This is part of the mechanical alignment of the heads, and can easily
produce the symptom you describe. It refers to the 'tilt' of the heads,
left to right so to speak, of the heads as you face them. That is, as
you face them the heads are supposed to have their 'gaps' perpendicular
to the direction of tape travel. This is normally set with a MRL or STL
alignment test tape with a phase meter or more properly (IMHO) with a
o'scope. For 'special' reasons it can me deliberately misaligned to
match a tape made on a misaligned machine.
I'm likely not explaining this well.... As is common with someone who
has done it for so long... :>)
-----Original Message-----
From: Association for Recorded Sound Discussion List
[mailto:ARSCLIST@xxxxxxx] On Behalf Of Paul Tyler
Sent: Saturday, April 07, 2007 3:28 PM
To: ARSCLIST@xxxxxxxxxxxxxxxx
Subject: Re: [ARSCLIST] Need help with a Revox A77 [?] in Chicago
Ah, there's another word of which I was ignorant. Is the azimuth
related to the alignment? Could that be why one of the channels is way
muddier than the other?
Thanks
Paul
phillip holmes <insuranceman@xxxxxxxxxx> wrote: Paul, Could be the
playback head's azimuth was mis-adjusted (?).
Phillip
Paul Tyler wrote:
Hello,
I'm hoping someone can help an electronic ignoramus. Here's the
story. I have a hundred and fifty open reel tapes I recorded twenty
five years ago that I've been trying to digitize. Most are field
recordings I made on a Nagra on loan from the American Folklife Center
or on a Revox B77 (I'm unsure of the exact model number) owned by a then
brand new public radio station in Fort Wayne. The restof the tapes are
the 26 one-hour radio shows I produced using my field recordings. After
that gig ran it's course, I was left with the tapes and no machine. The
original field recordings are in the Archives of Traditional Music at
Indiana University, and what I have are earliest copies dubbed on the
ATM's Ampex decks.
Fast forward twenty years and I bought a Revox A77 on eBay and started
dubbing my field tapes in my spare time. Somewhere along the way my
preschool daughter filched a light bulb out the Revox--I don't know what
you call it but it was for a light activated shutoff. I took the Revox
to 20th Century Stereo on the north side. The elderly European-accented
proprietor ended doing $300 worth of repairs and adjustments. This was
two years ago, and I'm just now getting back to dubbing my tapes.
But they don't sound the same. I don't have the technical vocabulary
to describe the sound difference. The clarity is gone. It sounds like
my recordings have gone through some sort of filter that distances the
sound. Another description:
the loss of clarity sounds like what happens when you dub cassettes on
cheap portable decks from 1980.
Can anybody offer any help? Like what kind of words I should use if
I take it back to the old German guy. Or do you know any other good
repairman (or woman) in the Chicago area I could consult.
Thank you
Paul Tyler