Topp Music Gear T-FBK4 Series User manual

DIGITAL PROCESSOR
AUTOMATIC FEEDBACK KILLER
T-FBK4

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1. Introduction
2. Installation Tips
3. Usefull Data
4. Control Elements
5. Connection
6. User Setup
7. Technical Specifications
8. Guarantee
9. Notes
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* The peak inrush currents equal to 8.33 A.
*This device complies with part 15 of the FCC Rules. Operation is subject to the following two
conditions: (1)this device may not cause harmful interference, and (2)this device must accept any
interference received, including interference that may cause undesired operation. Changes or
modifications not expressly approved by the party responsible for compliance could void the
user's authority to operate the equipment.
NOTE: This equipment has been tested and found to comply with the limits for a Class B digital
device, pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable
protection against harmful interference in a residential installation. This equipment generates,
uses and can radiate radio frequency energy and, if not installed and used in accordance with the
instructions, may cause harmful interference to radio communications. However, there is no
guarantee that interference will not occur in a particular installation. If this equipment does cause
harmful interference to radio or television reception, which can be determined by turning the
equipment off and on, the user is encouraged to try to correct the interference by one or more of
the following measures:
-- Reorient or relocate the receiving antenna.
-- Increase the separation between the equipment and receiver.
-- Connect the equipment into an outlet on a circuit different from that to which the receiver is
connected.
-- Consult the dealer or an experienced radio/TV technician for help.

Introduction
Thank you for choosing TOPP PRO. The T-FBK4 is a Dual Channel Digital Processor. It is designed
to provide state of the art Feedback elimination processing, for fixed installation or live event,
while maintaining a simple and intuitive control interface.
Our Professional Audio Products are designed and tested by a highly qualified engineering team
with more than 20 years of experience. Great care is placed in delivering products with excellent
performance, specifications and dependable reliability. Also great emphasis is placed in creating
and bringing to market products that can fill multiple applications and also offer customers
exceptional value.
T-FBK4 is for professional use. It can be used in following electromagnetic environment:
residential, commercial and light industrial, urban outdoors. It is intended for rack mounting.
Under the EM disturbance, the ratio of signal-noise may be changed above 3dB。
Features
Usefull Data
Please write your serial number here for future reference.
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• 24 Programmable Filters per Channel
• Dual Independent Channel Processing
• Live and Fixed Filter Modes
• Automatic Live Filter Release
• 2*Input Channel Metering
• 24 LED Filter Metering per Channel
• 2*XLR and 2 x TRS Electronically Balanced Inputs and Outputs
• Rear Panel Lockout Switch

1. Input Level dBu
These four LEDs indicate input level of the T-FBK4 with a range from -10dBu to +15dBu.
NOTE: For maximum performance and proper operation, the average input signal should
consistently light up at the 0 dBu LED and the +10 dBu LED lighting occasionally.
2. Clip LED
This LED indicates that there is signal clipping at the Inputs. If necessary, setting the level of the
chain with a external pink noise signal.
3. Filters LEDs
The T-FBK4 offers 24 notch filters (RED LED) for each channel, which are used to indicate the
number of active notch filter. The LEDs that always blink for each channel is the last Live inserted
notch filter.
4. BYPASS
This button is used to bypass the notch filters in the signal path.
5. CLEAR/SET UP
a.) Pressing this button is to active the LIVE mode. (The light of button would be lit steadily.)
b.) Pressing this button again is to clear the setting created by LIVE mode. (The light of button
would be OFF.)
c.) Holding this button for 3 seconds is used to enter SETUP mode. (The light of button would be
kept flashing.)
6. Mode
a.) Pressing this button is to active the MUSIC mode. (The light of button would be lit steadily.)
b.) Pressing this button again is to enter SPEECH mode. (The light of button would be OFF.)
For more information, please refer to USER SETUP part.
7. Power Switch
It switches your T-FBK4 On/Off.
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Control Elements
Front Panel:
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(1) (3)(2) (4) (5) (6) (7)

