StudioLive AI-series mixer 96 kHz over the onboard FireWire 800 interface

Discussion in 'Consoles / Control Surfaces' started by audiokid, Nov 30, 2014.

  1. Boswell

    Boswell Moderator Well-Known Member

    Joined:
    Apr 19, 2006
    Location:
    UK
    Home Page:
    Ignoring for a moment the balanced/unbalanced problem, if you wire the output of the external Neve pre-amp to the SL's insert return point, the SL will continue to route and function exactly as before, except that now that channel will be handling a mic or line signal from a different input device (the Neve). When connected this way, if you are tracking via the SL's FW interface to a DAW, then the SL is acting purely as an A-D converter, like a line-level audio interface.

    The unbalanced nature of single-jack insert returns can be a problem when you are trying to feed them with quality pre-amps. We've had threads on this before, but basically you have a balancing problem and a level problem. Assuming the pre-amp has independent drivers for its + and - outputs, you need to use a cable wired to take the + signal from from the pre-amp's output jack or XLR to the ring connection of the mixer's TRS insert jack plug in order to carry an unbalanced signal into the mixer. However, top-range pre-amps tend to have either electronically-balanced or transformer-coupled outputs, and these need different wiring to take the output to the ring and sleeve (ground) of the TRS insert jack. Note that in both cases the tip contact of the insert TRS plug is left unconnected, as this is the send signal, i.e. the output of the mixer's internal pre-amp.

    The nominal level at unbalanced insert returns is usually -2dBu, this being the 6dB reduction from +4dBu through loss of half the signal. Full-scale (FS) levels are typically 18dB higher than this. The -2dBu nominal figure can be an acceptable match to the output of many mid-range pre-amps when just a + output is taken. However, with electronically balanced or transformer-coupled outputs, not only will both of these will deliver the pre-amp's full range output into a balanced or an unbalanced load, but it's a frequent production requirement to drive these pre-amps into slight overload to take advantage of the sound of transformer saturation. In this case, you may be presenting something like a +32dBu peak signal to an insert point that has only 18dB headroom above a nominal level of -2dBu, i.e. +16dBuFS. It's time to reach for the in-line attenuators...
     
    bigtree and pcrecord like this.
  2. pcrecord

    pcrecord Quality recording seeker ! Well-Known Member

    Joined:
    Feb 21, 2013
    Location:
    Quebec, Canada
    Home Page:
    Very good point Boswell !
     
  3. Boswell

    Boswell Moderator Well-Known Member

    Joined:
    Apr 19, 2006
    Location:
    UK
    Home Page:
    Not really any need, as it's all clear from the block diagram. Top left corner shows the insert return feeding only the input buffer of the ADC.

    Don't forget that on all digital mixers, the faders and EQ operate in the digital domain. There's no concept of an analog insert point that is post-fader or post-EQ.
     
    pcrecord likes this.
  4. pcrecord

    pcrecord Quality recording seeker ! Well-Known Member

    Joined:
    Feb 21, 2013
    Location:
    Quebec, Canada
    Home Page:
    :oops: Yeah, I don't know where my head was this morning!! ;)

    @Chris ;
    Unless you are planning to sell your converters, I'd keep sending the high end preamps to those, combined with the direct outs of the AI.
    Or start with comparing both setups to know which are the best converters and decide accordingly
     
  5. audiokid

    audiokid Chris Staff

    Joined:
    Mar 20, 2000
    Location:
    BC, Canada
    Home Page:
    Thanks for all the info guys, I keep forgetting about stuff lately. Seems I don't retain half of what I read until I actually use something.
    I remember our past conversation about overloading those inputs, now I get it.
    I'm planning to do a few comparisons with this console so I'm basically getting ideas for the party.
    The direct outs would be the way I would go when combining this for sure.

    @Bos, you linked a few products before. I should buy a few to have on hand. Was it similar to the Shure? Do these effect the sound, or better yet, would they match up "close enough" from one to the next?

    Are there recommended 8 in/out in-line attenuator bays or are they best built in singles?
    http://www.shure.com/americas/products/accessories/microphones/microphone-problem-solvers/a15as-inline-switchable-attenuator
    here for High Fi.
    http://www.musiclinkav.com/store/index.php?option=com_virtuemart&page=shop.product_details&flypage=flypage.tpl&product_id=722&Itemid=1
     
  6. audiokid

    audiokid Chris Staff

    Joined:
    Mar 20, 2000
    Location:
    BC, Canada
    Home Page:
  7. Boswell

    Boswell Moderator Well-Known Member

    Joined:
    Apr 19, 2006
    Location:
    UK
    Home Page:
    Apart from knowing that different sorts and values of attenuators are easily available, my feeling is that the thing to do is work out how your connections are going to be made. I would write down a table (or spreadsheet) with the models of pre-amps in the leftmost column, then in further columns their output configuration (unbalanced, floating, balanced, transformer etc), their maximum output level and the connector type. Leave columns to fill in with sort of connection and attenuation needed. Only when you have a handle on how the connections are to be made would I start to look at what attenuators to consider.

    PS The Presonus documentation is largely very good, but I can't find any info on the clipping levels at the insert returns.

    PPS You could share the spreadsheet with the rest of us here at RO - many others may find it quite useful!
     
