rega Aethos Stereo Amplifier Instruction Manual
- May 15, 2024
- Rega
Table of Contents
AETHOS
World class hi-fi made in England.
For user instructions in your language, please visit www.rega.co.uk and go to the download section of your chosen product page.
Introduction
The Aethos stereo amplifier is housed in a brand new custom designed case. Employing four 160 W 16 Amp output transistors per channel, this delivers 125 W per channel into 8 Ω. The Aethos is a dual mono design using a custom wound toroidal transformer and regulated supplies for the sensitive amplification and driver stages. The pre-amplifier stage uses class-A discrete circuitry throughout. The Aethos is a no compromise product with one goal, to deliver your music as faithfully as possible.
Installation and ventilation
The AETHOS amplifier will work well on most surfaces, such as a shelf or a table, provided there is sufficient air around the heat sinks to prevent overheating. If using a turntable, avoid magnetic interference by positioning the amplifier as far away from the turntable and phono amplifier as possible. Keep other equipment away from the amplifier. Due to the layout of Rega’s amplifier circuit designs, they are virtually insusceptible to electromagnetic interference, and by virtue of the case, emit practically no electromagnetic radiation. However, placing any electronic equipment, such as sensitive phono amplifiers close together may impair the performance of one or both items. Never stack other hi-fi components on top of the AETHOS.
WARNING: DO NOT TOUCH HEAT SINKS, THEY CAN BECOME VERY HOT.
The heat produced by the AETHOS amplifier is dispersed via the heat sinks mounted on either side of the product. Please ensure the side section is always exposed to allow for sufficient airflow resulting in adequate cooling of the amplifier. If the AETHOS is driven at high volume for a long period, it will become quite warm. This is entirely acceptable and as long as there is sufficient ventilation, the amplifier will continue to work normally. Never place the amplifier on carpets, rugs or bedding. Do not force objects into the unit’s ventilation openings.
Rear panel connectivity
Line inputs 1 to 5 (1) – These inputs can be used for a DAC, CD player, network player, streamer, tuner etc. All inputs (other than the Direct input) are at standard analogue line level and can be used for any line level input.
Record input (2) and output (3) – This is a line level input and output intended for use with a recording device such as a CD/DVD recorder, MD, cassette & reel-to-reel tape recorder or sound card. Selecting the Record function on the amplifier front panel enables the input. This input is completely independent to inputs 1-5 and can be used to monitor the Record function and quality, without affecting the source being recorded. The output is a Record signal and is the same signal as selected by the main input selector 1-5 and is not affected by the volume control.
Record output link (4) – This output is in parallel to the Record output, and can be used to drive ancillary components like headphone amplifiers etc, when a signal unaffected by the volume control and selected by the main input selector is required.
Direct input (5) – This input is routed directly to the power amplifier input
with no volume control. The intended use is with multi-channel systems, where
the traditional two-channel system is used as the front speakers. This input
can also be used with an external preamplifier if so desired. The sensitivity
is 840 mV for maximum output.
Power amplifier gain = 31.6 dB.
NOTE: The Direct input button is located on the supplied handset only. The direct LED (16) will light on the front panel when activated.
CAUTION: As this input has no volume control, if a source like a CD player is connected to this input, the speakers will be driven to their maximum. This could potentially damage the speakers.
Pre-amp output (6) – The pre-amplifier can drive at least 5 power amplifiers, sub bass units etc. The pre-amplifier output uses RCA type (phono) connectors. The output level is 840 mV with the rated line input level.
Speaker terminals (7 – right and 8 – left) – These are intended for use with 4-16 Ω speakers. Sustained use into speakers of less than 8 Ω could make the unit run warmer than normal.
Mains fuse (9) – see back panel for rating – IMPORTANT replace with same type and rating.
Mains power inlet (10) – Connect to mains supply – IMPORTANT observe voltage – see product/rating label for details.
Front panel controls
Powering up
Pressing the power switch (11) to the left of the control panel turns on the
amplifier. The Rega logo (18) will illuminate red. After several seconds you
may hear a gentle click, indicating that the switch-on relay has been released
and the amplifier is ready for use. Always allow the AETHOS to fully power
down (indicated by the power switch LED extinguishing after 2-3 seconds)
before switching on again, so that the self-test circuitry can complete its
reset cycle.
Record selection
The record input is selected by pressing the Record button (12) on the front
panel, or via the remote control.
Mute
The mute function (13) mutes both the pre-amplifier and power amplifier
speaker outputs and can be selected via the front panel or remote control.
Input selection
The inputs are selected by pressing the Input button (14) on the front panel.
Repeatedly pressing the Input button will cycle through inputs 1-5. The
selected input is indicated by the input LED’s 1-5 on the front panel (16).
Headphone socket
The AETHOS is capable of driving all standard hi-fi headphones. The headphone
output (15) has been characterized to match most commonly used headphones (see
specifications for the output levels). When a headphone is inserted into the
socket, the speakers will automatically be turned off. However, it is
recommended to reduce the volume of the AETHOS before connecting any
headphones to ensure they are not damaged and prevent any hearing damage.
WARNING: TO PREVENT POSSIBLE HEARING DAMAGE, DO NOT LISTEN TO HEADPHONES AT HIGH LEVELS FOR LONG PERIODS OF TIME.
Volume control
The volume of the amplifier can be adjusted using the volume control knob
(17) on the amplifier and via the remote control handset. The control is
motorised and will independently move when the remote control is used to
control the volume.
