SpeakerCraft MZC-66 6 Zone 6 Source Multi Room Controller Amplifier

2 or three channels have a pop sound out of channels, Others work fine

Not sure what the issue is,

Selling with the issues

Free shipping to the lower 48

Number of Channels12
Power Rating30W x 2 into 8 Ohms
45W x 2 into 4 Ohms
Total Harmonic Distortion (THD)<0.7%
Input Sensitivity300 μV, VC; 2.8V NVC
Input Impedance>22 K Ohms
Output Voltage1.7V, VC setting, VC max
180 μV, NVC setting
(Pre-outs w/300 μV at source inputs)
Output Impedance<300 Ohms for pre-outs
Frequency Response20 Hz to 20 kHz
Channel Separation>50 dB @ 10 kHz
Crosstalk>65 dB @ 10 kHz
Signal to Noise Ratio>100 dB
Connectors6 x RCA (Stereo Audio, Composite Video) Inputs
6 x RCA (Stereo Audio, Composite Video) Outputs
6 x Composite Video Outputs (1 per Zone)
6 x Analog Audio (L,R) Pre-Outputs
6 x (L,R) Speaker Terminals
2 x RCA Inputs (Phone/Video Page)
2 x 3.5 mm Jack Trigger Inputs (Doorbell/Status)
6 x EZ-Pad Connectors
2 x RJ45 Jacks
1 x 3.5mm 4-Circuit Mini Jack Control Port
18 x 3.5mm Jack Outputs (IR Signals)
1 x AC Power Input
Controls1 x Firmware Upgrade On/Off Switch
1 x Hi/Lo IR Power Switch
6 x VC/NVC Switches
1 x Power Button
Indicators7 x Power LED
Video
Bandwidth10Hz to 6MHz +/- 1dB
(Outputs 75 Ohms terminated)
Input and Output Level1.0V p-p +/- 5%
(Outputs 75 Ohms terminated)
OtherContact closures: 2A, 30 VAC / DC max
Phone Page In Voltage/Impedance: Audio Line Level > 22k Ohm
Video Page In: 1.0V p-p 75 Ohms
Doorbell in 1 & 2, 3V-30V AC or DC: 10mA at 12 VDC / AC
Common IR out high power: 9V active high, 82 Ohms
Common IR out low power: 9 V Active high, 670 Ohms
Voltage/impedance Zone IR Outs: 9.2 V Active High, 620 Ohms
Voltage/impedance Source IR Outs (and Loop): 11.5 V Active High, 390 Ohms
Common Status Out (0 to 12V DC) 9.5 V @ 100 mA
General
Power Consumption120 VAC, 60Hz, 1.8A
1/8 rated power at 3.75 W/channel: 125 W
Idle: 55 W
FuseT5AL 250V
Dimensions (HxWxD)Without feet: 5.25 x 17 x 14.75" (432 x 133 x 375 mm)
With feet: 5.75 x 17 x 14.75" (432 x 146 x 375 mm)
Rack Mount: 5.25" (133 mm) high
Weight23 lb (10.5 kg)