After relying, for many years, on other manufacturers to power his headphones GRADO took the decision to design his own headphones amps: the RA1s.
Grado RA1 AC's features
•The “RA1 Bat” is a perfect match to any GRADO headphone. It will let you enjoy music anywhere for 40 hours (on a set of 2 X 9v batteries).
•The “RA1 AC”: as the name says, is powered by an AC adaptor (very hefty.
•The RA1 HG (special order) was designed for higher impedance headphones, (most German headphones).
These headphone amplifiers are housed in a solid block of mahogany and measure: 13cm (5") in width, 14cm (5 1/2") in depth and 4cm (1 1/2") in height; they weigh 336g (12 oz).
Anyone of the 3 above GRADO HEADPHONE AMP, coupled with a quality portable player, uncompressed music, will make a very high end portable audio system.
Studio Economik New 500 series preamp from Geoffrey Daking featuring vintage Trident A Range tone, Jensen input transformer and Class A circuitry. The variable high pass filter is indispensable for tracking sessions!
