Brand new for 2024, The Manley OASIS Phono Stage replaces the CHINOOK
At last, our favorite phono stage has been updated to operate with MANLEY POWER® which provides an even quieter blacker black background, yielding quicker sonic extremes over our older linear PSU designs. President EveAnna Manley recalls the moment she first made the comparison, “I brought a regular CHINOOK with its linear power supply, a stock unit, to Los Angeles to listen to it against a second CHINOOK that had been modified to work with our new MANLEY POWER® switch mode power supply. My buddy Pete Lyman at Infrasonic Mastering spun up some vinyl records that he had cut the masters for on his lathe. Using his mastering studio environment, we were able to conduct a very precise comparative listening test between the two units. And even though we could not see which unit we were listening to, the sonic differences were unmistakable, and we both heard the same superiority in the new power supply design. I still can’t believe what a stunning technical and sonic accomplishment MANLEY POWER represents, and delivers as we adopt more of our designs to take advantage of our proprietary system.”
The OASIS Phono Stage offers an improvement in convenience over the older CHINOOK as the GAIN selections have been brought out from inside the chassis to the rear panel for easier access residing next to the resistive and capacitive loading DIP switches. There are tons of loading options to mate with any Moving Coil or Moving Magnet cartridge. Once you have set your GAIN and Loading for your cartridge, you’re done! Set it and forget it!
The OASIS sports an upgraded more luxurious chassis design while its efficient internal build keeps the price affordable. And like all Manley products, each OASIS Phono Stage is loyally handcrafted in the USA by American men and women at our Southern Californian factory located just 35 miles east of Los Angeles.
The logical successor to the legacy Chinook, our new OASIS Phono Stage deploys our modern dedicated power supply and construction to usher a new series of Manley preamplifier designs to your home. Named after one of our dearest Mastering Studio partners, the OASIS carries forth the clean and precise audio circuits of the prior Steelhead and Chinook audio paths into a new age of high fidelity preampfification offerings from Manley Labs.
Like the Steelhead, each channel employs the two triode sections of a 6922 for amplifying duties assisted by low noise FETs receiving the signal below each cathode. Highly accurate passive RIAA equalization networks perform the decoding task to restore the originally intended frequency response to the audio signal. In the Oasis, the signal passes through no Integrated Circuits. There are ICs deployed in a servo configuration to apply a precise biasing voltage to the Gate of each FET, and you might notice some other chips who are performing some LOGIC functions to direct the turn on and shut down sequences invoking the MUTE relays to prevent unwanted bumps or noises when the unit is power cycling. Importantly, the signal is directly coupled from the gain stages to another 6922 dual triode serving as the output driver in a White Follower configuration. This output stage circuit is our favorite because of its super-low output impedance and beefy current-driving capabilities. It can drive long cable lengths and difficult loads, tube or solid-state. Bring it on. No wimpy cathode followers here!
The chassis is a new powder-coated over zinc passivated steel design which will be shared amongst 3 other upcoming new Manley preamplifiers. Through this efficiency we have splurged a bit and created a more luxurious housing with its large-radiused substantial top cover sporting smooth rounded side edges. Rounding out the casework, the frontal face is adorned by a 3/8” thick CNC milled facia with an intricately inlaid contrasting “racetrack” insert for visual interest. The OASIS moniker is laser-engraved into the oblong island on the façade. By popular request we have made the faceplates available in traditional “Manley Blue” aka “Pewter Grey”, Silver, or Black. Click on the main photo above to explore the color combinations.
SPECIFICATIONS
Vacuum Tube Complement: 6922 x 2 (gain stage) plus 6922 x2 (output stage). Any 6DJ8, 7308, ECC88 types may be used.
Unbalanced Input and Output connections via Manley Teflon ® & Gold plated RCA jacks
Automatic Mute Timer: On initial power up output jacks are muted for approximately 45 seconds. Automatic mute circuit allows tubes to warm up and circuitry to settle. At power down, output jacks are immediately muted.
Input Termination Capacitance: 3-position user-selectable capacitor values of 50pF, 100pF, and 200pF yield resultant combinations of: 50, 100, 150, 200, 250, 300, and 350pF. Use these settings typically for Moving Magnet (MM) cartridges.
