Tried and true: 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. Reliability that you can depend upon combined with musical accuracy and emotional authority is what these amplifiers promise- and deliver. They are able to switch operation modes allowing the listener to choose between the sonically seductive qualities of triode and the more powerful Ultra-Linear configuration. We use big, beefy reservoir capacitors in the high voltage supplies giving plenty of instant energy for dynamic performance of transient peaks and bass impact and weight which often exceeds that of rival solid-state amplifiers. We run high voltages on the plates of the output tubes but operate them at lower current which will result in their longer life. Although each output tube has its own bias-adjust, We carefully fit each amplifier with computer-batched tubes for optimum performance. The bias adjustment pots and measuring points are conveniently located behind the oval front panel insert.
To avoid a heavy power drain when the cold amplifier is first switched on, we conceived a "Soft-Start" mode which also functions as an "Ever-Warm" position allowing the amplifiers to be always warmed up for pleasurable listening. Each amplifier only consumes 30 watts of power in Ever-Warm mode. A blinking green LED reminds the user that the amplifier is in warm-up mode because as all the power supplies are at half-voltage, the amplifier will still operate at half power when the Ever-Warm mode is engaged, so the user should use the MUTE switch when in this mode.
The front-panel mute switch and angled-back chassis make it easier to hook up the interconnects, speaker cables, and IEC power cord.
In our own in-house magnetics department, our R&D team completely redesigned all of our output transformers in 1998 with the goal to reclaim that luscious rich mid-range of our vintage designs. In 2013 we reworked the output transformer to operate the output stage in Ultra-Linear mode which is a great sounding balance between the detail of triode and the brawn of Tetrode. We also specifically set out to achieve a deeper bottom register at higher power with lower distortion. Hours and hours of listening tests, measurements, and fine-tuning brought an exciting and stunning result to our ears. We hope you will agree.
ALL-TUBE monoblock design 10 x KT90EH Electro-Harmonix Russian output tubes
High current double 12BH7EH driver stage
Tungsol 12AT7 large plate input tube
BALANCED & UNBALANCED inputs
TRIODE / Ultra-Linear switching
SOFT-START/ EVER-WARM standby mode
MANLEY Precision output transformer
Factory set for 5 Ohms nominal
Front panel bias measurement and adjust (hiding under the black insert)
Large filter / reservoir capacitors 3800uF x 2
Angled rear of chassis provides for easy connections
WBT binding posts
Input sensitivity: 1V
Gain: 32dB tetrode; 30dB in triode
Input Impedance RCA: 116 kOhm @ 1KHz
Input Impedance XLR: 270 kOhm @ 1KHz; 20 kOhms @ 20KHz; 38 kOhm @ 20Hz
Noise Floor: Tetrode: -67dB; Triode -65dB typical
S/N Ratio: -80 dB
Dynamic Range: 96dB
FLAT frequency response: 10 Hz - 30 KHz continuous
Power Consumption: 30 Watts in "EVER-WARM"
Full power (tetrode): 500W
Full power (triode): 275W
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:
Dims: W=19", D=13", H=9"
Shipping weight: 82 lbs. each