EMU 1820 to 1820 M - Is it possible?

[luis]

Hi, i´ve been reading this forum for some time and decided to register and start with DIY!

I have an EMU 1820 audio interface witch is very good by the way, but the the 1820 M is better.

Is it possible to convert/mod the 1820 to the 1820M?



Thanks,
Luis Fernandes

[Svart]

Do you know what the differences are?

[ChrioN]

better converters

[luis]

The 1820 uses the BB PCM1804 converter, CS4392 D/A and N5532  OP Amps.

The 1820M uses the AKM AK5394, CS4398, JRC2068 .




Would this change be possible?

regards,
Luis

[Svart]

possibly change the opamps but I don't honestly think you will get much difference from changing the AD/DA parts.

[Rochey]

the TI PCM1804 is not pin for pin compatible wiht the AK5394A.

My suggestion would be to save up, get a PCM4222 EVM from TI and put it in a case with a power supply. Then bring in the signal over S/PDIF into your creative box.

That'd give you 123dB easily.

/R

[grifops]

I already wrote luis, but I had the same questions.  Obviously EMU was not willing to give up the schematics. SO, I did the next best thing.

Did some research, found the TI PCM4202.  SNR 118dB....  Pin for pin is the same as the 1804 but with some slight differences, I guess a different voltage reference.  

I had a EMU 1212m I picked up the EMU 1820 audio dock alone for $20 for the increased number of inputs and the monitoring options.  I was disappointed in the sound quality compared to the 1212m, which has the AKM A/D and the better D/A on the daughter card.  

Anyway, I did the swap, sounds good, I am noticing a certain clarity with the 4202 that just wasn't there with the 1804.  The recording I have done with the 4202 installed sounds much more like the recording I was doing with the 1212m.

Also, any 1820m users that also have the 0202 daughter card? Are the drivers the only thing holding us back from using both to give 10 inputs and 2 more excellent outputs?

[mhelin]

EMU 1616 also has the same PCM1804 converters so propably it's also possible to swap these with PCM4202's, right?  How about the 6.0V p-p full scale input on PCM4202 vs. 5.0V on PCM1804, is that a problem? Apparently the digital level used is 3.3V so that should be no problem.

[Skylar]

I worked at EMU for about 4 years as an SQA Engineer during development of these products.
We measured a 6–8dB SNR and dynamic range difference between the 1820 & 1820m docks (the m-grade being better obviously).
On some of the 1820m's that passed through the lab, we measured as high as 120dB dynamic range and -120dB SNR, both A-Weighted.
But typical performance was ~118dB.
These measurements were made via RMAA. On the AP1/AP2, these results were always a couple of dB higher.

1820 "non-m" always had 6–8dB lower dynamic range/SNR.

If I recall correctly, the circuits of the 1820m & 1820 are different enough that one cannot simply swap parts.


About the 0202 daughter card:
The drivers and software only allow either the audiodock or the daughter card to enumerate. Never both.
The system I am using right now has both plugged in; the audiodock will take precedence.


I have done a phenomenal amount of recording and listening to the "m" and "non-m" grade E-MU cards.
If I were given a double-blind test, I would probably be unable to distinguish them,
although there is a measurable performance difference.

[modhackmaster]

My 1820m audiodock died unepectedly after 4 years of light usage, and I was searching to replace the dock. I got a 1820 non "m" dock from internet, and successfully hook up with my exisitng cards comes with the original 1820m sets. So far, it is working. So, is the audiodock for 1820 and 1820m the exact same one? Does anyone know this?

[Skylar]

The 1010 PCI card works with both the 1820 and 1820m docks (as well as the 0202 daughter card).

1010 PCI + 1820 dock = 1820
1010 PCI + 1820m dock = 1820m
1010 PCI + 0202 card = 1212m PCI

The NEWER 1010 PCI will not work with the 1820/1820m docks. It only works with the 0202 card or the 1616/1616m docks.
You can identify a new 1010 PCI by the lack of a firewire port.

The difference between an m and non-m product is in the converters.
Read my previous post.
These are excellent cards (maybe I'm biased—I put a lot of my blood, sweat, and tears into those products), and you can't go wrong with the 1820m or 1820.

[modhackmaster]

Skylar,

Thanks for your lighting fast reply, and very appreciated it.

So, the audiodock is different between "m" and non "m".

It is a pity that my 1820m dock died, and I can't get it anywhere now. I am going to stick with 1820 dock atm, and hopefully, find a 1820m dock somewhere on internet in future.

[Skylar]

Well they're all "audiodocks", as termed by E-MU.

But there are different model numbers...
1820m
1820
1616m
1616

With the original 1010 PCI card (with firewire port), only the 1820 and 1820m will work.

With the new 1010 PCI card (no firewire port), only the 1616 and 1616m will work.

And yes, the "m" suffix means that the converters are "mastering grade."
So, the "m" docks are more desirable to most people.

[modhackmaster]

I actually have a 1010 PCI card withOUT firewire port, so does it work with 1616m? 
If it works, the old 1010 PCI card is gold then. 

[Skylar]

It really doesn't get any simpler than this:

With the original 1010 PCI card (with firewire port), only the 1820 and 1820m will work.

With the new 1010 PCI card (no firewire port), only the 1616 and 1616m will work.