Ace Frehley, the original lead guitarist for KISS, died after being taken off a ventilator following a nasty fall and a brain bleed … and tributes are pouring in from tons of rockers, including his KISS bandmates Gene Simmons and Paul Stanley.

In a statement to TMZ, Gene and Paul say … “We are devastated by the passing of Ace Frehley. He was an essential and irreplaceable rock soldier during some of the most formative foundational chapters of the band and its history. He is and will always be a part of KISS’s legacy. Our thoughts are with Jeanette, Monique and all those who loved him, including our fans around the world.”

Former KISS guitarist Bruce Kulick says “Ace’s passing is devastating to the world of rock. It has deeply affected me as well. He was one of a kind and truly an iconic guitar player. His undeniable role in the creation and success of KISS cannot be forgotten.  Not only was he loved by all, he influenced millions of guitarists around the world.”

Bret Michaels says he can’t thank Ace enough for years of great music, and he’s looking back on all the festivals they did … sending love and respect.

Andy Biersack is honoring Ace for being in what he believes is “the most important American rock and roll band of all time.”

Mötley Crüe touring guitarist John 5 says … “I am so shocked and saddened that this happened to my hero and my friend I’ve known Ace since 1988 and we’ve been very close ever since then. Ace changed the world. He influenced millions of people and changed my life.”

Guitarist Tom Morello says Ace was his “first guitar hero.” He says Ace “inspired generations to love rock n roll and love rock n roll guitar playing. His timeless riffs and solos, the billowing smoke coming from his Les Paul, the rockets shooting from his headstock, his cool spacey onstage wobble and his unforgettable crazy laugh will be missed but will never be forgotten.”

We broke the story … Ace was hospitalized and on life support, breathing through a ventilator after falling in his studio and suffering a brain bleed.

Ace’s family took him off the ventilator Thursday, and he died. He was 74.