ESI Audiotrak Dr.Dac Prime vs Arcam rDAC - DAC from the music department vs DAC from the Hi-Fi department

Dr. DAC prime is an external sound card for audiophiles, based on a top-end PCM1796 DAC with the ability to replace the op-amp without soldering. Using a high-quality SRC converter, the SRC4382 Prime can convert an audio stream to 192 kHz. In addition, the device can work as an external DAC without a computer or as an external DAC for a semi-professional sound card with ASIO.

Appearance of ESI/Audiotrak Dr. DAC prime

Evolution of Dr. DAC

Initially, ESI products were aimed at the professional market, and Audiotrak at the home market, for ordinary users. The main hit was the Audiotrak Prodigy 7.1 card, as opposed to the Creative Audigy 2 due to honest 44.1 without oversampling. The second hit was the Prodigy HD2 on the top-end AK4396 and the ability to change op-amps without soldering. As an evolutionary development, Dr. appeared. DAC, the first version also used a top-end DAC from AKM, replaceable op-amps and an additional battery. However, the relatively large dimensions did not bring success, and a second version was released - Dr. DAC 2 on PCM1798 with external power supply. Even though Dr. DAC 2 is not available on our market and is in short supply, but this DAC is still quite well known to everyone. ESI and Audiotrak operate in different countries and have different product lines for each country. At times it is a union of two companies, and at other times Audiotrak and ESI have nothing in common and position themselves as completely unrelated companies. One way or another, the ESI product range is more accessible in our market and the new DAC Dr. DAC prime is available in our market.

Appearance of Infrasonic S. DAC 5

We won’t mention the fact that Infrasonic is also somewhere next to ESI/Audiotrak. Formally, Dr. DAC prime is the third version. We can guess which version will be the fifth - this is the Infrasonic S.DAC 5 on PCM 1792, but so far things have not gone further than the announcement of this DAC for $700. We will wait until the “fourth” DAC comes out, and the “fifth” becomes cheaper :).

Appearance of JAVS DAC-1 OVERTURE (bottom) and JAVS UDT Transporter (top)

In general, looking at the appearance of sometimes identical products under different brands, it becomes obvious that some products are initially ordered and made by a third-party company. According to the description, JAVS DAC-1 OVERTURE is no different from Dr. DAC prime, just a slightly different case profile. Not supplied to our market. JAVS products appear a little earlier than ESI/Audiotrak and may be some kind of demo products for testing :). It is quite possible that we will see analogues of the new products JAVS UDT Tranceporter (digital signal switch) and DAC-2 March, which differs from the Prime PCM1792 DAC with an HDMI/I2S input and without a USB input. Perhaps the DAC-2 March will be the “fourth” model :).

What's new in Dr. DAC prime? Firstly, this external DAC is based on another top-end PCM1796, with also replaceable op-amps. The price is higher, and this is a price for increased functionality. An AK5386 ADC with recording capability was added, an SPDIF output was added, and an upsampling mode of 192 kHz was added. Small functions have been added, such as turning off the signal from the linear outputs, as well as the ability to separately adjust the signal level for headphones while maintaining a constant level for the linear output. The dimensions have increased slightly.

Appearance Dr. DAC prime

Frontal view of ESI/Audiotrak Dr. DAC prime

On the front panel there are toggle switches for turning on the device, disabling the linear output mode, activating the upsample mode and a three-position source selection switch (analog, USB, digital). On the right side there is a volume control and two headphone outputs of different sizes, 6.5 and 3.5 mm.

Rear view ESI/Audiotrak Dr. DAC prime

On the rear side there is a linear stereo output, a linear stereo input, and combined (coaxial + optical) digital output and input. USB input, power connector and volume mode switch.

ESI Audiotrak Dr.Dac Prime vs Arcam rDAC - DAC from the music department vs DAC from the Hi-Fi department

Back in the Soviet school, during my youth, when one of my classmates needed to buy an amplifier with speakers, we went in a crowd to the Electron store in Murmansk and conducted, in modern terms, marketing research. The results were often puzzling - some “Radiotechnica” amplifier and 30-watt speakers of the same name from the “Hi-Fi department” cost a total of one and a half times more than similar devices (an amplifier of the same first class, speakers of the same power - only worse) than in the “Musical Instruments” department.

More experienced high school students advised us in the school smoking room: “You see, they may sound similar. But there are more music lovers than musicians—just look at our school. Therefore, prices for musical equipment are lower.” In fact, there was only one group at school - on stage, however, no one had ever seen it, but the participants vividly described the rehearsals and even gave us something to listen to from their work - there were music lovers, every single one.

After such explanations, in order to meet the budget allocated by the parents, sometimes devices were purchased from the “music department”, and the issue was closed.

