This is Ibanez' first guitar effect pedal which was sold officially and internationally. The Phase Tone is a MXR Phase 90 knock-off and like the MXR the PT-900 has a slightly distorted sound with humbucking pickups. The second issue (inscription "Phase Tone" below Ibanez) sports a modified circuit with less distortion. The PT-900 was available through different brand names like Greco, Pax and Foot System.
01/27/2023: ToneHome is still looking for an Ibanez CS-505 narrow box first issue with flying finger side graphics. Any lead is highly appreciated. Other than that we're looking for an Ibanez AD3000 Professional Analog Delay & Multi Flanger. Please submit your offers or leads here: e-mail