Greetings, I've been using an LD15 amp for a few years now and I am happy with it in general. There is only an issue that hasn't been resolved over all this time i've been using it. When an MP3 is plugged in the MP3 input of the amp, the sound that comes out of the amp speaker is significantly lower and "weak", even when the device is set on its maximum volume. Looking at other similar topics in the forum, the cable has been identified as the culprit for this case, however, this is the 3rd time I've gotten a new cable and the problem is still there. The only way I have managed to get the full and loud sound that was supposed to come out of the speaker is when i press the jack slightly down on the amp end, which makes me believe that the jack fails to couple properly with the input. Assuming that this is the case, is there any fix that I can try for the input? Some sort of making it slightly narrower? Thanks in advance.