The MODAMP MODULE 1005 is a feature rich ring modulator to create metallic and bell-like sounds as well as many other modulation effects, modulation can be applied to any signals such as a signal from VCOs or LFOs via the INA and IN B jacks and is fed out via the VCA output. The 1005 features INA and INB attenuators, an UNMOD gain control lets you set the gain when in UNMOD mode, a VCA with gain control and a choice of exponential or linear response, Ratio and tune controls allow you to control and balance the frequency of 2 external VCOs for convenience. The illuminated UNMOD and MOD switches disable or enable modulation effects