Digidesign 442 Quad Interface (looking for schematic)

[clintrubber]

Digidesign 442 Quad Interface (looking for schematic)

Got a few Digidesign 442 boxes that might best be completely emptied & only
the case re-used, but was wondering how much use could be had from the analog
in- and output-sections when adding just some simple line-level processing circuitry.

There'll be some balancing to unbalancing going (and vv) as well as some pre- & post-filtering.
FWIW, the thing is full of RC5532(A), is this the less favourable Raytheon version by chance?
(saw that Fairchild did RC as well)

If anyone happens to have a schematic that would be convenient.

Thanks,

Peter

 

[MartyMart]

I just gutted two after paying £9 each for them !!
No help on the schem, though i did search and found some info on them.
I didn't think it was worth the effort, just dremel'd the board around the neutrics to keep I/O intact and kept a few parts.
It's a nice little project case now !
Marty.[/i]

 

[clintrubber]

Hi,

That approach might indeed be the best :thumb:
Some useful stuff in there still; the converters aren't interesting but for instance the dig receiver (CS8412 ?) might be of use for some gizmo-circuit... for instance using the digital section from AES or S/PDIF to the CS8412 for something like this: http://www.digido.com/bob-katz/digital-detective.html
(not checked yet)


Here they're EU15, but since they sent me a wrong one there's a 'new' one upcoming, bringing the price/box even further down to half of that.

What did these things cost back then ? (when they were still useful)

Bye,

Peter

 

[MartyMart]

I used to have a system 8 in 1995 with an 882 20 I/O
sold it for £80 about two years ago ... it cost me almost £800 !!!!

MM.

 

[clintrubber]

Before I gut them as well I was just curious if these boxes can be used as stand-alone AD or DA ? (as can the 888 as its manual mentions)

I'm aware of the 'obsolete bit-depths', but was just curious. I fed the 442 some S/PDIF signal but nothing happened. I won't keep trying but if a few minutes do the trick then why not ? If minutes become hours then it's time to stop this.

No real confirmation from here:
http://www.diyaudio.com/forums/showthread.php?threadid=38863

Regards,

Peter

 

[MartyMart]

Peter, I did some reading and found that they are not much use without the
now obsolete "nubus" connection ( pre G4 computers IIRC )
Seems like there's a "hack" to use them as a basic 20dB pre-amp, but nothing
made me want to save the boards.
Someone much less of a "hack" then me, suggested that the digital side could be
addressed, but it was a complex procedure at best !!.
One of mine is becoming a home for 1 or 2 API's, after filling the front row
of holes with "metal bondo" and a coat or three of black hammerite

Marty.

 

[clintrubber]

[quote author="MartyMart"]Someone much less of a "hack" then me, suggested that the digital side could be
addressed, but it was a complex procedure at best !!.[/quote]
The mod-info from diyaudio perhaps ? Haven't read it fully yet, but bet it will simply work, CS8412, converters, deal.

One of mine is becoming a home for 1 or 2 API's, after filling the front row
of holes with "metal bondo" and a coat or three of black hammerite

Marty.

Didn't knew about such a thing existing, good to know :thumb:
Hmm, hammerite, why not ? Thinking of it, for grins would love to see or make a box with the common green machine colour :wink:

But yes, I'd better stop & simply re-use. With some hacks one could get at best some functionality that I have available in other boxes already. It's just that the decent stuff inside (well made) deserved a bit of hesitation before hacksaw :wink:

Cheers,

Peter

 

[Walrus]

[quote author="MartyMart"] snip.
One of mine is becoming a home for 1 or 2 API's, after filling the front row
of holes with "metal bondo" and a coat or three of black hammerite

Marty.[/quote]

That's a "Me too" there! Lets see who can be first with pics.... :grin:

 

[MartyMart]

It's called "Unibond metal repair" nasty stuff that sets hard in 10 mins -dont get it on your hands !!
once dry you can file it down / sand / drill it etc.
Yes it's kind of "sad" to gut them, but for £9 it was worth it just for the case alone .
MM.

 

[clintrubber]

[quote author="MartyMart"]It's called "Unibond metal repair" nasty stuff that sets hard in 10 mins -dont get it on your hands !!
once dry you can file it down / sand / drill it etc.[/quote]
Thanks :thumb:

Yes it's kind of "sad" to gut them, but for £9 it was worth it just for the case alone .
MM.

True !
Too bad the original XLRs are PCB-mounted, so a bit enlarging of the rear-holes required to fit the usual type of XLRs, but that's not too big a problem... wait, I'm not sure the original pitch accomodates 'normal' XLR-connectors. FWIW...

API-micpre... did you keep the switchmode supply ?

 

[Walrus]

[quote author="clintrubber"]

AP-micpre... did you keep the switchmode supply ?[/quote]

I'm going to try it with my one, as it's easier! It was good enough for Digi.....

 

[clintrubber]

[quote author="Walrus"]It was good enough for Digi.....[/quote]
Hmm, note that the 442 does line-levels, not microVolts.
Which doesn't mean that it can't be done of course, there'll be perfectly good micpre's out there with a switchmode supply.

On the other hand, there are also micpre's out there who keep the AC-side of the supply out of the box altogether.

In other words: keeping the switchmode might save time at first, or might cost you additional time later on when you have to debug.

I'll be doing line-level stuff in the 442-box, so will keep the switchmode.

Happy re-using, enjoy :thumb:

 

[Walrus]

[quote author="clintrubber"][quote author="Walrus"]It was good enough for Digi.....[/quote]
Hmm, note that the 442 does line-levels, not microVolts.[/quote]
Yeah, it is one of the things that may make it a dismal failure. But nothing ventured, nothing gained! :grin:

 

[MartyMart]

Switch mode !!! ..... YUK !
No, have a toroid in there and a spare 9k PSU board for +/- 24v and 48v
( I'm using a Fabio/Ptown 990 kit so it's happy at +/-24v )

MM.