Looks like an SR2 with the tweeter. If you clean the control
take it apart & ONLY get the cleaner in the pot ! The dial cord
is imposable on these so stay clear of it. IIRC to pull back
remove screws & front knobs. On/Off switch comes through
its hole & a bit tricky. Its actually the front you are taking off.
I have SR1, SR2 & SR3. Only thing I need now is the super rare
model with a cassette deck.
BTW the only common fail on these are bad on/off switches.
73 Zeno
LFOD !