[Harp-L] Re: Squeal Killer and feedback devices in general

[Randy <randy@xxxxxxxxxxxxxxxxx>]

Feedback devices operate in different ways, one of the most effective is 
a notch filter device which removes the offending frequency using a 
filter. By removing the frequency, tone is altered slightly, the real 
problem comes in when one tries to increase volume while using this 
device because feedback will then return but at a lower frequency. The 
device will usually have multiple filters and either automatically or 
manually you can notch out the new feedback frequency, well as you can 
see, the more we increase volume the more frequencies need to be 
filtered out and the more tone is effective.

Another is the Kinder Anti-Feedback, this is an excellent device that is 
very effective at keeping feedback at bay, I do not know exactly how it 
works but it does alter tone with solid state compression, some people 
like the compression, some don't; but again, it is very effective.

Another device is the Squeal Killer which uses a preamp tube at low 
voltages, this reduces the volume entering the amp which counters the 
excessive preamp gain of a guitar amp. The result is very similar to 
replacing the 12AX7 preamp tubes with 12AU7's. This is a good option for 
anyone not wanting to perform tube swaps in their amp.

One more device is the Harp Shield, which uses a noise gate to turn the 
mic off while you are not playing. The Harp Shield works good but it is 
dependent on good mic technique and a tight cup while playing. One side 
effect is that when playing very softly and depending on the sensitivity 
setting you can detect the opening of the gate.

They all have their positives and negatives and all work better when you 
practice good mic handling techniques. There are many players using each 
of these examples with good results

--
Randy Landry
Lone Wolf Blues Co
866-386-0777