I don't know of any such device and I don't even think it's possible as the firewire would require some heavy processing before it could be used by another device. It's probably not a case of simple format translation. I could be wrong though.

One option although it may not be what your looking for is to use the direct outs (DB-25 to TRS) into something like an AI3 which would give you the ADAT connection. That's how I use my 1620 for overflow pres.

Thanks for that. I suspected this would be the case, but I had to ask.

Tell me, the AI3.... I've heard that they are only 20bit converters. Is this correct? Or is there an old 20bit model?

only one model for the Ai3.
20 bit ??
mmmm
I don't like to answer questions like this with simple answers cos they is always a ... rub.

more importantly is the fact that the lightpipe interchange of many of these units are using the Wavefront chips 1401 & 1402
and most manufacturers just implement the Wavefront application notes and so are very similar internally.
Including the ADA8000

from the 1402 data sheets
The AL1402 provides support for both the ADAT Type I format (16-bit) and the ADAT Type II
format (20-bit). Data lengths of up to 24 bits are supported..

I could say it is 24 bit

the Alesis web site currently says,
8-Channel 24-Bit A/D/A Connectivity at a Breakthrough Price .

I can't find my old literature on the Ai3 to see how Alesis used to describe it.

Alesis also say
ADAT Optical…the World’s Digital Standard
The AI-3 will convert any analog signal to the ADAT Optical digital standard. ADAT Optical is the most widely-used digital interfacing protocol, since it carries eight channels of digital audio at up to 24-bits of resolution using a compact, inexpensive fiberoptic cable.

as i've "said" before...... the ai3 has a S/N ratio of 100dB...

that means that it only delivers 16(.5)bits resolution...although it says 24bit (20bits is 120dB S/N... 24bits is 144dB)

so i must conclude that it is a crap product!!

what chips it uses is irrelevant in this (poor) case....

iznogood wrote: as i've "said" before...... the ai3 has a S/N ratio of 100dB...

to properly specify s/n you must say more than just X dB
see the Rane Library notes on specifications.
I can easily make you a a 24 bit D to A that only gives 50 dB s/n at either a or c or any weighting you want me too.

It does matter what chips are used
AND
it does matter how the topology is implemented.

The Wave Front chips are not 16.5 bit.

I don't know of anything that can convert your firewire signal to ADAT, however, any set of digital converters should be fine... I would recommend RME converters as they all have ADAT outputs and sound pretty good. The old Swissonic ones sound good too, but they aren't made anymore.

The Onyx has a pre-fade direct analog out that is pretty clean. With DB25 connectors (tascam pinning), you get a ballanced out (rather than the old half insert unbalanced thing).

--Ben

sorry
I just had to come back and add to what I was saying above about s/n ratios

here is a quote from the Rane Tech Library
http://www.rane.com/par-s.html#S_N

S/N or SNR (signal-to-noise ratio) An audio measurement of the residual noise of a unit, stated as the ratio of signal level (or power) to noise level (or power), normally expressed in decibels. The "signal" reference level must be stated. Typically this is either the expected nominal operating level, say, +4 dBu for professional audio, or the maximum output level, usually around +20 dBu. The noise is measured using a true rms type voltmeter over a specified bandwidth, and sometimes using weighting filters. All these thing must be stated for a S/N spec to have meaning. Simply saying a unit has a SNR of 90 dB means nothing, without giving the reference level, measurement bandwidth, and any weighting filers. A system's maximum S/N is called the dynamic range. See RaneNote: Audio Specifications.
http://www.rane.com/note145.html

Kev,

Thanks for the info. I've wondered about the 20 vs. 24 bit of the AI3. Mine says 24 bit but I've seen older ads claiming 20 bit. I don't really hear any discernable difference between my AI3 and my Layla 24/96 which is true 24 bit so I have always assumed the AI3 is labled truthfully.

Kev wrote: [quote=iznogood]as i've "said" before...... the ai3 has a S/N ratio of 100dB...

to properly specify s/n you must say more than just X dB
see the Rane Library notes on specifications.
I can easily make you a a 24 bit D to A that only gives 50 dB s/n at either a or c or any weighting you want me too.

It does matter what chips are used
AND
it does matter how the topology is implemented.

The Wave Front chips are not 16.5 bit.

please kev..... stop lecturing me..... i know your a knowledgeable guy so you don't have to show off to me....

i know about S/N..... and you're right.... i was just quoting the alesis web page.... so once again:

A/D

Signal To Noise (A-wtg.):
_100dB balanced, 100dB unbalanced

Dynamic Range (-60dBfs, 1kHz):
_96dB balanced, 96dB unbalanced

D/A

Signal To Noise (A-wtg.):
_98dB balanced, 98dB unbalanced

_Dynamic Range (-60dBfs, 1kHz): 95dB balanced, 95dB unbalanced

so you can see this is a bit less than stellar specs for a socalled "24-Bit Analog-to-ADAT Optical Interface"

most converters boast about 20bits of S/N.... i think the most i've seen is 20,5 bits...

so to release a "24-bit" converter where you get NOTHING out of the last 8 bits is a bit of a hoax..... and anyway it tells me that their implementation of the chips is less than optimal.....

and yeah i know that the chips matter.... but not if the design is so flawed as i think the ai-3 must be....

they didn't even "invent" better specs as most company's do....

sorry
lecturing is not my intention
just to play devil's advocate
specs of unequal weight do get thrown about here

and although I am a tech and specs and testing is my bread and butter ...
specs can very misleading at times.

a unit as cheap as the Ai3 or an ADA8000 shouldn't have to go one on one spec wise with a unit at multiple thousands.

they are cheap and useful ... that's all

iznogood wrote: i know about S/N..... and you're right.... i was just quoting the alesis web page....

yes
and shows another example of how manufacturers can use spec incorrectly ... or incompletely

Dynamic Range (-60dBfs, 1kHz):
_96dB balanced, 96dB unbalanced

so you can see this is a bit less than stellar specs for a socalled "24-Bit Analog-to-ADAT Optical Interface"

definitely not stellar
but may be due more to the analog stage rather than the optical chips.

Both the units above return different s/n figure even though they use the same topology of analog stage.
straight from the Wavefront application notes ... as is most of the units that use these chips. !!

BUT
both these units have been set up to run at different analog levels
the Ai3 ids quite low at around 16 or 17 dBu

most converters boast about 20bits of S/N.... i think the most i've seen is 20,5 bits...

20.5 bits ???

so to release a "24-bit" converter where you get NOTHING out of the last 8 bits is a bit of a hoax..... and anyway it tells me that their implementation of the chips is less than optimal.....

you get what you pay for

an LA2 or LA3 or LA4 may not return good s/n figures , well below the Ai3
but that shouldn't stop you buying one
(LA4 is easy to improve)

and people still haven't noticed the reason they haven't bothered to go for the extra s/n
ADAT Type I format (16-bit)
ADAT Type II format (20-bit)
Data lengths of up to 24 bits are supported

how many manufacturers are willing to to state what format they currently use ?
when did the adat world agree to a 24 bit standard ?

old units ... new units
at least it is all compatable so far

from a Black Adat through a Korg1212 to the newest tascam or tango ... or whatever
it all still does pass a signal
so no dead gear
8)

... they didn't even "invent" better specs as most company's do....

:D :D :D
good to see you are cynical when it comes to manufacturer statements
8)

here is a lightpipe audio converter- I'm thinking of getting one for my motu 828mkii so I can get 8 more ch pres in via adat

http://www.musiciansfriend.com/srs7/g=live/search/detail/base_pid/240162/