Impedance Issue between preamp out (EZ1290) and Audio Interface Line IN (Prism).....Help!

[inkster]

Pin 3 hot...lots of companies selling sorta balanced gear including some well known widely used recording interfaces don't like gear with pin 3 hot which I see some times and I still get calls like "my manley sounds weak and thin" and I ask "when did you install the new protools rig?"

 

[kags]

Pin 3 hot...lots of companies selling sorta balanced gear including some well known widely used recording interfaces don't like gear with pin 3 hot which I see some times and I still get calls like "my manley sounds weak and thin" and I ask "when did you install the new protools rig?"

Are you saying that the new Avid interfaces are pin 3 hot? I've installed hundreds of HDI/O, Carbons, and MTRXs and haven't had an issue, but nothing surprises me anymore! I have compared the DB25 analog pinout from the Carbon to the Tascam standard, and it matches, as did the older 192 interfaces.

 

[Matt Syson]

There is a more than subtle difference in the term 'hot' so you HAVE to read the whole story. Hot can mean it has active signal on it which may or may not be in phase with either other outputs or the 'cold' signal which if active could be referred to as hot but phase inverted. Most manufacturers aim for coherent phase response from input to output BUT occasionally things get messed up. Thus pin 2 of an input XLR is now (mostly) trated as being inphase and pin 2 of an OUTPUT XLR of the same gear should also be 'inphase although if it is an EQ the 'phase' may be 'out' at various frequencies) (delay).

 

[kags]

For multichannel setups one of my first priorities is to verify consistent polarity for all the speakers and drivers in a system. Many systems use passive speakers for surrounds (and L,C,R in cinema systems). I find sloppy Dsub pinning and speaker wiring polarity problems. I have not found any interfaces or monitor controllers where input to output polarity is not maintained. I don’t doubt they exist, based on the comments in this thread, however, I will be vigilant in testing every device for intput to output polarity integrity.

 

[Matt Syson]

I suppose testing a bunch of convertor ('interfaces) by parallel feeding the digital signals and comparing the analogue outputs for phase cohrerence could be fun on a boring wet day!