You might have noticed that most inexpensive banjos have guitar type keys and most expensive banjos have planetary keys. And you may have wondered why. If so, read on…
I will first address the inexpensive banjo with guitar keys. This part is simple, inexpensive guitar keys are in abundant supply, Manufactures use these to keep the cost of the instrument low.
Your more expensive banjos with have planetary keys. Banjo players who seek to improve their tuning experience will often ask advice about swapping their banjo keys for high end guitar keys because of the higher gear ratio of the guitar keys.
My main instrument is guitar and I grew up with the distinct notion that the higher the gear ratio of your tuning keys, the better the keys. For novices, the gear ratio for a tuning key refers to the amount of full turns of the key that it takes for the string post to make 1 complete revolution. The more turns it takes, the more precisely you can tune. Therefore, in theory, a 12:1 gear ratio, common for Guitar, would be better than say a 4:1 gear ratio which is common for a planetary banjo key. So then, this knowledge may lead you to more questions like “why not put guitar keys on your banjo” and “if I did, is that an upgrade?”
First you should realize that it is not all about the Gear Ratio for all pickers. Banjo players, especially bluegrass players, are by nature a traditionalist lot. Most of them will agree , as my grandpa would say, “Planetary keys just look right on my banjo” this of course might simply be because banjo keys originated as friction pegs that stuck straight out the back just like Planetary keys do. But there is more to it than that. I think most banjo players would agree with my grandpa about a few other aspects were he here today. He once told me “I have no problem tuning fast and accurate with planetary keys” He explained that because he used many different tunings, he could switch tunings faster, which he could do in nano seconds it always seemed. The other thing he pointed out was that he frequently broke strings and the lower gear ratio of his keys also made it faster to change strings and get back in tune. All of these aspects were important to him.
You should realize that there is no “right/wrong’ scenario here. It is all a matter of personal preference and what is important to you. If you prefer guitar keys, by all means, use them, if you’re a traditionalist and or are happy with your keys, let them alone.