M-Audio DMP3 and audio interfaces

[Robert****]

Monkus, you can help with this.

The DMP3 - I have been looking at that one and I'm seriously interested in getting it. It's getting great reviews.

What I am wondering is, when using a mic pre like the DMP3, the output usually goes into a kind of audio interface, and these often have built-in mic pres. If you can't turn off these mic preamps in the audio interface, will this affect the sound negatively?

I have an old Tascam US-122 USB audio interface, and it's been working great for me. I think it has some basic preamps built into the mic inputs, but they can't be turned off. My US-122 also has 1/4" TRS Balanced Line Inputs.

So if I get the DMP3, how should I hook it up to my US-122? Into the mic input or into the line-in input?

And what kind of cables should be used from the DMP3?

Ok bear with me. I am finding the answer to this as I'm typing... from the DMP3 manual:

----
A "balanced" line runs the signal on two wires of opposing polarity, as a
‘twisted pair’ surrounded by a grounded shield. Doing so, it can send a
‘hotter’ signal over a longer distance with less added noise. Using a TRS
(tip-ring-sleeve, sometimes referred to as “stereo”) plug on the 1/4” outputs
of the DMP3 will give you this balanced line—tip positive, ring negative,
and sleeve ground. Generally speaking, if the DMP3 outputs connect to a
system that accepts a balanced line at +4dB (nominal level) operating level,
you should use TRS plugs on the outputs.
---

Here is a good page about different cable connectors:
http://www.sweetwater.com/shop/cable...ying-guide.php

Regular guitar cables are unbalanced.

So in my situation, I would use the line-in inputs on my US-122, and I would use TRS cables like this:



Case closed?

[Monkus]

I found the specs on Your Tascam interface here

Use TRS cables to connect the DMP3 outputs to the line level inputs on the Tascam.

A neat trick is to use the regular inputs on the interface and tweak the input levels. Depending on the unit, the additional pre's distort the sound slightly giving it some warmth. A lot of studios use that method to warm up digital sounds to make them sound more analog. Tweak to your hearts content!

For your application, DMP3 --trs--> Tascam --usb--> Mac is fine. Monitor your input levels in Garageband to make sure you're not clipping and you should be good to go.

In my experience, the DMP3 boosts the signal cleanly and transparently. While the firebox works great at entry level, I thought I needed a little more for recording vocalists. I've found that its not which preamp is better, but which one you prefer for each application. Except of course for the ones that introduce noise or raise the noise floor. Let us know how it goes !!!

I just remembered, don't get caught in the cable marketing wars. Monster cables are just as good as the others and waaay overpriced. I've got cables that are going on 15 years. In the case of recording however, the shorter the better. Also try not to run power and audio cables next to each other, if they must cross, try to get it at a 90 deg angle.

[Robert****]

Is the Dmp3 quiet? My ART preamp is quite noisy. But it's like $30 or so, not exactly high end...

[Monkus]

Very quiet. To actually hear the increase in the noise floor you have to turn it up to about 85%.

Couldn't find the actual article but heres an excerpt:

“One of the quietest preamps available anywhere, regardless of price. For comparison’s sake, this tiny difference [between original source and mic pre output] is far less than the degradation I’ve heard in the most expensive world-class A/D converters.” — Pro Audio Review

Here's another one from sound on sound:

http://www.soundonsound.com/sos/May0...les/maudio.asp

One note though, its a little taller than a 1U rack space so it needs a custom built space or it just sits on your desk.

My wish list after I win the lottery:

http://www.avalondesign.com/instrudi.html

http://www.music123.com/Focusrite-Re...25396.Music123

http://www.soundonsound.com/sos/mar0...enagepre73.htm
http://www.jrrshop.com/golden-project-pre73-p-8299.html

So the DMP3 is really good for the price, and its entry level.

[Robert****]

Why do you need to upgrade?

[Monkus]

Preamps like guitars or amps are a pretty subjective thing. I love the singing voice, especially how harmonies interweave and strengthen the subject matter. Not too much on acapella groups though.

Certain preamps 'color' the vocal in an albeit subjective way. The Avalon and Neve 1063 have been standard in megastudios since 1974 or so and were the sought after 'sound', they still are. I upgraded because some of the contemporary gospel I've been recording. At first glance, preamp discussions will lead you into thinking that they should be transparent and not add anything to the sound. The more expensive preamps are expensive because they color the sound, in a way deemed to be good.

taken/borrowed from Studio-Central

The Mic preamp is one of the most expensive components on the audio interface, which is why some do not have them, figuring you'll add your own via a mixer or by stand alone preamps. How good are they? Of course it varies. The preamps on the cheapest audio interfaces are not as good as common mixer preamps. They may lack the gain to drive some microphones, but usually work fine with common condenser mics. As you move up in the range of over $400 interfaces the preamps also improve. For example with my two interfaces, the Motu 828mk2 and the Emu 1820m, I'd rather use those preamps than those on my Mackie 1402 VLZ Pro, but it will be hard for me to tell the difference. They will all sound "very good". But if I plug in my Focusrite Voicemaster Pro preamp, there is finally some noticeable improvement. If I plug in my premium Great River preamp there is a huge sparkling difference.

For instance, Lady Monkus has a full soprano voice and can hit some really rich alto notes as well. We had a showcase at our church where members wrote original pieces and performed them. In recording the song, the firebox preamps, while adequate, didn't really 'get' the warmth of her voice. We switched a lot of mics and that didn't help much. When I got the DMP3, it added a clarity that we were looking for, it just clicked. The DMP3 imho, is the best bang for buck I've heard, and I was comfy (for a time) with the firebox preamps. Lets see how long that lasts lol !

Recording is a hobby for me but I want to do the best I can with the gear I have without compromising sound. If one day I have the extra cash to get an Avalon, or a Neve 1063, so be it. If not, it should still be ok because I'm a firm believer in tracking the best performance possible.

Hope that helps.

[Robert****]

Yeah, I'm in the camp who believes more in the room, the performer, etc than the value between a $400 unit and $4,000 unit.

Next question - how much does the audio interface affect sound quality? I have only had cheap gear - my Toneport UX1 and my Tascam US-122. Now if I were to get Apogee, Presonus, etc, stuff that costs $4-500 or quite a bit more, will I notice much improvement in overall sound?

My US-122 was considered a pretty good unit back in the day, but a lot has happened in the last few years. This thing must be 7-8 years old, at least. But I think it works great. It has the right features, and sound quality wise, it sounds good to my old ears. If I switched to a newer better unit, I'm wondering if I'll go "wow, what a difference!" or "hmm, perhaps a small improvement, I dunno?".

[Monkus]

You will know some of this already but I'll still try to cover everything I can remember for the benefit of those reading after.

Lets go ...

Audio interfaces can be technically divided into two components, Digital to Audio Converters (DAC's) and Software drivers. A few years ago you had to pay top dollar for a good interface due to the quality of the DAC's. As tech improved the DAC's became standard at 24bit, 44.1 KHz. Some interfaces have preamps and they also can affect the audio quality. Some dont.

Whether an interface is usb, firewire or pci doesn't matter really as they are just a means of transporting the data to and from the workstation (DAW). The DAC's actually touch the data. There's more.

The software driver is the management system that allows data to and from the cpu of your DAW. We've all had driver issues, so suffice it to say that drivers while hard to perfect, there are units that work well, once the drivers work properly.

Some things I've learnt:
Do I need spdif?
Not really, but the extra io is always good.

Whats io?
inputs/outputs - how many channels/tracks/going to your DAW

How much io will i need?
One more than the amount of things you need to record simultaneously.

Use smaller words?
If you are recording an acoustic guitar and a vocalist at minimum you will need two inputs/outputs. If you plan on mic-ing the guitar neck, soundhole and room (3 mics total), plus one for the vocalist, you will need 4 io-s. Get the drift? Plus one for security.

Lets talk about Levels

The mic is a very dynamic instrument especially when you put the proximity effect into the equation. Here is where preamps come in. You do a test run with the vocalist screaming parts and crooning soft parts and adjust your input levels so youre not clipping. In older analog boards when recording to tape, there was some headroom, (think VU meters) and 0db was a moving target. Not so with digital recording. When the signal gets too hot, it clips the peaks off the waveform resulting in some nasty distortion that cant be added back as its recorded to the hd that way. Since the mic or instrument level is weaker than line level, preamps are required to boost it up to line level.

Line level is a stronger signal going into the converters at a predetermined signal strength. Think of recording a radio into a tape recorder and turning up the volume cause its a great song while recording. It records however at one level.

Preamp and Tascam:

The Tascam US-122 DACs are 24bit, 44.1 KHz so thats great. Once it works properly and you don't get dropouts leave it, it aint broke. You're using Garageband if i remember correctly so the core audio drivers are up and running. Great. Just because its older doesn't mean we have to change it, vintage gear is the best.

The vocal mic will go into the DMP3, then into the line level input of the tascam. That way you will only be using the preamps on the DMP3. The signal will then be converted to 1's and 0's and stored on your HD. You can then use garageband's mixer to manipulate the audio data.

If however you want to record gigs, there are many ways to do that, but thats another topic.. I hope I haven't confused you more than necessary but it is a lot of stuff, understanding it will help us make less dud purchases.

Will it sound better?

If the DAC's in the Tascam are really 24bit 44.1 KHz, adding a decent preamp will definitely improve the quality of your recordings. If the preamps on the Tascam and the DMP3 are comparable you might not notice the difference. It will be however, better than the Art Studio. If you are thinking of recording more than two simultaneous tracks, research another interface, there are a lot of good ones available.

If anyone detects something thats in error, please let me know.