Absolute Headphone Amplifier
This masterpiece embodies high-performance flexibility for every person to be able to custom compose sonic performance reliably, repeatedly, or even spontaneously. The Manley Absolute Headphone Amplifier delivers artistic expression with sound. It is also an accomplished line-level preamplifier, too.
There are fifteen independent controls available, each of which was exhaustively developed for convenient adjustability and aural variety. Two selectable stereo RCA jack pairs receive the input signals. Even these RCA jacks are of Manley design. Teflon insulated and gold plated, Manley have been producing these excellent RCA jacks since the mid-1990s.
The volume is controlled on the facia by the sexy front thumb wheel and also by the included Radio Frequency remote control, both of which operate a precision stepped relay ladder matrix attenuator in half dB steps. The RF remote can be operated anywhere in the home, even through walls or cabinetry, especially useful when using the unit as a stand-alone preamplifier.
Next to the front volume control wheel you’ll find the Mute switch to instantly kill the signal. Spinning the volume wheel all the way to minimum also mutes the signal. There is also a user adjustable Headphone Overload Protection System which declares maximum output level to protect precious headphones and your ears.
In case your source needs some correction or if your own ears do not hear equally, Manley have included a Balance Control which can swing the signal up to 72dB either way. In its centre-detent position, this special balance control is completely out of the circuit. Also to be able to execute some sonic authority over what is handed to you in a given recording or to just make your headphones sound nicer (to you!) Manley have provided historically proven pleasing and gentle Tone Controls – and these Baxandall Bass and Treble equalizers can be completely bypassed at the push of a button. Try them! We think you really will enjoy having the choice to enliven and enrich your sonic experience.
Along those lines, the Variable Feedback control allows you to control the amount of overall negative feedback applied to the amplifier from 0dB, or no Global Negative Feedback, to 10dB of NFB. Negative Feedback in electronics is when a small portion of the output signal is re-introduced back to the input signal to provide a more stable and beneficial corrective result. This control is very useful when determining how tight you want your amplifier to sound.
For example, a simple female vocal with minimal percussion can sound more intimate with very little feedback, but a complicated symphony orchestra passage may sound better positioned with more feedback. Applying different amounts of negative feedback can also affect the slew rate and apparent speed of the sonic character.
Other aspects for which to listen include placement, forward or relaxed, darker vs shimmering, or punchy vs mellow. Feel free to play with this knob and listen for the not-so-subtle diversity that altering the amount of feedback provides. It is a favourite circuit trick and Manley have been pulling this one for decades.
The Absolute Headphone Amplifier features custom hand-wound air-gapped dual-mode MANLEY IRON output transformers, designed and manufactured at the Manley Labs factory in California. Interestingly, the output tube stage can be switched on-the-fly between all-triode Push-Pull to Single-Ended topology. This completely alters the harmonic structure from odd-order to even-order and basically halves the output power again providing yet another spicy ingredient to flavour the sound.
Additionally, with a push of a button, these transformers cycle through three ranges of output loads accommodating headphones from 12 to 600 Ohms or greater. Choose between three sets of outputs: the expected 1/4 TRS Headphone Jack, a 4-pin XLR Balanced Stereo Output for your high-end balanced headphones, and a set of stereo RCA outputs to use this component as your line-level preamplifier in your existing hifi system.
The Bypass Thru Mode sends RCA Input 1 directly to the RCA Outputs, when in STANDBY mode. Useful, as your main audio system sources can drive either playback system without having to change upstream cabling.
- Audiophile-quality vacuum tube headphone amplifier and line-level preamplifier.
- Striking sculptured artistic design, available in three finishes.
- Solid aluminium billet chassis.
- Uses easy-change, widely-available vacuum tubes.
- Fifteen independent controls, including MONO switch for mono recordings.
- Supplied with Remora RF remote control.
- Soft Start, 30 second mute-controlled power-up sequence.
- Made in California, USA.
- Amplifier Topology: Triode Vacuum Tube Output Stage, Switchable Topology Single-Ended or Push-Pull
- Vacuum Tubes: 2 x 12AX7 (ECC83), 4 x 6AQ5A (EL90)
- Inputs: 2 x RCA (Input 1 + Preamp Output = Pass-Thru when amplifier is in Standby or Off)
- Input Impedance: 50 kOhms (Pass-Thru = 300 kOhms)
- Maximum Input Level: 7.7 VAC RMS (+20 dBu)
- Load 16 Ohm: 12 dB (Min FB), 3 dB (Max FB)
- Load 62 Ohm: 17 dB (Min FB), 8 dB (Max FB)
- Load 200 Ohm: 22 dB (Min FB), 13 dB (Max FB)
- Input Sensitivity: 600 mV AC RMS for an output of 100 mW, 1.9 VAC RMS for an output of 1 W
- Volume Control: Precision Stepped Relay Attenuator 0.5 dB per step, 63 dB total attenuation, Volume setting to minimum = MUTE
- Outputs (transformer coupled): 1 pair RCA- Unbalanced (Preamp Output), 1 x TRS 1/4-inch JACK Unbalanced, 1 x 4 PIN XLR Balanced
- Output Impedance: Switchable: Low 12-50 Ohm, Mid 50-200 Ohm, High 200-600 Ohms
- Maximum Output Power = 1 W into 12 Ohms BW 22 Hz-22 kHz
- Variable Feedback Control (FB): MIN 0 dB, MAX 10 dB
- Signal to Noise Ratio: 83 dB (1 kHz sine wave, 100 mW output, BW 22 Hz – 22 kHz)
- Noise Floor: -80 dBu BW 22 Hz – 22 kHz, -85 dBu A-Weighted
- Channel Crosstalk: -71 dB Left Channel, -72 dB Right Channel
- Balance Control Channel attenuation: Left Channel = 72 dB, Right Channel = 72 dB
- Frequency Response: Push-Pull Flat 10 Hz – 20 kHz (-1 dB @ 40 kHz), Single-Ended 20 Hz – 20 kHz (-0.5 dB @ 10 Hz, -1 dB @ 50 kHz)
- Distortion: Push-Pull 0.16 % THD+N (BW 20 Hz – 22 kHz), Single-Ended 1.0 % THD+N (BW 20 Hz – 22 kHz)
- Operating Mains Voltage: 90-250 VAC, 50-60Hz, universal works worldwide
- Unit Dimensions LxWxH: 29.21 x 13.97 x 20.82 cm (11.5 x 5.5 x 8.2 Inches)
- Unit Weight: 5.44 kg (12 lbs)
- Shipping Weight = 6.12 kg (13.5 lbs)
- Power consumption STANDBY mode: 0.5 W, Max Power 80 W
- Heat Rise above ambient temperature at rear panel: 25C / 44F
- Heat Rise above ambient temperature at side panels: 15C / 26F
Full Manley Labs Range Available
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