the B in this case was for sure a more budget build. Design structure and manufacturing costs were trimmed. You have 3 boards combined into one, AMP, PS, Protect are all on one board on the B. The output sockets/sink are hard attached to the amp board as well. You can't rebuild the power supply without moving the main filters and speaker switch shafts. The tone board is vertical, and realistically not meant to be moved, you can take the front end apart if you don't mind a lot of extra work and don't mind re-stringing a tuner. To replace parts on the tone board you have to play Operation (for those of you who remember the 70's game) and use tricks. The lights are a step down, no vellum no classic Marantz look, some like the look at 2238B better though. The 2238B I just did had 4-5 Towa capacitors in it, not a huge deal just a few minor importance areas but another sign some pennies were being managed. When you go to change the lights on the 2238B the housing tabs will bust off, to be fair the previous series got frail too, but these are a step beyond - just thinking about changing the lights might make the tabs fall off.
This happened to ALL brands in the late 70s, figure out a way to cut costs overall.
All that said the 22388B does not look or sound bad, it just doesn't compare to the previous series.
