Nova Persei 1901 use to show regularly dwarf nova outburst. The last one started in August 2018. More details on AAVSO alert notice.
V392 Per nova eruption
Object previously known as dwarf nova erupted as classical nova on April 29, 2018. The outburst was discovered by Yuji Nakamura, Japan. Just few hours later confirmed by T. Tordai and P.A. Dubovsky from central Europe. Almost unprecedented event. However there are two similar object observed in the past. Prior to the nova eruption of V1017 Sagittarii in 1919 (6.2 mag) a dwarf nova outburst was recorded in 1901 (10.8 mag) – however, that dwarf nova outburst was noticed only 45 years later (McLaughlin 1946). V1213 Cen had classical outburst in 2016, then the dwarf nova behaviour prior to the nova outburst was discovered. In both cases first was the nova outburst observations. Now we have relatively well know dwarf nova with the range V = 14.1-16.9 suddenly erupted as nova. More information can be found in AAVSO alert notice.