TEAC has added three new Hi-Res Audio-focussed components to its separates-based Reference mini component system: The UD-505 USB DAC/Headphone Amplifier, the NT-505 USB DAC/Network Player and CG-10M Master Clock Generator.

TEAC UD-505

With a lineage going back to 2014, the UD-505 is the third and latest incarnation of a the popular USB/DAC Headphone Amplifier (replacing the UD-503), now updated with the latest Hi-Res technology available.

Key features

• Hi-Res Audio playback supporting DSD512 (22.6MHz) and PCM 768kHz/32-bit PCM
• Dual monaural circuit design with a high-end AKM VERITA AK4497 DAC on each channel
• 5 types of PCM digital filters and 2 types of DSD digital filters
• Up-conversion up to 24.5MHz DSD and 384kHz/32-bit PCM
• Dual on-board clocks for 44.1kHz and 48kHz frequencies, and 10MHz external clock input
• Bluetooth receiver supporting LDAC and Qualcomm aptX HD
• TEAC-HCLD output buffer circuit and TEAC-QVCS volume control for high quality sound
• 4.4mm 5-polar Pentaconn jack and dual 1/4in TRS jacks for balanced and active-ground drives
• TEAC's patent-registered 'Pin-Point' feet
• 'Bulk Pet' USB transfer technology, with four transfer modes to vary sound character
• Free TEAC HR Audio Player for DSD512 and PCM32/768 playback

A dual-mono design (with twin transformers), the UD-505 employs a pair of the latest 3rd generation VERITA AK4497 DAC chips (one on each of its two channels). Offering a signal-to-noise ratio of 116db (compared to the 112db of the outgoing UD-503 model), these latest Pro-grade DACs support all common audio formats, up to and including DSD512 (22.5MHz - the UD-503 supported 11.2MHz) and 768kHz/32-bit PCM (up from the UD-50's 384kHz/32-bit support).

The analogue audio signals for both the left and right channels are processed in full balanced mode immediately after the D/A converters all the way to the output terminals, contributing to an improved signal-to-noise ratio and extended dynamic range.

It's also possible to enhance lower resolution, legacy music. Thanks to RDOT-NEO (Refined Digital Output Technology NEO), a fluency algorithm that renders digital audio signals smoothly, the UD-505 up-converts PCM digital signals up to 384kHz/32-bit PCM and 24.5MHz DSD (UD-503 offered DSD up-conversion to 12.2MHz). Teac claims that one you activate it, you will hear an improvement in quality, even with music that you are familiar with.

DSD music fans will also appreciate the newly developed Digital filters. Where the UD-503 offered just a pair of simple 50/150kHz cut-off filters for ALL DSD content the UD-505 offers narrow/wide filters (eight in total) that operate at different frequencies, according to the specific type of DSD content being handled (2.8/5.6/11.2/22.5MHz).

As with all digital-based audio components, providing an accurate on-board clock is vital, especially if the source is the USB output from an (electrically) noisy computer. The UD-505 actually has two clocks - for 44.1kHz and 48kHz sampling frequencies (and multiples of those frequencies) - and applies the appropriate one to incoming digital signals, generating it from a high-precision, low phase-noise, audio-grade crystal oscillator.

If users want the very ultimate in clock accuracy the UD-505 also sports a 10MHz External Clock input, designed to allow the connection of the optional new CG-10M Master Clock Generator (see later).

Those who listen to most of their Hi-Res music via USB from a PC will also appreciate a new facility called 'Bulk Pet'. Normally, when transferring large volumes of digital data for Hi-Res Audio sources through USB cables, variations can occur in the processing loads of the sending computer and the receiving USB DAC. These can occasionally cause sound to drop out entirely.

Bulk Pet addresses the issue by constantly transmitting a fixed amount of data and so levelling out the overall quantity of data transmitted and so reducing the load on both the source and the UD-505. Which means less likelihood of drop-outs.

As you'd expect from this class of device, headphone users are very well catered for. New for this model, as well as the expected standard, balanced and unbalanced modes, the UD-505 incorporates an additional new mode called Active-ground Drive. This lowers the ground level to 0v, lowering the noise floor and so enhancing the reproduction of subtle musical detail.

Headphone enthusiasts will also be both pleased and intrigued to see the inclusion of a Pentaconn socket. This is a 4.4mm, 5-pole jack design that allows a single-jack solution for balanced headphones. It's a newly developed connection type, so there are relatively few headphones and cables using it at the moment, but more are expected to adopt in the near future, UD-505 owners will be ready to take advantage of them.

Last but not least, the UD-505 features a trio of TEAC's patent-registered 'Pin-Point' feet. Comprising two separated metal sections in an integrated housing, these vibration-resistant feet endow the unit with excellent stability, even on uneven surfaces.

