Kara OK Preamplifier Board – M65831AP + NE5532, AC12V-15V Dual Voltage, With Reverb Delay Adjustment

About This Product

If you're into DIY audio gear or want to build your own karaoke setup, this preamp board is a solid choice.
It's built around the original M65831AP chip from Mitsubishi – that's the heart of the reverb and delay effects – paired with dual NE5532 op-amps for the input and output stages.

That combo gives you clear, natural sound with good detail.
The board runs on AC 12-15V dual voltage, and it's got a nice big 3300uF filter capacitor from a reputable Taiwan brand, plus a beefy rectifier that supports 5A or more for solid power delivery.

Dimensions are 117.
5mm by 68.
5mm, so it fits in most chassis.

PCB is 1.

6mm thick double-sided with 2oz copper, so signal integrity stays clean and noise is low.

The controls are simple – from left to right you've got OK1, OK2, reverb depth, and music volume.

There's also an onboard reverb delay adjustment switch.

Great for karaoke machines, PA systems, or hifi projects.
Good quality components and a clean layout.