Fidelix CAPRICE DAC/Preamp

Fidelix CAPRICE is equipped with the highest performance ESS 32-bit DAC chip ES9018. To take full advantage of this performance, the ultra-low jitter clock is powered by a high-speed bipolar input amplifier instead of CMOS, and is supplied with current from a dedicated shunt power supply. In addition, we have developed and installed key devices such as a quick-response power supply with ultra-low noise and no overshoot, which is about 30 dB lower than a general 3-terminal regulator, and a class A ultra-low noise OP amplifier (1.8 nV/√Hz) that is all JFET with a focus on sound quality. The IV conversion section consists of two circuits of this OP amplifier in parallel. The coaxial input uses a high-speed pulse transformer (115MHz, 0.5pF with shield between PSs) and a high-speed comparator with hysteresis due to bipolar input to prevent jitter from entering. TOSLINK uses a high-speed type (25MBPS), and both SPDIF inputs support 24Bit/192kHz sampling (32Bit/192kHz sampling has also been confirmed to work). Coaxial is equipped with 2 inputs and TOSLINK is also equipped with 2 inputs. However, one of the three digital systems that can be switched with the rotary switch on the front can be switched between coaxial and TOSLINK on the back. Additionally, the 3 digital inputs can be switched using the remote control.

 It has two analog input systems, one of which can be optionally converted into a phono equalizer (input equivalent noise voltage -140dBV) using an all-JFET OP amplifier. As a further option, it is also possible to switch between SP and LP curves. In addition, the analog signal is injected into the differential IV conversion circuit via a real-time BTL circuit (consisting of a JFET input OP amplifier) ​​developed in-house. Note that this injection circuit is disconnected during digital operation.

*Both USB and AES/EBU connections can potentially cause some adverse effects, especially USB, which is prone to picking up significant switching noise from PCs and other devices. Therefore, it is intentionally avoided, and using these connections converted to coaxial is recommended. 

Variable output via the front volume is provided on the rear RCA jacks. This makes it very convenient to use as a DAC/preamp. This line amp is a fully DC-coupled amplifier with JFET-input op-amps arranged in two parallel circuits. It has ample driving power, so it also serves as a headphone output. The DAC’s direct output, which bypasses the volume control, offers balanced XLR output (pin 2 hot). For unbalanced use, only pins 1 and 2 of the XLR are used (pin 3 remains unconnected). The design intentionally eliminates balance-to-unbalance conversion circuits that would degrade the signal’s freshness. The unbalanced output using XLR pin 2 is 2.7V, while the balanced output using pins 2 and 3 is 5.4V, with an S/N ratio and dynamic range reaching 131 dB, among the best in the world. It has been demonstrated that clock jitter is exceptionally low. Distortion achieves a world-class level of 0.00064% at 1 kHz with 5.4V output (BW = 30 kHz).

Regarding the power supply, based on experience where crosstalk through the power supply is non-linear and extremely detrimental, independent power supplies for left and right channels are adopted. Digital inputs allow for a digital volume controlled by the remote, enabling the XLR balanced output to be sent directly to a power amp’s balanced input. When paired with the CERENATE power amp, this results in a simple configuration that completely bypasses any balance-to-unbalance or unbalance-to-balance circuits, delivering a fresher sound. However, digital volume cannot be used for analog inputs, so they provide fixed output.

The power transformers for analog circuits are independent for left and right channels, and a total of three are used together with the digital transformer. The two analog transformers are connected in a way that cancels out leakage magnetic flux. Even in environments with high power noise, these transformers demonstrate their ultra-high performance, with noise filters attached to the power supply. Schottky barrier diodes that do not generate power noise, audio-grade capacitors, and audio-grade resistors are used. By extensively adopting non-magnetic audio resistors from the U.S. company PRP, the overall sound quality has been further enhanced. The connector-less design ensures high reliability, and major external terminals are gold-plated. Some of the transformers and parts are mounted at an angle, reflecting a design that prioritizes electrical properties and performance.

The board is equipped with input terminals for I2S signals and DSD signals, capable of handling 32-bit/192 kHz and 24-bit/352.8 kHz inputs (optionally, an isolated PS AUDIO-compliant HDMI input can be installed internally as a sub-board). Dip switches located at the bottom allow settings for sharp roll-off, slow roll-off, PLL bandwidth, DSD filter characteristics, oversampling, and jitter reduction functions. The design is filled with curiosity and playfulness.

*About I2S Specifications: The I2S specification follows the PSAudio standard. I2S connections support signals up to 192 kHz/32-bit.
*About DSD Specifications: The DSD format uses three signals (L, R, and Clock), but it is a Fidellix-specific DSD-only device using an HDMI connector, and SPDIF signals cannot be used. It also does not support DSD signals via HDMI according to AV amplifier standards.

The ES9018 contains eight sets of differential DACs inside, all of which can be used as a single-channel mono. In this case, you can set it for either the right or left channel. By using two CAPRICE units and setting these options via the dip switches on the bottom, theoretically, you can achieve near-infinite separation. Furthermore, by parallel-connecting the two-channel outputs of one unit, you can achieve a dynamic range close to 135dB, making it possible to realize the ultimate performance at present.

"An astonishingly realistic soundstage that makes you forget the existence of the hardware" "Natural, analog-like sound quality" *Wireless & Experimental

I also listened to sources at 192kHz/24bit sampling and discovered several performances that made me realize their brilliance for the first time. At the very least, it reproduces the sound of classical music very lifelike, and I was impressed by that capability. Astonishingly diverse expressions. Builds music with overwhelming amounts of information. *Audio Accessory