2 line in input audio interface gainstaging?

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rsergio007

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Hi everybody,

I'm new to the forum and I'll start with a classic "what should I buy?" question.

First my environment:
I record vocals, acoustic guitar, electric guitar, electric bass, keyboard, and electronic drums.
All these inputs are fed to an old Mackie 1604 VLZ Pro I love. The keyboard and drums also go to computer via Midi.
I used to use a Delta 1010 card (from the Mackie Direct Outs into the line ins) to record into a desktop PC with Cubase. In this manner I could record 8 separate tracks independently (the most I ever tracked simultaneously were 4 tracks).
I've switched to a Macbook Pro laptop with Cubase.

Because I don't really want to spend too much with an interface, usually loaded with functionality I don't use, my idea is to just get the simplest but worthy USB, 2 in 2 out, Midi included audio interface and live with recording two tracks. My idea is to go from the Mackie Tape Outs (less hot that the Main Outs) into the interface and Mac, record in Cubase, return from the interface line outs into the Mackie Tape In.
My main concern is to get an interface with line inputs and outputs able to match the operating range of the Mackie.

I tested both the Presonus AudioBox 22VSL and 44VSLs (to test the Mic/Inst vs the Mic/Line inputs) but didn't like them. After inputing the signal I really have to keep the levels down to avoid clipping on the interface (I guess I need a Pad button?). Also the output level of the Presonus boxes is really low. I tried returning the sound to the Mackie mixer via both the Tape In and normal Channel Ins, and in both cases I have to boost the signal between 10-20dB. This means I'm quite far from optimum operational levels, not to mention that all this leveling is a pain without proper meters and signal levels.

So my question is: does this exist, a USB audio interface with Midi, without like 18 ins and 16 outs, with functionality to level the operating levels as part of a signal chain. That allows you to match the Mackie mixer 0dBu output to a 0dBu input, A/D converted to -18dBFS, recorded at -18dBFS, D/A converted to 0dBu, and output back to mixer at 0dBu? Or do I have get a higher end interface to get this kind of functionality?

I appreciate your input on this.
 
Initially my idea was to get something under $300. I just don't see many units under that price allowing plenty i/o level flexibility and accurate metering.
I had never considered the Tascam US-1800 because it has a ton of Mic Inputs I won't use.
But It does look interesting in terms of i/o levels settings.
Just feels wrong to have a rack unit like this to just use 2 ins and 2 outs :S
 
Buy 2 now and you'll want more later! It's got 6 1/4" TRS line inputs (2 of which can be guitar level) or all those mic inputs could be used from the track sends on your board.
 
It's true, I could use the 6 1/4" TRS inputs for my main and sub outs, and even plug the channel direct outs into the XLR Mic inputs. But these XLR inputs are really not ideal to get such a strong signal from the Mackie direct outs, right? I mean, these direct outs are rated at a maximum of +22dBu, (I usually keep individual channels operating between +7dBu and -7dBu but peaks do occur), but the Tascam XLR Mic ins are rated at 14dBu maximum. With channel peaks over 14dbBu on the Mackie I would be hitting the ceiling on the Tascam Mic ins all the time right?
 
Although not USB, and still Presonus unfortunately, the Firestudio Mobile is well worth a look as the line in's aren't combo mic/line in's so it doesn't pass through a preamp stage in the firestudio. Also, MIDI in and out. £160 new. i bought one for use with a macbook pro at the start of the year as i have a lot of external preamps and had fallen pre to double amping a signal through interfaces that have the combo mic/line in's which sell pass the signal though a preamp so wanted a box with as many line in's as possible for a reasonable price
 
Ethan Winer said:
I got a Focsurite Scarlett 8i6 for $250 from Sweetwater and it's been terrific. It does everything you need including MIDI.

--Ethan
Click to expand...

I looked into the Scarlett 8i6 exactly at the time I tried the Presonus, but I still think that both the line inputs and outputs are a bit low at +16dBu and +12dBu respectively. And the issue is not merely the level, it's the double amplification of the signal.
 
rsergio007 said:
It's true, I could use the 6 1/4" TRS inputs for my main and sub outs, and even plug the channel direct outs into the XLR Mic inputs. But these XLR inputs are really not ideal to get such a strong signal from the Mackie direct outs, right?
Click to expand...

If you're using the preamps in a Mackie mixer, then you'll send those direct outs into line inputs on the sound card, not mic inputs. The main two inputs on my Focusrite 8i6 I mentioned has Neutrik combo connectors that can be switched between mic and line signal levels.

but the Tascam XLR Mic ins are rated at 14dBu maximum. With channel peaks over 14dbBu on the Mackie I would be hitting the ceiling on the Tascam Mic ins all the time right?
Click to expand...

The obvious solution is not to run the preamps that hot! That's what the preamp Trim (gain) control is for. My Mackie outputs about +5 dBu when the sound card hits 0 dBFS.

--Ethan
 
Ethan Winer said:
The obvious solution is not to run the preamps that hot! That's what the preamp Trim (gain) control is for. My Mackie outputs about +5 dBu when the sound card hits 0 dBFS.

--Ethan
Click to expand...

I know, you're right, but, and maybe I'm wrong in the way I see it, I was trying to run each device as hot as possible, or more accurately, as much in its optimal range as possible. To me, the ideal scenario would be an audio interface able to take in +26dBu and output +22dBu. Or better, just to be rated +4dBu (pro level) on both ins and outs, with no pre's nor gain controls, where you can take for granted -18dBFS on the Mac and interface equate to 0dBu on the analog world. This way, you just connect all your gear, never touch a gain knob (apart from the channel trims on the Mackie mixer), and trust the metering along the path.

I'm starting to realize that having that for under $300 might be quite tricky...
 
rsergio007 said:
maybe I'm wrong in the way I see it, I was trying to run each device as hot as possible, or more accurately, as much in its optimal range as possible.
Click to expand...

Running audio signal levels as hot as possible is not the best approach. Unless you're after a grunge type sound. If the output of your preamp hits between 5 and 15 dBu at Digital Zero into your sound card, that's about right. Most music recorded by microphones in a room has a dynamic range around 60 dB at most. A sound card and digital recorder has a dynamic range greater than 90 dB. That's 30+ dB more than you need.

I'm starting to realize that having that for under $300 might be quite tricky.
Click to expand...

Not at all. The Focusrite Scarlett 8i6 interface I have, which I mentioned, is only $250 and does everything you need.

--Ethan
 
And what do you think about the Motu Audio Express vs the 8i6?
Is it worth the price difference?
I'm liking the maximum input and output levels, trimming, and the metering but, brand wise, I'm not that familiar with Motu.
 
Well guys I appreciate all your inputs on this. After much research, including the suggested Tascam 1800, Focusrite 8i6 and Presonus Firestudio, and including a stage I got completely sidetracked and said "I'll just buy the best 10 in 10 out pro level interface I can afford If I mortgage my house and put an end to this quest" I decided to stretch a bit my budget and go for the Motu Audio Express.
I think next week I'll be able to post some kind of review or at least give you some feedback about this unit!
 
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