W6-M

About the W6-M

The Heathkit W-6M is a vintage high-fidelity amplifier introduced in 1957, designed as a Williamson amplifier popular in the 1950s audiophile community. It delivers 70 watts of power using a pair of 6550 output tubes. The amplifier includes a unique variable damping control that senses speaker current and feeds it back to the negative feedback loop to optimize bass response depending on speaker requirements. It does not have built-in volume or tone controls, as it was intended to be used with the Heathkit WA-P2 preamplifier, which provides those functions and input switching. The W-6M contains power supply circuitry to power itself and the WA-P2 preamp, including 120V AC, 6.3V AC for tube filaments, and 300V DC for tube plates. The rear panel features input/output connectors, an eight-pin socket for the preamp power cable, fuse, switched and unswitched 120V AC outlets, speaker terminals with selectable loads (4, 8, 16 ohms, and 70V output), and a power switch. It also includes a front panel meter for adjusting the resting current and bias of the output tubes. The amplifier measures approximately 14.25 x 9.06 x 11.88 inches and uses five tubes in total. The W-6M is no longer manufactured and is considered a classic vintage amplifier.