Unique Melody Amber Pearl Hybrid IEM
Unique Melody, abbreviated as UM, is renowned for its high-end professional and custom-made in-ear monitors. UM is located at the east end of Zhuhai City while Cayin is at its west end. We were known as "the sound of Zhuhai" in China audiophile community and we are proud with this team identity.
In fact, before this point in time, Cayin and UM were often adjacent to each other at many shows and exhibitions. When we conduct subjective listening tests during new product development, there is always one or more UM IEMs in our reference monitor bench, and UM also involves Cayin’s DAP and amplifier during their development process. However, the two brands have yet to join forces in a project officially. The Amber Pearl IEM for N30LE finally break the ice.
The name Amber Pearl basically follows UM’s naming convention with Amber representing the warm yellowish color and Pearl representing the 30th anniversary (of Cayin) as well as the number of transducers in the IEM. There are 15 drivers per unit or 30 drivers per pair altogether.
The First Design from the Sound of Zhuhai
From a product development point of view, the joint development of two HiFi brands such as Cayin and UM means finding the best synergy between electronic products and acoustic products. The good thing is, the synergy is not achieved by mix and match but through the proper engineering process, and we can safely expect that we can achieve 1+1>2 when we combine the talent and expertise of two excellent products. Therefore, Cayin and UM engineers collaborated in this development process. We meet to discuss options and conduct subjective listening tests together.
The application of bone conduction units is one of the important parts of UM acoustic engineering. Therefore, Cayin engineers have devoted a lot of effort, and with the assistance of UM engineers, explored various bone conduction units, understanding the difference between piezoelectric type and coil type, and the characteristic of Silver-Palladium Alloy and Frequency Shift in piezoelectric Bone Conduction Drivers. They also performed extensive testing and conducted blind listening sessions on existing UM products. Finally, together with UM engineers, the following configuration was determined:
Driver configuration: 4 Bass BA Drivers + 2 Mid BA Drivers + 2 Mid-Treble BA Drivers+ 4 Treble BA Drivers + 2 Ultra-High EST Drivers + 1 Frequency-Shift Piezoelectric Bone Conduction Driver
Amber Pearl consists of 15 drivers with a 6-way Crossover. The theory is simple but the reality is another story. The drivers should operate independently within a specific frequency band, as controlled by the crossover. To crossover, the circuit will also coordinate and control the drivers to minimize bleeding into adjacent regions. Cayin has built speakers and IEM but our track record was limited to 2-way and 3-way crossover. We understand all too well that the complexity and difficulty of crossover design is not a linear progression. When you move from 4-way to 5-way, or from 5-way to 6-way, the complexity will increase exponentially. Without the involvement of UM team, we couldn’t be done this properly.
After we get the crossover right, the Amber Pearl is highly resolving with density, the image of the music being very clear. The Frequency shifting BCD has become the most important element in perfecting Amber Pearl. The frequency shifting technique has enhanced the transparency, frequency extension, and density of Amber Pearl to the next level.
When we design the chassis for Amber Pearl, we have our eyes set on the Prestige Stabilized Cholla wood chassis of Manson. We prefer a warmish tone to resemble the vacuum tube glowing. UM tried different resin and has finally adopted a yellow-orange resin and we decided to call it Amber. UM will reserve this resin for Cayin exclusively, so this particular IEM chassis finishing will only appear in the 99 pairs of Amber Pearl IEM.
The cable of Amber Pearl is custom-made by PWAudio, it is a 2-wire 4 conductors design, and each conductor is independently shielded 26AWG 6N OCC Copper. To implement the cable for the 4.4mm five-pole connection, we have connected the shielding layer of each conductor to the ground connection of the 4.4mm ground pin, making it a perfect fit for the 4.4mm connection of N30LE. This cable has never been used in previous UM products, and it is unlikely that the cable will be used again in forthcoming UM IEMs.
The Amber Peral IEM will come with AZLA SednaEarfit Xelastec SS MS M and UM Silicone Eartips S M L ear tips.
The Final Refinement and N30LE Amber Pearl Customization
In order to truly achieve "1+1>2", Cayin and UM have conducted numerous meetings to fine-tune the synergy and audio performance of N30LE and Amber Pearl IEM. As a result, there are two versions of N30LE: the standalone version and the Amber Pearl Combo version, the latter includes a further customized and enhanced Amber Pearl version N30LE and a pair of UM Amber Pearl IEM. Some minor adjustments have been made to the Amber Pearl (AP) combo version N30LE:
- Crystal Oscillator: the standard N30LE uses Accusilicon AS318 series crystal oscillators. The AP combo version uses CRYSTEK CCHD-575 series crystal oscillators. Both oscillators are femtosecond-grade but the typical phase jitter of CCHD-575 is rated at 82fs RMS at 100 MHz, noticeably better than AS318 at 200fS at 100MHz. In terms of actual listening experience, N30LE with the CCHD-575 series crystal oscillators provides Amber Pearl with more spaciousness and rich overtones.
