The Manley 500 and 250 Watt Monoblocks are our most powerful push-pull production-models. Both the circuit design and the selected componentry have been refined over years and years of development.

• ALL-TUBE monoblock design: uses 10 x EL34JJ output tubes
• Driver Stage: High current double 12BH7EH (x2) Electro-Harmonix Russian
• Input Tube: 12AT7EH large plate Electro-Harmonix Russian
• BALANCED & UNBALANCED inputs: RCA and XLR jacks (switchable)
• MUTE switch: on front panel
• TRIODE / TETRODE switching: on front panel
• SOFT-START turn on mode: minimizes in-rush current by first powering up amplifier to half voltages
• EVER-WARM mode: for standby keeps tubes warmed up at half voltages
• MANLEY Precision Output Transformer: designed and wound at Manley Labs
• Front panel bias measurement and adjust: Concealed under the black oval insert
• Output Tube Standing Current: 27.5mA
• Set Bias for: 275mVDC measured across each bias tip jack to ground
• Large filter / reservoir capacitors: 3800uF x 2
• Angled rear of chassis: provides for easy connections
• WBT binding posts: CE compliant for European models
• Input Sensitivity: 1V for full power
• Input Sensitivity Triode: 174mV for 1 watt into 8 ohms
• Input Sensitivity Tetrode: 146mV for 1 watt into 8 ohms
• Gain Triode: 30dB
• Gain Tetrode: 32dB
• Input Impedance RCA: 116 Kohm @ 1KHz
• Input Impedance XLR: 270 Kohm @ 1KHz; 20Kohms @ 20KHz; 38Kohm @ 20Hz
• Actual Output Impedance Triode: 0.538 ohm
• Actual Output Impedance Tetrode: 0.465 ohm
• Optimum Speaker Load: 5 ohms
• Damping Factor Triode: 14.8
• Damping Factor Tetrode: 17.2
• S/N Ratio Ref 1W into 8 ohms: -80 dB; -90dB A-WGT
• Dynamic Range: 93dB
• FLAT frequency response: 10 Hz - 30 KHz continuous
• Full Power Tetrode: 250W @ 1.5% THD into 5 ohms
• Full Power Triode: 100W @ 1.5% THD into 5 ohms
• Power Consumption: 30 Watts in "EVER-WARM" mode
• Maximum Power Consumption: 815 Watts at full power
• Operating Mains Voltage: Factory set for 100V, 120V or 220-240VAC operation for original destination country's mains voltage.
• Operating Mains Voltage: changeable with power transformer re-wiring and fuse value change.
• Mains Voltage Frequency: 50~ 60Hz
• Mains Fuse 100-120VAC operation: MDA 10 Amp SLO-BLO Ceramic Time-Delay fuse
• Mains Fuse 220-240VAC operation: MDA 8 Amp SLO-BLO Ceramic Time-Delay fuse
• B+ Fuse: MDA 1 1/2A SLO-BLO Ceramic Time-Delay fuse
• Badge Illumination: Units produced before 4/2003 use 8V, 0.3A "Fuse-Lamp" 1/4" X 1 1/4"
• Serial numbers after N250188 use LED illumination which probably won't burn out
• Power Cord: Detachable IEC standard. Appropriate power cord supplied for destination country
• Dimensions: W=19" x D=13" x H=9"

Your local dealer is the best resource for purchasing and support of Manley products. If there are no Manley dealers in your area, please contact us with your needs and interests and we'll see if we can help.