Audio question- RJ-45 extenders/baluns

[Spehro Pefhany]

Hi, all:-

What's in these things? A friend is interested in extending some
high end microphone cables (not line level). Does this make any sense?

Some (eg. instasnake) seem to pass phantom power- as well.
Transformers and blocking capacitors per channel?

 

[Nico Coesel]

Hi, all:-

What's in these things? A friend is interested in extending some
high end microphone cables (not line level). Does this make any sense?

Not much. The best option is to use shielded twisted pair microphone
cable all the way. I don't see the need for baluns either unless the
cable length is several km/miles.

 

[Spehro Pefhany]

Not much. The best option is to use shielded twisted pair microphone
cable all the way. I don't see the need for baluns either unless the
cable length is several km/miles.

What about using CAT5 (4 twisted pairs) to carry 4 microphones?

I've asked what the max length he's interested in. For now, I'd guess
100 feet or more, judging by the 30' tripods he bought.


Best regards,
Spehro Pefhany

 

[Nico Coesel]

What about using CAT5 (4 twisted pairs) to carry 4 microphones?

I wouldn't go that route. Microphone signals are very weak. 20dB
amplification is often required to get to line level. A single
shielded cat5 cable for each microphone probably works.

 

[Spehro Pefhany]

I wouldn't go that route. Microphone signals are very weak. 20dB
amplification is often required to get to line level. A single
shielded cat5 cable for each microphone probably works.

For length, 50-250 feet, with 100 feet as the nominal is about right.

Do you think they actually have transformers at each end? If so, $300
is reasonable for 8 high quality audio transformers, connectors etc. I
think he'd be p*ssed off if he got them and there was nothing inside.


Best regards,
Spehro Pefhany

 

[Tony]

For length, 50-250 feet, with 100 feet as the nominal is about right.

Do you think they actually have transformers at each end? If so, $300
is reasonable for 8 high quality audio transformers, connectors etc. I
think he'd be p*ssed off if he got them and there was nothing inside.



Best regards,
Spehro Pefhany

Microphones are already balanced, and so are mic pre-amps, so baluns are quite
inappropriate..Dynamic mics are 2 wire devices, so connect right onto the Cat5e. Condenser
mics are another thing, and need a return path for the phantom power (perhaps the overall
screen, or dedicate a pair to ground?). I have actually used multiple dynamic mics over a
single Cat5e with no problems of any kind, although I did keep the cable away from nasty
interference sources; I seem to remember that the mic screens were all grounded at the box
at the mic end of the Cat5e. And there might be a case for adding a few small caps across
the receiver end to drain the RF energy from the antennae.
Tony