Today, remembering that distant time, we will also try to compare two devices for different purposes - one made for small “project” studios, and the second created by a famous Hi-Fi manufacturer. Moreover, both are made on chips from well-known Hi-Fi and Wolfson Microelectronics in the world, which is not surprising, since digital-to-analog converter chips are produced by only a few companies in the world.

ESI Audiotrak Dr.Dac Prime RUB 15,850

The device is housed in a metal case of an original shape - the sides are rounded, as if emphasizing its “non-hi-fi” origin. There are rubber feet on the bottom, the back and front surfaces are flat, not counting the protruding toggle switches, volume control, and rear connectors. The design seems to emphasize that the device was created for work, and not for decorating a room.

The device was created for home studios, fans of home computer work with sound and has rich functionality. There is an S/PDIF input and output (a coaxial digital jack is combined with an optical one, which requires an optical cable with a special connector), a USB port, an analog input and an RCA output.

The presence of an analog input and digital output in the DAC was somewhat surprising, since their use remained unclear - either they are intended to organize an end-to-end path, or the functionality of the device can be significantly expanded.

On the front panel of the device there is an abundance of switches, regulators and indicators. There are two headphone outputs (1/4" (6.3 mm) jack and 1/8" (3.5 mm) minijack), output volume control (and on the rear panel there is an adjustable or fixed output level switch), switch through signal bypass, source switch. It is possible to temporarily disable the mute signal, and finally, there is even a unique upsample function that allows you to recalculate the sampling frequency up to 192 kHz.

Of course, the device is not professional equipment, because unlike an analog-to-digital converter, which is the most important component of a recording studio, a digital-to-analog converter in its pure form is practically not needed in a studio; combined ADC/DAC devices are usually used there, but Dr.Dac Prime makes no claims to this.

Arcam rDAc RUB 19,990

The device is made in an aluminum case with rounded corners, the base is rubberized, preventing slipping on the surface. On the top panel there is a button that switches inputs, and the indicator corresponding to the active input lights up green. There is also a power button on the back panel; the device has no other switches or adjustments. There, on the rear panel, there are three digital inputs: S/PDIF, optical Toslink and USB, and an unbalanced analog output. The device is designed for power supply with a voltage of 6 V and a current of 600 mA; an external power adapter is included in the kit; the connection socket is also located on the back.

The device is implemented on a Wolfson Microelectronics chip, WM8741. Let us remember that this chip began to be produced by the company back in October 2007 and was the flagship chip for more than a year - the WM8742 was released in January 2009.

However, the Burr Brown PCM1796, the competitor in our test, is also quite familiar to technology enthusiasts - it can be found in digital-to-analog converters several times more expensive than those tested.

But let's return to Arcam rDac. As can be seen from the interface, a digital signal can also be supplied via USB - in this case, asynchronous technology is used, patented by Data Conversion Systems, designed to reduce digital signal transmission errors.

By the way, on the basis of this device, Arcam produces a more expensive model (four thousand more expensive in Russia) - Arcam rDac Wireless, capable of receiving a signal via Wi-Fi. In all other respects the models are identical. In our simpler version, in the place where the Wi-Fi antenna should be located, the DAC has a hole on the back wall covered with a plug. The LED on the far right under the word “Wireless” will also, of course, not light up.

LISTENING.

Hearing testing of digital devices, in particular converters, is a very difficult matter. Unlike aural comparisons of electroacoustic transducers, such as loudspeakers, the difference in the sound of electronic devices is minimal and elusive. If the difference is noticeable and tangible, this means only one thing - the devices clearly belong to different quality classes and it is incorrect to compare them. In other words, for good technique there should be almost no difference.

So does it make sense to compare electronics by ear? It is clear that purely laboratory measurements of the electronic path using measuring equipment can and should be carried out, and they will show real differences, but what about listening? I think that, despite the subtle difference, it’s still worth listening to. Because even a minimal difference can appear in some circumstances, for example, when using specific devices in powerful sound reinforcement systems, when this minimal difference increases many times, as if under a magnifying glass, and becomes noticeable.

The devices presented for testing belong to the same class in terms of circuit design, components used and price category, so the difference in their sound should be minimal.

When listening, we used our editorial CD player Denon DCD-2000AE, using it as transport - the digital signal was recorded via coaxial. By the way, I liked the sound of his onboard DAC more than the sound of the guests. Both devices have good scene and detail, but the tonal balance is shifted towards the mid-range. This was especially noticeable after switching the amplifier selector from the input to which the Denon was connected to the input of one of the DACs.

On a variety of material (from experimental “live” jazz to Edvard Grieg’s “Peer Gynt”), we listened to both devices for several hours, trying to grasp

the elusive difference in sound - this was the main purpose of listening, - after all, the devices initially have different purposes.

