I was just given an 8-channel mic preamp identifed only by

ULTRA SOUND, INC / CMD, INC

It's a small production unit with nicely made circuit boards JT-16A
input transformers, unidentified output transformers. The guts of each
channel has an LF353, a TL071, and in the middle a square potted
discrete module (clear potting compund) identified, at least top and
sides (I can't see the bottom since they're soldered in place and I
haven't removed one yet) by the number "129" on the module board.

It requires an external power supply, probably just +/- 15 or so volts
plus phantom power. Easy to identify, I just haven't hooked one up
yet.

The case is one of those made from extruded aluminum pieces. This one
is obviously part (maybe half, maybe less) of a system since the front
panel sections are numbered 9-16. Controls for each channel are gain,
polarity, and phantom power.

Obviously there's at least one other of these. Anyone seen or have
one? Wasn't Ultra Sound (or was that Ultrasound?) one of the companies
that supported the Greatful Dead? I'm not dreaming that this is is a
valuable piece of history, just curious while I dig around for
something to power it up to see how it sounds or check the color of
the smoke.



--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me he double-m-eleven-double-zero at yahoo

Mike;

I sold small quantities of 990 op-amps potted in clear-epoxy to
Ultrasound back in the early 1980s (I vaguely recall). They were
affiliated with the Grateful Dead, but I can't remember if it was "Ultra
Sound" or "Ultrasound".

The number "129" may be the three digit date code that I wrote on the
p.c. board of each module between the row of four pins and the edge of
the board, hand-written in black ink. The "1" represents 1981, and "29"
is the week of that year.

But the clear potted modules may not be my 990s at all. Just a
possibility. Thanks.

John Hardy
The John Hardy Co.
www.johnhardyco.com

In article writes:

I sold small quantities of 990 op-amps potted in clear-epoxy to
Ultrasound back in the early 1980s (I vaguely recall). They were
affiliated with the Grateful Dead, but I can't remember if it was
"Ultra Sound" or "Ultrasound".

How very cool! I took a closer look and discovered that the modules
are socketed. I pulled one off and darn if it doesn't say

JH (in script like your sometimes logo)
990
15V

I'll have to dig up a copy of Jensen's application note and see if
what's here is his buildup around the 990 module.


--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me he double-m-eleven-double-zero at yahoo

In article znr1087659066k@trad, (Mike Rivers) wrote:

I was just given an 8-channel mic preamp identifed only by

ULTRA SOUND, INC / CMD, INC

It's a small production unit with nicely made circuit boards JT-16A
input transformers, unidentified output transformers. The guts of each
channel has an LF353, a TL071, and in the middle a square potted
discrete module (clear potting compund) identified, at least top and
sides (I can't see the bottom since they're soldered in place and I
haven't removed one yet) by the number "129" on the module board.

It requires an external power supply, probably just +/- 15 or so volts
plus phantom power. Easy to identify, I just haven't hooked one up
yet.

The case is one of those made from extruded aluminum pieces. This one
is obviously part (maybe half, maybe less) of a system since the front
panel sections are numbered 9-16. Controls for each channel are gain,
polarity, and phantom power.

Obviously there's at least one other of these. Anyone seen or have
one? Wasn't Ultra Sound (or was that Ultrasound?) one of the companies
that supported the Greatful Dead? I'm not dreaming that this is is a
valuable piece of history, just curious while I dig around for
something to power it up to see how it sounds or check the color of
the smoke.



--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me he double-m-eleven-double-zero at yahoo


I believe CMD (Concert Music Designs) was a company who later became IMS
(Integrated Media Systems) and then developed the Dyaxis recorder/editor. We
have a custom IMS 4 channel preamp that uses a +/- 15, +/- 24, +48 VDC external
power supply. The IMS preamp is a DC servo transformerless design and it sounds
great (except for channel 3 that doesn't sound at all...) No documentation,
alas. Ultrasound did a lot of custom speaker enclosure and studio rack
furniture work in addition to making whatever the Dead seemed to want at the
moment.

-Jay
--
x------- Jay Kadis ------- x---- Jay's Attic Studio ------x
x Lecturer, Audio Engineer x Dexter Records x
x CCRMA, Stanford University x http://www.offbeats.com/ x
x-------- http://ccrma-www.stanford.edu/~jay/ ----------x

In article writes:

I believe CMD (Concert Music Designs) was a company who later became IMS
(Integrated Media Systems) and then developed the Dyaxis recorder/editor.

Interesting. Were they a San Francisco area company also? It's been so
long since the Dyaxis I don't remember where they were from.

I powered it up over the weekend, only had a +/-12V supply available
but except for one channel that hums and switches that need cleaning,
it seems to work. Just a quick check with my voice, it sounds sort of
like, but less airy than my Great River, probably mostly because of
the similar input transformers. The humming channel is quiet until a
mic is plugged into it, so it's possibly as simple as a miswired input
connector.

Not a bad find for free.

--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me he double-m-eleven-double-zero at yahoo

In article znr1087836339k@trad, (Mike Rivers) wrote:

In article
writes:

I believe CMD (Concert Music Designs) was a company who later became IMS
(Integrated Media Systems) and then developed the Dyaxis recorder/editor.

Interesting. Were they a San Francisco area company also? It's been so
long since the Dyaxis I don't remember where they were from.


IMS was in San Carlos (a little south of SF) when they started the Dyaxis
project. We had a big audio crossbar switch system made by CMD that ran from an
Apple II to distribute the audio output of the Samson box synthesizer back in
the dark ages.

-Jay
--
x------- Jay Kadis ------- x---- Jay's Attic Studio ------x
x Lecturer, Audio Engineer x Dexter Records x
x CCRMA, Stanford University x http://www.offbeats.com/ x
x-------- http://ccrma-www.stanford.edu/~jay/ ----------x

In article znr1087836339k@trad (that's me!) writes:

Interesting. Were they a San Francisco area company also? It's been so
long since the Dyaxis I don't remember where they were from.

Jensen weighed in today with info that they sold transformers to Ultra
Sound in 1981, and they were indeed in "Dead" country. Still no
guarantee that these were built for the band, but the location and
time were right.


--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me he double-m-eleven-double-zero at yahoo

In article writes:

We had a big audio crossbar switch system made by CMD that ran from
an
Apple II to distribute the audio output of the Samson box synthesizer

Maybe CMD was the builder, and Ultra Sound was the designer.

--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me he double-m-eleven-double-zero at yahoo

Mike Rivers wrote:

Jensen weighed in today with info that they sold transformers to Ultra
Sound in 1981, and they were indeed in "Dead" country. Still no
guarantee that these were built for the band, but the location and
time were right.

GD weren't/aren't Ultrasound's only client.

--
ha