[Steve[_3_]]

Hi All;

I currently have a Behringer ADA8000. After the current project I have is
finished I was considering replacing it or upgrading it.

I was considering the Mackie 800R, or opening this beast up and trying my
hand at modding the ADA8000. Has anyone tried it? What can be done to it
and how easy is it? Should I even bother or should I sell it and buy the
800R?

My favourite pre to my ears pre is my FMR RNP, how does the Mackie compare?

If anyone can provide some info on modding the ADA8000 I would appreciate
it.

Thanks;
Steve

[Mike Rivers]

Steve wrote:

My favourite pre to my ears pre is my FMR RNP, how does the Mackie compare?

The Mackie Onyx (which is what an 800R is) is more full and open than
the XDR series (VLZ, VLZ-Pro, VLZ3) Mackie preamps, but it's still a
"clean" preamp with minimal coloration. The RNP has an intentional
coloration. I can't say that you'd like the 800R just as much as the
RNP, or if you do, it will be for different reasons. But if I was going
to have eight of them, I'd rather have an 800R than four RNPs. But then,
I prefer the clean sound and might want to use an occasional preamp for
color.

If anyone can provide some info on modding the ADA8000 I would appreciate it.

If I'm not mistaken, I seem to recall hearing that Jim Williams (Audio
Upgrades) has upgraded it. I've never looked inside one so I don't know
how completely integrated it is. An upgrade would probably involve
replacing the mic preamp chips and converter chips, but there might not
be equivalent better grade parts.



--
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'm really Mike Rivers
)

[David Light]

On Thu, 11 Sep 2008 17:09:01 -0400, "Steve" wrote:

I'm considering bypassing the mic pre on the ada8000 also. I found
a schematic on www.gyraf.dk that shows what is there. It doesn't look
that hard to bypass the pre's.

Hi All;

I currently have a Behringer ADA8000. After the current project I have is
finished I was considering replacing it or upgrading it.

I was considering the Mackie 800R, or opening this beast up and trying my
hand at modding the ADA8000. Has anyone tried it? What can be done to it
and how easy is it? Should I even bother or should I sell it and buy the
800R?

My favourite pre to my ears pre is my FMR RNP, how does the Mackie compare?

If anyone can provide some info on modding the ADA8000 I would appreciate
it.

Thanks;
Steve

[Mike Rivers]

David Light wrote:

I'm considering bypassing the mic pre on the ada8000 also. I found
a schematic on www.gyraf.dk that shows what is there. It doesn't look
that hard to bypass the pre's.

You can probably find quieter transistors, but the mic preamp doesn't
look too harmful and a TL074 isn't so bad. You'll want to measure the
level coming out of the preamp stage (the transistors) and into the
first TL074 stage to find out how to adjust the gain structure. The
Wavefront AL1101 specs look OK, but that doesn't tell you how it sounds.
I guess it's pretty common, though, so unless you change that out,
you'll end up with an A/D converter that sounds like a number of others.

It's worth an experiment if it's constructed so that you can dig into
it, but don't expect miracles.

--
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'm really Mike Rivers
)

[Federico]

Be aware that opening a Behringer unit is difficult.
Many parts are glued together and most electrical pieces are behind the
frontal plate where the space is little.
F.

[Arny Krueger]

"David Light" wrote in message


On Thu, 11 Sep 2008 17:09:01 -0400, "Steve"
wrote:

I'm considering bypassing the mic pre on the ada8000
also. I found a schematic on www.gyraf.dk that shows
what is there. It doesn't look that hard to bypass the
pre's.

It turns out that the performance of the ADA8000 input stage as a line input
is not necessarily problematical. The probable primary source of
performance limitations is the converter chip. Dynamic range is generally
well over 90 dB, so your system performance limits are very likely to be
elsewhe

http://www.audiorail.com/ADA8000_RMAA_summary.gif

The biggest loophole in the design of the ADA8000 mic input stage appears to
be its lack of protection from transients and only mild protection from EMI.
I don't see any clamping diodes or small chokes.

I've had two ADA8000s in service for over 3 years, and they have performed
almost perfectly. The exception is a single mic input (of 16) that seems to
have stopped being balanced. I guess I need to check to see if the
corresponding line input is OK. If so, the failure relates to very few
parts.

[David Light]

On Fri, 12 Sep 2008 08:23:48 -0400, "Arny Krueger"
wrote:

"David Light" wrote in message


On Thu, 11 Sep 2008 17:09:01 -0400, "Steve"
wrote:

I'm considering bypassing the mic pre on the ada8000
also. I found a schematic on www.gyraf.dk that shows
what is there. It doesn't look that hard to bypass the
pre's.

It turns out that the performance of the ADA8000 input stage as a line input
is not necessarily problematical. The probable primary source of
performance limitations is the converter chip. Dynamic range is generally
well over 90 dB, so your system performance limits are very likely to be
elsewhe

I have used the line inputs several times and have no real
complaints, but... The schematic shows that the line input runs
through the same gain stage as the mic. pre which I find odd. Seems
like there should be a better way to do it.

http://www.audiorail.com/ADA8000_RMAA_summary.gif

Thanks for the test info. How was the testing done?

The biggest loophole in the design of the ADA8000 mic input stage appears to
be its lack of protection from transients and only mild protection from EMI.
I don't see any clamping diodes or small chokes.

I've had two ADA8000s in service for over 3 years, and they have performed
almost perfectly. The exception is a single mic input (of 16) that seems to
have stopped being balanced. I guess I need to check to see if the
corresponding line input is OK. If so, the failure relates to very few
parts.

