I made test schem for TDA7056, but it do not work.  Simulation results: `Circuit: gooduntitled``Doing analysis at TEMP = 27.000000 and TNOM = 27.000000``Warning: vsignal: no DC value, transient time 0 value used` `Warning: singular matrix:  check nodes r2_1 and r2_1``Note: Starting dynamic gmin stepping` `Note: One successful gmin step` `Note: One successful gmin step` `Note: One successful gmin step` `Note: One successful gmin step` `Note: One successful gmin step` `Note: One successful gmin step` `Note: One successful gmin step` `Note: One successful gmin step` `Note: One successful gmin step` `Note: One successful gmin step` `Note: One successful gmin step` `Warning: singular matrix:  check nodes r2_1 and r2_1``Warning: Dynamic gmin stepping failed` `Note: Starting source stepping` `Warning: singular matrix:  check nodes r2_1 and r2_1``Note: One successful gmin step` `Note: One successful gmin step` `Note: One successful gmin step` `Note: One successful gmin step` `Note: One successful gmin step` `Note: One successful gmin step` `Note: One successful gmin step` `Note: One successful gmin step` `Note: One successful gmin step` `Note: One successful gmin step` `Note: One successful gmin step` `Note: One successful source step` `Warning: singular matrix:  check nodes r2_1 and r2_1``Warning: singular matrix:  check nodes r2_1 and r2_1``Warning: source stepping failed``Transient solution failed -``Last Node Voltages` `------------------``Node                                   Last Voltage        Previous Iter` `----                                   ------------        -------------` `vsignal_1                                         0                    0` `vcontrol_1                                        0                    0` `v1_1                                              0                    0` `r2_1                                              0                    0` `r2_2                                              0                    0` `volprobe                                          0                    0` `v1#branch                                         0                    0` `vcontrol#branch                                   0                    0` `vsignal#branch                                    0                    0``doAnalyses: iteration limit reached``tran simulation(s) aborted` `Error(parse.c--checkvalid): volprobe: no such vector.` `ngspice-26 done`