I initially planned to create a video to share my thoughts on this topic, but after three or four attempts, I realized it was too challenging to express myself coherently in a single take. Writing my impressions instead allows me to be more precise, refine my ideas, and develop my thoughts gradually—unlike the continuous stream of consciousness required for a video review.
In this write-up, I’ll give my impressions on three DACs from my current collection and share my personal experiences, insights, and anecdotes—specifically focusing on sound and synergy.
----> iBasso DC Elite – The Super-Dongle <----
Overview
I fairly recently acquired the iBasso DC Elite, celebrated as the ultimate dongle DAC, said to deliver desktop-grade performance in a compact form. It’s a power-hungry beast, thriving best with a clean USB source or battery pack to unleash its full potential.
Sound Characteristics
The DC Elite’s performance is top-tier:
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Huge, expansive soundstage
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Bold, clean, and precise note delivery
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Tight and very structured presentation
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Incredibly low noise floor, aiding in sense of cleanliness and especially layering.
It makes dynamic drivers sound almost planar-clean, which is frankly wild.
Frequency Extension
The DC Elite stretches wide, achieving insane end-to-end extension. The frequency spectrum feels complete and ultra-composed. Thanks to the expansive canvas it paints sound on, you can tell exactly when a transient begins and ends. Instruments appear to float on their own layers, spaced far apart, creating a vivid and open stage that feels like it fully extends outside your head.
Analogy: The Artisan vs Grandpa’s Guitar
The DC Elite is the artisan’s finely tuned instrument. Every string resonates fully. Notes vibrate with precision and speed, giving a sense of total resolution and balance. In contrast, as I’ll describe later, the Cayin RU7 is more like your grandpa’s old favourite guitar—three strings in the middle intact, outer strings missing—offering a different, more focused character and timbre.
Despite the DC Elite’s technical prowess, it doesn’t sound overtly analytical. It just has an excellent foundation of competent sound reproduction—clean and natural with superb resolution. Having paired the EJ07 OG with countless delta-sigma DACs, the DC Elite stands unrivaled among them. Its whisper-quiet background, effortless extension, and composed delivery make it the gold standard for IEMs among delta-sigma designs.
So it is rightfully the ultimate expression of delta sigma sound.
That said… it doesn’t hold a candle to the magic of the synergy I get with the Cayin RU7 and the EJ07, while the DC Elite outshines the RU7 in technical prowess—clarity, cleanliness, dynamics, and precision—the RU7 brings a unique synergy with the EJ07 that’s unmatched, a special sauce driven by the the Ru7’s signature described further down and EJ07’s unique dark tuning and its four EST drivers solely handling the treble.
Synergy & Pairing
The DC Elite excels with IEMs and headphones that lack natural extension—particularly single-driver dynamics or IEMs that aren’t inherently U-shaped. Planars, however, don’t pair as well. They already offer the same strengths as the DC Elite: extension, transparency, and clarity. Instead, planars benefit more from components that adds power, warmth, and substance—qualities that the RU7, as we’ll see, better provides.
----> Cayin RU7 – The 1-Bit Funnel <----
Overview
The RU7 is a 1-bit DAC dongle, a unique contrast to the delta-sigma prowess of the DC Elite. I’ve heard three different 1-bit DACs so far: the RU7, the Topping D90 Discrete, and a high-end speaker DAC whose name I don’t recall. Interestingly, they all share the sonic traits below:
Sound Characteristics
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Blackground
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Transient smoothness
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Lower midrange emphasis
The RU7 leans slightly more musical than technical, with a smooth yet engaging tone—some extra energy in the lower mids and a gentle roll-off moving upward. This signature also allows for cranking the volume without being screamed at by the music. Very engaging, as an increase in volume inherently carries with it enhanced dynamics, and the life of music is contained inside the dynamics!
The “Funnel” Effect
What stands out most to me with 1-bit DACs is what I call the “funnel effect”, which is its special sauce. Imagine the 1-bit DAC architecture as a funnel receiving the signal—wide and spacious at the entrance, but narrowing down as it progresses, focusing and condensing the sound toward a central point.
