Soviet copy of E88CC. Very linear and good sounding triode but has same problems as all soviet tubes – large quality and parameter variance. This particulate “Reflector” example from the ’62 has a really clean spectrum, same as Siemens E88CC, but for a 1/100 of a price. Other factory/year – can have traces of higher harmonics that you can’t get rid off no matter what operating point you choose. Another difference is absence of grid current at low BIAS voltages which is an advantage compared to E88CC.