I recently asked about the general setup of our Talking Newspaper recording studio (Undestanding a recording studio configuration).

From the answers given, it seems that without buying extra compressors, the audio chain is probably as well set up as it can be. I spent the evening at the studio, and found the manuals for our various bits of equipment. For some reason, reading manuals always seems to leave me more confused rather than less!

Our mixing desk is a Soundtracs Topaz 14-4 - the manual for this says the Master Outputs (balanced) are +27dBu

The mixer feeds into our compressor, a Drawmer DL251 dual spectral compressor - this states the XLR inputs can be set as +4dBu or -10dBV, with the output being the same.

The compressor output feeds into the distribution amp - a Chilton +26 (2 in/12 out in pairs) - this states max input +26dBu, preset to unity gain for +4dBu input and get the screwdriver out to change the variable resistors inside if your input isn't +4dBu

The distribution amp provides signal to (currently) 4x Tascam 130 cassette decks (input 97 mV, 50k Ohms), a monitor speaker, and computer via an M-Audio Delta 44 sound card, which again takes either +4dBu or -10dBV balanced/unbalanced inputs.

If I understand correctly, the compressor takes a +4dBu signal, and outputs a +4dBu signal after doing it's magic to make the quiet bits louder and the loud bits quieter… The distribution amp similarly takes a +4dBu signal, and makes sure it's still at +4dBu when it is split to six different devices, which all expect to receive a +4dBu signal.

The bit that troubles me is that the mixer says it is outputting a +27dBu signal. Am I fundamentally misunderstanding something in the figures? Or, is this usual? Does the +27dBu carry through the chain, or should the compressor still only output +4dBu?

As the system has been set up like this for several years, I am at least hoping that if there is something "wrong" with it, it is only affecting the sound quality of the final recording! As a small charity, buying a whole load of new equipment isn't really an option, but it would be really nice to properly understand what we have, and to make sure it is working properly for us.

(NB as was pointed out in an answer to my previous question, the mixing desk doesn't have master inserts, or in fact group inserts so to make real use of a compressor it has to be on the master ouput, or limit it to just working on two of the five mic channels we run.)

I recently asked about the general setup of our Talking Newspaper recording studio (Undestanding a recording studio configuration).

From the answers given, it seems that without buying extra compressors, the audio chain is probably as well set up as it can be. I spent the evening at the studio, and found the manuals for our various bits of equipment. For some reason, reading manuals always seems to leave me more confused rather than less!

Our mixing desk is a Soundtracs Topaz 14-4 - the manual for this says the Master Outputs (balanced) are +27dBu

The mixer feeds into our compressor, a Drawmer DL251 dual spectral compressor - this states the XLR inputs can be set as +4dBu or -10dBV, with the output being the same.

The compressor output feeds into the distribution amp - a Chilton +26 (2 in/12 out in pairs) - this states max input +26dBu, preset to unity gain for +4dBu input and get the screwdriver out to change the variable resistors inside if your input isn't +4dBu

The distribution amp provides signal to (currently) 4x Tascam 130 cassette decks (input 97 mV, 50k Ohms), a monitor speaker, and computer via an M-Audio Delta 44 sound card, which again takes either +4dBu or -10dBV balanced/unbalanced inputs.

If I understand correctly, the compressor takes a +4dBu signal, and outputs a +4dBu signal after doing it's magic to make the quiet bits louder and the loud bits quieter… The distribution amp similarly takes a +4dBu signal, and makes sure it's still at +4dBu when it is split to six different devices, which all expect to receive a +4dBu signal.

The bit that troubles me is that the mixer says it is outputting a +27dBu signal. Am I fundamentally misunderstanding something in the figures? Or, is this usual? Does the +27dBu carry through the chain, or should the compressor still only output +4dBu?

As the system has been set up like this for several years, I am at least hoping that if there is something "wrong" with it, it is only affecting the sound quality of the final recording! As a small charity, buying a whole load of new equipment isn't really an option, but it would be really nice to properly understand what we have, and to make sure it is working properly for us.

(NB as was pointed out in an answer to my previous question, the mixing desk doesn't have master inserts, or in fact group inserts so to make real use of a compressor it has to be on the master ouput, or limit it to just working on two of the five mic channels we run.)