Default Input Impedance: 47k Ohms, with no other DIP switches selected. Use this setting typically for Moving Magnet (MM) cartridges.
Selectable Input Impedance: 5-position user-selectable resistor values of 50, 100, 200, 400, and 800 Ohms. There are 32 possible loading possibilities. Use these resistive loading choices typically for Moving Coil (MC) cartridges.
Custom cartridge input load impedance. (Internal. Must solder your own fixed resistor value, suggested 1/4 Watt or 1/2 Watt - 1% - Metal Film resistor, and use the internal jumper to switch between positions default or a custom load impedance). Keep in mind that when installing a custom resistor value, all of the resultant values shown will be different as they will be calculated in parallel with your resistor value!
Gain: Rear Panel DIP switches select 45dB, 50dB, 60dB, or 65dB (whenever the phono amplifier gain is changed, the output RCA jacks are muted. The automatic mute circuit activates for approximately 18 seconds to allow circuitry to settle).
Inter-channel differential gain: Less than ± 0.5 dB from 20Hz to 20kHz at any gain setting.
Deviation from RIAA curve: Less than ± 0.5 dB from 20Hz to 20kHz at any gain setting. Typically less than ±1dB from 10Hz to 100kHz.
Distortion (THD+N) (47k Ohm Input Termination, 45dB gain, 1kHz sine, 0dBu output):
Typical 0.030% THD+N, into 100k Ohm load, BW = 100Hz-22kHz
Distortion (THD+N) (47k Ohm Input Termination, 45dB gain, 1kHz sine, 0dBu output):
Typical 0.070% THD+N, into 600 Ohm load, BW = 100Hz-22kHz
Dynamic Range (47k Ohm Input Termination, Gain set to 45db, 200 Ohm source):
88dB @ 1kHz, 0.1% THD+N, BW = 22Hz-22kHz
Dynamic Range (47k Ohm Input Termination, Gain set to 45db, 200 Ohm source):
102dB @ 1kHz, 1.0% THD+N, BW = 22Hz-22kHz
Noise Floor at 45dB gain setting with shorted input: -84 dBu, A-weighted
Noise Floor at 60dB gain setting with shorted input: -74 dBu, A-weighted
Noise Floor at 65dB gain setting with shorted input: -69 dBu, A-weighted
Maximum Input at 45dB gain setting with 20 Ohm Source Z @ 1kHz into 10 kOhm load:
210mV RMS = +34 dBu @ 1% THD+N BW=22Hz-22kHz
Maximum Input at 60dB gain setting with 20 Ohm Source Z @ 1kHz into 10 kOhm load:
21mV RMS = +33.5 dBu @ 1% THD+N BW=22Hz-22kHz
Maximum Output: +35dBu @ 1kHz, 1.5% THD+N into 100 kOhm load
Output Impedance: 104 Ohms
Minimum Recommended Load: 2500 Ohms
Internal Switch Mode Custom Power Supply: Fully regulated High Voltage (B+), Heater, and control voltage rails.
Operating Mains Voltage: 90-254VAC (internal universal supply)
Power Consumption in Standby mode: Less than 1 Watt
Power Consumption: 30 Watts (250mA @ 120VAC)
Mains Voltage Frequency: 50 ~ 60Hz (47Hz to 63Hz)
IEC Mains Fuse & SMPS fuses: 2A ~ 250VAC (Type: Slow-Blow, Body: Ceramic or Glass, Size: 5mm x 20mm)
Chassis Dimensions: W=17”, L=14”, H=3 1/2” (Occupies 2RU)
Shipping Box Dimensions: W=23”, L=18”, H=7”
Shipping Weight: 20 Lbs.
“The Oasis is based on the classic Chinook phono preamp, with a more upmarket chassis, external gain switches, and a significant upgrade to the power supply.
I put on a record I've had since high school: Boz Scaggs' Silk Degrees. Did this take me back? Right back to a sock hop on the gymnasium floor! Sonics were spacious, rhythmic, and propulsive and I wanted to boogie out of my chair when the track Georgia came up.”
- John Hughes, Positive Feedback, March / April 2024 -