As a result, oddly enough, the sound of both instruments was practically indistinguishable, the difference bordering on subjective error.

RESULTS.

Does this mean that the converters are equivalent and interchangeable? But this is unlikely, because you also need to take into account the functionality, and they are significantly different for both devices.

Of course, many of these features are redundant for simple home listening, but for an active audiophile who is interested in experimenting with sound, trying different connection options, using a device with several signal sources and sound reinforcement systems, such a device will be more interesting than a simple DAC without any adjustment options .

In addition, the ability to adjust the signal level allows you to use ESI Dr.Dac Prime as a pre-amplifier combined with a DAC; a headphone output would also be useful. From all this it follows that the functionally sophisticated DAC Dr.Dac Prime has great promise.

In terms of sound quality, it is not inferior to the simpler Arcam rDAc, although, however, it is not superior. Its versatility - by the way, at a lower price - is achieved without sacrificing sound.

Of course, Arcam rDAc finds its buyer - in the world of hi-fi lovers, the Arcam brand is much better known than ESI - as we used to say at school: “there are more music lovers than musicians.” But our little research clearly shows that, in the language of my youth, “the goods in the music department can be just as good.” And the question is closed.

Based on materials from the publication Consumer Author Anatoly Veytsenfeld, Igor Maksimov.

Equipment Dr. DAC prime

Equipment ESI/Audiotrak Dr. DAC prime

In the box except for Dr. The DAC prime contains a power supply, a USB cable, two adapters for optical cables from the combined digital connectors, a hex key and a spare bolt for the volume knob, adhesive transparent rubber feet and a manual. With this package you don’t need to buy anything additional.

Components and technologies used in Dr. DAC prime

Tenor TE7022L controller

Communication with USB is implemented through the Tenor TE7022L controller.

Specifications Tenor TE7022L:

• high speed (12MHz) USB audio streaming controller
• Full USB 2.0 & USB Audio Class 1.0 support
• Resolution up to 24 bits and reference frequency up to 96 kHz
• Support S/PDIF TX and RX, AES/EBU

PCM1796 (right) and LME49860NA

A top-class PCM1796 converter is used as a DAC. The same DAC is used in ASUS Xonar D2. A full differential circuit with three LME49860NA op-amps is used. Op-amp distortion does not exceed 0.00003%.

PCM1796 specifications:

• THD+Noise: -106 dB (0.0005%)
• Dynamic run-up, S/N: 123 dB
• Stopband Attenuation: -98 dB

ADC AK5386 and op-amp 4550

The AK5386 delta-sigma ADC is designed for DVD recorders and musical instruments. Before the ADC in the circuit, an op-amp is used in the 4580 crib. When using a non-top class ADC, the advantage of being able to replace the op-amp is small, but this option is attractive.

Specifications of AK5386:

• THD+Noise: -96 dB (0.0015%)
• Dynamic Range, Signal to Noise: 110 dB
• Stopband Attenuation: -80 dB

SRC4382

The SRC4382 is used for upsampling. The converter is considered one of the best in its class.

Specifications of SRC4382:

• THD+Noise: -125 dB (0.000056%)
• Dynamic range, 128dB

As an illustration from the manual, you can look at the spectrum of the signal after conversion from 44.1 kHz to 192 kHz. As you can see, there is no distortion above the noise level.

TPA6120A2

The headphone amplifier used is a TPA6120A2 from Texas Instruments. The same amplifier is used in ASUS Xonar ST/STX.

Specifications TPA6120A2:

• 80 mW into 600 ohms with ±12 V supply at 0.00014% THD + Noise
• The minimum permissible load impedance is 8 ohms, the minimum recommended is 16 ohms.

Dr. The DAC prime consists of two boards internally.

Circuitry - general information

Dr.Dac 2 and Dr.Dac 2 Muses use the same PCM1798 DAC.

Main characteristics of PCM1798:

• Supports sampling formats up to 192 kHz
• THD+Noise: 0.0005%
• Dynamic Range, Signal to Noise: 123 dB

The new version of Dr.Dac 3 uses an older version of PCM1794.

The new version of Dr.Dac 2 DX Muses, as the name suggests, uses the new Muses series op amps, specifically designed for audio use. However, there are four op-amps in the line and this version of Dr.Dac 2 DX Muses comes with the junior model 8820. The cost of the junior model is comparable to other popular op-amps and not everyone agrees that Muses are the best solution; rather, it is an alternative competitive solution. The older versions of the Muses 1/2 op amp cost about $50, and five of these op amps are comparable in cost to the Audiotrak Dr.Dac 2 DX Muses itself. Thus, formally, the potential of the device has not been greatly increased from the basic version, and if in the future it is interesting to get the most out of Dr.Dac 2 DX Muses, then purchasing other op-amps cannot be avoided.

