Premier Guitar August 2015: This year's annual Amp Issue features a smorgasbord of invaluable knowledge for guitarists and bassists - from beginners to advanced players. For starters, AmplifiedParts.com's tube guru Kurt Prange goes deep on power tubes, detailing the crucial tonal characteristics, important historical developments, and quintessential reference recordings for EL34, EL84, 6L6, 6V6, KT88 and KT66 valves. Then Mark Gooday, founder of Ashdown Engineering and former head engineer at Trace Elliot - two of the most influential and highly respected new bass-amp companies of the last 30 years -ÿdemystify power amp classes (A, B and D), as well as how to read power ratings to ensure you get the tone and oomph requisite for your needs. PG Senior Editor Joe Gore's The Recording Guitarist column also offers savvy tips for using frontman and Allman Brothers all-star Warren Haynes, influential British guitarist Richard Thompson (Fairport Convention), fingerstyle acoustic Guitarist Ryley Walker, and Ruban Nielson from garage-psych band Unknown Mortal Orchestra. Our latest Forgotton Heroes installment takes a look at the fascinating life and enduring legacy of Pops Staples -ÿAn influential gospel guitarist and friend and comtemporary of blues gods Charlie Patton, Robert Johnson, and Albert King. Gear reviews this month include guitar and bass toys from Electro-Harmonix, Eden, TC Electronic, Ibanez, Fender, Orange, Aria, Fishman, and more.