delta 1010 balanced jack query

[mellodge]

Hi people, Just got my new delta 1010. I used to have a similar card (the much inferior hoontech c-port) it had unbalanced -10db trs jack sockets. Naturally I want to take advantage of the 1010's balanced pro +4db jack sockets, my question is ,do I have to use stereo trs jacks,as I only have mono ones. Dont fully understand the balanced unbalanced thing.

[JA]

You can only take advantaged of the balanced inputs if the device(s) you are connecting have balanced outputs; this does require the use of TRS balanced cables.

[mellodge]

O.k I get that, I've reset my Mackie big knob to accept +4db and I've made sure that my outboard gear is reset to accept +4db were applicable. I've also made sure I utilise xlr to xlr leads were my gear permits. I have an anologue mixer (soundcraft fx 8) which has direct outs, so, I use mono jack patch cables from my dir outs to the 1010. But ,how do I know if my patch leads are balanced?

[JA]

I looked over the FX 8's manual and it looks like the direct outputs are balanced. A TRS balanced cable has 2 black rings on the connector (you're thinking stereo, but in this application it's balanced mono). The cable you're referring to as "mono", probably has 1 black ring on the connector (like a guitar cable, but in this application is an unbalanced 1/4" cable).

[mellodge]

O.k., Thanks for your efforts, my suspicions were correct; I have unbalanced patch leads, I guess I'll have to purchase balanced ones.
Thanks again.

[tonymite]

HI,

I am using DELTA 1010 with breakout box. I am sending the "balanced - TRS" outputs through to an SSL-G series Master/Bus Compressor (custom made for me by Malkjos - www.malkjos.com).

I am then sending the TRUE BALANCED outputs from the compressor back into the " balanced TRS" inputs of the DELTA 1010.

For starters, I first noticed a gain drop on the input of the DELTA (even when truly by-passing the SSL-G compressor by disconecting it completely from the signal chain and just bridging the outputs & inputs with TRS balanced cables.

After mucking about with the -10/+4dB switches we realised the input on the DELTA 1010 was lower than the output - so we decided to send a test tone through the DELTA 1010 and sent it to an osciloscope - the signal coming from the TRS "balanced" outputs was only sending signal ONLY on the HOT (tip) of the TRS connector - whereas the output of my CUSTOM NEVE 1073 - also made by MalKjos sent out a TRUE BALANCED output on HOT(tip), COLD(Ring) and GND(Sleve).


If anyone has an answer other than the DELTA 1010 has ONLY UNBALANCED I/O's and is made to "accept" TRS balanced signals - only to unbalance the signal - please help out.

Thanks in advance

[JA]

The outputs are impedance balanced. They only output a signal on the hot pin, but the inverted pin is connected with the same source impedance to ground. This does result in better SNR than just running it unbalanced.

[tonymite]

Balanced audio is a method of interconnecting audio equipment using impedance-balanced lines. This type of connection is very important in sound recording and production because it allows for the use of long cables while reducing susceptibility to external noise.

Balanced connections use three-conductor connectors, usually the XLR or TRS jack plug. XLR connectors, for instance, are usually used with microphones because of their durable construction, while TRS jack plugs are usually used for mixer inputs and outputs because of their smaller profile.

http://en.wikipedia.org/wiki/Balanced_audio

It is a shame that a company like M-AUDIO has stooped so low as to falsely advertise/mislead their clients in such a way.

Full Features
10 x 10 24-bit/96kHz full-duplex recording interface
8 x 8 analog I/O on balanced/unbalanced 1/4” TRS
S/PDIF digital I/O (coaxial) with 2-channel PCM
SCMS serial copy management control
digital I/O supports surround-encoded AC-3 and DTS pass-through
up to 24-bit/96kHz fidelity
1 x 1 MIDI I/O
analog outs can directly drive up to 7.1 surround
+4dBu/-10dBV operation individually switched on rack-mount unit
word clock I/O for sample-accurate device synchronization
software-controlled 36-bit internal DSP digital mixing/routing
zero-latency monitoring
Apple G5 compatible - Incompatible exceptions
includes Ableton Live Lite music production software, so you can make music right away

I will be contacting AES, consumer affairs and my lawyer to discuss how this sort of propaganda can be allowed.

[JA]

The outputs are truly balanced. This is from the article you linked above:

Differential signaling

Signals are often transmitted over balanced connections using the differential mode, meaning the wires carry signals of opposite polarity to each other (for instance, in an XLR connector, pin 2 carries the signal with normal polarity, and pin 3 carries an inverted version of the same signal).

Despite popular belief, this is not necessary for noise rejection. As long as the impedances are balanced, noise will couple equally into the two wires (and be rejected by a differential amplifier), regardless of the signal that is present on them. A simple method of driving a balanced line is to inject the signal into the "hot" wire through a known source impedance, and connect the "cold" wire to ground through an identical impedance. Due to common misconceptions about differential signalling, this is often referred to as a quasi-balanced or impedance-balanced output, though it is, in fact, fully balanced and will reject common-mode interference.