1994 Honda Accord revving before going into 2nd- alternator or automatic transmission?

I have found two different opinions online, but trust this site most. Taking off from stop, car revs before going into 2nd. Is this most certainly the transmission and will get worse, or could it be the alternator (or alt belt)? Want the cheapest fix, of course…or will sell the car if tranny.

And if I let up off the gas, it will kick in. 150K miles, gets 32 MPG, no repairs until this problem. Been great little car.

alternator isn’t part of your problem, you need your tranny checked, fluids, levels, when last changed, condition, and you probably have sticky accumulator or a bad set of 2nd clutch paks…

Would an independent mechanic know about this? Or should I go to the dealer? Or a transmission shop?