The headphone amplifier path contains not only a replaceable op-amp, but also a transistor buffer. In this way, it is possible to achieve high output power with a wider choice of op amps to suit taste preferences. In the new version of Dr.Dac 3, the amplifier part has been radically changed in favor of a separate TPA6120A2 microcircuit and, in fact, Dr.Dac 3 overlaps very closely with ASUS Essence STU.

Tenor TE7022L is responsible for communication with USB, thanks to which Dr.Dac 2 DX Muses can receive an audio stream of up to 24 bits, 96 kHz. Today this is not the highest figure, and the next version of Dr.Dac 3 already supports up to 192 kHz via USB, despite the fact that support for 384 kHz would be more relevant for leading positions. However, here the Audiotrak product line is hostage to the use of selected DACs from Burr-Brown PCM1798/1794. Dr.Dac 3 uses a more advanced PCM 1794 with a better signal-to-noise ratio and is technically compatible with PCM1798 (which saves the manufacturer from redesigning part of the device). The signal-to-noise parameter is still a strong argument among marketers, but using PCM1795 with support for 384 kHz does not provide such signal-to-noise. At the moment, PCM1792/1794 have not yet been updated to “PCM1791” with support for 32 bits and higher frequencies, and those manufacturers who are not satisfied with the choice between record signal/noise and the highest supported frequency are switching to DACs from ESS. However, the advantage of the PCM1794 is not only in the signal-to-noise parameter, but in the fact that older converters have higher potential in overall sound quality. Another question is how far this potential has been revealed?

The modes are controlled via toggle switches, which is very convenient.

The playback frequency indication and deeply recessed LEDs in the holes, which do not shine light into the eye, like Dr.Dac prime or ASUS Essence One, deserve special praise.

The device is very compact, the power supply is used externally, those who are itching can replace it with something “better”.

There are two headphone outputs, the coefficients differ. amplification, so it is advisable to use low-impedance headphone models through the first output, and high-impedance ones through the second.

When connecting to a computer, no drivers are needed, everything is determined automatically. For playback, the main recommendation is to use a player that supports audio output via Wasapi for modern Windows operating systems.

The sound quality of the new version is barely different from the old version, the difference with the Audiolab M-DAC or Antelope Zodiac 192 is more pronounced. Usually, owners of expensive DACs speak condescendingly or with hostility about both Dr.DAc2 and any other DACs under $1000. However, at the same time, they forget the laws of pricing and the bar after which the price rises significantly with a negligible increase in quality. Compared to more expensive devices, Dr.Dac 2 DX Muses is slightly inferior in terms of slightly less free sound or audibility of small details when connected to a path costing more than $5000. Typically, those who can afford a DAC for only $300 usually have a much simpler audio system and, accordingly, the quality of expensive DACs is often excessive.

When used as a combiner, the Dr.Dac 2 DX Muses shows its strong side as a good headphone amplifier. Compared to the ASUS Essence STU, the Dr.Dac 2 DX Muses provides more intelligible sound from the headphone output. If we compare Dr.Dac 2 with separate premium headphone amplifiers (typically from $1000, for example SPL Auditor), then Dr.Dac 2 will seem harsher and without a clear attack in small details. Those. Dr.Dac 2 is not the ultimate Hi-End level with high technical performance, but it is one of the best solutions in its price category.

Ease of use Dr. DAC prime

Dr. DAC prime does not require special drivers and is installed automatically. It is very comfortable. In the system, the device is designated as “Dr. DAC prime”, which is clear and understandable, unlike various other USB DACs with the faceless name “USB audio DAC”. By default, after installation the volume is set to 50%.

I would like to note the convenience of switching between the adjustable volume output of the linear outputs and the fixed maximum volume. The headphone output always works.

Compared to Dr. DAC 2 is slightly less comfortable with the volume knob on the left when headphones with a large jack are plugged in. In all other respects, the convenience is at a similar level. Different formats of jack connectors with 6.5 and 3.5 mm are very convenient and eliminate the need to use adapters.

The display is quite clear, the only thing is that in MUTE mode the choice of PCM/UPSAMPLE modes is not displayed.

In STANDBY mode, the device is not visible to the system, so it is not recommended to disable prime during playback.

Technical measurements

The results are generally the same with microscopic differences. Technically, we can say that in terms of distortion levels, almost everything that was possible was squeezed out of the DAC. The only question that remains is to further increase the signal/noise parameter.

In the regular version of Dr.Dac 2, when operating from USB, one could observe a slightly lower level of jitter, expressed in a rise in the noise floor. In the standard sine test with a frequency four times lower than the sampling frequency, there is not much difference.

