Effects ranging from involuted mellow funk lines to slashing thing chops can be instantaneously and sensitively controlled …

I see. Guitar Player, January 1977 features six Electro-Harmonix ads. I guess there weren’t that many high profile guitar mags back then about which to spread promotion. The Doctor Q envelope filter isn’t nearly as sought after as, say, the E.H. Queen Triggered Wah, but it’s still a pretty bitchen old pedal.