Project Description

AllNIC D5000 DHT DAC, £9000

With an Allnic designed pure Direct Heated Triode analog output section and a unique digital section by Waversa systems the D5000 DHT is a true ground breaking product and very different to pre-existing DAC designs on the market. It has been priced extremely competitively by Allnic but also benefits from Lotus’s very generous and fair importation rates (US rrp converted to GBP plus VAT and DUTY). The net result is a product that can stand tall against competition from any price bracket.

The D5000 DHT gives us all that one would expect from Allnic and a DHT circuit, an extremely vital and alive sound, extended at the bottom and in the highs, incredibly spacious and holographic, very real sounding with fantastic texture and tonal colour and no shortage of dynamics and drive. What I perhaps didn’t expect form this DAC is just how tuneful it is. KS has perfected this source so that it conjures forth the melody, tune and rhythmical flow in even the most complex and discordant of music. This means a DAC that boogies, grooves, swings, rocks and sucks you into the music in the most addictive way. All the hifi stuff is there in spades but the biggest thing that strikes you with the D5000 is just how melodious it is; totally unmechanical and ‘un-hifi’ like this DAC is so involving and the very closest I have heard to a good turntable. It demands your investigation no matter what level you may be shopping at.

Available in silver or black. 2 year warranty on all Allnic Audio Products , 1 year on factory supplied tubes. Part exchange welcome, just get in touch for in-store or home demo.

The analog output uses a fully balanced circuit from input to output with no coupling capacitors, only all pure nickel permalloy cored transformers. Each channel uses twin 3A5(DCC90) DHT tubes. The DHT 3A5 amp’s frequency range is from 20 Hz to 50 kHz (-3dB) with a perfect square wave form of 20 kHz. 3A5 tubes operate at a very low temperature that ensures long tube life. The circuit displays no negative feedback, not even a partial feedback. This design has absolutely no microphonic issues, which is the biggest obstacle to DHT realization. KS Park’s design resolved this issue through a newly designed 7-pin gel damper socket. In addition, the main PCB is floated with a drum rubber specific for this application. High S/N ratio and dynamic operation is achieved through full tube designed automatic voltage regulation which protects the DHT amp from both internal and outside voltage irregularities. The front panel displays a current meter which monitors safe operation and status of the tubes.

The D5000 is very unique in today’s DAC world because most of its components are not from any routine audio market source except the DAC chips. The USB interface, SPDIF receiver and high end upsamplers are all specifically customized for this application. D5000 uses very unique technologies for audio signal processing. The clock does not directly connect to the DAC chip. Instead, the audio processor uses clock alignment algorithms that determine exact alignment for the DAC chip in a real-time manner. The ES9018K2M SABRE 32 Reference DAC chip is a high performance 32-bit, 2-channel audio D/A converter with sampling to 32/384 kHz, 128 DSD and uses a 1.5 MHz upsampler through a field-programmable gate array USB interface.

While most ES9018K based DACs use the dac chip for audio processing, the D5000 has a proprietary internal processor that performs real time PCM upsampling or upsampling and conversion to DSD. The SABRE Reference DAC chip only performs the digital to analog conversion.

Real-time PCM to DSD conversion function is implemented when “conversion” is selected. All input samples are converted to 128 DSD with an internal 5.6 MHz/32 Bit upsampler and DSD converter. When de-selected, input audio sampling is either upsampled, if selected, or bypassed to the DAC chip.

The USB interface is implemented through custom hardware by Waversa Systems and is UAC2 standard compliant. This provides very clean audio through complete galvanic isolation, thereby stripping the digital signal of any PC noise commonly created by the server’s internal power supply. Thesycon driver is provided for Windows application. Drivers are not required for Mac/Linux.

1) Toslink Sampling limit 96 kHz (Note: In case of TOSLINK, some devices will work correctly with D5000 at any rate. This depends on the signal quality of the transport.)
2) AES/EBU and Coax sampling limit 192 kHz (if the source is SPDIF standard compliant). Higher sampling rates have been demonstrated with some source components.
3) USB Sampling limit 384 kHz, DSD128
4) USB Input Custom USB Audio Interface design with Cypress FX2/FPGA
5) DAC Dual Mono/Mono ES9018K-2M Reference Audio DAC
6) Word Clock: Clock Reference Output, Clock Reference Input
7) DSD Conversion FPGA Based DSD Converter: PCM to input DSD128
8) Upsampling FPGA Based Upsampler: Up to 384 KHz
9) Mac OSX 10.6, Linux OS with UAC2, Windows OS (Thesycon Driver)

Inputs:
• One (1) X optical digital
• One (1) X USB
• One (1) X AES/EBU (XLR)
• Two (2) X coaxial digital (RCA)

Outputs:
• One (1) pair X unbalanced (RCA)
• One (1) pair X balanced (XLR)