TEAC NT-505

The 2018 follow-up to the NT-503 USB DAC/Network Player offers improvements in every key area of performance (it uses the same uprated digital processing engine as the new UD-505) while it adds new streaming-related functionality, notably MQA (Master Quality Authenticated) decoding as well as support for TIDAL and Qobuz music subscription services.

Key features

• Hi-Res Audio playback supporting DSD512 (22.6MHz) and PCM 768kHz/32-bit PCM
• Dual monaural circuit design with a high-end AKM VERITA AK4497 DAC on each channel
• Supports MQA decoding, music subscription services (TIDAL and Qobuz) and is Roon-ready
• DSD128 (5.6MHz) and PCM 192kHz/24-bit Network streaming from NAS/PC
• 5 types of PCM digital filters and 2 types of DSD digital filters
• Up-conversion up to 24.5MHz DSD and 384kHz/32-bit PCM
• Dual on-board clocks for 44.1kHz and 48kHz frequencies, and 10MHz external clock input
• Bluetooth receiver supporting LDAC and Qualcomm aptX HD
• TEAC-HCLD output buffer circuit and TEAC-QVCS volume control for high quality sound
• 'Bulk Pet' USB transfer technology, with four transfer modes to vary sound character
• Free TEAC HR Audio Player and TEAC HR Streamer app

Another fully dual-mono device, the NT-505 offers the same processing performance as its UD-505 counterpart (using identical AKM VERITA DACs) but in a package where the focus is tilted towards network audio, delivered from PC or NAS (Network Attached Server) and controlled via free TEAC apps for iOS and Android smartphones and tablets.

As well as listening to their downloaded MQA content, the NT-505 also now supports the TIDAL Hi-Res music streaming service (which now offers MQA content). For those more interested in Hi-Res FLAC streaming there's also full support for the Qobuz streaming service (offering 40 million titles, in up to 24-bit/192kHz quality).

The NT-505 is also Roon-ready. Roon is a music management and listening application that neatly integrates and presents music files, Internet radio streams and TIDAL content while delivering bit-perfect playback of most Hi-Res Audio file formats.

The focus on Hi-Res Audio compatibility also extends to the unit's wireless functionality. The outgoing NT-503 supported aptX Bluetooth - the NT-505 now boasts for the superior aptX HD standard, offering support for 24-bit/48kHz content streamed from mobile devices, as well as LDAC (24-bit/96kHz) transmission. Those that prefer a more physical option meanwhile, can elect to play back Hi-res Audio content (up to DSD128 and 24-bit/192kHz PCM) stored on USB flash drives.

Headphone users have not been forgotten. The same TEAC-HCLD (High Current Line Driver) buffer amp circuits used in the UD-505 (designed to enhance current supply) are employed here to drive the (one) single-ended headphone output. A Ground-separate headphone drive mode guarantees excellent channel separation.

With a host of TEAC HR (Hi-Res) Streaming apps provided free of charge (Windows/Mac/iOS/Android) the NT-505 lets you control your music streaming activity with ease and versatility.

TEAC CG-10M

Designed in collaboration with engineers from Esoteric, the CG-10M is a Master Clock Generator designed to deliver an incredibly accurate clock signal simultaneously to up to four components that support a 10MHz clock input.

Key features

• High-precision TEAC Reference OCXO - an 'oven-controlled' crystal oscillator
• ±3 ppb frequency temperature characteristics, ±0.1 ppm frequency precision
• 4 x 10MHz clock output connectors (gold-plated BNCs)
• Completely independent and isolated circuit
• High capacity toroidal-core power transformer
• OVEN STATUS gauge with dimmable backlight for monitoring oscillation stability
• 3 Patent-registered 'Pin-Point' feet to minimise vibrations
  Full-metal body to eliminate incoming electromagnetic noise
• Compatible with TEAC UD-503 and NT-503

Generating an accurate clock signal - which can then be used as a timing reference by Digital-to Analogue converters and other components - is an absolute essential if you want to create musically authentic content.

Most mass-market DACs, CD players, Network Players etc have reasonable digital clocks built into them. They can usually be bettered but at a significant cost, one that's rarely justified on cost/performance grounds. A handful of high-end audio brands - TEAC's sister company Esoteric is one - offer standalone Master Clock Generators, as they are known, but they are rarely, if ever, encountered in more mainstream hi-fi ranges.

Equipped with a 10MHz clock (or crystal oscillator, as it's more properly known), TEAC has gone to extraordinary lengths to maintain the CG-10M's fundamental accuracy.

As well as being equipped with a high-capacity transformer (to ensure stable current delivery), the CG-10M's crystal oscillator in encased in its own temperature-controlled 'oven' because temperature fluctuations adversely affect clock accuracy. A backlit 'Oven Status Gauge' located on the front panel lets the user know exactly when the CG-10M is operating at its optimum temperature.

Every individual part of the circuit within the CS-10M has been completely electrically isolated and equipped with buffer amps (one for each of the 4 x 50 Ohm BNC outputs) in order to prevent any possibility of cross interference when multiple devices are connected to it.