The result? Notes that feel more centralized, more condensed as if the air and details are being drawn inward toward the note’s origin, rather than expanding outward. This creates a heightened sense of blackness in the background, as no air is illuminating what is around the note, which in turn helps to separate and define notes better by creating a sort of black vacuum around the notes.
Stage & Settings
This unique “funnel” characteristic contributes to the RU7’s unique sense of depth and imaging. The unit offers three DSD upsampling settings (64, 128, 256), which extend the frequency range in both directions, creating a progressively more U-shaped signature. That said, I personally find the 128 and 256 settings slightly edgy, so I stick to DSD64 for a smoother, more coherent result that also maximizes the funnel effect.
Synergy & Tuning
Thanks to the funnel effect, the RU7 wraps the stage around your head and creates imaging that feels substantial and tangible in 3D space in front of and around your head. This works exceptionally well with multi-driver IEMs, helping multiple drivers coalesce into a single, unified sound. You get coherency while retaining the advantages of separate drivers.
For instance, the RU7 paired with the EJ07 is nothing short of audio ecstasy. The EJ07, with its unique dark tuning and four EST drivers dedicated to the treble, synergizes with the RU7 in a way that’s unmatched among the roughly 40 IEMs I’ve tested. The RU7’s smooth, musical tone and its ability to condense and focus the sound bring out a hyper-immersive, truly holographic quality in the EJ07.
I’ve heard the term “holographic” thrown around for IEMs like the MEST Mk1, Mk2, or ISN H60, all of which I have owned, but the EJ07 with the RU7 takes it to another level entirely. It’s so far ahead of every other IEM I’ve tried that it’s almost unfair to compare. This makes me wonder: the vast majority who’ve heard the EJ07 likely paired it with a delta-sigma DAC like the DC Elite, meaning they haven’t, as far as I am concerned, experienced this IEM at its absolute peak.
On the flip side, single-driver setups (including headphones) sound muted, blunted, and lacking in clarity and extension with the RU7. In those cases, a good delta-sigma DAC, like the DC Elite, performs better outright!
-----> Earmen L-Amp - Semi-portable OTL <-----
Overview
The Earmen L-Amp is no ordinary DAC/Amp. It’s a transportable tube-based marvel that combines the soulful warmth and bloom of tubes with the precision of an ESS chip, delivering a delta-sigma experience that has had its shortcomings largely addressed.
Sound Characteristics
The L-Amp’s performance is vibrant and engaging:
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Rich, forward mids with exceptional density
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Punchy mid-bass with lively dynamics
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Smooth, extended wet liquid-like highs that never fatigue, opposite of dry but without sibilant splashiness
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Musical flow from tubes, tying the sound together like glue with warmth and emotion
It transforms even modest headphones, like the Thieaudio Ghost, into something super pleasant, despite imperfect synergy with the Ghost’s tuning.
Analogy: The Studio Vocalist vs. The Technician
If the DC Elite is a technician meticulously laying out every detail of a track with non-discriminatory precision, at equal distance, the L-Amp is a studio vocalist sitting close to the microphone pouring emotion into every note. Vocals feel intimate, almost tangible, with a sense of imaging movement and vibrancy that makes the music feel alive and soulful. There is a bloom to the presentation, like every note has extra rich filling.
Frequency Extension
While the DC Elite delivers a flat, balanced spectrum, the L-Amp emphasizes the midrange, enriching it with saturation and intimacy. The mid-bass punches hard, and the highs are smooth and fluid, creating a warm, cohesive sound. Though not as cleanly extended as the DC Elite, its frequency response feels dynamic and emotionally compelling.
Synergy & Pairing
The L-Amp shines with headphones and power-hungry planar IEMs that crave warmth and vibrancy. It’s less suited for sensitive IEMs. Dynamic driver headphones benefit most, gaining a lively, soulful character. However, IEMs or headphones that are already mid-forward or warm may not synergize as well, as the L-Amp’s tuning could overpower their natural sound.
