longer. Coming in at $10.49 per pack, each one could last you twice or even three times the time of a normal string, making it well worth the investment.

This 5-pack of D’Addario XLs is down to just $26.99, which is an uber-cheap $5.39 per pack. D’Addario strings are renowned for their durability, giving players long-lasting tone. Their signature feature is the colored ball ends, which make for easy restringing. You won’t mix up your B and G strings with these!

This deal is available on both the Super Slinky and Regular Slinky gauges, working out to $5.49 per pack. Slinkys are one of the most popular string sets for good reason, with killer tone and excellent durability. The strings come in individual packaging, which makes them easy to keep track of when restringing.