Bandwidth problem

[abbey road d enfer]

Hi,

I have calculated the THD (5 harmonics): 0.015%.

Also i tested the board (1 layer pcb), with a picoscope with a test signal: 1.23v @ 1khz sinewave.

the results were:  THD +N : -42,82 dbc ( below carrier)
                                        SINAD:    -42,82 dbc
                                        SNR:            43,27dbc
                                        IMD:            0,07%

I suppose these results can be better with a 2 layer pcb, good vias placing, and keeping sensitive opamp nodes clean of parasitic traces, etc...

What do you think?

Jay x

All this shows a serious noise issue. But in the absence of information about what your circuit does, it is difficult to help you. For a line level unit - which I believe is the case considering the test signal of 1.23V - , achieving 80 dB S/N requires almost no specific precaution, only basic shielding and grounding.