Hi Brian, Jim,
It sounds like this was essentially a "hum-bucking" coil. I have
often wondered if the power transformer is inducing hum into the
internal wiring in the PS-3. A while back I started to experiment with
both twisting various wires and shielding the transformer to see if it
dropped the noise floor, but time constraints cut that short. I will
have to look at that again one of these days.
I paid a visit to the Neotek factory ca. 1988. One of the reasons
that I went was because of the kind of thing that Brian is talking
about, although I got the feeling that folks were at least /trying/ to
be helpful. This would have been during their "we have a switch problem
era" when they were having to repair or replace literally thousands of
defective Schadow switches. I remember seeing a bench where several
motherly looking ladies were, IIRC, replacing the actuators in the
Schadow switches in what must have been Elite modules.
On that visit, I met Craig, the owner/designer, and he seemed
pleasant enough until I started to push the issues that I was having
with PS-3's at the time. Then he seemed to lose interest in the
discussion fairly quickly and I was ushered out... I'm not sure when
Neotek was sold to Martinsound, but this must have been around the time
that the wheels were starting to come off, so I'm sure he had a few
things on his mind.
It's too bad that we don't have any former Neotek staff on this
list, the way we have some very prominent former Ampex people on the
Ampex list.
Best,
Ike
On 1/31/2010 10:42 PM, Brian Roth wrote:
Hey Jim,
It may have been only three or four feet of wire vs. six or
eight....it's been over 20 years ago. BUT, after months and multiple
phone calls to Chicago (with the desk's owner muttering about legal
action), we finally received that "solution" from a tech there. It
seemed this desk was not the only one with the problem.
Indeed, the wad of wire reduced the noise floor, which was most
noticeable on the 2-mix bus, down to an OK (but not perfect) level. I
vaguely recall a -60 something noise floor before, and maybe high 70's
after.
Sidebar: Neotek's owner/designer (one and the same? I never knew)
would not take calls, and we dealt with a few less-than-friendly or
un-helpful folks along the way.
Best,
Bri
Jim wrote:
Hey Brian,
How goes buddy!
Anyway, I'm having a hard time getting my head around this
statement....................
Solution? Install six or eight feet of 18 or 16 GA wiring INSIDE of
the PS-3 (??) PSU box in series with the "ground return" wiring, and
then fuck with the positioning of that series "wads of wire" inside
of the PSU to "null" the noise.
WTF?
Regards, Jim
At 03:16 AM 1/29/2010, you wrote:
Hello Ike, et al:
I recall a new Neotek desk that was delivered here in OKC... 20+
years ago. I cannot recall if it was an Elan or Elite.
From DAY ONE it had "hum issues" on every bus. As I worked with it,
I was shocked to discover the grounding system, which was "every
ground was connected to every ground", including random connections
to the metal work on the front panels.
This was a NEW desk from Chicago.
Audio ground returns were randomly connected to the front panel metal.
I quickly tested the desk with a battery=powered power amp/speaker
combo in order to eliminate any wiring probs, with no I/O besides my
battery-powered system, and at other times my iso'ed scope.
It still hummed/buzzed. Many other tests done..including one
oddity...as I "unscrewed" modules from the frame, the noise changed.
Desk's owner yelled and cried at "Chicago", with no replies for
months. Desk owner SCREAMED, and finally had a reply apparently
from the "unknown mystery circuit designer"...
Solution? Install six or eight feet of 18 or 16 GA wiring INSIDE of
the PS-3 (??) PSU box in series with the "ground return" wiring, and
then fuck with the positioning of that series "wads of wire" inside
of the PSU to "null" the noise.
That came directly from "Chicago".
Egads.....
Best,
Bri
--
Ike Zimbel
Zimbel Audio Productions Ltd.
Toronto
416-720-0887
"Studio House Calls". Authorized Warranty service for Allen& Heath, Clear-Com,
Drawmer, Soundcraft, SPL and Yamaha. Repairs and upgrades to analog audio equipment
including: AMEK, dbx, Neve, Neotek, MCI, Soundcraft and more. Ask about our RF Frequency
co-ordination services!
www.zimbelaudio.com
------
View the list online at: http://www.mail-archive.com/[email protected]
You can unsubscribe at anytime by sending an email to mailto:[email protected] with
"unsubscribe neotek" in the message body. If you have any difficulties, or
questions --please send an email to mailto:[email protected].
The Neotek list is lovingly hosted by Catapult Web. Remember that any message
or reply sent to the list will be automatically forwarded to all subscribers.
Vive Le Neotek!
Thanks.
