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Title: PFL problem on Yamaha MG32/14FX
Post by: Stephen Patterson on May 14, 2014, 04:37:50 PM
I'm having a hard time figuring out the PFL on our board.  When I hit PFL on our mic channels, the pfl button lights up, but I can't hear anything in the headphones... even if I max the gains and headphones.  The only time I can hear PFL is on channels 29/30 and 31/32, which are rca (white/red) - not xlr.  I've got everything else off.  Thanks for any help.
Title: Re: PFL problem on Yamaha MG32/14FX
Post by: Tom Young on May 14, 2014, 06:23:57 PM
I'm having a hard time figuring out the PFL on our board.  When I hit PFL on our mic channels, the pfl button lights up, but I can't hear anything in the headphones... even if I max the gains and headphones.  The only time I can hear PFL is on channels 29/30 and 31/32, which are rca (white/red) - not xlr.  I've got everything else off.  Thanks for any help.

Is there anything inserted into the mono channels ?

Are the mono channels working, other than the PFL function ?
Title: Re: PFL problem on Yamaha MG32/14FX
Post by: Stephen Patterson on May 15, 2014, 10:07:14 AM
Is there anything inserted into the mono channels ?

Are the mono channels working, other than the PFL function ?

Yes, everything but PFL.  Mics in most of them.  Some wireless, some xlr.  Don't think this matters, but we run sound out of the main mono and stereo and 4 aux.  Some mics are grouped.  No effects.
Title: Re: PFL problem on Yamaha MG32/14FX
Post by: lindsay Dean on May 15, 2014, 01:35:48 PM
Yes, everything but PFL.  Mics in most of them.  Some wireless, some xlr.  Don't think this matters, but we run sound out of the main mono and stereo and 4 aux.  Some mics are grouped.  No effects.

hello
make sure none of the other pfls or afls are set on  any other places on the board.subgroups mons.  etc.
there are quite a few
Title: Re: PFL problem on Yamaha MG32/14FX
Post by: Stephen Patterson on May 15, 2014, 02:54:42 PM
hello
make sure none of the other pfls or afls are set on  any other places on the board.subgroups mons.  etc.
there are quite a few

Checked that again to be sure, but no.  Plus the stereo channels are working (even though I have to turn the headphones pretty high to hear - vs their afl level).  I tried running a cd player through one of the mono channels.  Same thing.  I can hear pfl, but only if I turn the gain and headphone volume up quite a bit.

I don't think this could be related to gain structure, but I'm no pro.  We're set to where unity on the channels and the main is the right level.  Amps are turned down pretty low - 30-35%.  Primaries are JBL CBT 70 - sound good.  Just the pfl problem.  May try another mixer.  Maybe internal problem?
Title: Re: PFL problem on Yamaha MG32/14FX
Post by: PAULBORDON on May 15, 2014, 02:56:54 PM
When I hit PFL on our mic channels, the pfl button lights up, but I can't hear anything in the headphones...

I had a eerily similar problem.  What it turned out to be was the individual channel gains were turned way down because a few places in the master chain (board and EQ) they had turned the gains way up..

Try this….  plug a mic 57/58 directly into the board and turn the gain up (there is also a Pad switch) until you see a red indicator (overload) on that channel only. Back it off a bit and then see if it will show up in the head phones with that the only pfl button down.  (MAKE Sure the pa speakers are off).. 

The master LR meter was also registering low (when in that mode) the meter display is selectable as I remember.

There is something about those cd playback channels on the MG32 that just gets WAY to much gain and a series of different operators can get the gain stages out of whack.

This is all coming from my grey matter on a system I worked on 15 yrs ago sooo... my grey matter is churning... and churning... ouch stop the pain... Ha!
Let us know what happens on this simple experiment.
Bless you
Title: Re: PFL problem on Yamaha MG32/14FX
Post by: Stephen Patterson on May 15, 2014, 05:58:47 PM
I had a eerily similar problem.  What it turned out to be was the individual channel gains were turned way down because a few places in the master chain (board and EQ) they had turned the gains way up..

