I collect these Roland badge rebranded Department Store units from 1967 - 1971.
They were, indeed, made in Japan by Roland (later Rotel). Seems they wanted to make a name for themselves and over-engineered their units and built them to last.
Started with tubes around 1964 and as transistors became more powerful they made Solid State units. First had only 8 or 12 watts but each year saw huge improvements and we all know how this led to the Receiver Wars just a few years later.
Germanium all around and (a guess) they never made silicon units for others and went into their own line around 1971.
Transformers for all of their units are well made and work 60 years later.
The name was always on the FM dial glass, and thus easy to rebrand for any customer.
Some badges:
Belcor in Canada.
Martel for USA west coast for unknown dept chain.
Monarch on USA east coast unknown.
Rolecor for EJ Korvettes. Most units I have gotten are from metro NYC and Philadelphia areas.
XAM possibly Korvettes as owners cat name was Max, and also XAM was the brand of speakers sold with Rolecor at Korvettes.
These speakers are ordinary in sound but do have vintage styling.
Allied possible as well as others.
Possible they learned from Trio/Kenwood factory hence similar styling.
Sound on all are punchy, warm, and louder than wattage would suggest. FM stage is good and phono and line are good as well.
Bass is outstanding and often needs to be turned down with modern speakers.
I have 17 W 630 and 12 W 600.
Martel 800 likely top of line 30 W a guess.
Rolecor are $60. Martel and Monarch go for $200 to $400