Dr.Dac 2 DX Muses via USB is more susceptible to jitter, however, without a psychoacoustic model, judging by the audibility of jitter, one can only talk about the technical implementation. Those who are eager to do modding should pay attention to this. Those who want to get the most out of Dr.Dac 2 DX Muses by using a separate USB-SPDIF converter should first make sure that the converter has low jitter.

Driver operation Dr. DAC prime

Diagnosis RMAA Dr. DAC prime

Device:Dr. DAC prime (usbaudio.sys)

Features: Device has not enough hardware 2D buffers Device has not enough hardware 3D buffers EAX 1.0: N/A EAX 2.0: N/A EAX 3.0: N/A EAX 4.0: N/A EAX 5.0: N/A

Rates: dwMinSecondarySampleRate 100 dwMaxSecondarySampleRate 200000

Free buffers stats: dwFreeHw3DAllBuffers 0 dwFreeHw3DStaticBuffers 0 dwFreeHw3DStreamingBuffers 0 dwFreeHwMixingAllBuffers 0 dwFreeHwMixingStaticBuffers 0 dwFreeHwMixingStreamingBuffers 0

Max buffers stats: dwMaxHwMixingAllBuffers 0 dwMaxHwMixingStaticBuffers 0 dwMaxHwMixingStreamingBuffers 0 dwMaxHw3DAllBuffers 0 dwMaxHw3DStaticBuffers 0 dwMaxHw3DStreamingBuffers 0

Misc stats: dwFreeHwMemBytes 0 dwTotalHwMemBytes 0 dwMaxContigFreeHwMemBytes 0 dwUnlockTransferRateHwBuffers 0 dwPlayCpuOverheadSwBuffers 0

There is no game support. The likelihood of no sound in games is unlikely, but to get maximum quality it is worth using cards that have such support, through the use of higher-quality sound processing algorithms. Here the leaders are cards from the X-Fi and ASUS lines. Dr. DAC prime can be used with low-end X-Fi cards as an external DAC via SPDIF.

For professional tasks, the device does not have ASIO support, which causes audio playback and recording to occur with a greater delay. This is only important when playing instruments live. There were no problems when working in Ableton Live under the MME interface.

Audiotrak Dr.Dac2

Dr.Dac2 succeeds the first version of Dr.Dac and is a versatile device that can work as an audio interface (via USB), external DAC, pre-amplifier for a power amplifier and as a headphone amplifier.

The first version of the device was a purely external DAC with a headphone amplifier and battery power on a top-end AKM4395 converter for portable use. An alternative is a similar device from iBasso D1 on the top-end CS4398 converter.

The second version has external power and the ability to connect to a computer via USB for stationary use.

Like the previously reviewed ProdigyHD2 Gold, Dr.Dac2 belongs to the highest class of devices that use one of the top PCM1798 DACs with high-quality op-amps. Since the device has not been announced for our country, it is worth noting its cost - $299 plus shipping (to Moscow approximately $30~60).

PCM1798 specifications:

• Supports sampling formats up to 192 kHz
• THD+Noise: 0.0005%
• Dynamic run-up, S/N: 123 dB

After the DAC, a Triple OPAMP circuit is used (the circuit design of this solution assumes higher quality) on three NE5532 op-amps (as in the Prodigy HD2). After the Triple OPAMP circuit, the signal goes to the OPA2604AP if the headphone mode is selected, or to the OPA2134PA if the line output is selected. All these op-amps can be changed without soldering. By the way, the Prodigy HD2/Gold can only change the op amp in the Triple OPAMP circuit, but the op amp from the amplifier to the headphones cannot.

The device can work as a regular headphone amplifier or pre-amplifier, receiving a signal through a line input. The line input circuit uses a standard JRC4580. This is the only op-amp that does not change without soldering, which is a little upsetting, since when using Dr.Dac2 as a pre-amplifier as part of a Hi-End complex as a link between a CD/SACD/DVD player and a power amplifier, this op-amp will formally become narrow place.

Driver

The driver is standard for USB devices, there are no additions or features.

Unlike internal cards with fast buffering of the audio stream, some delay is sometimes noticeable during playback, for example, when switching tracks in Foobar2000 there is a slight hitch.

The reference frequency machine works correctly, the selected frequency is highlighted by a green LED.

In use

During operation, Dr.Dac2 heats up noticeably, and it is advisable to place it in a well-ventilated place.

Separately, I would like to note the convenience of switching speakers/headphones via a toggle switch and the fact that volume adjustment is possible for both headphones and line output.

When connecting Dr.Dac2 via coaxial or optical, the device works properly at a maximum sampling frequency of 192 kHz, but when connecting via USB, it only works up to 96 kHz and when playing formats with a higher sampling rate, it switches to 44.1 kHz mode.