  8. audiokid

    audiokid Chris Staff

    Joined:
    Mar 20, 2000
    Location:
    BC, Canada
    Home Page:
    Wonderful info Bos, if you want to do this, we could upload it, or post it for everyone. I had no idea it was this detailed but like everything pro, the last 2% is 98 percent of the problem solved or the reason why we are doing it all in the first place. :)

    I'm not clear if you need my input on a list of pre's I use though? My list of Pre's is dropping off like flies. My "go to" is the Millennia M-2b for value and I'm considering an HV-3D for wideband transparency. I love the SPL Premiums but in the last 1/4 of this year, I'm pretty sold on transformeless pre-amps. I know and respect the Millennia Media sound so am very curious how the SL and Xmax compare. It would be fun to let you all hear the difference between an $1800 vs $130 per channel comparison. High end transformerless does not sound sterile at all. I compare it to fine sheer silk over an HD picture.
    I wish I had more time just to do all the fun stuff like this. I'd love to have an extension to this site where we demystify all the nonsense. Which is really where I am heading half the time.

    What can I do to help?
     
  9. DonnyThompson

    DonnyThompson Well-Known Member

    Joined:
    Nov 25, 2012
    Location:
    Akron/Cleveland, OH
    Home Page:
    I wouldn't think that would be all that tough to do, after all, you do have both, right?

    Although I'm a bit curious as to why you would want to compare them...other than just for fun... an $1800 dollar pre with a $130 pre - I would expect there to be be a pretty big difference, as one would, considering the price difference.

    I don't think that the XMax would sound as good as the Millennia. And, I don't believe the XMax is a bad preamp, either - I really like their transparency, and in that price range, or maybe even a bit above it, I think you'd be hard pressed to do any better than a Presonus or a Focusrite, because of her transparency and gain, but I wouldn't think either one would sound nearly as good as your Millennia, nor would I really expect them to.

    Would you? (not being sarcastic... I'm serious with that question). ;)

    Let us know if you end up doing an A/B.
     
  10. audiokid

    audiokid Chris Staff

    Joined:
    Mar 20, 2000
    Location:
    BC, Canada
    Home Page:
    Yes, I have the console now.

    Hopefully I get a good singer in here that will indulge me ;) If not, I will do it with speech by me. That's all I really need for where I am going with this.

    I can't imagine anything rivaling the M-2b size or silkness, its a pretty unique design in that it is a Transformerless valve topology, on big rails. But, I can imagine other pre's being contenders in a best suited for a particular texture shootout.
    I'm curious to see how the PreSonus sounds if I narrowed the bandwidth on the M-2b to match a XMax size, then how the pre in a Prism Atlas compares. I'm not looking for texture. I am interested to hear how these three compare when I roll off to try and match the smallest "one" in the comparison . This is where I'm going with this.
    If this makes any scene, I'm inclined to believe some of why we choose particular pre's (maybe more than we think) ,has something to do with bandwidth capture.

    I'm thinking the M-2b would make a great room pre too. It seems the best mixes I get, or those that are the easiest to dial in, are when the room has the largest canvas to paint with. So, for those that don't get the whole HPF thing when mixing, your mix can only be as big as your captured canvas. I am of course, getting artsy fartsy here.
     
  11. Kurt Foster

    Kurt Foster Well-Known Member

    Joined:
    Jul 2, 2002
    Location:
    77 Sunset Lane.
     
  12. audiokid

    audiokid Chris Staff

    Joined:
    Mar 20, 2000
    Location:
    BC, Canada
    Home Page:
    I've read that one too, thanks for posting that Kurt. :)

    We're told the SL pre's are the same as the Xmax but I'm also told that the AI Series sound better than the first Generation of StudioLive Consoles. Which has me scratching my head. (The mystery of 3 versions of Xmas pres).
    I have nothing to compare between both versions now but I'm hoping Dave sheds some light on this in time. He has the first gen of StudioLives and is planning to upgrade? (y)

    Being said, it would be even more interesting to learn how the Xmas rack pre compares to the consoles too? Do they all sound different and why? All builds say they have the 30v rails.
     
  13. Kurt Foster

    Kurt Foster Well-Known Member

    Joined:
    Jul 2, 2002
    Location:
    77 Sunset Lane.
    are the XMax pres transformer balanced?
     
  14. audiokid

    audiokid Chris Staff

    Joined:
    Mar 20, 2000
    Location:
    BC, Canada
    Home Page:
    Good point, I think there is better of that on the AI. the first gen SL didn't have as good a PSU either. Maybe there is something to do with a "lack of" rather what the specs say.

    How does the PSU effect balancing?
     
  15. Kurt Foster

    Kurt Foster Well-Known Member

    Joined:
    Jul 2, 2002
    Location:
    77 Sunset Lane.
    i've always been under the impression that PreSonus pres were transformer balanced ...... the very first ones used Jensens and they supposedly sounded better than later versions.
     
  16. DonnyThompson

    DonnyThompson Well-Known Member

    Joined:
    Nov 25, 2012
    Location:
    Akron/Cleveland, OH
    Home Page:
    From what I've researched, XMAX is a Class A, discrete transistor design that does not use op amps.

    According to Presonus, the Xmax pres in the studio/live desk are the exact same Xmax pres in the rack mount versions.
     
  17. Kurt Foster

    Kurt Foster Well-Known Member

    Joined:
    Jul 2, 2002
    Location:
    77 Sunset Lane.
    probably the same type of twin servo pre design with "improvements" that PreSonus has been making for years. a lot like the Hardy 990 pre only not.
     
  18. kmetal

    kmetal Kyle P. Gushue Well-Known Member

    Joined:
    Jul 21, 2009
    Location:
    Boston, Massachusetts
    Home Page:
    The eureka is transformer balanced.

    I dunno, if they are the same Xmax pres through and through, it really proves hwhat most designers say that it's the overall design, not just one or two components, cuz I've used the Xmax pres in the SL, the 2ch, and the rack unit, and they perform differently. The older digimax being the worst, so maybe they have been making improvements in areas other than profits. Maybe. Prob not. It's probanly just due to the pres incorporation in a different overall design.
     
  • AT5047

    The New AT5047 Premier Studio Microphone Purity Transformed

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice