DA24QSDS
The DA24DS is a double-speed version that operates at rates exceeding 96kHz and is smaller and more cost-effective than the DA24QS, making it suitable for integration into devices like CD players. The DA24QS supports a broad range of sample rates, with the S/P-DIF receiver IC (Cirrus CS8416) specified for frequencies from 30kHz to 216kHz; however, the DA24DS can function down to 16kHz, albeit with a notably low signal-to-noise ratio at the audio outputs. Due to its simplified design, the DA24DS does not support quad-speed operation. All connections are located at the rear of the unit. In the absence of a digital audio signal, both DACs produce their own digital "zero" audio signal at a rate of 96kHz. The DA24QS allows the selection of up to four inputs via a rotary switch on the front panel, featuring three onboard digital audio inputs: two optical (Toslink) and one unbalanced, transformer-coupled RCA input. An additional balanced digital audio input with its own transformer is available in the DA24QS-IOP version or can be connected externally. The DA24DS includes two digital audio inputs: one optical (Toslink) and one unbalanced, transformer-coupled RCA input, with automatic input selection. When a signal is detected at the optical input, it is enabled; otherwise, the coaxial input is selected. The DA24QS is prepared for balanced outputs via XLR connectors, delivering output levels of 4.91VRMS at 100% full scale, corresponding to +16dBu, which is 12dB above the standard studio level of +4dBu, providing a headroom of 12dB. Additional balancing output amplifiers are required for these outputs. The power supply for both devices is 12V DC. The DA24QS consumes between 200mA (at low sample rates without audio) and nearly 300mA (at 192kHz with full-scale sine wave signal), resulting in noticeable heat generation. The DA24DS consumes approximately half as much current. The 3.3V regulator (LM317) in the DA24QS can reach temperatures around 60°C (108°F) above ambient, which is considered normal. It is advisable to use regulated power supplies to minimize hum, as unregulated supplies can decrease the dynamic range of the output signal, which is measured at approximately 109dB for the DA24QS and an expected 111dB for the DA24DS. Even using a bare 9V AC supply yields around 105dB. The hardware mode of the Cirrus Logic CS8416 "192 kHz Digital Audio Interface Receiver" is utilized. For the quad-speed DA24QS, a more complex control CPLD is integrated to enhance functionality, allowing the selection of four digital audio inputs via the receiver's multiplexer. This version features two optical input devices (Toslink TORX147PL) and one unbalanced electrical output (0.5 VPP @ 75Ω terminated). Additionally, it can be equipped externally with a professional digital audio input, either balanced (XLR, AES-3, 2 VPP @ 75Ω terminated) or unbalanced (BNC, 1 VPP @ 75Ω terminated). Onboard decoupling transformers and termination resistors are included.
The DA24DS and DA24QS DACs are designed with specific applications in mind, particularly in high-fidelity audio environments. The DA24DS, while more compact and economical, sacrifices some features such as quad-speed operation, making it ideal for simpler applications where high sample rates are still required. The DA24QS, on the other hand, is tailored for more complex audio setups, offering extensive input options and balanced outputs, which are critical for professional audio applications where signal integrity and dynamic range are paramount.
The automatic input selection feature in the DA24DS enhances usability by ensuring that the active input is always prioritized based on signal presence, thus streamlining operation in environments where multiple audio sources may be utilized. The design considerations for power supply and heat management reflect a professional approach to ensuring reliability and performance in demanding situations.
In conclusion, both the DA24DS and DA24QS represent significant advancements in digital-to-analog conversion technology, catering to the needs of audio professionals and enthusiasts alike. Their respective designs highlight the importance of flexibility, performance, and ease of integration into various audio systems, ensuring high-quality sound reproduction across different applications.The DA24DS is a double speed (up to more than 96kHz) version, slightly smaller and cheaper than the DA24QS, particularly intended to be built as a module into e. g. CD players. The DA24QS operates over a wide range of sample rates. The S/P-DIF receiver-IC ( Cirrus CS8416 ) is specified from 30kHz up to 216kHz, but my sample works even with 16kHz fr
om the AD24QS (though, at 16kHz, with a remarkably low SNR at the audio outputs). Due to its simplified circuit diagram the DA24DS does not support the quad speed range. All connections are made on the rear. When no digital audio signal is present, both DACs generate their own digital "zero" audio signal at a rate of 96kHz. DA24QS: Up to 4 inputs are selected with the rotary switch on the front panel. On-board there are 3 digital audio inputs: Input 1 and 2 are optical (Toslink) ones and input 3 is an unbalanced, transformer-coupled RCA input.
