M-Audio DMP3 Pre-Amp - Balanced or Unbalanced Guitar Inputs?!

  • Thread starter Thread starter Lauren
  • Start date Start date
L

Lauren

New member
Hi, I'm currently looking to buy a Pre amp and this is one of the models in my list. I was however hoping to get one which had all balanced inputs. When I read the online manual it gives two completly contrasting pieces of information.

In the intro..."plus an alternate high impedance instrument input on 1/4" TS jacks.".......TS as in mono, as in UNBALANCED.

In features...."2 alternate, independant 1/4" unbalanced, high impedance inputs"....again, UNBALANCED.

but...

In the breakdown of the 'Rear Panel' diagram....number 4 in the list refering to the instrument inputs on the back of the unit..."These jacks are 1/4" TRS"....huh?....is it a typo?...it goes on..."and will accept either 1/4" TRS or TS plugs (balanced or unbalanced, respectively).".......well this bit could refer to an unbalanced input again which simply won't fuss if you stick a balanced signal in there (but won't benefit from a balanced cable)....or it accepts both, uses both...becase the input is TRS?

So....can anyone out there clarify?...maybe someone who owns the DMP3?...are the guitar inputs TRS or not?....I'm using balanced cables and was very much hoping that they would be used in conjunction with the preamp and benefit from it.

Thanks for any replies!
 
I don't know the answer. I'll take a look at mine when I get home. However, standard guitar cables are not balanced. Unless you have active electronics on your guitar, there's no point in using balanced cables. For short cable runs, it won't make a noticeable difference, anyway. Now, if you're running through some amp modeler/DI that has balanced outs, you could always get a 1/4" TRS to XLR cable and go in through the balanced XLR inputs.

The outputs on the DMP3 are balanced TRS.
 
Pretty sure the INPUTS are unbalanced since it wouldn't make that much sense to have both a 1/4" balanced and an XLR input. And the 1/4" OUTPUT is balanced.

I know for a fact the output is balanced, and again it wouldn't make much sense to have a 1/4" balanced input when theres that XLR because you could just use an XLR to TRS. Using a TRS in a TS input, or the other way around may just "work" as state(I have accidentally done this before with equipment), but it probably won't work optimally.

Thank you I am accepting donations. :D
 
Hmmm...ok....so what about guitars then...should I only insert a TS plug in to the input because thats what the the input is and inserting TRS won't make a difference? it won't benefit in anyway?

Whats the significance of active electronics and TRS? My bass has active electronics...are you saying that it creates a TRS signal, stereo signal?

I'm interested in whats been said about the XLR input on the dmp3...I was under the impression you could only insert condensor mics in there because I thought that input only works with phantom power, which of course guitars don't want. Are you saying you can put anything in there and it will work alright and you don't have to turn on phantom power?....If that is the case, I could use a TRS to XLR cable to take me from guitar to the dmp3. But...is the signal from the guitar just Unbalanced anyway (unbalanced input on body?), therefor it won't make a balanced signal anyway.

So...is the moral of the story, only use unbalanced TS cables with guitars because thats what signal is sent out. I would just go TS to TS from guitar to dmp3. I could do TS to XLR or TRS to xlr....but won't the signal just remain unbalanced because of the Guitar?

Any more insight would be much appreaciated!! :confused:
 
Guitars send an unbalanced signal. No, you will not benefit from trying to balance it going in. The 1/4" jacks are "smart jacks" and will accept either an unbalanced or balanced input. The output is balanced in any case. By using the hi/lo switch on the front, the rear jack will accept either a line in or instrument input.-Richie
 
I opened the manual to my DMP3. The 1/4" input is DEFINITELY TS(unbalanced). The impedance is way different from the XLR inputs. The OUTPUT you can use an unbalanced, or balanced cable. So just like I thought.....

XLR/Mic in = balanced cables

1/4"/TS = unbalanced cables


This allows you to connect unbalanced or balanced sources to the DMP3. There would have been little benefit to having 2 different kinds of balanced inputs. I haven't read the online manual but I have a DMP3 and I read the real manual. Are you sure you weren't getting confused with input and output? But either way whichever kind of cables you need to use for either input or output the DMP3 will accommodate.
 
Richard Monroe said:
Guitars send an unbalanced signal. No, you will not benefit from trying to balance it going in. The 1/4" jacks are "smart jacks" and will accept either an unbalanced or balanced input. The output is balanced in any case. By using the hi/lo switch on the front, the rear jack will accept either a line in or instrument input.-Richie
Click to expand...

In the manual it says nothing about using the hi/lo switch to change from TS to TRS. the hi/lo is for gain. It says the output can accept unbalanced as well.
 
Manx is basically right, I mis-spoke. The HI/Lo switch doesn't have anything to do with balanced/unbalanced, but it is adviseable to use the hi gain setting with an instrument input. Yes, the rear jack us unbalanced, but it will accept a line level TRS input. It will accept it as an *unbalanced* signal, and send out either a balanced or unbalanced output, depending on the output cable and the device receiving that signal.-Richie
 
Lauren said:
Hmmm...ok....so what about guitars then...should I only insert a TS plug in to the input because thats what the the input is and inserting TRS won't make a difference? it won't benefit in anyway?
Click to expand...

That's right. You get no additional benefit from running a TRS cable out of a guitar.
 
Thanks, I'm getting a clearer picture now...

Two things remain of interest though, is it true that I can use the XLR input for something other than microphone?...Like a stereo keyboard signal? Or an acoustic guitar with XLR connection?

And on a slighty different note...with the dmp3...it has 2 channel of input...can I have a guitar in channel one (ts) and a condensor in channel 2 (xlr, phantom power engaged)? I think I've read that the answer is NO...so its either 2 guitars in OR 2 mics...I'd need two separate dmp3s to record electric guitar and vocals at the same time?...are all preamps like this?

Thanks again for your help! :)
 
Balanced and stereo are not the same thing. Don't confuse the cable with its purpose.
 
Lauren said:
can I have a guitar in channel one (ts) and a condensor in channel 2 (xlr, phantom power engaged)?
Click to expand...
Yes, that's perfectly OK. Phantom power is not supplied on the TS inputs, only on the XLRs.
 
A guitar's SIGNAL is not balanced, so there is no way to get any benefit from a "balanced cable" or input.
 
You must log in or register to reply here.
Back
Top