Fix crackling sound volume fader old vintage car booster graphic equalizer Proline arrow GP-870XII

In this video, it is told about a vintage cars equalizer 7 band audio booster brand Proline Arrow model GP-870XII that tells about technical problems, test, and component function. Volume potentiometer : Aiko B50k SPECIFICATIONS Signal input impedance : 47 Ω (4 or 8 Ω acceptable) Band frequencies : 60Hz, 160Hz, 400Hz, 1KHz, 2KHz, 6KHz, 12KHz TONE control range : ±12dB at each center frequency Input sensitivity : 300 mV (at 1W output power) Frequency response of power amplifier20 ~ 22 KHz (-3dB) Matching speaker impedance4-speaker connection = 8Ω 2-speaker connection = 4 or 8Ω Power supply voltageDC 14.4 V Negative Ground (10 - 16 V) Current drain 0.3 A(Idling) - 7 A (Max. power)