R2R | DIGITAL TO AUDIO CONVERTER

The Heléne is our smallest digital to analogue converter

“The Heléne is our smallest digital to analogue converter. Regardless, by DAC standards it is still quite a large device weighing in at 40 kilos. In designing the Heléne we held firm to the Aries Cerat philosophy of maximum performance first, other considerations second. Borrowing technology from the Kassandra Series, and with the addition of some tricks of it’s own, the Heléne is a remarkable machine in it’s own right, setting a new previously unreachable level of performance vs price ratio.”

DESIGNER

In designing the Heléne we held firm to the Aries Cerat philosophy of maximum performance first, other considerations second

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Ladder DAC

The Heléne is a bit-perfect ladder DAC and uses NO data processing, upsampling or oversampling – all data is converted at their native sample rate and bit rate.

Taking technology we pioneered in the Kassandra Series, the converter banks are implemented around a matrix of eight R2R converters per channel, running in parallel. The two independent banks use eight R2R matrixes from the Analog Devices AD1865N-K in current mode.

These are driven by our custom logic that handles the syncronisation, data and work buses. Our Super Clock technology used in our bigger models is also standard in the Heléne DAC, negating the use and need of an external aftermarket Word Clock.

The USB input is double Reclocked, as are the digital S/PDIF and AES inputs using the internal Super Clocks of the converter. The digital input Reclocker is also bypassable on the fly.

I/V Stage

Converter banks run in current output, thus  IV conversion stage quality is detrimental to the SQ. The IV (current to voltage) stage is implemented by a special IV transformer with custom ultra high MU core, directly modulating the bias circuits of the analog tube stage.

Gain Stage

The analog stage is again borrowed from our bigger models, and is a small SET amplifier built around the E280F super tube, loaded by a custom special quality output transformer.

Power Supply

The analog stage PSU is tube rectified using the GZ34 rectifier, while triple choke / film capacitors provide very low noise voltage rails for the SET amplifier. The tube is also biased with triple filtered ultra low noise bias circuits.

Power supplies of both the digital and analog sections of the converter system are carefully designed around oversized capacitor banks and extensive RF choking filters, distributed at all points of the circuit.

ARIES CERAT SYSTEM WITH THE HELENE DAC
Technical Specifications

DIGITAL SECTION

IC Chip Array:

8 R2R converters per channel, complimentary current output using the top grade Analogue Devices AD1865N-K  with 4 converters per bank, 8 per channel

Regulators:

Four discrete ultra-low-noise regulators for the 4 converter banks

PSU:

Over engineered power supply, power input filters.

Current to Voltage Conversion:

Transformer I/V conversion with custom wideband transformers, balanced current to single ended voltage conversion.

Additional Clock:

Internal Super-Clock by-passable on the fly,  triple regulated supply

INPUT & OUTPUT SECTION

PSU:

Over engineered power supplies, power input filters, large toroid transformer & capacitor banks

Gain Stage:

Transformer loaded super tube output stage using the E280F tube.    5:1 step down transformer & double choke filtered supply

Output:

30Vpp output @ 0db 10Vrms

Output:

2 x RCA, 2 x Balanced. True Balanced output standard.

Floating RCA output switchable (ground loop resolver)

Output Impedance:

50 ohms (balanced and SE output)

USB input:

Data rates up to 24/384KHz

Jitter attenuation:

Down to femtosec level

Dimensions:

500mm W x 430mm D x 165mm H

Weight:

40kg