Diagnosis of RMAA

There is no game support. This means that there may be no sound in games, or some samples may drop out. Audio processing will be mediocre if developers by default outsource audio processing to a sound card like X-Fi or Audigy 2. Today, advanced audio processing algorithms use X-Fi. X-Fi will not have advantages only in those games where sound processing will be handled exclusively by the game engine, without using the capabilities of the sound card driver. If you want to get the most out of everything, you can take the younger X-Fi XtremeMusic or XtremeGamer, and use Dr.Dac2 as an external DAC. In conjunction with XtremeMusic, there were no problems; Dr.Dac2 worked stably at sampling frequencies of 48 kHz and 96 kHz (X-Fi in game mode can only output a signal via SPDIF at 48 and 96 kHz).

The much larger power reserve of Dr.Dac2 gave more effective reproduction of special effects, in comparison with headphones connected directly to X-Fi XtremeMusic.

In a professional way. application, the device does not have ASIO support, which, in turn, leads to a greater delay in the signal during playback. If working in a sequencer consists of adjusting parameters with the mouse and composing a track from cubes/loops, then the advantage of ASIO support in professional products will not be obvious. ASIO support is needed, first of all, when working live with an external instrument.

There were no problems when working in Ableton Live under the MME interface.

Objective measurements

As measured through the E-MU1616m, output distortion using three NE 5532s was 0.0009%. The level of distortion, depending on the measurement conditions (power supply, volume level, interference from external devices) can vary within small limits. During measurements with the replacement of the op-amp, the distortion turned out to be equal to 0.0010%

combination with the best quality

Test report in RightMark Audio Analyzer

Replacing with higher-quality LM4562 op-amps made it possible to achieve 0.0005% (the same value for the DAC according to the data sheet), but it is important to note that there is no talk of a radical change in distortion - the nature of the distortion remained the same, just the distortion of the second and third harmonics became slightly lower. For those who are interested in getting the most out of the DAC, the cost of one LM4562 op-amp is 190 rubles. Taking into account the cost of Dr.Dac2, the amount for the upgrade is insignificant, and the result obtained is “squeezing the maximum out of the DAC.”

To record changes from the op-amp in objective tests, it is necessary to have a high-quality interface, at least an E-MU series “m”. For example, measurements of the Prodigy HD2/HD2 Gold in its own loop are of no use due to the ADC of a lower class. And even the E-MU “m” ADC class is only comparable to the Dr.Dac2 DAC class, and the result is still a little underestimated.

Detailed report

Headphone output

There are two headphone outputs, differing in different maximum output power. No differences could be detected in sound quality, either subjectively or in objective tests.

Comparison of spectrum for 1 V at various loads

According to measurements, distortion depends little on the load; only below 33 Ohms can a slight increase in the second and third harmonics be observed. There are no higher order harmonics, this is an excellent result, since above 1 V is usually required only by low-sensitive headphones. And even at higher output power, distortion is moderate.

The output power level is significantly higher than that of popular sound cards. For example, the E-MU1616m and Audiotrak HD2 Gold have a maximum output power of approximately 60 mW, but the maximum values ​​​​are only obtained in a certain load range, in general the values ​​​​are lower. Dr.Dac2 has a power exceeding 100 mW per channel in the load range (from 16 to 460 Ohms). In the region of 50 Ohms the power reaches 1 W.

Up to 50 Ohms, the power was determined only up to the level of distortion growth, and at high loads the volume control was in the max position, and in this position no sharp increase in distortion was observed.

The second important feature is the very low output resistance; for low-resistance and high-resistance modes it is close to 0 Ohm. For comparison, the E-MU1616m has 22-28 Ohms, the HD2 Gold in high-impedance mode has about 50 Ohms, and the X-Fi XtremeMusic has 61 Ohms. Unfortunately, accurate data cannot be obtained without ultra-precise equipment, and the data obtained have a fairly significant error, allowing us to judge only an approximate value.

A low output impedance will have a beneficial effect on the articulation of low frequencies, for example, the X-Fi headphone output is a sore spot - on low-impedance headphones you can hear a “buzz” at low frequencies. On the other hand, a high output impedance can have a beneficial effect on the quality of mid and high frequencies, since the amplifier is less dependent on parameter drift during operation with headphones. However, high-end headphones, as a rule, are distinguished by the stability of their characteristics.

Detailed report output 1 Detailed report output 2

Pre-amplifier

Tests have shown that Dr.Dac2 adds virtually no distortion, the difference between the distortion spectra in the E-MU1616m’s own Loop and with Dr.Dac2 is vanishingly small (white and green spectra). The only thing is that on the spectrum you can see a little more noise due to a small ground loop. To prevent this from being distracting, the noise spectrum is additionally shown in blue.

