Audio signals from the amplifier’s speaker
are picked up by the microphone and fed back into the
amplifier where it is amplified again resulting in what we
know as feedback; the Harp Shield will prevent this process
from ever starting by using noise gate technology. The Harp
Shield is designed to mute the microphone when you are not
playing by decoupling the microphone from the amplifier,
thus preventing feedback. With the Harp Shield your
microphone is muted when not playing and as you begin to
play, the Harp Shield will unmute and allow your signal to
pass through to the amp; when you stop playing, the pedal
automatically mutes the microphone to prevent feedback. The
pedal has a sensitivity control to prevent background noises
from opening the audio path and inducing feedback. In the
event that feedback does occur, just press the footswitch (a
momentary switch) to reset the pedal and stop the feedback.
When using this pedal, it is still necessary to use proper
microphone handling techniques to help prevent feedback
while playing. The Harp Shield differs from guitar noise
gates in that the gate range is set for microphone levels
and the fact that you will not lose any tone.
UPDATE 10/21/12 - In response to some questions that I have
received I am adding the following information. The pedal
requires a minimum level of signal from the mic to open the
gate and when the signal drops back down to the same minimum
level the gate will close. This function is not noticeable
with the sensitivity set low (CCW) but is noticeable with
the sensitivity set high (CW); but this is only a factor
when playing softly. The pedal is not a silver bullet, it
has its limitations. One is when the room acoustics are
horrible for feedback, small and hard walled (like a spare
bedroom), it does not help at all. The second is a tight
band setting that is very loud (all too common), this is due
to the fact that when the sound levels hitting the
microphone are too high it can keeping the gate open. In the
last instance one must also roll off the volume on the
microphone when not playing.
The only control is the SENSITIVITY control.
With the control all the way CCW the pedal is most sensitive
and will allow virtually any signal to pass through the
microphone; but, the mic will be more susceptible to a low
volume noise opening the pedal and inducing feedback.
Turning the control CW increases protection from feedback by
requiring a higher level of audio to unmute the microphone
and pass the audio. With the control turned too far CW you
may not be able to pass audio while playing softly. The foot
switch is a momentary non-latching switch; pressing the
switch mutes the microphone (kills the audio) and resets the
gate stopping feedback. The Harp Shield should go last in
your pedal train.
The Harp Shield
operates off of a 9v battery or a 9vdc power adapter. To
make it all just a little easier Lone Wolf is offering a
power supply for US and EURO customers to power your pedal.
The ac adapter requirements are 9V DC with a minimum 100mA
output and a 2.1mm x 5.5mm connector with a negative center
and the outer positive. The battery is switched off when an
external power supply is used and the unit is always powered
whenever the mic is plugged in.
Jason Ricci... ”Randy from The Lone Wolf
Blues Company has made a new Anti Feed Back pedal. The Pedal
is simple in design with one knob and extremely effective at
fighting feed back. I would go as far to say that it
eliminates feedback better than any existing devices I have
tried whether they were aimed at amplified harmonica playing
or other wise. The Pedal is small and a nice gold color,
it's cheap too, hundreds cheaper than comparable box's.
Randy is a great dude has a fantastic return policy and
sincerely and truly cares what we all think of his stuff.
The Harp Shield is True Bypass (No signal loss) and the same
size as the other LWBC pedals (Except the Harp Attack). It
can also be powered with a 9v converter or a battery! A few
have been made (mine) and some sold instantly at SPAH but
there here. For those of you who enjoyed the extra
distortion/compression that came with the other blue AFB
made, the "Harp Shield" coupled/ in conjunction with the
"harp break" or "Harp Attack" by LWBC will produce the same
results with more user manageability and control. For those
who disliked the old AFB designs and it's tone changing
properties the "Harp Shield" DOES NOT CHANGE TONE!” Jason