strange noise...
Scott Goldstein
and neither have helped! Can I try again??
-----
Hi. Never had this happen b4:
Turn on my PA and start playing a piano patch. All is well, then all of
a sudden, a small pop and wild distortion as if there was a fuzz box
attached. I unplug, bypass my BBE 482 and my compressor, turn everything
back on and all is well... for 10 seconds. Another small pop and big
distortion. I also notice this time that with every note I play, the
power indicator on my Furman power conditioner goes way down, as if
simply putting a signal thru the PA is draining power.
If you can troubleshoot for me with this info, great! If not, let me
know what specifics about my setup you need and I'll list them. Thanks
in advance for the help.
Scott
Chuck
>I don't want to be a pest, but I only got 2 responses to this problem
>and neither have helped! Can I try again??
I also notice this time that with every note I play, the
>power indicator on my Furman power conditioner goes way down, as if
>simply putting a signal thru the PA is draining power.
I can't troubleshoot FOR you but I can make a few suggestions.
The first is to isolate every piece of gear from the gearboard back
through the chain to see what unit causes the problem.
If it only happens with your keyboard, and you have repatched it to
another channel with no love there either, then its probably your
keyboard output.
If you get love with the new channel, maybe its the channel on the
board.
Try the keyboard directly into another amp. Is it ok?
If not, there you have it...
etc., etc., etc.......
Scott Goldstein
Chuck <whyd...@care.com> wrote:
OK - will try this. I wonder why the power drain on the furman... maybe
it is just the keyboard - i'll isolate that 1st.
Matt Stoody
a stage amp, make sure it's okay. If the key's okay, blow out
everything in your typical signal path but pre-amp (mixer?), power amp.
Still there? Try another channel in your mixer. Still there? Does
this distortion come out of both sides of the PA, BTW? Try another
power amp. Does it only occur on your key channel(s) or everything in
the PA? I gotta go.
Matt
Shaun
> OK - will try this. I wonder why the power drain on the furman... maybe
> it is just the keyboard - i'll isolate that 1st.
Make sure your power amp(s) ARE NOT GOING THRU THE FURMAN!!! Bad idea in
the first place. Never do that.
--
Shaun Wexler,
Hellsgate Sound
http://www.hellsgate-sound.com
mailto:sh...@hellsgate-sound.com
Matt Stoody
Matt
Scott Goldstein
No stage amp - I'm a 1 man band with everything going into the mixer to
PA.
> Try the k/brd with
> a stage amp, make sure it's okay. If the key's okay, blow out
> everything in your typical signal path but pre-amp (mixer?), power amp.
> Still there? Try another channel in your mixer. Still there? Does
> this distortion come out of both sides of the PA, BTW?
I shoulda been clearer in original post: it's not just the keyboard. I
ran a sequence thru all of my modules and everything was distorted and
showed a drain on the furman unit.
> Try another
> power amp. Does it only occur on your key channel(s) or everything in
> the PA? I gotta go.
I haven't tried the other side of the PA yet, but will try all of these
suggestions. Thanks a lot.
Scott
Scott Goldstein
Shaun <see.sign...@email.address> wrote:
> "Scott Goldstein" <hen...@optonline.net> wrote:
>
> > OK - will try this. I wonder why the power drain on the furman... maybe
> > it is just the keyboard - i'll isolate that 1st.
>
> Make sure your power amp(s) ARE NOT GOING THRU THE FURMAN!!! Bad idea in
> the first place. Never do that.
Hmmm... I've always had everthing powered thru the Furman. Not a good
idea, huh?
Chuck
>OK - will try this. I wonder why the power drain on the furman... maybe
>it is just the keyboard - i'll isolate that 1st.
One thing at a time....find out what first...then ask why! ;)
Mike Tulley
Here's a shot in the dark: you amp si drawing heavy current through a
poor AC power feed. Every time it gets loud, the AC voltage drops.
Your keyboard is more sensitive to AC voltage level than anything
else; it goes wonky on the short brown-out.
Try plugging the power amp into a different AC circuit.
Mike T.
Rob Beech
.....might listen to you tho.. aparantly there were only 2 replies????
i sent 2 and there were at leat a dozen more.
Anyway to add to this. Obviously the Keyboard is DC (well i've nto
seen one AC yet.....) and being a keyboard player myself i know they
are EXTREMELY sensitive to the very slightest alteration in current,
voltage or anything including the colour of socks you wear. i
normally know when the microwave in the kitchen downstairs has
finished as the keybaord flicks on about 3 voices or patches.
Do make sure the alternative AC cirucuit is on the same phase as the
rest of the equiptment. as this is not an issue in the home it can be
quite a problem to find that outlets on one stage side are off a
differnt phase to the ones on the other.
Also, do make sure there are no obvious over driven signals.
think about that logically before passing it as "oh he thinks i know
nothing"
Its quite normal for a variable resistor in a gain control to become
dirty and the current is lowered for a certain time even if the conrol
is set to maximum gain.
This seems very odd this situation although i have known somethign
similar before.
If you use a mixing desk. are there obvious peaks on either input or
output on the desk?
Does the power amplifers peak or CLIP lights come on when this
distortion is present.
is there a short circuit in a speaker cabinet?
are you using a signal lead to connect power amplifeir to speaker?
have you tried pluging a set of phones into the output of the keyboard
to check the signal is ok from the keyboard......
then check with phones from the next item (mixing desk or effects)
and so on up to the amplifier where you clearly monitor with the
speakers.
are you driving one amplifier channel with no speaker connected?
check EVERY SINGLE lead you use in the connection.
it could be that a lead is only just connected and after a time
connects fully allowing the true signal to reach the amplifier.
Since the problem has started have you had to drive units harder to
get the same output?
What keyboard do you use?
Just a few.. or alot of questions to answer and reply or just to
answer and check . Do let me know if any of this fixes your problem
as we all like to know that our advice has helped other people.
Regards.
Rob
Graham Stevenson
> I don't want to be a pest, but I only got 2 responses to this problem
> and neither have helped! Can I try again??
>
> Hi. Never had this happen b4:
>
> Turn on my PA and start playing a piano patch. All is well, then all of
> a sudden, a small pop and wild distortion as if there was a fuzz box
> attached. I unplug, bypass my BBE 482 and my compressor, turn everything
> back on and all is well... for 10 seconds. Another small pop and big
> distortion. I also notice this time that with every note I play, the
> power indicator on my Furman power conditioner goes way down, as if
> simply putting a signal thru the PA is draining power.
>
> If you can troubleshoot for me with this info, great! If not, let me
> know what specifics about my setup you need and I'll list them. Thanks
> in advance for the help.
>
> Scott
Dead easy. You have for some reason HF ( ultrasonic oscillation ) somewhere
in your system. The pop is classic - the onset of oscillation - and the
power drain is all that VHF going into your HF drivers most likely.
Loads of possible causes !
I would check all your wiring / grounding as a first off.
Also - are all your connections balanced ? It may help if they are.
< wonders about the advisability of mentioning disconnecting the screen at
the receiving end of a balanced connection >
Bad earthing maybe ?
Graham
Rob Beech
from keyboards and synth modules etc will not be balanced. - which can
be a pain in the arse but doesn't normally cause alot of problems.
Keyboards are DC
Regards
Rob.