Yep. Rhayader > Maen Serth > Esgair Perfedd > Craig Goch dam > cycle track to Garreg Ddu dam > up past the church to Ciloerwynt > Claerwen Res. > Claerwen Farm > L @ Teifi Lakes to bivvy spot.
Retrace to Claerwen the next day > S of the river to Llanerch Cawr > Gro Hill > The Clyn > Dolafallen bridge > Rhayader. Lovely.