The Yamaha Magicstomp pedal is a multi-effects processor that allows players to use select from 20 different effects. This bass effect does not allow multiple effects to be simulated simultaneously, a feature typically common with this type of pedal. The Magicstomp EB pedal was the version marketed towards bassists, but this particular Yamaha bass pedal was nearly identical to the guitar version of the Magicstomp. Both versions can be used equally well to manipulate a bass tone. This model has been discontinued by the Yamaha Corporation.
The Yamaha SPX90 is a rack-mounted digital processor that can be used as a bass effect. The Yamaha SPX-series is primarily designed as a reverb effect. This means it alters the tone of an instrument to make it sound as though it is reverberating within a room. The actual process to achieve the reverb sound uses a variety of different effects working in conjunction. Bassists can use this Yamaha bass effect to create a reverb effect or separate out the individual effects to achieve a different bass tone.
The Yamaha Corporation SPX2000 is an upgraded variant of the Yamaha-SPX-series. The main purpose of this effect is still to create a reverb effect. The SPX2000 does not have any significant additions in terms of features compared to older models, such as the SPX90. This particular Yamaha bass effect is an overall upgrade through the entire effect. The sound quality and processing capability are substantially higher than the previous version. In addition, the algorithm used to create the reverb effect has been refined further by Yamaha. Superficially, there is nothing the SPX2000 noticeably can do that the SPX90 cannot. The difference comes in the higher quality audio produced by the SPX2000 over earlier SPX-series models.