At the same time, you can see that when Dr.Dac2 is enabled via SPDIF, the level of distortion decreases. In these measurements, three LM4562 were used in the Triple Oamps circuit; perhaps, if a similar circuit were implemented in the E-MU1616m, the second and third harmonics would also be lower. At the same time, the spectrum of the E-MU1616m has slightly fewer higher-order harmonics.

Subjective listening

Line output - Dr. Dac2 vs E- MU1616 m vs Prodigy HD2 Gold

The E-MU1616m is a multi-channel professional card and is similar in sound to the E-MU1212m, which has fewer input and output channels. Therefore, the result of the E-MU1616m will be similar to the result of the E-MU1212m.

Despite the high quality of the E-MU1212m's converters, the card is very inconvenient to operate and has received many complaints from audiophiles during operation. However, the price of the card is relatively low, and this maintains its popularity.

In Russia, Prodigy HD2 is sold with a somewhat simplified DAC harness, and Prodigy HD2 may perform slightly worse than HD2 Gold. However, HD2 can be upgraded to the Gold version by replacing the op amp without soldering.

All devices use top-end DAC models from different manufacturers, these are CS4398 from Cirrius Logic, AK4396 from AKM Semiconductor and PCM1798 from Burr Brown.

Path, listening conditions

Switching between sound cards was carried out through a router using passive elements - roller switches.

The amplifiers used were: professional amplifier Sakevich SK1200 Studio3, operating in class A ($900), top-class receiver Pioneer VST AX5i ($1500) in Direct mode via the multichannel input (bypassing DSP) and a laboratory amplifier based on LM3886. The monitors were speaker systems based on Eton8-800/37HEX + Vifa XT25. The same woofer is used in the ADAM S2.5A, and a similar tweeter is used in the BlueSky SAT 6.5 MK II satellites. For those who focus on quality = price, the cost of similar passive monitors with similar components will be approximately $2000-2500 per pair. The speaker impedance is 6 ohms.

Of the sound features of Dr.Dac2, we can only say that the quality is at a high level, reverberation, attack, panorama are perfectly conveyed, and all the details are audible.

Despite our best efforts, we were unable to discern a clear difference between the tested devices. This indicates that all devices are maximizing their potential.

Should we assume that there is no difference? With instantaneous switching, the fatigue effect of slightly more distortion cannot be taken into account. At the same time, during long-term listening, there are much more factors influencing the subjective perception of sound, and the influence of this difference in distortion from the DAC is much smaller, which negates the reliability of tests with long-term listening.

Thus, a higher price for a device that has no obvious differences in sound in a blind test and with a reasonable explanation of the improvement in circuitry should not be considered as unreasonably high. It would be more correct to consider it as a kind of guarantee of a quality reserve, albeit in excess. Unfortunately, for rare devices you can see sane explanations of their superiority over cheaper analogues from other manufacturers.

Those who need the highest quality source should pay attention to Dr.Dac2, since it is possible to replace the op-amp, and thus you can choose the sound “for yourself.” Even if all the improvements from replacing the op-amp occur at the level of self-hypnosis, the main thing is that the sound brings long-awaited satisfaction.

Headphone amplifier - Dr. Dac2 vs E- MU1616 m vs Prodigy HD2 Gold

The popular high-impedance audiophile Sennheiser HD650 and low-impedance isodynamic professional Fostex T50RP were used for the test. Additionally, Technics RP-F880 were used as low-impedance ones, since the specificity of the T50RP as isodynamic headphones with low impedance deviation can give a slightly different result than with other dynamic headphones with low impedance.

All devices worked synchronously, via SPDIF the signal from the HD2 Gold was supplied to the E-MU1616m, then from the SPDIF output of the E-MU1616m to Dr.Dac2. From all amplifiers the signal went to a router made on a switch. This made it possible to instantly switch the source and use one player or sequencer to play audio content.

About the “stuffing” of the amplifier outputs for headphones - Dr.Dac2 OPA 2604, E-MU1616m JRC 2114, HD2 Gold JRC4580. This is a rough guide as a lot depends on the specific implementation.

The undisputed leader is Dr.Dac2. The sound is excellent, with great detail. There is no audible distortion even with low sensitivity Fostex T50RP, which ensures high comfort during long listening sessions.

The E-MU1616m is inferior in output power and slightly inferior in quality on low-impedance headphones compared to Dr.Dac2.

The HD2 Gold is superior to the E-MU1616m in terms of output power, but inferior in quality. The difference is insignificant.

Is it worth pursuing high output power from a headphone amplifier? When listening to loud recordings on sensitive headphones, a powerful amplifier will most likely not be needed. The reserve for reproducing peaks without distortion is useful in some cases. This can be a classical recording with high dynamics or a recording of non-electronic music styles.

