Sometime in the 70s my dad's band "The Shades" had a rehearsal space at "the alley" rehearsal studios in Hollywood... Jackson Browne's space was down the hall and apparently Howard Dumble had a space too.
They all spent a lot of time there and I asked my dad and uncle to recall what they could about HAD... I don't know how clear these guys memories are from the time because there was a lot of drinking and drugs going on or whatever but I'll tell you what they told me.
HAD had his bench/equipment set up so that he could show up in a van and roll it in to the space and set up to work on amps for Jackson Browne and David Lindley.
He was a super hippie and also pretty "sciency". He wore a Hawaiian shirt sometimes.
They said the main thing they remember is that he would leave part of a joint at their practice space and when they smoked it they would be absolutely stuck in their chairs giggling like they had never smoked before.
They said the amps he was doing at the time were absolutely wonderful sounding and super easy to play like nothing they had every heard or played.
Enjoy
