i now have a good loud model 20 both channels working,sounds great but i remember many years ago sounding slightly better,and i also have one with lites on,dead..no soundd also a model 20 turntables work enough on these one has no needle,an one has a new one,wonderful..but my latest purchase is a nice lookin model 24,an i thought o k,it makes sound its working,has a nice dust cover an both workin ones pick up stations like crazy,sadly though an i didnt know..the model 24 only works on one channel,very pure though very slightly cleaner than model 20,so which one,,if both working properly would be best,i have over extended my self and i aint shippin these no where dangit.nearest old school vintage repair guy like 80 miles away.so,he said he would prefer the 24,but most you hear about is model 20 allways an 4 ohms,mines wonderful on my at10 cerwin vegas,4 ohms.so now..what do i do,im an addict an i want ar 3a speaker s but cant do that. my model 24 is bare,no extra switches at the bottom,i was just unplugging it to turn it off,an was told turn it off maybe at or under stylus..which is preferred for loudest purest sound.........model 20 sounds massive like 50 or more watts per channel,old school marantz like power but sure maybe its 25 per chanel or so..talk to me on these..