When listening to music “louder,” the hearing quite quickly adapts to the increase in volume, and with a consistent increase in volume, it is subjectively difficult to say that “that’s it, there’s no need to make it louder.” O becomes clear when the pain threshold is reached - if you are lucky, the ear will hurt for a couple of weeks and return to normal.

Among audiophiles, it is fashionable to listen to recordings with a large dynamic range and the desire to listen to these tracks at maximum volumes of 120 dB or higher - until the roar of a jet engine is close. Dynamic range is the difference between the quietest part and the loudest part. If the volume changes smoothly along the track, then there will be no “high dynamic range” effect due to adaptation to smooth changes in volume (similar to vision with adaptation to bright or dim lighting), and if there are strong changes in volume in the track, then this will similar to the blinding effect of a flashbang in the middle of the night. You shouldn’t strive for extremes, especially since advertised discs with “super recordings” often turn out to be not so good when tested.

The greatest justification for a powerful headphone amplifier appears when watching action films, where there are short and loud scenes with explosions, shootouts, etc. with fairly moderate dialogue volume throughout the rest of the film. For example, in Hitman only with Dr.Dac2 you can “enjoy” a shootout, while with the E-MU1616m there is a feeling of loss of drive due to quiet explosions.

conclusions

Dr.Dac2 is a 3 in 1 device and is a very high quality solution. Usually, during “meticulous” testing, shortcomings are discovered in any device, but Dr.Dac2 confidently passed all tests without any significant comments. One can only express a wish for the development of the product in the form of the appearance of support for ASIO and gaming 3D sound, but this will undoubtedly affect both the positioning of the product and the cost.

To summarize, when working as an external DAC, the sound from the analog output is at a very high level and is not inferior to the professional E-MU1616m interface, as a pre-amplifier does not distort the signal, and the headphone outputs deserve the highest rating. At the same time, Dr.Dac2 provides convenient switching between monitors and headphones with convenient volume control. For audiophiles endlessly striving to improve sound quality, there is a significant plus - the ability to replace op-amps without soldering.

Based on the testing results, the cost of the device does not seem high, quite the contrary.

Sound - subjective impressions of Dr. DAC prime

Path with acoustic systems and Dr. DAC prime

A laboratory amplifier based on LM3886 was used as an amplifier. The monitors were speaker systems based on Eton8-800/37HEX + Vifa XT25. The same woofer is used in the ADAM S2.5A, and a similar tweeter is used in the BlueSky SAT 6.5 MK II satellites. For those who focus on quality = price, the cost of similar passive monitors with similar components will be approximately $2000-2500 per pair. The speaker impedance is 6 ohms.

The sound can be described as very high quality. I would like to note that for devices of this class, regardless of their cost, the difference in sound quality varies little and the choice of one or another DAC is a pursuit of a shade of sound, as well as exclusivity/prestige. The quality of the amplifier and speakers is also more critical for finding the difference between sound sources.

Of greatest interest is the difference in sound in Bypass and Upsample modes. The difference is not dramatic, but it is there and can be heard well. Upsample mode changes the transmission of the attack. Strings and keyboards sound less accented. In electronic music, the detail and intelligibility of high frequencies changes noticeably. In fact, upsample mode is a mode of calm, non-aggressive sound. It can be useful when listening to recordings with “sandy tops” - an increased level of distortion at high frequencies, which the upsample mode will smooth out.

The sound of headphones with Dr. DAC prime

Formally, you could choose any headphones presented on our market. The choice of headphones includes quite popular, recognizable models with different levels of sensitivity and resistance. For Dr. DAC prime used:

• The Sennheiser HD650 are audiophile headphones that can be considered standard classics.
• Fostex T50-RP are isodynamic headphones that are quite demanding on the amplifier due to their low sensitivity.
• AKG 272 Studio - studio headphones with neutral sound, low impedance, medium sensitivity.
• CEC 53HP is a low impedance, high sensitivity headphone.

The headphone amplifier provides a high level of volume headroom. There were no complaints about the quality. There is no distortion with either high-impedance or low-impedance headphones. You can also note the absence of any sound color. Fans of “interesting”, “soulful” and “exciting” sound may not like the sound of the amplifier, this will depend on their preferences for sound and the available headphones paired with the prime.

Conclusions about Dr. DAC prime

Dr. DAC prime is a pretty successful device with high-quality sound, as well as audiophile capabilities - op-amp replacement and a separate upsampling mode. Convenient switching capabilities. Unlike the previous version of Dr. DAC2 functionality has increased, an additional ADC and digital input have appeared. The quality of the ADC is subject to criticism, but most likely it will not matter to consumers of such a device. The headphone amplifier is quite powerful with a neutral sound.

Author: January 13, 2010