Akai-ADAM meter bridges on an analog mixer?

[Keoki]

The Akai A-DAM was one of the first digital audio multitracks; a huge
rack-mountable box with separate 12-track meter bridges. I never owned
one myself, altough I did run a pair for a while in a university
studio 20 years ago.

These days I'm looking for an input metering solution I could add to
an analog mixer - and I ran into a deal where I could buy a mothballed
A-DAM system's meter bridges cheap. The question is, did anyone ever
succeed to make these Akai bridges (or any other unit's meter bridges)
work with plain vanilla analog signals from a mixer?

The Akai units have big D-Sub connectors, not sure if their pins carry
digital signal, analog signal, power too, or what mix of these; if
inserting them before my mixer is just a matter of manufacturing an
analog cable snake ending in a D-Sub plug, or there's more to this.
Anyone knows? Thank you in advance.

[Mike Rivers]

On 12/30/2010 1:47 PM, Keoki wrote:

> These days I'm looking for an input metering solution I could add to
> an analog mixer - and I ran into a deal where I could buy a mothballed
> A-DAM system's meter bridges cheap. The question is, did anyone ever
> succeed to make these Akai bridges (or any other unit's meter bridges)
> work with plain vanilla analog signals from a mixer?

I doubt that anyone's ever tried it. I'd say there's a
better than 50-50 chance that their inputs are digital. You
could open one up and probably make a good guess by looking
at what's inside.

If you could get them for free, or borrow them to take a
look before you decide to buy them, then it might be worth
investigating. Otherwise I wouldn't bother. Think of what
you'd have to do, and probably without any documentation -
figure out the inputs, make a power supply, mount and
connect them.

A better idea would be to try to find someone parting out an
Ampex MM-1100 or MM-1200 recorder and buy those meters. Not
only are they analog, but they're pretty close to being real
VU meters.



--
"Today's production equipment is IT based and cannot be
operated without a passing knowledge of computing, although
it seems that it can be operated without a passing knowledge
of audio." - John Watkinson

http://mikeriversaudio.wordpress.com - useful and
interesting audio stuff

[Keoki]

Hello Mike,

Thank you for the tip. I went back to eBay, my usual haunting grounds,
looking for Ampex parts. There were a busted few, but I had an
epiphany.

I suspected correctly originally that there must to be a market for
self-standing meter bridges. My mistake was to search for the wrong
keyword on eBay. I searched originally (and got meager results of) was
"meter bridge." The right phrase is "vu meters". Pronto, a whole
truckload of devices from TSL, Coleman Audio, Wohler and SM Pro Audio
appeared! The largest was 20 channels, but it's just a matter of time
before a 24-er shows up, I think.

Question. Are LCD meters really that much worse than classical VUs for
distortion reading? I kinda like the vertical LED column look, it's
easier to keep an eye on 24 while I play / compose.

[Arny Krueger]

"Keoki" > wrote in message

> Hello Mike,
>
> Thank you for the tip. I went back to eBay, my usual
> haunting grounds, looking for Ampex parts. There were a
> busted few, but I had an epiphany.
>
> I suspected correctly originally that there must to be a
> market for self-standing meter bridges. My mistake was to
> search for the wrong keyword on eBay. I searched
> originally (and got meager results of) was "meter
> bridge." The right phrase is "vu meters". Pronto, a whole
> truckload of devices from TSL, Coleman Audio, Wohler and
> SM Pro Audio appeared! The largest was 20 channels, but
> it's just a matter of time before a 24-er shows up, I
> think.
>
> Question. Are LCD meters really that much worse than
> classical VUs for distortion reading? I kinda like the
> vertical LED column look, it's easier to keep an eye on
> 24 while I play / compose.

The role of the dynamics of the meter movement have been taken over by
electronics. This especially applies to peak response. The actual display
device, whether LCD, fluorescent panel, incandescent lamp, CRT, plasma or
whatever is not the deciding factor.

The level meters on my 02R96 and and Fastrack are very different, but I
find both of them to be acceptable. I would rate the Fastrack LCD somehwat
higher for the way it stretches peaks and overages. But, that's entirely up
to the electronics (and software) that drive the display, not the display
devices themselves.

[Mike Rivers]

On 1/2/2011 5:53 AM, Keoki wrote:

> I suspected correctly originally that there must to be a market for
> self-standing meter bridges. My mistake was to search for the wrong
> keyword on eBay. I searched originally (and got meager results of) was
> "meter bridge." The right phrase is "vu meters". Pronto, a whole
> truckload of devices from TSL, Coleman Audio, Wohler and SM Pro Audio
> appeared! The largest was 20 channels, but it's just a matter of time
> before a 24-er shows up, I think.

That's all good stuff. I'm surprised that there's one as
large as 20 channels. You may need to put two together to
get 24 channels. With luck, you'll be able to find two of
the same model for cosmetic purposes.

> Question. Are LCD meters really that much worse than classical VUs for
> distortion reading? I kinda like the vertical LED column look, it's
> easier to keep an eye on 24 while I play / compose.

