TEAC UD-701N USB DAC and Network Player

We have incorporated an extravagant dual mono structure throughout the unit, from the power circuit with independent left and right toroidal core transformers to the D/A converter section and analog output stage. This dual model structure, which has complete mono circuits for each of the two channels, prevents interference between the left and right channels, enabling the realization of rich musical expression that reproduces the sense of space and dimension.

The fully balanced transmission of both the left and right analog output signals from after D/A conversion through the final output stage contributes greatly to improving the signal-to-noise ratio and increasing the dynamic range. This conveys signals in a purer state without losing the sense of air that high-resolution audio sources have.
*The circuit boards in this photos are under development.

Not only as a USB DAC/Network player that employs two sets of coaxial and optiocal digitla inputs, the UD-701N also works as a high-quality analog preamplifier by employing additional analog audio inputs via RCA and XLR connectors that allow users to connect conventional audio sources.

Our TEAC-QVCS (Quad Volume Control System) is a variable gain amp volume control with four independent circuits for left, right, positive and negative (L+, L−, R+ and R−). Placing this in the audio signal route makes it as short as possible, preventing the degradation of audio signals caused by drawing them through signal lines. Moreover, since the volume can be adjusted in extremely fine 0.5dB intervals, you can achieve the ideal volume for the audio system or headphones that you are using.

A total of four diamond buffers, one in each of the left, right, positive and negative circuits, are used in the dedicated headphone amplifier, enabling the connection of balanced drive headphones. Moreover, even during single-end use, by driving these amps in parallel, they can provide stronger drive than ordinary single-end headphone amplifiers. This enables the potential of many types of headphones, including 600Ω high-impedance headphones, to be realized.

Active ground is a drive method, based on the principles of a balance connection, that approaches 0 V by connecting the COLD connector to the ground and driving the ground forcibly using an amplifier circuit. Not only can a more ideal ground be realized than when using an ordinary ground, the impact of humming noise coming from the power can also be suppressed. Moreover, by lowering the noise floor, we can expect silence to be deepened, allowing the breathing of the artists and the texture of sounds to be felt more intimately.

MQA (Master Quality Authenticated) is a high-quality audio codec that enables playback at the same quality level as studio masters. The UD-701N has an MQA decoder that controls D/A-converted waveforms with a precision as fine as 5 ms in order to achieve analog waveforms that are true to the original recordings. Playback sound that seems like the original to the human ear can be achieved by greatly reducing the “sound blurring” that occurs easily when sounds start suddenly and at other times when sound pressure differences are extreme.

Since a full decoder is included, in addition to file and network playback, MQA data from digital inputs can also be decoded. Playback of MQA CDs is possible by connecting the digital output of a CD player to the UD-701N.
* When you MQA decode a signal from a digital input, the signal must be received bit-perfect. For this reason, please use the CLOCK SYNC setting as "OFF" or "ON (DIN SYNC)". Also, if the CD player is set to ON (DIN SYNC) without clock synchronization, skipping or choppy sound may occur.

Common control apps that support OpenHome can be used with the UD-701N, which also supports this platform. Moreover, playlists on the UD-701N can be managed using TEAC HR Streamer and other control apps that support OpenHome. Gapless playback is also supported. With support for Roon Ready, functions provided by RAAT (Roon Advanced Audio Transport), including high-quality audio playback, easy and convenient operation using apps, and multi-room synchronized playback, can be used without limits.

When transmitting large amounts of digital data by USB cable from high-resolution audio sources, large inconsistencies arise in the processing loads of both the sending computer and the receiving USB DAC, and audio dropouts and other problems can occur. Using the Bulk Pet USB transfer technology, however, the same amount of data is transmitted at a steady rate, leveling the processing loads of both sides and realizing stable data transmission. Since changes in computer load conditions can also affect audio quality, you can select from four preset transmission modes to choose the preferred audio quality.

A floating structure is utilized to keep transformers, which can easily cause vibrations, isolated from the bottom panel. The lengths of all the side fins, which are for heat dispersion, have also been adjusted to prevent sympathetic vibrations.

In addition to using the minimum number of circuit board attachment screws, TEAC original pinpoint feet that utilize a new mechanism to provide play where they contact the bottom panel are used to thoroughly suppress vibrations that affect audio quality.

TEAC HR Audio Player, which supports 22.5MHz DSD playback with both Windows and Mac, provided for free