Question some urgent help required. feedback issue

[sanderhermans]

Just back from rehearsal and we have a gig tomorow so i need some help here.
Today i had some trouble with alot of feedback and squeeling of my amp. The problem got worse as i faced the pickup of my bass towards the amp. Now i play at reasonably high gain in different stages. Get some gain from my comp. Then into a moderate fuzz and into my sansamp wich drives the signal some more. Then i go into my power amp.

The thing is that i never had this problem before. Even with the same settings altough i did ad the compressor just lately. But now i tested it again at home to fix the problem and its sudenly gone. So can this be caused by bad power suply at our rehersal room? One more thing, ive noticed is that some hiss it get gets less when i put my compressor in passive mode. But always tought i should put it in active with my stingray... is it bad if i put it in passive mode? Also this hiss occurs here at home and didnt seem to be as loud at our rehersal area. But there i had the feedback issue. So it seems to have something to do with where i plug it in.

more details on my setup are in my signature. All cables are tested and good and i have decend power suply for my pedals. So that cant be it.

One thing else. I have a boss noise supressor laying around here. Could/should this be used for (high gain) bass?

Thx in advance for anny help.

 

[sanderhermans]

One more tought i just had is mayebe i need to lower my pickup a bit with this volume and gain settings? It is now on factory standard.

 

[Golem]

`

Solid body electric basses, such as includes EBMM basses, are
not especially prone to feedback. It may relate to WHERE you
play but not to the AC [mains] supply .... more likely it's the
room acoustics.

For your emergency situation, get rid of all that crap between
you ax and your amp. Set your PU height reasonably close to
spec and don't stand face-to-face with the bass drum [ie your
back to the house].

You can mess with your pedals later when you are past your
emergency and have a chance to do some testing. My guess
is that one of them is boosting some freq that is harmonically
resonant to the wooden structure of the bass, or perhaps to
one of the strings.

 

[sanderhermans]

Exta update... (i know ) just put my boss ns2 at the end of my effects line, after preamp. And it seems to work verry well for this. It gets rid off all the hiss i get at home. Just not sure if it will delete the feedback i get at rehearsal. But it doesnt seem to affect my sound at all. I guess adding the compressor was one gain stage too much without doing annything to counter it.
Anny sugestions are stille welcome tough

 

[sanderhermans]

`

Solid body electric basses, such as includes EBMM basses, are
not especially prone to feedback. It may relate to WHERE you
play but not to the AC [mains] supply .... more likely it's the
room acoustics.

For your emergency situation, get rid of all that crap between
you ax and your amp. Set your PU height reasonably close to
spec and don't stand face-to-face with the bass drum [ie your
back to the house].

You can mess with your pedals later when you are past your
emergency and have a chance to do some testing. My guess
is that one of them is boosting some freq that is harmonically
resonant to the wooden structure of the bass, or perhaps to
one of the strings.

Well playing with nothing in between is really a last resort as i would get a verry different sound not really fitting the music i play. Then about the feedback. It really did not sound like a string or frequency was being overboosted but more of an electrical problem lilke a beeping sound. Propably the cause was too much gain. But it was verry different from your usual feedback. It was like i just could not come too close to my amp (not my cab) so no resonance isue more a "magnetic field isue" mayebe bad ground or something....

 

[Golem]

`

So you seem to NOT be getting acoustic feedback but rather
are receiving broadcast noise from the electronics in your amp.
Lotsa amps now have digital effects, and also high frequency
switching circuits [which replace output transformers]. All that
stuff can broadcast noise.

If you're receiving broadcast noise ["radio interference"] then
it really IS possible that the AC mains circuits are different in
the various places you play. Two issues would be [1] noise on
the power [hot] side of the AC supply in the building, and [2]
the integrity of the ground side of the AC lines.

