The v5 uBITx has an LM386 for the audio amplifier stage. Philip G7JUR suggests connecting a 10 microFarad capacitor to the LM386. The +ve end should go to pin1 and the -ve end of the capacitor to pin 8. The easiest place to access is to solder to C75. This will give a bit more gain, and bass.
Ashhar Farhan VU2ESE commented that the LM386 distortion really increases with increased gain. He also notes that more gain is not increased sensitivity. He thinks a better idea might be to bypass pin 7 to ground with the 10 uf. Either way, he suggests that Philip keep experimenting!
Jerry KE7ER suggests for uniform gain from 300 to 2300 Hz
with no capacitor gives at least 26dB but under 46dB with a 10uF capacitor.
Adding a resistor in series with the 10uF cap would reduce the gain.