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hi folks

i recently bought a tfpro16x preamp for my studio setup. now i ask myself if the luna i/o boxes i use are still the right choice. you know, unbalanced inputs, not rackmountable, and looks like a cheap 50$ soundbox...

has anyone done a side by side test luna and a16 ultra?

how big is the improvement of the balanced inputs on a16 ultra in comparison to the unbalanced luna i/o's?

any other recommendations for ad/da-conversion in a 1u box and 16 channels in the league and price level of a16ultra? i'd like to have an apogee, but, you know, the money-thing

thanx for helping!
katano

noone?

the a16 is very good, and i don't think you'll find better for the money. as to whether you'll see much of an improvement from the luna box, depends on what you put into it. i would bet that the converters are the same. if you're feeding it an unbalanced -20 signal, the luna box is just fine.

i don't think that the lower priced apogee converters are any better than the a16.

<font size=-1>[ This Message was edited by: garyb on 2005-10-21 03:01 ]</font>

thanks garyb

'till yet I had only an unbalanced signal (took the channel insert from my mackie cx20) and there was no need for balanced inputs on a/d.

but now i have balanced outs in my new tfpro16x, so i guess it would make sense to have balanced inputs on the a/d section, wouldn't it?

katano

sure, but don't expect the difference to be drop-dead dramatic. you may notice a nice improvement, but your audience likely won't notice.

ok, but i hope the change of my preamp will make the difference also the audience can hear thanx

you have a lot of confidence in people...
is it a public event or is the audience hand-selected and specially invited ?

kidding, Tom
convinced that his ancient (non-ultra) A16 w. 18bit converters sounds just fine...

<font size=-1>[ This Message was edited by: astroman on 2005-10-21 04:42 ]</font>

astroman, i'm shure you know that young kids who wants to record a demo or ep will be convinced when you have a massive rack of outboard gear at the studio ) so, it's just a kind of marketing to buy an a16ultra )

serious, nevertheless the a16 ultra definitely looks professional, compare to the luna i/o box, which seems fishy to me, even after two years of working with... can't tell you why... hmm, because no rackmount )

so, i think i'll buy this converter at the end, and only for my satisfaction. but i'm shure my customers will be satisfied to

The Luna I/O box is *excellent*

The sound quality thru it's converters is excellent !! Seriously !! We headphone monitor in the studio from a Rane Mojo MH4 coming from our Luna box with Ultrasone HFI-2000 headphones (perfect for the Rane BTW) The rane is fed an excellent signal when our source is good.

It may be worth mentioning that Alesis made a very nice converter with 8 balanced I/Os, which will do a good job if you can spare the Adat ports

On 2005-10-21 06:05, katano wrote:
serious, nevertheless the a16 ultra definitely looks professional, compare to the luna i/o box, which seems fishy to me, even after two years of working with... can't tell you why... hmm, because no rackmount )

To be honest, i *hate* the RCA phono jack sockets on the Luna box. I can never understand why these are implemented, as 95%+ of studio connections are via 1/4" jack or XLR (balanced or not) That said, for some reason, top manufacturers have used these connections for years. Other examples of excellent AD/DA converters using unbalanced RCA phono would be the Fostex VC-8 & Spirit's 8ch I/O TDIF box for the 328 digital, but why RCA phono ? This one is a mystery to me.

Anyway Katano, i thought i'd mention that the Luna I/O boxes *Can* be rackmounted. They are 1/2 rack size & should rackmount no problem in a suitable rack tray, just as with the Fostex VC-8 converter.

Unbalanced signals are cheap.

Balanced signals used to require transformers (i.e. veeeeeery expensive). These days crappy chip op amps are used to "balance" signals. But they are still way more expensive than unbalanced signals, and especially so if you don't want the signals to sound crappy.

Although I can't tell whether or not I detect it hearing-wise, the one big advantage of using chips for balancing over transformers that I've read about (i.e. hearsay) is that transients are passed through a chip with less distortion, less loss of fidelity, than through a transformer. Depending on the slew rate and all that jazz of the chip, of course. (Please someone who actually knows this stuff -- Tom? Gary? Et al -- chime in and correct me! )

However apart from the somewhat esoteric aspect of transients, the *general* difference between transformers and chips is most certainly audible. Especially for older and cheaper transformers. Transformers just sound better 7 times out of 10. They shape your audio in a way that's not dissimilar to subtle EQ, or even tape or tubes. ICs almost always give your signal a sort of grittiness that is harsh and unnatural. As opposed to the transformer sound, which is creamy and unnatural. Funny how nothing reproduces sound very well.

But man the right chips or the right transformers make cool sounds all right!

The ideal audio setup, fidelity-wise, would be all unbalanced connections with proper grounding and no radio wave or other interference. Internally, of course, all devices use unbalanced signals, because the only time you need balanced cables is when you have long antenna-like runs.

But unfortunately the "ideal" unbalanced audio setup is almost impossible to actually achieve in a complex studio environment, without noise and RFI.

(Nevertheless I would like to hear it some day -- hear whether it really does sound closer to the original than IC- and transformer-balanced signals! )


EDIT: whoops, mis-read your post Shroomz. The reasons for RCA are simple: 1) to save real estate; 2) to save money. RCA jacks are small and cheap. XLR jacks are big and expensive. TRS and TS jacks are big and expensive.


<font size=-1>[ This Message was edited by: blazesboylan on 2005-10-24 23:04 ]</font>

Thx Blaze, i think i vaguely learned a thing or 2 there

Makes sense that *cost* rules the roost from a manufacturing POV, but a great example of why we'll probably ditch the Luna boxes at some point in favour of balanced converters, is simply *monitoring*. The last thing we want at the output stage of Scope is potential signal loss or interference, so we'll no dought go with an A16u & a couple of Alesis AI 3's at some point.

Without the expense of going for 2/3 Scope pro's, we're thinking the optimum setup would be :

Scope Pro Z-link connected to A16 ultra
2 x Pulsar II Adat, with 2 Alesis AI 3's connected to one or both of them.

Comments on that setup are welcome as this is our *wanted* setup. We've been talking about upgrading the whole lot since buying our first Pulsar II. It seems pointless to only be using 1 STDM bus on our Pulsar II, with it connected to 2 Lunas, so we're talking about upgrading the Lunas to a Scope Pro Z-link & Pulsar II Adat.

The Alesis AI 3's are selling at Turnkey (now Sound Control) in London, for £220 if anyone's interested in 8ch balanced analogue to Adat converters.