I wish to hook up the line-out from a digital piano to a surplus 4 ohm 15w speaker unit. I bought a simple Amplifier module and connected it up.
My plan was to roughly assemble the circuit and, if it worked ok, transfer to strip-board with RCA connector for Audio and a DC power socket and some sort of quick connector for speaker cable.
When I play a note on the piano I get a good level of sound from the speaker but the quality is very poor.
I guess I need to use better wiring on the input side of the amp?
Here's a photo:
- Battery: 12V SLA 3.3Ah
- Speaker: 4 Ohm 15W
- Amplifier: Kemo M031N 4.5-12V, 3.5W "Music power", for 4-15 ohm speaker, 40Hz-20kHz,
- Source: Line-out 1/4" TR connector (left channel, set to mono).
- Pot: 10K Linear
The speaker is a rear satellite speaker unit from an old TV that had 5.1 surround-sound. The speaker enclosure contains two sounders (approx 5" and 1").
The digital piano is powered through a mains adapter (100-240 VAC 0.2A 50-60Hz) connected using a USB cable (5V 1A). It is light so assume switched mode.
Notes sound rather buzzy. There is mains hum in the background.
What steps can I take to improve the quality of the sound?