Try this….  plug a mic 57/58 directly into the board and turn the gain up (there is also a Pad switch) until you see a red indicator (overload) on that channel only. Back it off a bit and then see if it will show up in the head phones with that the only pfl button down.  (MAKE Sure the pa speakers are off).. 

The master LR meter was also registering low (when in that mode) the meter display is selectable as I remember.

There is something about those cd playback channels on the MG32 that just gets WAY to much gain and a series of different operators can get the gain stages out of whack.

This is all coming from my grey matter on a system I worked on 15 yrs ago sooo... my grey matter is churning... and churning... ouch stop the pain... Ha!
Let us know what happens on this simple experiment.
Bless you
No go.  Turned the gain all the way up, no pad - MAX - where it just peaked.  Backed off a little and with someone basically yelling into the microphone, I could pick up a whisper of their voice in the headphones turned all the way up.  I do appreciate the suggestion.

Is it possible the pfl function just died and everything else is fine?  I have a small mixer I can try in its place and I'll post later.  Thanks again.
Title: Re: PFL problem on Yamaha MG32/14FX
Post by: Jim Thorn on May 16, 2014, 01:35:12 AM
Stephen,

   I seem to remember some of the earlier versions of the MG series mixers having the headphone jack reproduce whatever was showing on the meters, and the meters were switched to do double duty.  In one switch position, main outs and PFL/AFL signals were in the meters and phones, and in the other position, the group signals were in the meters and phones.  If I remember correctly, when groups were displayed, PFL was heard only as a bleedthrough.  I wonder if that is what you're facing?
   I looked at the block diagram on Yamaha's website, and they show the headphones getting the PFL signal before the meter select switch, so that may be the way the current models work, but I do remember being puzzled by an earlier model.
   And, it is possible that the intetnal PFL summing amp is bad; if it were, it would affect no other outputs.  Do the headphones sound strong when listening to the main stereo outputs?

Best regards,
Jim Thorn

I'm having a hard time figuring out the PFL on our board.  When I hit PFL on our mic channels, the pfl button lights up, but I can't hear anything in the headphones... even if I max the gains and headphones.  The only time I can hear PFL is on channels 29/30 and 31/32, which are rca (white/red) - not xlr.  I've got everything else off.  Thanks for any help.
Title: Re: PFL problem on Yamaha MG32/14FX
Post by: lindsay Dean on May 16, 2014, 01:30:44 PM
Stephen,

   I seem to remember some of the earlier versions of the MG series mixers having the headphone jack reproduce whatever was showing on the meters, and the meters were switched to do double duty.  In one switch position, main outs and PFL/AFL signals were in the meters and phones, and in the other position, the group signals were in the meters and phones.  If I remember correctly, when groups were displayed, PFL was heard only as a bleedthrough.  I wonder if that is what you're facing?
   I looked at the block diagram on Yamaha's website, and they show the headphones getting the PFL signal before the meter select switch, so that may be the way the current models work, but I do remember being puzzled by an earlier model.
   And, it is possible that the intetnal PFL summing amp is bad; if it were, it would affect no other outputs.  Do the headphones sound strong when listening to the main stereo outputs?

Best regards,
Jim Thorn

totally throwing at the wall here
You have checked another set of phones on the headphone output ?
if so maybe its internal , we have the same board in our gym. basketballs and all its been bullet or ball proof.
Title: Re: PFL problem on Yamaha MG32/14FX
Post by: Jim Thorn on May 19, 2014, 12:35:21 AM
Stephen,

   After my last post, I re-read your post that said the following:
 "...the stereo channels are working (even though I have to turn the headphones pretty high to hear - vs their afl level).

   Since the block diagram shows separate summing amps for AFL and PFL functions, I'm betting the PFL summing amp has died, but the AFL summing amp is still chugging along.

   It shouldn't take a repair technician long to track it down if that's the case.

Good luck with it!
Jim Thorn
I'm having a hard time figuring out the PFL on our board.  When I hit PFL on our mic channels, the pfl button lights up, but I can't hear anything in the headphones... even if I max the gains and headphones.  The only time I can hear PFL is on channels 29/30 and 31/32, which are rca (white/red) - not xlr.  I've got everything else off.  Thanks for any help.