The singarounds I attend are 'acoustic'. That is we don't want amplification of vocals. A small portable amp/speaker set-up was allowed when my brother played very good fretless bass with our group. Another player also uses a small amp for a bass when he plays with his group. A third performer does occasionally play electronic keyboard to great effect. But we draw the line at amplifying vocals. The acoustic vocals set the low level of the necessarily amplified instruments.

If the vocals were amplified too, then it would become an open mike session not a singaround, and the audience would be likely to treat it like wall-paper music and talk loudly all over it.

Tone