Output Frequency Range:
• 20Hz – 20KHz flat

Output RMS Voltage:
• 2.5 volts

Output Impedance:
• 150 Ω (Constant)

Total Harmonic Distortion (THD):
• Less than 0.1%

Signal to Noise (S/N) Ratio:
• – 86db (CCIR, 1KHz)

Power Consumption:
• 23W at 230 V / 110/120 V / 50 / 60 Hz

Tubes:
• Four (4) x 3A5 – Output stage tubes: equivalents are DCC90 and CV808
• One (1) x 5654 – Voltage error detector: equivalents are 6AK5W, E95F, M8100, 6096, CK5654, 5654W, GL-5654, CV4010, CV850, 5654RT
• One (1) x 7233 – Voltage regulator: no equivalents

Fuse:
• AC 2A, 250V

Dimensions:
• 430mm (16.93 inches) x 290mm (11.42 inches) x 150mm (5.91 inches) (W x D x H)

Weight:
• 9.2 Kg (20.3 lbs.) unpacked
• 11 Kg (24.3 lbs.) in original packing

With a digital section designed by Dr. C. Shin, principal of WAVERSA SYSTEMS and an expert in high-resolution digital and digital to analog design for both military and commercial applications, the D-5000 DHT DAC is unique in the marketplace. Except for the DAC chip it employs, the ES9018K2M SABRE 32 Reference DAC (“Sabre DAC”), most of the D-5000 DHT DAC’s components are not sourced from the audio supply market. In addition, the USB interface and SPDIF receiver are specifically customized for use in the D-5000 DHT, and custom built, high end up-samplers are utilized for user selectable DSD conversion and PCM up-sampling.

The D-5000 DHT offers the listener the flexibility to select listening directly to:
• the source drive’s audio signal at its native sampling rate, or down-sampled if that signal is above the limits of the Sabre DAC (the maximum Sabre DAC specification is DSD 128, sampling to 32/384KHz, and internal 1.5MHz up-sampling);
• a PCM signal from the source drive converted to DSD 128 in “real time”; or
• a PCM signal up-sampled from the source drive’s native rate by a custom up-sampling chip.

The ES9018K2M SABRE 32 Reference DAC is a high performance 32-bit, 2-channel audio D/A converter with sampling to 32/384 KHz, DSD 128 and a 1.5 MHz up-sampler using a field-programmable gate array (“FPGA”) USB interface. In the D-5000 DHT, the Sabre DAC chip is used for audio signal processing only when the user has not specifically selected conversion to DSD or up-sampling.

The D-5000 DHT converts PCM to DSD in real-time when “Conversion” is selected using the D-5000 DHT’s chassis face or remote controls. When conversion to DSD is selected, all PCM input samples are converted to 128 DSD via a custom built internal 5.6 MHz up-sampler and FPGA DSD converter.

The D-5000 DHT up-samples PCM when “Upsample” is selected using the D-5000 DHT’s chassis face or remote controls. When up-sampling is selected, all PCM input samples are up-sampled using a custom built audio signal processing chip.

The USB interface is implemented through network player hardware by Waversa Systems and is UAC2 standard compliant. This provides an extremely clean digital audio signal through complete galvanic isolation, which strips the digital signal of any PC noise commonly created by a server’s internal power supply. Firmware updates and music data are also communicated through the single provided USB input. This is accomplished by a special interface, again unique to Waversa Systems.

Data under-run or over-run and, therefore, distortion can occur when a source’s word clock and a DAC’s internal word clock are not synchronized absolutely. When an external clock is used, potential errors caused by data under-run or over-run inside a DAC can be eliminated. The D-5000 DHT provides connections for an external word clock. In addition, the D-5000 DHT’s current high-end internal word clock implementation will be updated to an even more highly advanced mode in the next update phase, currently planned for within a few months of initial release of the D-5000 DHT DAC.

It is also intended to provide an I2S input in the near future. This separate system will be connected to the D-5000 DHT DAC by a proprietary method through the AES port. The I2S system will provide not only PCM but also DSD and have the capability to support extreme up-sampling and cross conversion between DSD and PCM. Details will be published at a future date.