Rear panel conectivity
Front panel controls
Thermal cut-out and DC protection
If the amplifier reaches a temperature liable to cause internal electronic damage, a thermal protection sensor will shut the unit off. If this occurs, there will be no sound emitted from the speakers. The unit should be turned off for at least 10 minutes to allow for cooling. After this period, the amplifier should automatically reset and continue to work normally. If it does not, turn the unit off for a longer period, allowing complete cooling of the amplifier before retrying.
The thermal cutout should only occur with continuous high level driving of a difficult load. If it occurs under normal conditions, there could be a problem with insufficient airflow around the heat sinks or a fault with the loudspeakers. In this case it is advisable to contact your Rega dealer.
One of the design requirements of the AETHOS was to keep the capacitors in the signal path to a minimum to prevent unnecessary sound degradation. In order to achieve this requirement, the outputs of both the pre-amplifier and power amplifier (speaker) are DC coupled. A servo control is applied to the pre- amplifier. In the unlikely event of a circuit failure causing any one of the above outputs to produce an excessive DC voltage, the DC protection will activate within milliseconds, protecting any connected device.
Operating temperature and short circuit protection
The recommended ambient operating temperature is 5 °C to 35 °C. Allow adequate air circulation around the heat sinks on the left and right hand sides, as these are the heat sinks for the power amplifier and will run hot with high listening levels. This unit is intended for use in moderate climates.
If in the event that the speaker leads are shorted, the fold back short circuit protection will protect the output stage from excessive currents. This protection circuit is not placed in the audio signal path and therefore does not affect sound quality.
Warning: To reduce the risk of fire, electric shock or product damage, do not expose the unit to rain, moisture, dripping or splashing and ensure that no objects filled with liquids, such as vases, shall be placed upon it. Do not remove the case covers. There are no user serviceable parts inside.
No naked flame sources, such as lighted candles, should be placed on the apparatus.
1. Remote control
The Solaris system remote (supplied) is a system remote handset. It allows you to operate all the various remote controllable functions of this and many other Rega products (batteries included – 2 x AAA Alkaline).
Specifications
Power outputs at rated 230/115 V supply voltage:
125 W RMS| both channels driven into the rated load of 8 Ω
156 W RMS| both channels driven into 6 Ω
Note: Continued high level use into 6 Ω may cause the case to exceed 40 °C above the ambient temperature and activate the thermal shutdown.
Headphone output:
No load| 12.5 V
32 Ω| 2.7 V
54 Ω| 4 V
300 Ω| 9 V
Source impedance| 109 Ω
Record output:
Record output level (with rated input levels)| 219 mV
Record output impedance| 560 Ω
Pre-amp output:
Pre-amp output level (with rated input levels)| 840 mV
Pre-amp output impedance| 100 Ω
Input sensitivities for rated output level:
Input 1-5 and record input sensitivity| 224 mV @ 17 kΩ
Maximum input level| 11.5 V (record output amplifier overload point)
Direct input sensitivity| 840 mV @ 50 kΩ
Power amplifier gain| 31.6 dB
Frequency response @ 100 W into 8 Ω:
Line input| 1-5 and record 10 Hz (-0.8 dB point) to 30 kHz (-0.5 dB
point)
Direct input| 10 Hz (-0.8 dB point) to 50 kHz (-0.5 dB point)
THD+Noise @ 100 W into 8 Ω:
Direct input (Power amplifier only)| Typically 0.007% @ 1 kHz
(measurement bandwidth 22 Hz to 30 kHz)
Line input| Typically 0.007% @ 1 kHz (measurement bandwidth 22 Hz to 30
kHz)
Power consumption| Maxiumum output: 415 W @ 230 V / 220 V / 115 V / 100
V into the rated load of 124 W RMS into 8 Ω
Fuse ratings| T5 AL 250 V – 230 V / 50 Hz and 220 V / 60 Hz
T8 AL 250 V – 115 V / 60 Hz and 100 V 50/60 Hz
Dimensions| W 433 mm x H 95 mm x D 360 mm (including speaker terminals)
Weight| 17.5 kg
Safety and warranty
Service
With the unit disconnected from the mains, only clean with a micro fibre
cloth, (lightly damp if necessary). Do not remove any coverings; there are no
user serviceable parts inside. If the unit performs erratically or emits smoke
or odour, disconnect from the power supply and take it to a qualified service
technician.
Warranty
All Rega products are covered by a lifetime warranty against manufacture
defects. This warranty does not cover wear and tear. Any unauthorised
modifications or failure to follow the Rega recommended guidelines may
invalidate the warranty. If returning goods for inspection to your retailer,
the original packaging must be used to preserve the warranty. Damage caused
during transport due to incorrect packaging may invalidate your warranty.
Replacement packaging is available from any Rega retailer. Your statutory
rights are not affected.
Safety instructions
- Do not use this unit near liquids or expose to moisture.
- Do not use near sources of heat such as radiators, vents, stoves, or candles.
- Ensure adequate ventilation around the product, at least 10 cm in all directions, and avoid placing the unit on soft surfaces such as long carpet and fabric.
- Do not open the product enclosure or force objects into openings in the unit.
- Place the unit on a fixed level surface where it will not fall or tip.
- The unit should only be used in moderate climates between 5 °C (41 °F) and 35 °C (95 °F).
- Keep packaging material and small pieces out of reach of children.
- Unplug the power supply if the unit is unused for extended periods of time.
AETHOS
Rega Research Ltd., 6 Coopers Way, Temple Farm Industrial Estate,
Southend-on-Sea, Essex, SS2 5TE
User Manual | Revision 3