I have some of these modules, which are diy kits (some are self assembly, which is how I started getting them, but some are not available as self assembly, but offer the dc input i wanted) ,,, I found a schematic that looks to be right for one of them. The resistor values are different on the dc one, which is the one I'm using now, but otherwise I think the schematic is very similar.

I want to know if there is a way to get more bass out of it, or if not really. I have this other little amp to drive the same speaker cab , it only has treble and bass tone knobs, but does sound really mid-scooped, probably to eliminate hum, and although it has that familiar store stereo sound, the kit I have sounds much better for the speakers at least, although it does have a bit of hum at the moment. I do think the complete amp seems to have more bass clarity, and I'm wondering if some capacitor changes could give me a bit more from the equalizer.


Is this the wrong tree? I don't know anything about it all. This is the sale link for the one I want to modify, which is a different one from the schematic, but I do think the amplifier and eq have identical component layouts but with different resistor values to work with the dc vcc. Amazon.com: KIMISS Dual Channel Preamp Module for Audio Amplifier, 12V-24V DC NE5532 Tone Board, Hi-Fi Preamplifier with Low Noise & High Fidelity : Electronics

This schematic came from this thread here: Ebay NE5532 pre amp tone control gain reduction | diyAudio

 

It would be very easy to set this up in LTSpice and run a frequency sweep analysis to see the effect of each component. At the moment my best guess is that the 4u7 output capacitor and 10k volume control gives a 3dB roll-off at around 3.3Hz. The Bass pot is ineffective above approx 70Hz (3dB point)