 

FEATURES

Waversa Systems’ digital features include:
• operations via Linux OS with UAC2 and MAC OSX 10.6, with the Thesycon driver incorporated for use in Windows OS environments
• dual mono ES9018K2M SABRE 32 Reference Audio DACs
• real-time PCM to DSD 128 conversion using a custom built 5.6 MHz up-sampler and FPGA DSD converter
• custom built, FPGA based, 1.5 MHz up-sampling to 384 KHz
• all digital inputs and a customized S/PDIF receiver accommodating rates up to 192 KHz
• a UAC2 standard compliant custom audio interface design, with Cypress FX2/FPGA USB input handling:
o DSD 64, DSD 128
o PCM 44.1 KHz, 48 KHz, 88.2 KHz, 96 KHz, 176.4 KHz, 192 KHz, 352.8 and 384 KHz.
• in and out reference word clock connectors for use with an external clock

On the analog side:
• the D-5000 DHT is Permalloy transformer coupled; no coupling capacitors are used.
• to help prevent microphonic interference from vibrations, the D-5000 DHT’s main PCB is suspended with a specially made drum rubber.
• Allnic Audio’s patented and newly designed “Absorb GEL tube damper” technology prevents harmful vibrations from reaching the signal / gain tubes and, therefore, prevents micro-phonic noise propagation in the tubes. The Allnic Audio Absorb Gel damper technology effectively solves a problem that plagues most tube amplification systems. Provided other tube components do not introduce micro-phonic noise into your system, with the Absorb Gel damping system, you will enjoy a degree of transparent sound that will surprise and please you.
• the D-5000 DHT uses NOS DHT 3A5 tubes, DHT tubes that were nonetheless manufactured in a very sophisticated and modern way, and that have a frequency range of 20 Hz to 50 KHz (-3 dB) with an extremely beautiful square wave form at 20 KHz
• low voltage and temperature operation of the 3A5 DHT tubes ensures tube longevity

In addition, the D-5000 DHT also has the following features:
• Zero negative feedback design
• Pure Class A operation
• Fully balanced circuit from input to output
• As are all Allnic Audio products, the D-5000 DHT DAC is fully RoHS (EU Reduction of Hazardous Substances regulation) compliant in construction and materials.

In the early years of the last century, the directly heated triode (DHT) was invented independently, and almost simultaneously, in the USA and Austria. This simple device, an anode, a cathode and a grid in a vacuum contained in a glass bottle , transformed the world. Over one hundred years later, the very first triode remains a favourite audio amplification device for devoted music lovers worldwide.

Debate about the quality of the DHT’ s sound reproduction potential continues even today. One of the interesting aspects of these debates is the degree to which they ignore analysis of common, fundamental assumptions about DHTs. Those assumptions are based on many decades of circuit and mechanical experimentation and compromise. Indeed, because of the difficulty of using DHTs for audio , many circuit design issues have evolved into assumptions about the audio characteristics of DHTs themselves.

Allnic’s Mr. Kang Su Park has spent a lifetime studying and designing circuits and transformers for use of DHTs in audio reproduction. Mr. Park has questioned basic assumptions about DHTs, reexamined variations of DHT circuit designs, and researched and experimented rigorously. His work has resulted in some remarkable audio power amplification devices. For example, Allnic’s 300B amplifiers produce significantly more power than normally expected . They do this without shortening tube life because the power increase is not achieved by increased bias. In conjunction with an increase in power, Mr. Park’s 300B amplifiers also have exceptional ly low distortion and wide bandwidth.

Mr. Park successfully combined elements of what he learned and invented over decades to the development and production of a pure, direct heated triode (DHT) based amplifier and preamplifier : the A – 5000 and L – 5000, respectively. The main breakthrough was the design of a circuit, valve and transformer combination with astounding measured results . The purity of its square wave reproduction – as perfect as anything he had ever seen from a DHT valve amplification circuit – had him questioning what he was seeing ! Of course, he replicated these tests many times and recorded them and their results before assuring himself that there was no mistake.

With such an unprecedented superior outcome for the circuit design, Mr. Park could not be satisfied placing a DHT stage after one or two stages using indirectly heated triodes. That approach is used in a number of commercially available preamplifiers using DHTs, but it is a compromise. It does not result in PURE DHT amplification . It introduces the characteristics of indirectly heated triode sound into the circuit . The output DHTs are only amplifying a signal already determined by the initial stage indirectly heated triodes. In contrast, Mr. Park has created devices that use DHTs at each amplification stage. In his design, the output stage DHTs do not merely amplify the signal from indirectly heated triode stages. The A – 5000 DHT, L – 5000 DHT , and H – 5000 DHT amplifier, preamplifier and phono – preamplifier are pure DHT , from signal input to output; and now , Allnic has produced the D5000 DHT DAC with a pure DHT analogue output signal path.

“listened to straight out of the box, the Allnic presented its signature strengths: an up-front, present, and tactile sound with exceptional color, impact, and drive. Indeed, the first recording I heard through the D-5000 triggered a true Holy shit moment—one in which it was already apparent that the Allnic was among the very finest-sounding digital products I’ve heard.”
Art Dudley, Stereophile
Sonically the D5000 is a marvel. It has an organic, lifelike character that will, I suspect, be extremely appealing to vinyl or hardcore analogue enthusiasts. “Musically rich with depth, body and harmonic detail, the D5000 has that unique character among great Hi-Fi components where it sounds incredibly revealing while remaining warm and engaging, creating that addictive listening experience we so often strive for.”
David McCallum, My Hifi life