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 tetrode 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.
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. Although each output tube has its own
bias-adjust. we carefully fit each amplifier with computer-batched tubes
for optimum performance.
We added a front-panel mute switch and created a new angled-back chassis
to make it easier to hook up the interconnects, speaker cables, and IEC
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. 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.
A satisfied customer wrote to us about his 500's:
Bass performance is astonishing in either tetrode or triode mode. It is
deeper and fuller with more bloom and extension, while at the same time
being faster and tighter than my solid state units. The lower midrange
to deep bass is seamless and lends a satisfying richness to the musical
content as a whole. From Paul Chambers' acoustic bass to Peter Gabriel's
megabass, wow !
As great as the bass is, the midrange is killer. It has a smoothness and
richness which is just breathtaking. Gobs of detail, with crisp attack.
and long decay notes defining spatial imaging beyond expectation. The
high end is even more extended and lacks the grain and edge of solid
state amps. It is sweeter and more detailed. Listening sessions last a
long time. Friends won't go home! Thanks again for a great product at a
great price. Best regards, Geoffrey Wyshak"
Features and Specifications
Manley 500 Watt Monoblock
- ALL-TUBE monoblock design 10 x KT90EH Electro-Harmonix Russian output tubes
- High current double 6414W GE driver stage
- 12AT7EH large plate Electro-Harmonix Russian input tube
- BALANCED & UNBALANCED inputs
- MUTE switch
- TRIODE / TETRODE 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
Specifications subject to change because they just might.
Manley 500 Watt Monoblock FAQ
FAQ 251: Help! A tube blew!
Read this: Checking your bias, B+ fuse, tube and Cathode and Screen Resistors
Also shows Cathode & Screen Resistor locations and PCB layout and
tells you what to do if a tube blows. And even how to fix it without