Noise [1] on the hot side can be introduced by motors and/or
lighting transformers [neons, fluorescents, etc] on the circuit
you're using. An AC clean-up device, a "power conditioner", is
often the answer there. AC conditioners will do NOTHING for
any [2] broadcast noise problems. When you touch the metal
parts of your bass that are internally grounded to the eq-pre,
you change the capacitance of the entire electronic package
of your bass in your hands, and this tends to reduce hiss and
hum from broadcast sources, mainly by "retuning" the radio
frequencies that are favored by the antenna ... the antenna is
your whole package.

One thing you can't get rid of is odd clicks and pops, or voices,
that come from AM radio such as emergency vehicles. It's also
possible that your amp is producing AM radio signals. In that
case, try shielding the amp. You can't just put it in a metal box
cuz then it gets hot and the knobs are hard to access, but you
can find ways to shield it, especially in the direction of your ax.
Also, in such a case, cables may matter, as they may extend
the "broadcast antenna" of your amp right past any shielding
you attempt. Solution ? No cable, use wireless. Costs money,
sorry about that, but makes stage life more mobile/fun so it's
not just money spent on fighting noise.

Environmental AM radio noise is everywhere. It's not just from
real radio transmitters. AM is crude stuff. Anything that makes
sparks [motors, switches etc] or magnetic pulse [motors again,
relays, etc] is an AM broadcaster. You have too much crap in
between your amp and your ax. All the cabling and the internal
internal circuit boards of your toys are antennae that help pick
up AM noise. To make matters worse, you have too many gain
stages in series, so every little AM noise is magnified. AM is a
verrrrrry crude broadcast, therefore verrrrrry hard to filter out.

 

[Golem]

`

One more thing about broadcast noise. The main antenna on
your bass is the string set. Your playing position affects the
performance of that antenna. Here is the deal on the possible
positions of that antenna:

Horizontal: Highly directional at right angle to the antenna,
and is [within the directional limit] the MOST sensitive.

Vertical: Omnidirectional, and LEAST sensitivity.

Angled 45 degrees: Semi-directional, medium sensitivity.
The direction effect is NOT at right angles but is along the
plane which the antenna shares with a vertical line cast
thru the antenna IOW, it's "edge-on", not right angle. For
instance, with the neck horizontal, it's very receptive to a
signal from out in the audience [or behind you, or above
you]. The 45 degr position is directional, but not as focus
in it's directionality as is the horizontal. Medium sensitivity
and medium directionality, together. At 45 degr directivity
is now to your left and your right and above or below you,
very different from horizontal.


Horizontal can be the WORST noise cuz it's most sensitive,
but if there's ONLY ONE SOURCE of noise, then horizontal
can be the LEAST noisy, cuz it's so very directional that you
can just aim it AWAY FROM that single source [altho that
sometime puts you sideways to your audience, sideways is
more of a problem for lead players than for bassists].

OKEEDOKEE ?

 

[Holdsg]

Man, I learned some stuff today

 

[sanderhermans]

Thx alot golem. This really helped. My findings are that is really can only be the first problem you have expained anda power stabalizer or something like that really couldnt hurt.
Never really picked up any radio noise or at least nothing audable. One thing i did notice is cellphone transmision noise. I get this when my mobile internet is on at rehearsal and im too close to my amp. You get this typical dialing noise. Well if you activate the boss ns2 this will disapear completely. And i must say again that my first findings with that pedal are great. It doesnt seem to change anny of my sound and it helps alot. Annyone else use this here?

 

[Golem]

`
Well I learn something too. I'm
gonna look into that Boss NS2.

 

[sanderhermans]

Down side to the ns2 is definetly that it only cuts off hiss and squeels in between notes when youre not playing. There is also an efects loop on it and i will try puting my gain based affects between it. This cirquit should reduce hiss and squeels even when playing. Im gonna try this setup out tomorow. But for the gig we had today the normal aplication (muting between notes) was good enough. One more tought ive had recently is that i might be puting a too high signal into my power amp. Mayebe i need to use less preamp gain and volume and use more oweramp gain....