BALANCED VS UNBALANCED Is there a dramatic difference? PLEEAASE HELPa!!

[cadbawdbawks]

I just bought an M-Audio DMP3 preamp for my Tascam US 122 Interface.

Previously, my connections were basically: Condenser Mic -->XLR Cable 25 FT --> Tascam US 122 XLR Mic In --> Computer

Currently, my connection is: Condenser Mic --> XLR Cable --> M-Audio DMP3 XLR Mic In --> M-Audio DMP3 1/4" Line Out --> TS Cable 20 FT --> Tascam US 122 Line In --> Computer

Upon recording, immediately I hear a difference. I noticed that with the DMP3 preamp setup, when I monitor my recordings through my headphones, I can barely hear anything through the headphones. This was a significant difference from my previous setup without the DMP3 which allowed me to hear myself clean and clear through my headphone monitors while recording.

The only difference I can really spot is that with my previous setup, I connected the mic directly with a balanced chain into my Tascam US122. Whereas with the DMP3, I am using a balanced cable initially, which is then converted to a 20 FT unbalanced TS cable at the DMP3 output into my Tascam US 122.

Could the use of balanced and unbalanced cables dictate these significant changes?

I honestly prefer using my Tascam built in preamps over the external DMP3 Preamp at this point and am very frustrated with my purchase. The DMP3 clips before I can even hear myself through the headphone monitors whereas for the tascam, I can hear myself loud and clear and would not clip anywhere near as frequently as the DMP3.

PLEEASE HELP ME! I'VE BEEN PULLING MY HAIR OUT OVER THIS!

Thankyou for reading all that...I do appreciate any and all help that is offered!

 

[dementedchord]

balanced v unbalanced is nit that big of a deal in most situations... i suspect that what you are hearing is attributale to a gain staging issue... you'll want to dig a bit deeper than this but essentially we're talking about using each piece of gear in it's own optimum range...

 

[TheChikenMaster]

wooopps mistake.

 

[TheChikenMaster]

It could be that your chain is confused. Meaning from the dmp3 is a mic level not line. Your chain is running from mic to the linein of the interface that may create some issues in levels. what i suggest is using a trs to xlr cable from dmp3 to the interfaces mic input, thus keeping the levels even.

 

[Richard Monroe]

It could be that your chain is confused. Meaning from the dmp3 is a mic level not line. Your chain is running from mic to the linein of the interface that may create some issues in levels. what i suggest is using a trs to xlr cable from dmp3 to the interfaces mic input, thus keeping the levels even.

Sorry, but that is dead wrong, as well as the original post. The 1/4" outputs on a DMP3 are balanced outputs. The high/low switch on the front panel changes the output from -10dBV to +4 dBu. Of course, you could use TS cables out, which would unbalance the signal, but you don't need to. What Chickenmaster suggests is plugging a line level out into a mic level in, which is quite capable of frying components.

Ideally, you want to use 1/4" TRS cables from the line outs on the DMP3 to 1/4" line level inputs on the Tascam, in other words, a TRS to TRS cable. As a rule, although not always, -10 line level inputs use RCA jacks, and +4 inputs use 1/4" jacks. I don't know about the Tascam, but a lot of digital recorders have switches to change the line level inputs between -10 and +4. Do not confuse the type of connector with the type of connection. Balanced signals can be made with either XLR or 1/4" connectors. RCA jacks, on the other hand, *cannot* support balanced connections, as there are only 2 contacts.
Some preamps have XLR line outs, but the DMP3 isn't one of them. *Never* connect a line out to a mic level input. Even if you don't blow anything up, it will suck.

Now, to the original question. What happens you use an unbalanced connection? In general, you will lose a small amount of gain, about 6db, and you will have increasing noise and eventual loss of signal if long runs of cable are used- over 20'. So- from a studio perspective, it is no big deal if you use unbalanced connections, although balanced connections are usually preferred. Some pieces of studio gear do not support balanced connections, such as the FMR audio RNC compressor. So when I use it with my Avalon AD2022 preamp. it "unbalances" the signal. Now the Avalon has only XLR outputs, no 1/4". It does, however have balanced XLR's and unbalanced XLR's. Let's say I have 2 cables. One is XLR to TS, and the other is XLR to TRS. I could use either one, and I could plug either one into either the balanced or unbalanced output and then to the 1/4" inputs on the RNC.
Net result? No difference. The RNC will accept either one and put out an unbalanced signal, because that's all it does. So- you could run a TRS to XLR cable from your DMP3 to the XLR mic level XLR input on the Tascam, which would be OK, only if the Tascam's XLR inputs can be configured to accept a line level input. Many digital recorders have mic/line XLR inputs, so you set the mic/line dial to "line", and it will be OK. I don't know whether the Tascam does that.

What should you take away from this?

1. 1/4" or XLR connectors can be used to transmit balanced or unbalanced signals. You need to know which one you are dealing with.

2. Using unbalanced connections is no big deal, unless you are using runs of cable longer than 20'.

3. Some inputs can be configured to receive mic or line level inputs. They are called mic/line inputs, and you need to know if you have them or not. Plugging a line level output into a mic level input is very, very, wrong.

4. The DMP3 supports balanced connections, but there is nothing to prevent you from unbalancing that signal if you need to. The moment you plug a TS cable into it, you have done that.

5. Not all line level signals were created equal. There is -10 line level, which is what most home stereos, CD players, and MP3 players use. Think of this a "consumer" line level. It is pretty close to the output of a headphone jack. Then there is +4 line level. This is what most pro audio gear uses. The DMP-3 can be configured to put out either one.

BTW- if you ever need to change +4 to -10, or the other way around, this is a really handy bugger to have in the studio:

http://www.8thstreet.com/product.asp?ProductCode=3104&Category=Recording_Accessories

Hope this helps- Richie

 

[TheChikenMaster]

I stand corrected. I dont own the dmp3 . I should have done my research. A preamp with only line outs? I assumed they were mic level outputs. That would have been bad.

 

[mattr]

A preamp with only line outs? I assumed they were mic level outputs.

Errr, wha? That would just defeat the whole concept of a preamp...

 

[TheChikenMaster]

kinda wierd ehh?

 

[mattr]

I wasn't agreeing. I meant what would be the point in a mic preamp with mic-level outputs?

 

[Richard Monroe]

The purpose of a mic preamp is to convert the weak output of a mic into a line level output. *All* mic preamps put out line level. That's what they are for. There may be some preamp that has a mic level output, but if there is, I've never seen it.-Richie

 

[TheChikenMaster]

I wasn't agreeing. I meant what would be the point in a mic preamp with mic-level outputs?

your disagreeing with a fact?