- JFET tube timbre circuit output: As mentioned previously, the timber circuit adopts a three-stage amplification structure and we have a low-noise audio-grade N-channel JFET before and after the 6P1. The standard N30LE employs Toshiba's 2SK209 JFET while the AP combo version utilizes TI's JFE150 JFET which dated back to Burr Brown. The JFE150 has a stronger current output capability, when we customized the Timber circuit to handle Amber Pearl, we decided to use adopt a different JFET in the timbre circuit. When Amber Pearl IEM is Amber Pearl is driven more fully when paired with electronic tube sound. Whether users choose the "Modern" or "Classic" mode, Amber Pearl exhibits outstanding performance and distinction in terms of rhythm, speed, and natural rendering of extremely low-level details. The JEF150 is indeed more expensive, but the component was selected for its designated purpose, not because of its price.
- The differential input stage of discrete phone amplification circuit: We have stated in the functional diagram that the phone amplifier circuit adopts “Matched Toshiba N-Channel JFET” as Differential Input. The standard N30LE adopts Toshiba 2SK2145 dual JFET while The AP combo version adopts the highly acclaimed Toshiba 2SK389 Dual JFET (which has been discontinued for many years). We need to adjust the static operating point of each level in the circuit, this step is crucial in building a high-quality discrete circuit. The internal pins of both matched JFETs within 2SK389 are individually wired. When we conduct subjective listening tests on Amber Pearl, we connected different resistors in series with the source of the two matched JFETs inside the 2SK389, the circuit characteristics are adjusted using local negative feedback technology, which changes the open-loop gain (feedback coefficient). The resulting changes in the load include improved linearity and variations in harmonic distribution. This will improve the synergy between N30LE and Amber Pearl, the combo presents a natural and realistic sound signature that is smooth and ethereal while eliminating any trace of harshness.
The circuit changes are subtle but significant, but they are ”invisible” to users, so we have added the following cosmetic differences:
- The back of the N30LE AP combo version is engraved with "N30LE" and "Amber Pearl," representing the names of both the DAP (Digital Audio Player) and the IEM. It also signifies a collaborative tuning effort and serves to differentiate it from the standard N30LE DAP in terms of appearance.
- The serial number will be engraved differently, the standard N30LE is 30LE001 to 30LE300, and the AP combo package is Pearl 01 to Pearl 99
- The leather case will be marked differently (please refer to the following diagram)
- The packing box will print the model number explicitly.
I hope this will explain the difference between the standard N30LE and N30LE Amber Pearl combo version in detail. I’ll further explain the technical details related to the tuning process but it may be difficult to understand for some readers. Essentially, Cayin insists on using discrete components in portable products like N30LE because they offer adjustable characteristics; however, this approach is subject to product positioning and cost limitations. We have clarified many times that Cayin doesn’t adjust the sound signature through a firmware update, we have been very particular about this practice since the original N6 DAP and we have explained our position in previous product discussion (
HERE,
HERE). We prefer fine-tuning the sound signature of our product through circuit design, choice of components, and adjustment of circuit operation parameters, this is our strength and the basic building block of the Cayin house sound.
In practice, Amber Pearl sounds excellent even when paired with standard N30LE. During its design process, we have extensively tested various headphones and backend equipment combinations alongside N30LE itself. However, because Hi-Fi products always strive for continuous improvement, audiophiles always want to squeeze out the final bits of performance through cable or accessories changes. As a product designer and manufacturer, we have the unique opportunity to do that at circuit and component level modification. When we have a specific IEM pairing in mind, this presents a unique opportunity to fine-tune the sound signature for this particular IEM and deliver further enhancement.
To give an inappropriate analogy, if my subjective listening experience of the N30LE standard version + Amber Pearl is rated at 98 points, then the package version would be rated at 99 points. Please be reminded that this is only an analogy, listening experience is subjective and quantitative description to express the opinion of Cayin and UM's joint subjective evaluation is purely for illustration purposes. By the way, the perfect score of 100 will never exist; it always lies in the future – that's what Hi-End pursues.
Is it possible that the N30LE AP combo version paired with other earphones achieves a rating of 98 points while the standalone N30LE model achieves a rating of 99 points? The answer is yes. Audio products, whether electronic devices (such as players or amplifiers) or electroacoustic devices (such as IEM, headphones, or speakers), are all playback equipment with their own tendencies and limitations. N30LE itself has undergone multiple adjustments in design and various load combinations during its development process. It also possesses strong driving capability. The slight difference between ratings can be attributed to specific tuning considerations.
Music is diverse, and users' IEM and listening preferences are also diverse. The purpose of presenting various modes and tones is to facilitate users in finding their own preferences when choosing equipment. This is our intention, and this is hidden in the DNA of our flagship products, and N30LE is no exception. Experience different combinations, discover synergy, and find your flavor tone at a specific time, for a specific moment - this is the charm of Hi-Fi.
It will be better if you can provide both version on HKAV so we can bring our IEM and prove your statement