8. AC Inlet and Fuse holder
Standard IEC receptacle. Connect your T-FBK4 to the AC Inlet with the supplied AC power cord.
Before powering up your T-FBK4 for the first time, make certain the stated power requirement of
the unit matches the voltage supplied by the AC socket.
If the fuse blows, replaced with a fuse of the correct type only.
9. Input/Output Connectors
Two types of input connectors are provided for input connections: 2 x female locking XLR type
connectors, and 2 x 1/4" TRS jack connectors (tip-ring-sleeve).
The maximum input level that the processor can accept is +15dB(4.356Vrms).
10. Lock Switch
This switch locks / unlocks all access to the front panel of the T-FBK4.
Rear Panel:
Control Elements
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Insert on the MIC channel
1. Connect the TRS (tip-ring-sleeve) stereo jack into the mixer MIC channel, Insert socket.
2. Connect the Send stereo jack (unbalanced) to the CH1 Input of T-FBK4 and the CH1 Output of
T-FBK4 with a Return stereo jack (unbalanced).
3. Set the sensitivity at -10dBu on the T-FBK4 and adjust the MIC Gain control on the MIXER for
having a necessary level on T-FBK4.
4. Repeat the same step connections for the CH2 of T-FBK4 if you like to use.
--- For maximum performance and proper operation, the average input signal should consistently
light up at the 0dBu LED and the +10dBu LED lighting occasionally.
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Connection
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INSERT MIC 2
INSERT MIC 1
SEND
SEND
RETURN
RETURN
MIC 1
MIC 2

Insert on the SUB GROUP/MAIN L-R of the Mixer
1. Connect the TRS (tip-ring-sleeve) stereo jack into the Mixer SUB GROUP/ MAIN L-R, Insert
socket.
2. Connect the Send stereo jack (unbalanced) to the CH1 Input of T-FBK4 and the CH1 Output of
T-FBK4 with a Return stereo jack (unbalanced).
3. Set the sensitivity at -10dBu on the T-FBK4 and adjust the SUB GROUP/ MAIN L-R, fader control
on the MIXER for having a necessary level on T-FBK4.
--- For maximum performance and proper operation, the average input signal should consistently
light up at the 0dBu LED and the +10dBu LED lighting occasionally.
Connection
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INSERT SUB 2
INSERT SUB 1
SEND
SEND
RETURN
RETURN

ON LINE with the Outputs of the Mixer
1. Connect the Outputs L-R from the mixer to the inputs CH 1 & CH 2 of T-FBK4 with the XLR or
TRS (tip-ring-sleeve) stereo jack.
2. Connect the Outputs CH1 & CH2 of T-FBK4 at the Inputs of power amplifiers.
3. Set the sensitivity at +4dBu on the T-FBK4 and adjust the L-R fader control on the MIXER for
having a necessary level on T-FBK4.
--- For maximum performance and proper operation, the average input signal should consistently
light up at the 0dBu LED and the +10dBu LED lighting occasionally.
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Connection
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SPK IN
OUTPUT CH1-CH2
AMP IN CH1-CH2
AMP OUTPUT CH1-CH2
SPK IN
MIX OUT L-R
INPUT CH1-CH2

1. Setting Audio System
There are three basic ways you can use the T-FBK4 combine with your audio system.
It can be:
1).Connected to a MIC channel of a MIXER, into the "Insert" jack (send/return).
2).Connected to the SUBGROUP/MAIN OUTPUTS (L/R) of a MIXER into the "Insert" jack
(send/return).
The connection of T-FBK4 to Insert points, is probably the best selection, the levels present in
most mixers are pre-fader, (normally 10 dBu) and flow direct to T-FBK4.
In this way any fader level variations do not modified the setup of T-FBK4.
--- For the best performance and proper operation, the average input signal should consistently
light up at the 0dBu LED and the +10dBu LED lighting occasionally.
3).Connected "ON LINE" between mixer and PA system. From output of the Mixer to input of
T-FBK4 and from Output of T-FBK4 to PA input (Stereo Amplifier).
The above setup is used when insert points are not available, set the T-FBK4 at +4dBu, this value
is correct when you connect the outputs of any mixer directly to the input of T-FBK4.
--- For the best performance and proper operation, the average input signal should constantly
light around 0dBu LED and the +10dBu LED should light only occasionally.
2. SETUP & LIVE Mode
The T-FBK4 offers a total number of 24 notch filters for each channel (CH 1/CH 2) and two main
operation modes:
a. SETUP mode, with the fixed filters.
b. LIVE mode, with the free filters not used in SETUP mode.
The SETUP mode is used to detect and remove feedback problems in the audio system due to the
microphone placement, different environments shapes, etc.
Once these filters are set, they can't be removed unless you reset then again.
The LIVE mode is used to detect and remove feedback in "real-time", during the musical events.
The free filters, not used in SETUP mode, automatically work in LIVE mode, the last filter included
blink.
1). Using SETUP Mode (SOUND CHECK)
Fixed filters are set before a performance in a process called ringing out a system, this is done
after all other setting system has been done.
a- First, bring down the main mix, turn off all music sources and open the MIC (if you use Vocalist)
or the different MIC (if you use a Sub-Group).
b- Place the T-FBK4 in SETUP Mode by pressing and holding the CLEAR/SET UP button for more
than 3 seconds.
c- The CLEAR/SET UP LED will start flashing, indicating SETUP mode is selected for CH1 or CH2 or
together.
d- Set the level of each CHANNEL with PFL and slowly turn up the Main Mixer Volume, raising the
gain of the system, until feedback occurs.
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6User Setup

