TU-3 : Tu3 - Industry Standard Tuner

What can I say, this is a tuner designed to tune your guitar.

It is also perhaps the most fundamentally essential piece of kit that any guitarist should own. It is built very solidly and offers cents resolution for getting that precise tuning for your guitar and bass guitar. Accepts 9v and power supply (sold separately) which for its price is a little disappointing.

Not many people know this, but you can use these tuners as DI pedals as well, as the input impedance is set to 2M ohms which is the same as most instrument DI and Hi-Z inputs. Ive used this once or twice when I was short a DI on stage and it did the trick.

Conclusion:

This is perhaps still a little pricey when it comes to tuners. There are other cheaper alternatives out there that all tune a guitar. However, this is the best built (IMHO) and allows for the most accuracy and speed of tuning. There is a reason why the Boss TU line of tuners are so ubiquitous and considered the "industry standard". After using one for months you will understand why. Highly recommended.