Power Acoustik OV4-600

[m4ick]

This amp powers up and produces audio on all channels.

This amp has a 2/3/4 channel switch, a single LP filter pot for all four channels and each set of 2 channels has a LP/Full/HP switch. Channels 1 and 2 work fine on HP/Full when set to 4 channel mode.

The problem is that when the amp is set to 4 channel or 3 channel mode I get nothing from channels 1 and 2 on low pass, when I set it to 2 channel mode I get output from all channels on low pass.

Should this amp have output on channels 1 and 2 when set to four channel mode with channels 1 and 2 set to low pass or is it designed for low pass on all channels only in 2 channel mode?

[Perry Babin]

Have you tried operating all switches through their entire range with speakers connected to channels 1 and 2, in 4-ch mode and feeding channels 1 and 2 to see if the amp ever produced audio (or any sound) in low pass mode?

Does it have a subsonic filter switch?

[m4ick]

The only way to make channels 1 and 2 produce audio in low pass mode is to set the amplifier to 2 channel mode. 3 and 4 channel modes produce no audio on channels 1 and 2 in low pass mode

There is no subsonic filter.

[Perry Babin]

Can you post a photo of the preamp area of the board, particularly the section with the op-amps for channels 1 and 2.