We show efficient generation of mid-IR pulses tunable between 1 and $5\mathrm{\mu m}$ from $100\mathrm{kHz}$ class femtosecond systems. The concept can be applied to various sources, particularly based on Ti:sapphire and the newly evolving ${\mathrm{Yb}}^{+}$ lasers. The mid-IR pulses are generated as the idler of a collinear optical parametric amplifier pumped by the laser fundamental. The seed for this amplifier is the idler of a previous amplification stage pumped with the second harmonic and seeded with a visible continuum. This enhances the energy and allows us to influence the bandwidth of the final output. Pulses with microjoule energy and Fourier limits of $50\mathrm{fs}$ are achieved.