Overview
The Heathkit WA-P2 is a classic mono tube preamplifier from the golden age of high-fidelity audio (mid-1950s). This vintage audio component features tube-driven signal conditioning with switchable equalization standards for vinyl playback. The WA-P2 is designed to mate with Heathkit power amplifiers (W-4M, W-5M, W-6M, W-7M series) and delivers the warm, detailed tone characteristic of mid-century audio design.
Key Features
- Tube Complement: Dual 12AX7 tubes and a 12AU7 for low-noise signal amplification and phase inversion.
- Five Input Channels: Microphone, phono, tuner, and two auxiliary inputs with individual level adjustments.
- Multi-Standard Equalization: Separate turnover and rolloff switches for LP, RIAA, AES and early 78’s records.
- Tone Control Precision: 18 dB boost and 12 dB cut at 50 CPS on bass and 15 dB boost and 20 dB cut at 15,000 CPS on treble.
- Flat Response: Frequency response within ±1½ dB from 15 to 35,000 CPS with low hum and noise level.
- Rolloff Positions: Four positions of 8, 12, 16 dB and one flat position for noise reduction.
Technical Specifications
- Configuration: Mono preamplifier with master volume control.
- Tube Types: 2× 12AX7 (dual triode), 1× 12AU7 (dual triode).
- Input Voltage (AC): 6.3 volts AC at 1 ampere filament heating.
- Input Voltage (DC): 300 volts DC at 10 mA (supplied by companion power amplifier).
- Frequency Response: ±1½ dB from 15 Hz to 35 kHz.
- Microphone Input: ~5 mV sensitivity (balanced or unbalanced).
- Line Output: ~2 volts at 1 kHz nominal.
- Inputs: Microphone, Phono, Tuner, Auxiliary 1, Auxiliary 2.
- Controls: Master volume, bass, treble, phono turnover switch, rolloff switch, source selector.
- Construction: Chassis-mounted with tube shielding and sealed capacitors.
- Era: 1954–1958 production (mid-vintage).
- Manufacturer: Heathkit (Heath Company, Benton Harbor, Michigan).
Typical Applications
- Restoration and repair of classic 1950s hi-fi audio systems.
- Integration with vintage Heathkit power amplifiers (W-4M, W-5M, W-6M, W-7M) in analog playback chains.
- Vinyl turntable preamplification with switchable RIAA, AES, and 78 RPM equalization curves.
- Mono or single-channel audio recording and mastering in retro-audio studios.
- Collector-grade restoration for audio enthusiasts valuing tube-era sonics and original design.
Compatibility & Replacements
Compatible With
- Heathkit W-4M, W-5M, W-6M, and W-7M mono power amplifiers.
- Vintage turntables with moving-magnet or moving-coil cartridges.
- Tape decks and tuners with standard RCA/phono connectors.
- Audio systems requiring balanced or unbalanced low-level inputs.
- 12AX7 and 12AU7 tube sockets (common vintage tube types, widely available).
Replaces / Drop-In Replacement For
- Earlier Heathkit WA-P1 preamplifier (if seeking a feature upgrade).
- Other mono preamplifiers of the mid-1950s design era requiring similar tube complement and input/output structure.
- Note: The WA-P2 is inherently a mono unit; stereo systems require two units in parallel configuration.
Works With
- Standard RCA/phono analog connectors (input and output).
- AC power from companion Heathkit amplifiers via shared power supply bus.
- Vinyl records in LP, RIAA, AES, and 78 RPM formats via switchable equalization.
- Original Heathkit assembly manuals and service documentation (readily available via archive).
