This is my second bulk purchase of these Yamaha strings. I work work with three Yamaha APX guitars (the best live guitars in the world!) and was stringing them with Martin strings for years. I didn't realise that Yamaha made a set designed for the APX. And these are Phosphor Bronze which I wasn't really used to playing with. However, the sund is beautifully rich and warm. The strings liven the bass sound even more when unplugged and these strings are lovely to play live. Very good value and even better if you buy in bulk. Highly recommended.