New DoBlue SLASH6 Bluetooth 5.1 Receiver with USB DAC AMP and Optical In/Out
New DoBlue SLASH6 Bluetooth 5.1 Receiver with USB DAC AMP and Optical In/Out - while the old model was good, the new one is even better.
Date: 28-Oct, 2023
Introduction
I had shared the news about the SLASH series Chuseok discount event a week ago, and I immediately purchased the new SLASH6 model and replaced my old SLASH6 with it, which I'm now using at home.
* Chuseok is a holiday like Thanksgiving Day in Korea.
** SLASH6 is a device that can add Bluetooth and DAC functions to the Hi-Fi amplifier just by plugging it into the RCA terminal.
The DAC used in SLASH6 has been changed to the ESS Sabre Quad DAC ES9219, and while this might not represent a significant difference from the ES9218P, and the most notable change in SLASH6 is that the Bluetooth chipset has been changed from Qualcomm CSR8675 to Qualcomm QCC5125.
When I asked to DoBlue about the possibility of firmware updates for the old SLASH6 model, they explained that they had no choice but to change the Bluetooth communication chip to fully implement the latest high-quality Bluetooth codecs.
Thanks to this change, new SLASH6 now supports LDAC, aptX HD, and aptX Adaptive codecs as well. Personally, the addition of the LDAC codec is the most welcome part of this upgrade.
Furthermore, the adoption of the aptX Adaptive codec is noteworthy because it's still relatively rare due to its expensive licensing costs. In the SLASH series, DoBlue is going above and beyond by offering support for not only aptX Adaptive but also LDAC and aptX HD codecs in a cost-effective manner. This represents DoBlue's commitment to prioritizing sound quality over cost.
Exterior and Main Features
The packaging of this product was also different from the white paper box of the previous model, and the design of the box that reminded me of the gift box was also impressive.
On the back of the box is printed with key specifications.
I'm glad to see that LDAC, aptX Adaptive, and aptX HD high-quality Bluetooth codecs are all supported.
The user manual is also neatly enclosed.
The Slash6 main unit is securely housed, and a USB-C cable is enclosed underneath it.
The components include SLASH6 unit, USB Type-C cable, and user's manual.
The recommended current capacity for the USB power adapter is 5V 1.0A, but SLASH6 is said to be designed compatible with all power adapters.
For small-signal audio output, this amount of current (1.0A) is sufficient anyway.
Unlike the thin cable used in previous models, the USB cable has been changed to a premium cable with a fabric sheath.
The USB cable looks much more durable.
The SLASH6 new model looks much more sophisticated with a dark navy finish, and the gold paint on the panel has also changed to a calmer color.
Also, the finishing quality of the terminal part has become more luxurious compared to the previous model.
The gold-plated RCA terminals are eye-catching.
If you look at the RCA terminal from the front, you can see the color that distinguishes the left and right.
The 3.5mm input/output terminals have both optical input and optical output functions. And the terminal part is slightly embossed unlike the previous model, so I think it will reduce scratching of the panel part even when the cable is plugged in and removed from the invisible position on the back of the SLASH6.
In addition to the LED display function, new SLASH6 also includes the Multi-Function Button (MFB) in the place where only the LED display was used in the previous model.
Multi-function button makes it much easier to disconnect Bluetooth pairing and pair new devices.
* Please refer to the table below for the key specifications of Slash6.
|
Product Type |
Bluetooth DAC Receiver |
|
Model Name |
SLASH6 (new) |
|
Bluetooth Chipset |
Qualcomm QCC5125 |
|
Bluetooth Version |
5.1 |
|
Bluetooth Profile |
A2DP, AVRCP |
|
Bluetooth Codec |
LDAC, aptX Adaptive, aptX HD, aptX LL, aptX, AAC, SBC |
|
Bluetooth Range |
Up to 10m |
|
DAC |
ESS Quad DAC ES9219 |
|
PCM Support |
Up to 384kHz/32bit |
|
SNR |
130dB |
|
THD |
-112dB |
|
OP Amp |
TI OPA1692 (low power, low noise, low distortion) |
|
USB DAC Input |
Up to 24bit 96kHz |
|
Audio Output |
RCA (2.7Vrms), 3.5mm (1.0Vrms) |
|
Audio Input |
3.5mm 1.0Vrms |
|
Optical Input |
3.5mm jack (common to analog audio input jack) |
|
Optical Output |
3.5mm jack (common to analog audio output jack) |
|
Power Input |
USB Type-C |
TRY TO EXPERIENCE
: Upgrading the old analog amplifier to a digital & wireless HiFi
■ Bluetooth Pairing
After connecting the power using the USB-C cable, SLASH6 initiates a Bluetooth connection search.
* I have two versions of New SLASH6. So, some photos in the post have a slightly different imprint.
The Bluetooth device name is found as SLASH6.
If the old SLASH6 is also connected to another device, it is confusing because the name of the new SLASH6 and Bluetooth device is the same.
In that case, it is good to change the device name on your smartphone.
For your information, the changed device name is stored on the smartphone, not on the SLASH6 device.
▶ Utilizing High-Quality Bluetooth Audio Codecs
On Android smartphones, high-quality audio codec connectivity is enabled only when set to "quality-first" mode. Depending on the settings in the DAP, an additional setting may not be required.
When I set it to "Quality First" and reconnected SLASH6, it shows that my smartphone is connected at LDAC 96 kHz 32 bits.
There is also an optical output signal from the OUT terminal, and if it is necessary to connect the signal received by SLASH6 to another audio device as an optical input, this output terminal can be used.
