  We describe the design, commissioning and operation of an ultra-low-vibration
closed-cycle cryogenic ion trap apparatus. One hundred lines for low-frequency
signals and eight microwave / radio frequency coaxial feed lines offer the
possibility of implementing a small-scale ion-trap quantum processor or
simulator. With all supply cables attached, more than 1.3 W of cooling power at
5 K is still available for absorbing energy from electrical pulses introduced
to control ions. The trap itself is isolated from vibrations induced by the
cold head using a helium exchange gas interface. The performance of the
vibration isolation system has been characterized using a Michelson
interferometer, finding residual vibration amplitudes on the order of 10 nm
rms. Trapping of $^9$Be$^+$ ions has been demonstrated using a combination of
laser ablation and photoionization.
