The Secret Society of Lathe Trolls

ormandylives · Joined: 04 Mar 2008 Posts: 7 Location: Massachusetts

Hello There,

Is anyone out there familiar with RCA's Dynagroove of the 60's??????

What was going on and can it be somewhat compensated for when listening to a Dynagroove disc. ?????????

Thank you

ormandylives

Perisphere · Posted: Fri Mar 14, 2008 7:52 pm Post subject:

Dynagroove was designed to do two things: Overcome the dynamic range limitations of domestic console stereos of the era (it was introduced in c.1963) through manipulation of the frequency balances of sounds depending on the dynamics and loudness of them (somewhat compressing bass and midrange more than the top end) and reducing inner-groove distortion (by way of introducing a degree of distortion opposite in polarity to the pinch distortion that inner grooves suffer from worse than any other).

AFAIK these processes were introduced at the disc cutting stage. I think the first processing (the dynamics stuff) was discontinued around 1967. The latter is what must be what was used for some years afterward where Dynagroove is mentioned on the backs of some RCA LP sleeves into 1968, even though it was not shown on record labels after the introduction of the orange labels. (The first album from Brotherhood, RCA LSP 4092, was originally issued on orange labels, but has a small Dynagroove blurb on the back of the sleeve, for example.)

The pre-distortion was designed with the limitations of conical styli in mind.

Hope this helps!