Modifications for reduced interference and louder sound

[radiola2]

I made some modifications to my ATS-mini.
First I put copper tape to the inside of the plastic case.
It makes contact with the antenna connector and the interference from the display is noticeably reduced when I use the whip antenna.

Then I made some modifications to get louder sound.
I bypassed R24 with a short wire and replaced C20 (100 nF) with a bigger capacitor (1 uF) to get higher audio signal to the speaker amplifier. It works well and I can even make the speaker distort at the highest volume. :)

I also soldered bigger capacitors (1 uF) in parallel with the original ones (C25 and C26 (100 nF)) for more bass and higher output to line out or headphones.

The sound level is adequate with my Sony in-ear headphones.

[cdtsuipo]

Modifications were made to the C20 C25 C26 capacitors.At first I used shorting R24 and the sound didn't get louder, it became distorted. I replaced R24 with a 1kohm resistor and it worked much better and got louder.

[radiola2]

That is strange, I got a very obvious boost of the sound when shorting R24. Maybe you have the new version with integrated headphone amplifier?

[cdtsuipo]

That is strange, I got a very obvious boost of the sound when shorting R24. Maybe you have the new version with integrated headphone amplifier?

It is the original opensource version. Maybe because the antenna matching modification i made , causing the audio amplifier to saturate.