RM9

About the RM9

The RM9 Special Edition is a tube power amplifier originally manufactured in the early 1990s, now considered a collectible piece. It features a main B+ voltage of 450V with solid-state rectification and a reservoir capacity of 800µF. The amplifier uses hand-wound, vacuum-potted output transformers weighing about 10 pounds each, designed for 2, 4, and 8 ohm loads with selectable negative feedback to optimize stability and gain. The bias is conservatively set for long tube life, typically using EL34 or KT88 output tubes, with the KT88 version noted for more engaging musicality. Gain can be adjusted via a 3-position toggle switch (LO, MED, HI) to fine-tune the amplifier's interaction with speakers, affecting tonal balance and soundstage clarity. The RM9 delivers approximately 100 to 125 watts per channel into 8 ohms, with a frequency response from 2Hz to 60kHz and total harmonic distortion around 0.5%. It is praised for its even tonal balance, incisive imaging, and rich midrange, making it suitable for demanding audiophile applications. The Special Edition variant is a refined version of the original RM9, maintaining the core design philosophy but with cosmetic and minor functional improvements. Typical used prices are around .