Maxon is the name used by the Nisshin Onpa company of Japan for its line of effects pedals designed for guitar and bass.
During that time Nisshin Onpa was responsible for building a fuzz-wah pedal that was very popular, being marketed under a multitude of trade names including Ibanez.
During the 1970s Ibanez became one of the company's main OEM customers.
Nisshin Onpa designed and manufactured the now legendary TS-808/TS808 and TS9 Tube Screamers for Ibanez, and many other models, including the FL9 Flanger, CS9 Chorus, and AD9 Analog Delay.
Nisshin Onpa also marketed its pedals under its own Maxon name during this time.
Ibanez still make these classic pedals but using different circuitry, thus losing some of the classic Tube Screamer tone, hence the Maxon models are so sought after.
Maxon still makes these pedals today under their own company name (called Overdrives: the OD-808 and OD-9 as oppose to Tube Screamer, TS).
However, supply of these pedals is very short and because of this, the Maxon pedals using the original Tube Screamer circuitry are little known and often overlooked.
Currently, Maxon manufacture around 23 effects pedals for guitars.
When Nisshin Onpa and Ibanez parted ways in 2002, Nisshin Onpa began to more aggressively market its own line of Maxon pedals.