Here is a Revive Audio Modified ART Pro MPA II in very nice working and physical condition. It does have some very light rack rash which is pictured. It works as it should. Below are the modifications done to it.

1. Burr-Brown op-amp upgrades. They replace or upgrade the op-amps in the input, output, and buffer stages with higher-performance Burr-Brown components. The objective is lower distortion, improved clarity, and better signal handling.

2. Capacitor upgrades. They modify coupling and decoupling circuitry throughout the preamp using premium Panasonic components. These changes are intended to improve frequency response, reduce noise, and improve stability.

3. Power supply modifications. They rework portions of the power supply to reduce noise and increase available headroom.

4. Increased analog rail voltages. This is particularly interesting. They increase the analog supply voltages to give the circuitry greater signal-handling capability before clipping.

5. New vacuum tubes. Their current mail-in modification description specifies Tung-Sol tubes, while their listing for a complete modified unit specifies JJ Tesla tubes. Tube selection may therefore depend on the package.

Revive claims the resulting preamp has wider frequency response, lower noise, greater dynamic range, and improved stereo imaging.

Please message me with any questions. The unit will be packed securely and fully insured and shipped via UPS. Check my feedback and buy with confidence. Thanks!