A 4th balanced digital audio input with its own digital audio transformer is included in the version DA24QS-IOP or can be connected externally. DA24DS: On-board there are 2 digital audio inputs: Input 1 is an optical (Toslink) and input 2 is an unbalanced, transformer-coupled RCA input.
The inputs are selected automatically: When an input signal at the optical input is detected, this input is enabled, otherwise the coaxial input is selected. For the DA24QS as options, balanced outputs are prepared for XLR-connectors carrying output levels of 4.
91VRMS at 100%FS, which corresponds to +16dBu or 12dB above the standard studio level of +4dBu (i. e, the headroom is 12dB). They need extra balancing output amplifiers to be placed. On the photo you see these amplifiers and the Micro-Match connector for the balanced outputs populated, but the XLR-connectors are not connected. See the DA-IOP or DIY section for details how to connect XLR connectors. The power supply is 12V DC for both devices. The DA24QS`s current consumption is from 200mA (low sample rate, no audio signal) up to almost 300mA (192kHz, full scale sine wave signal), so the DA24QS gets warm.
The DA24DS`s current consumption is approximately half as much. BTW, the DA24QS`s 3. 3V regulator (LM317) gets quite warm, about 60 °C (108 °F) above ambient temperature. Maybe you`d call it even hot, but you can still touch the plastic housing for a couple of seconds. This is normal and far away from being critical. For mechanical reasons I do not recommend to provide an extra heat sink but I recommend to screw the LM317 onto the PCB as intended. I recommend to use regulated power supplies because due to the hum of unregulated ones in spite of the DACs` quite high power supply rejection ratios the remaining hum in the output signal might noticeably decrease their dynamic range (unweighted measurements).
BTW, I measured a dynamic range of approx. 109dB for the DA24QS supplied by a full-wave rectified 9V transformer (i. e. , without buffer capacitor). 111dB can be expected for the DA24DS. Even the use of a bare 9V AC supply (which is possible, too) leaves about 105dB (unweighted!). I use a Cirrus Logic CS8416 "192 kHz Digital Audio Interface Receiver" in hardware mode. For the Quad Speed version DA24QS the CS8416`s hardware mode provides not quite enough functionality, i. e. , signal outputs from control, for my goals. To overcome this, in the DA24QS I introduced a more complex control CPLD. Four digital audio inputs can be selected by the receiver`s input multiplexer. On-board are two optical input devices (Toslink TORX147PL) as well as one unbalanced electrical output (0.
5 VPP @ 75 © terminated) provided. Moreover, the DA24QS can be equipped externally with a professional digital audio input, either balanced (XLR, AES-3, 2 VPP @ 75 © terminated) or unbalanced (BNC, 1 VPP @ 75 © terminated). The decoupling transformer and the termination resistors are provided on board. The optical input device (the obsolete TORX147PL or its replacement PLR 🔗 External reference
The DA24DS and DA24QS DACs are designed with specific applications in mind, particularly in high-fidelity audio environments. The DA24DS, while more compact and economical, sacrifices some features such as quad-speed operation, making it ideal for simpler applications where high sample rates are still required. The DA24QS, on the other hand, is tailored for more complex audio setups, offering extensive input options and balanced outputs, which are critical for professional audio applications where signal integrity and dynamic range are paramount.
The automatic input selection feature in the DA24DS enhances usability by ensuring that the active input is always prioritized based on signal presence, thus streamlining operation in environments where multiple audio sources may be utilized. The design considerations for power supply and heat management reflect a professional approach to ensuring reliability and performance in demanding situations.