e- The T-FBK4 will detect and remove feedback by placing notch filters on the proper frequencies.
Continue to slowly raise the gain until all feedbacks have been eliminated, then exit from SETUP
Mode by pressing and releasing the CLEAR/SET UP button quickly.
If all 24 filters have been used in SETUP Mode, the SETUP Mode is left automatically and no more
filters are available in LIVE Mode.
2). Using LIVE Mode (REAL TIME)
The T-FBK4 operates normally in LIVE Mode (24 notch filters minus the fixed used filters).
Live Mode filters are set on the feedback frequency as soon as a new feedback is detected,
according to the knob position of the selected LIVE Mode Variations (from MUSIC to SPEECH).
If all LIVE filters are used and a new feedback occurs, the oldest LIVE filter is cleared and reallocate
to the new feedback frequency (the correspondent led will light).
The T-FBK4 will continue to search feedback frequency through the LIVE notch filters.
MUSIC High Q mode, (use notch filters at 1/80th Octave), continuously variable until SPEECH Low
Q mode, (use notch filters at 1/5th Octave).
3. CLEARING FILTERS
To reset the LIVE filters, press the CLEAR/SET UP button on the selected channel (Button LED will
switch OFF). The currently active filters will be cleared and the assigned LED will turn off.
If you wish to "reset" all the filters, hold the CLEAR/SET UP button (more than 3 seconds) until the
button LED is "blinking", indicating that you have entered the SETUP Mode and that all filters
FIXED and LIVE have been cleared.
4. LOCK ON/OFF
When you finished setting the T-FBK4, you can save your setup, switch ON the LOCK selectors in
the rear panel.
After this it will be impossible to operate on front panel.
5. AUTOMATIC FILTER RELEASE
The T-FBK4 provides the user with 24 notch filters, for each channel, they are enough for normal
performances. If several numbers of filters are required, (more than 16), we strongly recommend
to operate a new setup of the sound system.
Anyway, even if the T-FBK4 uses very narrow notch filters, accordingly with the selected
application type, unused notch filters must be avoided, to always guarantee the best audio
performance.
The T-FBK4 constantly monitors the status of the LIVE filters and automatically removes the ones
that are no longer necessary.
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User Setup
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Hz
+3
+2
+1
0
-1
-2
-3
-4
-5
-6
-7
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-9 700 750 820 850 900 .95k 1k 1.2k
+3
+2
+1
0
-1
-2
-3
-4
-5
-6
-7
-8
-9
d
B
u
d
B
u
Music High-1/80th Octave
Speech 1/5th Octave
Notch Filter Q Diagram

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2 x female XLR and 2 x 1/4" TRS Electronically Balanced / Unbalanced, RF filter suppressor
Max Input line level
2 x male XLR and 2 x 1/4" TRS Electronically Balanced / Unbalanced, RF filter suppressor
Max Output level
Dynamic Range
D/A Performance
D/A Conversion
Sample Rate
THD+N %
Power Consumption
Analog Inputs
Input impedance 3.6K ohm
+15 dBu
Analog Outputs
Output impedance 120 ohm
+15 dBu
A/D Performance
114 dB, A-weighted
A/D Conversion 24 bit
Dynamic Range 106 dB, A-weighted
24 bit
System Performance
48 kHz
Dynamic Range 106 dB, A-weighted
0.01 %, 1 kHz
Frequency Response 20 Hz to 20 kHz, +/- 0.5 dB
Inter channel Crosstalk
Crosstalk input to output
Operating Voltage 230 VAC 50/60 Hz 115 VAC 50/60 Hz
15 W
86 dB, A-weighted
86 dB, A-weighted
Physical
S/N Ratio 106 dB, A-weighted
Dimension
Net Weight
483 x 195 x 44 mm
3.1kg

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Guarantee
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