SPL Diamond Premium DAC and preamplifier, black

SPL Diamond

Premium DAC with VOLTAiR technology.

Diamond is the perfect DAC and preamplifier for everyone who plays music exclusively from digital sources. Diamond offers connectivity for six digital sources and an external word clock. The superior VOLTAiR technology and the premium DAC with the unequaled DLP120 combined with an analog volume control allowing for highest resolution at any volume makes the Diamond an one-of-a-kind DA converter that delivers finest soundstages with an unrivaled analog feel.

Everything under control

The volume is adjusted with a solid, milled aluminum, rotary knob. The Alps RK27 “Big Blue” potentiometer gives a pleasant “spoon in the honey” rotary feel.

Source of joy

Up to 6 (!) digital stereo sources can be connected to Diamond.

Diamond offers each a stereo USB and AES input as well as each two optical and coaxial stereo inputs. Via USB, both PCM audio and DSD audio can be converted. PCM audio is received in S/PDIF format, both coaxial (RCA), optical (Toslink F06) and balanced (AES/EBU).

The source selection is done via the selection control on the front. The selected input is also shown in the dot matrix LED display: USB, COA1, COA2, OPT1, OPT2 or AES.

After approximately two seconds, the display shows the type of clock source and the detected sampling rate.

Always in time

Diamond can not only synchronize to the clock integrated in the digitally fed source signal. As a specialist for digital players Diamond offers a word clock input. The source of the clock signal can be selected via the CLOCK switch..

Source = Diamond synchronizes to the digital clock in the source signal.
Word = Diamond synchronizes to the digital clock present at WORD IN.

Well informed

The DAC automatically picks up the sampling rate and resolution of the digital playback source. No matter if a streamer, computer, CD player or an external word clock is connected.

The detected sampling rate and the selected clock source are shown in the dot matrix LED display. For example, U768 is an acronym for a clock signal in the USB stream with a
sampling rate of 768 kHz.

All variable – or Slave Thru

Diamond provides two stereo output pairs for connecting power amplifiers or active loudspeakers. One pair of outputs with XLR, the other with RCA outputs. Both have the same output signal, which is controlled by the volume control on the front panel.

The volume control for the RCA outputs can be switched out of the signal path via DIP switch on the back of the device. For example, a headphone amplifier with its own volume control can be connected to one of the outputs.

Converter

The highly acclaimed AKM AK4490 Velvet Sound™ premium DAC chip is used as the converter chip in the digital-to-analogue converter, which thanks to its architecture reproduces the finest sound details.

It converts PCM audio with a resolution of 32 bits and a sampling rate of up to 768 kHz, which is equivalent to 16 times CD resolution. Direct Stream Digital is also supported up to a resolution of DSD4 or DSD256. In contrast to the DAC 768xs, the DAC768 not only offers an AES/EBU digital input, but also the SPL DLP120 with VOLTAiR technology.

DLP120 (Dual Low-Pass filter)

The analog output of the DAC chip must be filtered by a low pass filter. Phonitor xe has two of them: One for PCM audio and one for DSD audio, since different roll-off frequencies are required.

In contrast to all other DACs in the world, the low pass filters here are built using VOLTAiR technology, which provides a plus in dynamics and headroom and sound.

Sounds good

With all devices of the Professional Fidelity series we develop not only according to plan, but also by ear. Many important components are installed on the circuit boards using Through-hole technology. This way we can ensure that we can use the best sounding components.

The VOLTAiR Technology

VOLTAiR stands for the 120V power supply technology used in SPL's Professional Fidelity range. Audio signal processing takes place in circuits with an incomparably higher symmetrical working DC voltage of +/- 60 V than usual. This is twice that used by discrete op amps of common design and even four times that of conventional solid state op amps.

VOLTAiR technology achieves excellent technical and sound parameters. Technically, especially in terms of dynamic range, dynamic reserve, reproduction of the finest details and overall, with regard to a relaxed sound experience, the music sounds completely natural.

Comparison

The following graphs show a comparison of VOLTAiR technology with other circuit designs. A direct relationship between the operating level and the maximum voltage level is essential for evaluation: the higher the operating level, the higher the maximum level the circuit can handle. And since virtually all essential acoustic and sound parameters depend on this relationship, higher operating voltage also has a positive impact on dynamic range, distortion limit and signal-to-noise ratio.

Note that the dB range does not represent linear but rather exponential increases. An increase of 3 dB corresponds to a doubling of the acoustic power, +6 dB corresponds to a doubling of the sound pressure level, and +10 dB corresponds to a doubling of the physically perceived loudness. When it comes to performance, VOLTAiR technology is so powerful that it exhibits double the maximum level and dynamic range of conventional components and circuits, as these values are approximately 10 dB higher. In addition, the THD measurement shows a difference of more than 8 dB compared to the TL071 IC at 30 V, which corresponds to an improvement of more than 130%. At the same time, the most common level of operating voltage used in audio components is only +/- 15 volts.

The word VOLTAiRE is composed of Volt and Air. Volt is a unit of electrical voltage and Air means transferred air, or an unlimited space in which music can breathe freely.