You might do well to read the article "Meter Madness" on my
web site. In general, a classic VU meter isn't a good tool
to tell you when you're approaching digital clipping
because, unless you re-scale it, there's 15 dB or more "off
scale" before you hit clipping. When I record, I'm very
conservative with levels so I've learned to work with VU
meters, at least for a stereo mix, but I'm unusual that way.

LED meters are rarely close to actual VU meters, neither in
scale or dynamic response. The top of the scale (the top
LED) is usually at the maximum output or input level of the
device that they're monitoring. But the problem with most is
a lack of resolution near peak level. The next lowest LED
might be 10 dB lower.

Meter should be your guide, not something to watch
religiously whle you're recording.


--
"Today's production equipment is IT based and cannot be
operated without a passing knowledge of computing, although
it seems that it can be operated without a passing knowledge
of audio." - John Watkinson

http://mikeriversaudio.wordpress.com - useful and
interesting audio stuff

[Trevor]

"Mike Rivers" > wrote in message
...
> LED meters are rarely close to actual VU meters, neither in scale or
> dynamic response.

As someone else said, LED's simply display whatever the maker decided for
their drive electronics. VU or PPM characteristics are quite possible, with
the benefit that you can either at the flick of a switch when so designed.
Or both at the same time in far less space than an analog meter.


>The top of the scale (the top LED) is usually at the maximum output or
>input level of the device that they're monitoring. But the problem with
>most is a lack of resolution near peak level. The next lowest LED might be
>10 dB lower.

Would be a fairly uncommon "meter" that had 10dB between the top 2 LED's.
More likely 3dB. *Many* would have 10dB or more between the bottom 2 of
course, but the more common arrangement is for the gap to decrease as you go
up, and *not* be just a constant gap across the whole range.

Trevor.

[Scott Dorsey]

Keoki > wrote:
>
>Question. Are LCD meters really that much worse than classical VUs for
>distortion reading? I kinda like the vertical LED column look, it's
>easier to keep an eye on 24 while I play / compose.

First it depends on what you want to read. Many of the LED meters do not
have VU ballistics when they claim they do. This may or may not be a
problem depending on what ballistics you expect.

Secondly it depends on the meter. Some LED meters don't have enough
elements to be useful, some do.

I like the RME and Dorrough meters, which are more versatile than
regular VU meters.

On the other hand, with a console bridge you don't need a lot of accuracy,
mostly you need to know just basic ballpark levels there.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Mike Rivers]

On 1/2/2011 4:58 PM, Trevor wrote:

> Would be a fairly uncommon "meter" that had 10dB between the top 2 LED's.
> More likely 3dB.

Wishful thinking. But look at any Mackie or Behringer mixer.
There's more of those than anything else, and that's where
too many people get the idea of how a meter is supposed to
look (and wonder why their levels aren't hot enough when it
was going "almost all the way to the top" most of the time.



--
"Today's production equipment is IT based and cannot be
operated without a passing knowledge of computing, although
it seems that it can be operated without a passing knowledge
of audio." - John Watkinson

http://mikeriversaudio.wordpress.com - useful and
interesting audio stuff

[Keoki]

I saw a nice looking Wohler MSLV-120 today on ebay... looked at the
back panel... what the @#$%! "Phoenix connectors?" (the manual calls
these abortive contraptions)

What were these people thinking?

[Scott Dorsey]

Keoki > wrote:
>I saw a nice looking Wohler MSLV-120 today on ebay... looked at the
>back panel... what the @#$%! "Phoenix connectors?" (the manual calls
>these abortive contraptions)
>
>What were these people thinking?

They're cheap, they're very easy to terminate to bare wires with a
screwdriver. This makes them very popular in the installed sound world
where most equipment gets connected to installed cabling and any time
saved terminating the cabling is a big plus.

Before we had phoenixes we had terminal strips with screws on the back
of lots of broadcast and installed sound gear.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Keoki]

On Jan 4, 12:58*pm, (Scott Dorsey) wrote:

> Before we had phoenixes we had terminal strips with screws on the back
> of lots of broadcast and installed sound gear.

I checked Wohler's other units, all seem to use phoenixes... $9 per
phoenix adapter, times 24 channels... the adapters might cost more
than the occasional unit itself, second hand! Now here's a phoenix I'd
rather see remain ashes... :-)

[Scott Dorsey]

In article >,
Keoki > wrote:
>On Jan 4, 12:58=A0pm, (Scott Dorsey) wrote:
>
>> Before we had phoenixes we had terminal strips with screws on the back
>> of lots of broadcast and installed sound gear.
>
>I checked Wohler's other units, all seem to use phoenixes... $9 per
>phoenix adapter, times 24 channels... the adapters might cost more
>than the occasional unit itself, second hand! Now here's a phoenix I'd
>rather see remain ashes... :-)

Adaptors? The connectors are five or ten cents each, you just put them on
whatever cables you're using. Digi-Key stocks them, they are field-installable
with a Greenie screwdriver.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."