▶ Connecting via USB DAC
When connected to a PC or laptop with a USB cable, the LED illuminates in bright green (light green) and SLASH6 operates as a USB DAC.
The computer recognizes it as an output device named "SLASH Hi-Fi".
You can set the sampling rate up to 24-bit 96kHz.
It would be better if all the chipset specifications (up to 384 kHz) were available, but I don't have much DSD images or sound sources above 192 kHz anyway, so supporting up to 96 kHz is enough for me.
▶ Optical Cable Input
To use Optical Input, simply connect the optical cable to the Slash6 IN 3.5mm audio jack.
PCM input signals that can be transmitted to optical cables support up to 32-bit 384 kHz.
I'm using SACD players, HDCD players, etc., so I don't need to connect optical cables to hi-fi devices, so I'm using the TV's audio output as an optical cable input for SLASH6.
Connecting SLASH6 to Hi-Fi audio systems with floor standing speakers, makes it more realistic and exciting when watching movies or OT dramas on weekends.
■ Enjoying High-Quality Music Wirelessly
▶ The sound quality of the new SLASH6 is still excellent.
Since it supports LDAC codec, it's great for wirelessly enjoying high-quality sound when playing digital music from albums mastered at the sampling rate of 192kHz or 96kHz or streaming high-resolution audio (HRA) contents.
▶ Of course, there are limitations to wireless codecs (in terms of pure audio quality).
Even though high-quality wireless codecs are available, it is impossible to transmit them in a completely lossless sound source because the transmission rate is limited to about 1Mbps at this point.
If we simply check the output waveform of SLASH6 with the test sweep waveform, we can see that the output of SLASH6 is significantly less reproducible than the source signal in over 16 kHz band.
Even compared with the analog terminal output of the low-cost DAP, SONY A55, we can see that the waveform of the Bluetooth-connected SLASH6 has less reproduction quality of over 16 kHz band.
* Here, I want to clarify a couple of points:
1) The lack of reproducibility of the ultra-high frequency range is not the limit of SLASH6, but the limit of the Bluetooth codec.
2) This characteristic does not cause any noticeable problems in listening, and it is a very reasonable choice in an engineering manner.
The reason for transmitting the signal in this manner is that if you have to sacrifice some data within the limited wireless transmission bandwidth, we can find it more rational to sacrifice the ultra-high frequency range that is difficult to perceive with the human ear.
Between 16kHz and 20kHz, there's about 4kHz band of audio signal, but it carries an entirely different level of information compared to the 4kHz in the lower frequency range in terms of perceptual audio.
For example, 16 kHz and 20 kHz are less than half an octave difference, but 20 Hz to 4 kHz has a range of sound that exceeds 7 octaves (just under 8 octaves). In addition, it belongs to the audible band that people can hear very well.
So, which range of 4 kHz band would you choose to stream more fully packed?
No matter who makes the decision, after pondering upon the above facts (even if you actually check them with your ears), it would be a much wiser decision to abandon a band above 16 kHz and transmit lower band signals more faithfully (fully packed).
And I'm a middle-aged person who can't defy biological aging, so I can't hear the frequency range above 16 kHz anyway.
So, from my point of view, there's no problem with some losses in bands above 16kHz, but rather, it's better to play the bands below 16kHz more faithfully.
■ A Significant Advantage of Direct RCA (Audio Input) Connection
When setting up a high-fidelity audio system, it's crucial that the source device effectively and faithfully transmits its signal to the amplifier without any loss or distortion, no matter how excellent the source's signal may be.
For example, even if you have an outstanding SACD player with satisfying sound characteristics, paired with preamps and power amps that match your speakers well and deliver excellent sound, if the interconnector cable between the SACD player and the preamp fails to transmit the original sound accurately and intactly, you won't be able to fully appreciate that excellent sound.
In practice, such occurrences are quite common, which is why substantial investments are often made in interconnector cables when setting up a high-fidelity audio system. The same applies to speaker cables.
The interconnect cables I'm using were chosen after many trials and error attempts and fall into a price range several times more expensive than the SLASH6.
SLASH6 is a fantastic product in its ability to alleviate the concerns about the interconnector cables.
I think it was a very good engineering idea that deserves praise to design this type of product.
Not only does it bring cost advantages by eliminating the need for interconnector cables, but more importantly, it offers a significant advantage in minimizing signal loss and distortion.
A concluding remark
: SLASH6 is the easiest way to transform old analog Hi-Fi systems into high-quality digital and wireless Hi-Fi.
: I'm again highly satisfied with the second purchase, and it's a product I'd highly recommend.
The new DOSLASH6 Bluetooth DAC receiver inherits its own functional and sound quality advantages, while also supporting the LDAC and aptX Adaptive codecs with Bluetooth.
These days, for convenience, people often listen to music or content by wirelessly connecting to network players or Bluetooth devices, and it is really appealing that you can enjoy it in a higher audio quality in such wireless audio streaming environments.
And above all, the sound quality is quite impressive.
I personally purchased the new DOLASH6 model, and it's a really satisfying product to use, so I leave it as a brief review for information sharing.
For those interested in this product, I hope this article will help you understand the product and make decision.
If you want more information about DoBlue and SLASH6, you can find the product in Amazon online shop.
BLUETOOTH DAC AMPLIFIER BLUETOOTH DAC RECEIVER BLUETOOTH RECEIVER DAC AMPLIFIER DOBLUE DOBLUE SLASH DOBLUE SLASH6 SLASH6
https://brightandwiser.blogspot.com/2023/10/new-doblue-slash6-bluetooth-51-receiver.html