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A/D Converters in the ART Digital MPA - Any thoughts?

Discussion in 'Converters / Interfaces' started by lostindundee, Jun 20, 2009.

  1. lostindundee

    lostindundee Active Member

    Hi there

    I have a MultifaceII and use all my 8 analog inputs with the 8 preamp channels I currently own. However, since I sometimes require to use more than 8 channels simultaneously, with my requirements possibly going up to 12 or beyond, I find myself contemplating a digital preamp or two. Going adat and s/pdif into my MultifaceII would make sense as opposed to shelling out for a linked FF800 or completely new replacement interface to boost my analog input capabilities.

    What I'm considering are a pair of ART Digital MPAs. I may do the tube swap thing if I think I require it after hearing it.

    What I was wondering was - What you folks make of the converters in the ART Digital MPA?


  2. Jeremy

    Jeremy Active Member

    Is going to a Mackie Onyx 1640 out of the question?
  3. hueseph

    hueseph Well-Known Member

    I'm guessing you're on a tight budget. Kind of limiting. I think you'd get better mileage out of a Focusrite Octopre 8 or a Presonus Digimax.
  4. lostindundee

    lostindundee Active Member

    Cheers guys

    I forgot I posted here. Sorry for taking so long to get back to you. I've already ordered one ART Digital MPA. I could use it S/PDIF though and still fit in an ADAT unit.

    Budget-wise, I'm not looking to break the bank. I already have two Porticos (5012 and 5016) and plan on getting a Sytek fairly soon (total of 7 pres + DI). These will be my main pres. The extra pres via digital are to fall back on should I require more than 7 simultaneous channels. The ART now gives me 9 pres (once I get the Sytek). I was just going to get another and have 11 pres but I'm considering taking advantage of the capacity ADAT has to offer. You just never know how your needs may pan out.

    Jeremy - I don't have desk space (or any space) for a mixer. If I did, I reckon I would be holding out for the Sonar VS-700 console when it's made widely available. Unfortunately, however, I have space for neither. You've given me the idea that I could easily plonk an Onyx 800r in my rack though. Cheers for that.

    Hueseph - I'm kinda digging that Presonus. It's about half the price of the Mackie Onyx 800r. I guess I could put a BNC through my ART into the presonus or Mackie and press the Terminate switch and select 75 Ohm (on the Mackie). I like the Presonus's inserts (and price) but I'm just wondering how well the preamps compare between the two.

    Incidentally, what is SMUX? Wiki was a little vague.

    Regards and thanks

  5. hueseph

    hueseph Well-Known Member

    Well until someone who knows what they're talking about comes along here's an explanation of smux:


    And a convoluted explanation which may or may not be related:


    As far as preamps are concerned, I think the 800R would probably have better preamps. I like Mackie products. I hate their customer support. But then, you have two Porticos. Neither will be any comparison I think.

    I have an ART TPS II. Not at all related to the MPA but it's ART. It sounds alright. Nothing to write momma about. It is built well though. The variable impedance is a nice feature. A great way to squeeze as much mileage as possible from your mics.
  6. lostindundee

    lostindundee Active Member

    Thanks Hueseph

    That info was really useful. I kinda understand the SMUX thing now. It's for sending split higher rate samples down the 48k ADAT path and reintegrating them at the receiving device.

    Regading the variable impedance settings. For example, I have an SM58 which is rated 150 Ohms with an "actual rating" of 300 Ohms. I figured I would just set the ART MPA's dial to 300, also matching other mics' to their respective impedances when used.

    What are the pros and cons of a variable impedance. For instance, setting an SM58 at 100, 600 or even 3K (max)?


  7. hueseph

    hueseph Well-Known Member

    LOL. Now that you've explained it, it makes sense to me too.

    Regarding the variable impedance. Changing the impedance changes the sensitivity of the mic as well as tonal response. You can use it or abuse it to your desire. Of course this may also impart a little bit of stress to your mic and there is also the potential to add noise, though not nearly as much noise as if you were to just max the gain.
  8. TheJackAttack

    TheJackAttack Distinguished Member

    In the FWIW category, I really like the Onyx 800r as a companion to my True8. The ADAT feature is ideal for my FF800 and/or HD24XR and that means the mixing board almost never leaves the barn anymore.
  9. lostindundee

    lostindundee Active Member

    Cheers Hueseph

    Great stuff!

  10. lostindundee

    lostindundee Active Member

    Cheers John

    I was thinking the same thing regarding my MultifaceII. :)

    Good to eventually find an 800r user. What do think of the quality of it? Also, do miss not having inserts.

  11. TheJackAttack

    TheJackAttack Distinguished Member

    I find the quality of the 800r to be very good and the converters are good too. The True Precision 8 is noticeably better but has no digital conversion. Both have variable impedence on 1 & 2. Both have a M/S decoder.

    I don't miss having inserts at all. I record primarily classical orchestra, chamber, solo, choir, and band concerts. If I were to need inserts for live concert purposes (extremely rare for me) I still have an Onyx 1640 board with plenty of features.
  12. lostindundee

    lostindundee Active Member

    Thanks John

    What is the quality of the adat like on the 800r?


  13. TheJackAttack

    TheJackAttack Distinguished Member

    ADAT is ADAT. Once the conversion has happened it's all 1's & 0's. As far as the lock, I have never had any issues with either the BNC word clock or the ADAT sync. I usually use the FF800 as the master clock but the Onyx circuitry is just fine.

    The key to ADAT performance is ALL in the cables. Cheap cables mean signal degradation. Scratched tips mean heartache and pain. Country songs could be written about bad ADAT cables.
  14. TheJackAttack

    TheJackAttack Distinguished Member

    Another nice feature, you can use the Onyx 800r as a stand alone AD converter. There is a DB25 Input connector on the back which bypasses the preamps. Additionally, if you have other converters you like better, there is a DB25 Output connector. It'a a pretty well rounded box. It won't do 16 channels but that was never its design intent.
  15. lostindundee

    lostindundee Active Member

    Thank you very much for your insights John

    This has been very helpful.


  16. lostindundee

    lostindundee Active Member

    Whilst on the subject of "country music" (ha ha), I only intend on using my ART DPMA via ADAT occasionally when I require more preamps than my normal quota.

    Regarding being permanently hooked up, would a constant optical signal (when receiving unit is switched off for long periods) do the equipment or optical cable any harm?

    Just wondering as the ends of these cable look pretty hot...lol


  17. TheJackAttack

    TheJackAttack Distinguished Member

    The ADAT cables can be connected 24/7 if you want. My home stereo connects to the DVD and CD players via optical and that's certainly a permanent installation. If this were a mobile rig I would disconnect them and leave them coiled (w/ tip protectors) in the case.
  18. lostindundee

    lostindundee Active Member

    Cheers for the info John. :)


  19. droc8705

    droc8705 Active Member

    I own the 800r too and from what i remember, the DB25 connector in the back doesn't bypass the preamps. I've been searching for a little bit now trying to find that source but I can't find it. Am I incorrect on this, because I'd gladly accept being proven wrong on this fact.

  20. TheJackAttack

    TheJackAttack Distinguished Member

    You are remembering correctly. I was apparently misremembering a different piece of gear I have. Definitely my mea culpa for not double checking.

    According to the block diagram in the manual, the DB25 connects to the line inputs. Sadly, this is notated prior to the preamp trim pot. This is perhaps able to be modified but I don't mess with PCB boards any more.

    There is a Unity Gain marking on the preamp knob but since it is not a detent pot it is perhaps not 100% repeatable.

    Thanks for the catch.

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