I have 1 ada8000 and a Frontier Tango 24. Both have worked fine.
Still the desire to mod is there.

[Paul Stamler]

"David Light" wrote in message
...

I have used the line inputs several times and have no real
complaints, but... The schematic shows that the line input runs
through the same gain stage as the mic. pre which I find odd. Seems
like there should be a better way to do it.

There is -- use a dedicated line-input amp and switch between that and the
mic input amp. But that costs more money, so almost nobody does it.

Peace,
Paul

[Mike Rivers]

David Light wrote:

I have used the line inputs several times and have no real
complaints, but... The schematic shows that the line input runs
through the same gain stage as the mic. pre which I find odd. Seems
like there should be a better way to do it.

This topology is almost universal. The fact that you have no complaints
is evidence that it's not a big deal. You need to look into some pretty
expensive gear before you'll find a separate low gain input stage for
line level sources (unless it's a line-level-only device). Attenuating
the line input and running it through the mic preamp stage is a cheap
trick that works quite well. You get a differential input, you get a
gain control, and you save money on parts. It's not difficult to build a
quiet mic input stage, and with the line input isolated from the input
impedance by a couple of fairly large resistors, you don't have the
input's effect on the microphone output stage to worry about like you do
when using it with a mic.

The way to make an ADA8000 into a line-input interface would be to
remove or bypass the mic preamp and build your own buffer stage, perhaps
out of the TL071 at the output of the mic preamp, if the gain structure
comes out right.



--
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'm really Mike Rivers
)

[philicorda[_6_]]

On Fri, 12 Sep 2008 02:34:19 +0000, David Light wrote:

On Thu, 11 Sep 2008 17:09:01 -0400, "Steve" wrote:

I'm considering bypassing the mic pre on the ada8000 also. I found
a schematic on www.gyraf.dk that shows what is there. It doesn't look
that hard to bypass the pre's.

I remember a thread on the Prodigy DIY forum about this... he
http://www.prodigy-pro.com/forum/vie...hlight=ada8000

The bits I understood looked useful.

[Scott Dorsey]

David Light wrote:

I have used the line inputs several times and have no real
complaints, but... The schematic shows that the line input runs
through the same gain stage as the mic. pre which I find odd. Seems
like there should be a better way to do it.

Yes, but it will cost a few pennies more. Doing this means you get
a balanced differential line input for free. Otherwise you would need
a second differential input circuit.

I think it's kind of a sleazy thing to do, but you'll find most budget
console manufacturers do the same thing.
--scott

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

[Paul Stamler]

"Scott Dorsey" wrote in message
...
David Light wrote:

I have used the line inputs several times and have no real
complaints, but... The schematic shows that the line input runs
through the same gain stage as the mic. pre which I find odd. Seems
like there should be a better way to do it.

Yes, but it will cost a few pennies more. Doing this means you get
a balanced differential line input for free. Otherwise you would need
a second differential input circuit.

I think it's kind of a sleazy thing to do, but you'll find most budget
console manufacturers do the same thing.

Not just budget; back in the 1980s I used an ADM board which padded the line
inputs down to mic level too. Of course, that was a wholly
transformer-coupled board, so a separate line input would have needed a
second input transformer, which even then cost a lot more than a few
pennies.

Peace,
Paul

[David Light]

On Sat, 13 Sep 2008 10:58:27 GMT, Mike Rivers
wrote:

David Light wrote:

I have used the line inputs several times and have no real
complaints, but... The schematic shows that the line input runs
through the same gain stage as the mic. pre which I find odd. Seems
like there should be a better way to do it.

This topology is almost universal. The fact that you have no complaints
is evidence that it's not a big deal. You need to look into some pretty
expensive gear before you'll find a separate low gain input stage for
line level sources (unless it's a line-level-only device). Attenuating
the line input and running it through the mic preamp stage is a cheap
trick that works quite well.

I guess I have been comparing with expensive gear. It still rubs me
the wrong to attenuate a line level to mic level then apply gain to
get it back where it was.

[Scott Dorsey]

David Light wrote:

I guess I have been comparing with expensive gear. It still rubs me
the wrong to attenuate a line level to mic level then apply gain to
get it back where it was.

I agree, but it's not too big a cut and paste job to add an unbalanced
line input that bypasses the mike stages. And I bet it will sound a tiny
bit better, too.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

David Light wrote:
My original plan was to make the input XLR a line input and make the
1/4 jack a monitor output of the A/D section. It may just be more
trouble than it's worth.

Easy to do IF you want to have both the input and output unbalanced. If
you don't need balancing and you can scrap the mike input completely, it
should be a fairly easy cut and paste job.

The unbalanced input will probably sound better anyway, just by virtue
of having less stuff in the signal path.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[David Light]

On 13 Sep 2008 09:38:53 -0400, (Scott Dorsey) wrote:

David Light wrote:

I have used the line inputs several times and have no real
complaints, but... The schematic shows that the line input runs
through the same gain stage as the mic. pre which I find odd. Seems
like there should be a better way to do it.

Yes, but it will cost a few pennies more. Doing this means you get
a balanced differential line input for free. Otherwise you would need
a second differential input circuit.

I think it's kind of a sleazy thing to do, but you'll find most budget
console manufacturers do the same thing.
--scott

My original plan was to make the input XLR a line input and make the
1/4 jack a monitor output of the A/D section. It may just be more
trouble than it's worth.