In conclusion, both the DA24DS and DA24QS represent significant advancements in digital-to-analog conversion technology, catering to the needs of audio professionals and enthusiasts alike. Their respective designs highlight the importance of flexibility, performance, and ease of integration into various audio systems, ensuring high-quality sound reproduction across different applications.The DA24DS is a double speed (up to more than 96kHz) version, slightly smaller and cheaper than the DA24QS, particularly intended to be built as a module into e. g. CD players. The DA24QS operates over a wide range of sample rates. The S/P-DIF receiver-IC ( Cirrus CS8416 ) is specified from 30kHz up to 216kHz, but my sample works even with 16kHz fr
om the AD24QS (though, at 16kHz, with a remarkably low SNR at the audio outputs). Due to its simplified circuit diagram the DA24DS does not support the quad speed range. All connections are made on the rear. When no digital audio signal is present, both DACs generate their own digital "zero" audio signal at a rate of 96kHz. DA24QS: Up to 4 inputs are selected with the rotary switch on the front panel. On-board there are 3 digital audio inputs: Input 1 and 2 are optical (Toslink) ones and input 3 is an unbalanced, transformer-coupled RCA input.
A 4th balanced digital audio input with its own digital audio transformer is included in the version DA24QS-IOP or can be connected externally. DA24DS: On-board there are 2 digital audio inputs: Input 1 is an optical (Toslink) and input 2 is an unbalanced, transformer-coupled RCA input.
The inputs are selected automatically: When an input signal at the optical input is detected, this input is enabled, otherwise the coaxial input is selected. For the DA24QS as options, balanced outputs are prepared for XLR-connectors carrying output levels of 4.
91VRMS at 100%FS, which corresponds to +16dBu or 12dB above the standard studio level of +4dBu (i. e, the headroom is 12dB). They need extra balancing output amplifiers to be placed. On the photo you see these amplifiers and the Micro-Match connector for the balanced outputs populated, but the XLR-connectors are not connected. See the DA-IOP or DIY section for details how to connect XLR connectors. The power supply is 12V DC for both devices. The DA24QS`s current consumption is from 200mA (low sample rate, no audio signal) up to almost 300mA (192kHz, full scale sine wave signal), so the DA24QS gets warm.
The DA24DS`s current consumption is approximately half as much. BTW, the DA24QS`s 3. 3V regulator (LM317) gets quite warm, about 60 °C (108 °F) above ambient temperature. Maybe you`d call it even hot, but you can still touch the plastic housing for a couple of seconds. This is normal and far away from being critical. For mechanical reasons I do not recommend to provide an extra heat sink but I recommend to screw the LM317 onto the PCB as intended. I recommend to use regulated power supplies because due to the hum of unregulated ones in spite of the DACs` quite high power supply rejection ratios the remaining hum in the output signal might noticeably decrease their dynamic range (unweighted measurements).
BTW, I measured a dynamic range of approx. 109dB for the DA24QS supplied by a full-wave rectified 9V transformer (i. e. , without buffer capacitor). 111dB can be expected for the DA24DS. Even the use of a bare 9V AC supply (which is possible, too) leaves about 105dB (unweighted!). I use a Cirrus Logic CS8416 "192 kHz Digital Audio Interface Receiver" in hardware mode. For the Quad Speed version DA24QS the CS8416`s hardware mode provides not quite enough functionality, i. e. , signal outputs from control, for my goals. To overcome this, in the DA24QS I introduced a more complex control CPLD. Four digital audio inputs can be selected by the receiver`s input multiplexer. On-board are two optical input devices (Toslink TORX147PL) as well as one unbalanced electrical output (0.
5 VPP @ 75 © terminated) provided. Moreover, the DA24QS can be equipped externally with a professional digital audio input, either balanced (XLR, AES-3, 2 VPP @ 75 © terminated) or unbalanced (BNC, 1 VPP @ 75 © terminated). The decoupling transformer and the termination resistors are provided on board. The optical input device (the obsolete TORX147PL or its replacement PLR 🔗 External reference