Topic: Doing an a/b mic comparison

[Massive Dynamic]

So, I'd like to do an a/b mic test, but I have limited equipment. I only have a PS-2/line transformers and one DAT deck. The plan would be to put both sets of mics on a stand, and begin with one set of mics plugged into the PS-2. Between songs, I'd unplug one set of mics and plug in the second. Do I need to power off the PS-2 when changing mics, or can I leave the PS-2 hot without damaging the mics? Any other pointers?  Thanks.

[Tim]

always turn the power supply off before connecting or unconnecting your mics. you risk serious damage to the microphones if the phantom power is on and you plug them in or unplug them

[heath]

always turn the power supply off before connecting or unconnecting your mics. you risk serious damage to the microphones if the phantom power is on and you plug them in or unplug them

qfmft

[MattD]

I could have sworn it was the power supply that was damaged rather than the mics. The mics are "used" to suddenly getting phantom or suddenly having it turned off. However, the power supply wants phantom turned off at the source, not suddenly broken because the mic is removed.

Either way, the advice is good. I'm just wondering about the reason. The reason I think the above is because my ULN-2 has a protection circuit that allows for hot-plugging if you forget to turn off phantom.

[Massive Dynamic]

Thanks, +t all round.  I was pretty sure it was a bad idea, just wanted to save time switching the connections, if possible.  On a related question, if I had two PS-2s, could I unplug one PS-2 from the transformers, and plug in the other, without powering them down?  Should only be a mic level signal output, right?  Not that the three seconds of time saved would be worth the extra gear, though, since I don't intend to do this test during any important shows.

[dnsacks]

one other concern -- I believe the ps2 has capacitors built in that will continue to provide phantom power for a few seconds after powering down.  I'd be really careful with this comparison and would likely do at least a "5 mississippi" count after powering down the ps2 before unplugging any connectors.

[Massive Dynamic]

one other concern -- I believe the ps2 has capacitors built in that will continue to provide phantom power for a few seconds after powering down.  I'd be really careful with this comparison and would likely do at least a "5 mississippi" count after powering down the ps2 before unplugging any connectors.

To be safe, I guess I could wait for the "no input" message on my M1 before unplugging.  I've actually done an a/b test of PS-2/LT vs pmod UA-5 where I was unplugging/plugging my one set of mics, no harm done.  Of course they are power hogs, so maybe they drained all the stored juice in short order.

[Nick's Picks]

this is where the R4 shines.


never liked cable jerking for comparrisons. 
To really do it right, I might try hacking the PS2 so it has 4 XLR outputs.