PrimaLuna ProLogue Six Monoblock Amplifier (Single)

70 W EL34 monoblock with Adaptive AutoBias, dual output transformers, and toroidal power transformer

The PrimaLuna ProLogue Six is a hand-wired, point-to-point monoblock amplifier that pairs the musicality of EL34 power tubes with robust engineering. Its heavy-gauge steel chassis, five-step automotive-quality finish, removable tube cage, chassis-mounted ceramic tube sockets, Nichicon and RealCap capacitors, and WBT-style speaker terminals all serve long-term reliability and consistent performance.

The circuit employs a dual-feedback topology—cross-coupled current feedback for impulse behavior and gain stability, plus a slight amount of negative feedback to set exact gain, lower distortion, and reduce output impedance. Each monoblock uses proprietary, wide-band, low-loss dual output transformers and adds a dedicated 2 Ω tap to maintain control into demanding speaker loads.

Adaptive AutoBias continuously monitors and sets tube bias automatically, reducing distortion and removing the need for manual adjustment or matched tubes. In addition to EL34s, you can roll 6550, KT88, KT90, 6L6GC, KT66, 7581, EL37, and their equivalents. A low-hum toroidal power transformer and conservative operating points keep the front end quiet and extend tube life. Connectivity is straightforward: one high-quality RCA input and 2 Ω, 4 Ω, and 8 Ω speaker taps per monoblock.

Included Accessories

• Removable tube cage
• IEC power cord
• User manual

Specifications

Output Power (8 Ω): 70 W (per monoblock)

Speaker Outputs: 2 Ω, 4 Ω, and 8 Ω taps

Inputs: 1 x RCA (per monoblock)

Frequency Response (±0.5 dB): 20 Hz–85 kHz

Total Harmonic Distortion (THD): < 1% at full power

Signal-to-Noise Ratio (S/N): 101 dB

Input Sensitivity: 911 mV

Input Impedance: 100 kΩ

Power Consumption: 210 W (per monoblock)

Tube Complement (per monoblock):
2 x 12AX7
2 x 12AU7
4 x EL34

Dimensions (WHD): 11" x 7.5" x 15.5" (279 x 191 x 394 mm)

Weight: 37.5 lb. (17 kg)