I just found out that Grado made this amp and I was curious to its sound qualities with Grados. If anyone has pics that would be sweet too.
post #1 of 20
6/8/05 at 11:41am
Originally Posted by GoRedwings19
From the pictures it looks quite substantial.
Originally Posted by Hirsch
The sound is similar to the RA-1, but in close comparison HPA-1 is smoother with noticeably less grain. The regulated power supply was a $125 option, and allows selection between AC and battery power (note the use of the Ultra-Wide Bandwidth Reference cable). It uses two 9v batteries, same as RA-1, but there's room in the battery compartment to carry a spare set. I got approx 25-30 hr on a pair of Plainviews.
There was never a production run, per se. All mechanical work was done by Joe Grado himself. All electrical work was done by an engineer who originally worked on QC for Marantz (I've forgotten his name, unfortunately). Those two people built all of the HPA-1's by hand.
It's a fairly warm sounding amp. The weak spot, compared to today's battery-powered amps, is the low end. There's less bass extension and definition than the best of the battery-powered amps (Headroom Cosmic, Gilmore AE-1, Ray Samuels SR-71 are some that I've heard with better bottom ends).