Rega IOS Reference : Compatibility
The REGA IOS Reference is the British brand’s ultimate phono preamplifier. This means that it has been designed to bring out 200% of the musicality of the APHETA 2 MC cartridge! It is also part of the company’s flagship ‘Reference’ range, joining the ranks of the Isis and Osiris.
This Rega IOS Reference phono stage is only compatible with MC cartridges! Rega do without moving magnets entirely, which may appear to be surprising, but we feel it is fully justified given the range of the product.
Rega IOS Reference : Internal circuit
The circuit of the Rega IOS Reference only includes the highest quality components, spread across four symmetrical amplification stages.
- The first stage uses a top quality step-up transformer: the SOWTER 8055 (report 1/10).
- The second comprises discrete components only, most notably the low noise Hitachi transistors.
- The third stage is also fully symmetrical and is a class A differential amplifier. It controls the low frequency part of the RIAA equalisation stage.
- The fourth stage is an low noise operational amplifier with a very high bandwidth.
The internal architecture of the Rega IOS Reference phono preamp has been thoroughly optimised and designed to reduce surface noise to a minimum.
The wiring uses conductors with very low capacitance and resistance.
The signal path uses low tolerance (1%!) polypropylene capacitors only.
Particular care has been taken over the IOS’ power supply. It uses fast, low noise diodes and regulators.
Rega IOS Reference : Front panel and settings
This Rega IOS Reference phono preamp has both symmetrical and asymmetrical inputs and outputs.
On the front panel, there is a two position gain selector (64 or 70 dB), a 5-position resistive load selector (50, 100, 150, 300 and 400 ohms) and a 5-position DC load selector (6.25, 8.75, 11.25, 13.50 ohms, nominal).
A button controls the mute function and, another, the mono function.
Rega features a filter that is designed for the Apheta 2 and the under-damped cartridges or giving a treble that is slightly too strong! It is also recommended with some pressings from the early sixties that were sensitive to surface noise. We recommend you try it out and use it sparingly…
Rega IOS Reference : Listening and test review
As soon as it is unpacked, its 17 kg weight is already impressive!
We could not resist combining the Rega IOS Reference with our Rega RP10 vinyl turntable and its Apheta 2.
From the first beats, we were forced to note that this is a fearsome combination. Quality and musicality were not lacking!
The dynamics are amazing and span evenly across the entire spectrum. The bass is deep and very well controlled. We discover the articulation and clean sound of the 'major' phono stages!
It cannot be compared on any way with its little brother, the Rega Aria phono preamplifier.
The sound stage is wide and very deep, but for all that the precision is just as good.
The vocals are perfectly positioned in the centre of the speakers and have outstanding presence. You could say that the equipment completely retires before the music. The sound quality is entirely proportional to the quality of the work and the pressing.
This IOS Reference gives amazing results with other cartridges than the ones available from Rega. With our benchmark MC, we found all the qualities mentioned above, with slightly more transparency and neutrality.
This REGA IOS Reference can be considered to be one of the best preamplifiers on the market. If you have a RP10 and an Apheta, no longer seek the absolute preamplifier! We have found it... Franck
Input sensitivity: 200mV
Output: 61uV - 70dB gain setting I 118uV - 64dB gain setting II
Gain: 64dB Minimum 70dB Maximum
Input load: 50, 100, 150, 300 & 400Ω
DC resistance: 5 to 7.5Ω (6.25Ω nominal) 7.5 to 10 Ω (8.75Ω nominal) 10 to 12.5Ω (11.25 Ω nominal) 12.5 to 15 Ω (13.5Ω nominal)
MC transformer: Sowter 8055
Max. input: 8.7mV - 64dB gain setting 4.5mV - 70dB gain setting
Max. output level: 14.7V RMS
Min. output level: 200mV
Output resistance: 100Ω
Min. output resistance: 1KΩ for –3dB to 15Hz
RIAA accuracy: 0.2dB
Frequency response: 14Hz to 54KHz (-0.5dB)
Distortion: under 0.008%
Output level: -85dBV. 64dB gain at 15Ω
Inputs: RCA and XLR
Outputs: RCA and XLR
Power supply: 230V
Power supply: 21 Watts