I'm wondering if any experts out there can enlighten me on where the dacs in the 1820m get their clock from? The breakout box where I assume the dacs reside is connected to a pci card through a cable that is something like firewire. Does the clock reside on the pci card and is transmitted over this cable, or is it in the breakout box?
thanks,
Dan
thanks,
Dan
ohhh that´s an interesting question....
i´m a owner of an 1616m Emu ..... and searching
for schematics
is there anybody else who use the emu external boxes?
@ Dan -
can you post some loopback measurements from the 1820m
with RMAA( PRO ) or is it the same breakout-bout
Test loopback 24Bit/44,1KHz sym/Pro-mode (ASIO)
Frequency response (from 40 Hz to 15 kHz), dB: +0.02, -0.16
Noise level, dB (A): -118.2
Dynamic range, dB (A): 118.0
THD, %: 0.0007
IMD + Noise, %: 0.0014
Stereo crosstalk, dB: -117.7
i´m a owner of an 1616m Emu ..... and searching
for schematics
is there anybody else who use the emu external boxes?
@ Dan -
can you post some loopback measurements from the 1820m
with RMAA( PRO ) or is it the same breakout-bout
Test loopback 24Bit/44,1KHz sym/Pro-mode (ASIO)
Frequency response (from 40 Hz to 15 kHz), dB: +0.02, -0.16
Noise level, dB (A): -118.2
Dynamic range, dB (A): 118.0
THD, %: 0.0007
IMD + Noise, %: 0.0014
Stereo crosstalk, dB: -117.7
ECBLN,
I'd be happy to post results as soon as I get the card. I just ordered a used one off ebay. The breakout box in the 1820m isn't identical to the 1616m since the 1820m has two more analog outs. Other than that, I'm not sure what the specific differences are.
Dan
I'd be happy to post results as soon as I get the card. I just ordered a used one off ebay. The breakout box in the 1820m isn't identical to the 1616m since the 1820m has two more analog outs. Other than that, I'm not sure what the specific differences are.
Dan
ah okay , thats fine - how much did you paid ?
specs are very good for both, but their output stage has some
distortion if you whant to use full level power of them ;
but the input of the A/D stage is very fine - really fine to use it
as a measurment tool or for recording ( specially for mics )
and the sound is fantastic - the headphoneamp too !
1820m
http://www.emu.com/products/product.asp?product=9871&nav=technicalSpecifications
1620m
http://www.emu.com/products/product...491&product=15189&nav=technicalSpecifications
btw : i own the PCMCIA version
specs are very good for both, but their output stage has some
distortion if you whant to use full level power of them ;
but the input of the A/D stage is very fine - really fine to use it
as a measurment tool or for recording ( specially for mics )
and the sound is fantastic - the headphoneamp too !
1820m
http://www.emu.com/products/product.asp?product=9871&nav=technicalSpecifications
1620m
http://www.emu.com/products/product...491&product=15189&nav=technicalSpecifications
btw : i own the PCMCIA version
I got it for 200 usd. That appeared to be a bit less than they were typically going for on ebay. How "used" it is, I'll find out when it arrives....
1212m to Microdock M
I'm interested in this as well. I have a modified 1212m that sounds really nice, but it uses an IDE ribbon cable to connect the main PCI card to the output daughter card. Transmission is I2S from main card to output card... clock is on the main card and I feel the ribbon cable I2S transmission is jittery and the output card power comes through the ribbon cable too. Not ideal, but it still sounds rather nice.
The Microdock M interface to the main card would be via CAT5 cable. I wonder if they use the main card's clock or if they just transfer music data to the Microdock box and clock it there. That would be best I think, but hoave no way of knowing if that is how the interface works. The CAT5 cable EMU provides is 3 meters long, so with that length they are not likely using I2S between the card and box. Sending a clock signal and music data via CAT5 seems unlikely too as we only have 4 wires in the cable to use. I'm hoping it is just a data transfer protocol with the clock in the external box. If that's the case it would be a great system to play with as the external box is isolated from the PC noise and power.
I have bypassed the opamp output stage after the CS4398 DAC chip and feed the signal to a cap then to a DIY version of Nelson Pass' B1 buffer. All electrolytic capacitors were changed to Sanyo WX and OSCON, Panasonic FC, or Nichicon Muse depending where they were located. It sounds very nice this way, but I hope the Microdock via CAT5 could be made better.
I'm interested in this as well. I have a modified 1212m that sounds really nice, but it uses an IDE ribbon cable to connect the main PCI card to the output daughter card. Transmission is I2S from main card to output card... clock is on the main card and I feel the ribbon cable I2S transmission is jittery and the output card power comes through the ribbon cable too. Not ideal, but it still sounds rather nice.
The Microdock M interface to the main card would be via CAT5 cable. I wonder if they use the main card's clock or if they just transfer music data to the Microdock box and clock it there. That would be best I think, but hoave no way of knowing if that is how the interface works. The CAT5 cable EMU provides is 3 meters long, so with that length they are not likely using I2S between the card and box. Sending a clock signal and music data via CAT5 seems unlikely too as we only have 4 wires in the cable to use. I'm hoping it is just a data transfer protocol with the clock in the external box. If that's the case it would be a great system to play with as the external box is isolated from the PC noise and power.
I have bypassed the opamp output stage after the CS4398 DAC chip and feed the signal to a cap then to a DIY version of Nelson Pass' B1 buffer. All electrolytic capacitors were changed to Sanyo WX and OSCON, Panasonic FC, or Nichicon Muse depending where they were located. It sounds very nice this way, but I hope the Microdock via CAT5 could be made better.
I admit that it's been a while since I opened my 1820m dock, but I'm almost certain that there is no separate clock - it is transmitted over the CAT5 cable. 12V power is also carried over the cat5 cable; if we assume one pair for 12v/gnd, one pair for an lvds clock signal, we have two pairs left for lvds data transfer - I'd guess that would be one pair for playback and one for record. [I don't know this is what they're doing, I'm just guessing]
I'm still using it bone-stock as my source, and I'm pretty happy with it. I do 'believe' that it does much better into a balanced amp than just using 'half' the signal as unbalanced; this would seem to make some sense, as electrical noise from the PC would then largely be common-mode and thus rejected. Or, maybe I'm just imagining things 🙂
I'm still using it bone-stock as my source, and I'm pretty happy with it. I do 'believe' that it does much better into a balanced amp than just using 'half' the signal as unbalanced; this would seem to make some sense, as electrical noise from the PC would then largely be common-mode and thus rejected. Or, maybe I'm just imagining things 🙂
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