strange occurrence with peavey vmp2

[ANON]

Archived from groups: rec.audio.pro (More info?)

i was using a peavey vmp2 with two mics for about a year with no problems

then tried just one mic, u87 in omni, into the vmp2 into a masterlink. the
other cable was left in the vmp with no mic connected, input volume turned
down to 0. strangely there was level on the channel with no microphone. the
miced channel had more level though. both channels sounded messed up on
playback as if there was no phantom power being supplied, crackly on peaks.

wondering what can cause these problems

i disconnected the input cable to the vmp with no mic, and disconnected the
input to the masterlink from the unused channel. this fixed the problem.
only one channel on playback and it sounds fine.

 

[Mikey]

Archived from groups: rec.audio.pro (More info?)

"anon" <anonymousm@nyc.rr.com> wrote in message news:<E547d.50292$Ot3.44732@twister.nyc.rr.com>...
> i was using a peavey vmp2 with two mics for about a year with no problems
>
> then tried just one mic, u87 in omni, into the vmp2 into a masterlink. the
> other cable was left in the vmp with no mic connected, input volume turned
> down to 0. strangely there was level on the channel with no microphone. the
> miced channel had more level though. both channels sounded messed up on
> playback as if there was no phantom power being supplied, crackly on peaks.
>
> wondering what can cause these problems
>
> i disconnected the input cable to the vmp with no mic, and disconnected the
> input to the masterlink from the unused channel. this fixed the problem.
> only one channel on playback and it sounds fine.

Were you routing thru a patchbay? Could the signal have been multed somehow?

Mikey Wozniak
Nova Music Productions
This sig is haiku

 

[Guest]

Archived from groups: rec.audio.pro (More info?)

anon <anonymousm@nyc.rr.com> wrote:
> i was using a peavey vmp2 with two mics for about a year with no problems

> then tried just one mic, u87 in omni, into the vmp2 into a masterlink. the
> other cable was left in the vmp with no mic connected, input volume turned
> down to 0. strangely there was level on the channel with no microphone. the
> miced channel had more level though. both channels sounded messed up on
> playback as if there was no phantom power being supplied, crackly on peaks.

> wondering what can cause these problems

> i disconnected the input cable to the vmp with no mic, and disconnected the
> input to the masterlink from the unused channel. this fixed the problem.
> only one channel on playback and it sounds fine.

Hmmmm, it was Colonel Mustard in the Library with the Wrench...I love a
good mystery.

Perhaps you can perform a few more tests. Leave the both sides connected
between the VMP and the masterlink. Does the problem only happen when
you leave that mic cable connected to the unused channel? Yes? No?

Then you could have a cable with a short in it.

How about if you do the same thing with a different mic, say a dynamic
with no phantom power? Does it go away?

I wonder if the problem is the mic cable, or could it be that there is
a problem in the phantom power circuit. If the resistors are very badly
matched, could this lead to crosstalk between the channels?

Rob R.