PlusSound Volta and Sonora Review

Disclaimer & Personal Bias

I received these as part of the PLUSSOUND Tour and would like to thank Sebastien Chiu and Christian Soriano.

These are my opinions and I have not been asked to say anything in particular, either positive or negative. At this point, I’ve owned quite a few headphones and iems, and have heard many around these respective price points, though the only one I have currently is the Campfire Trifecta.

I’m a borderline basshead and value impact, timbre, and musicality over everything else. If an iem doesn’t hit even with EQ, if vocals sound unnatural, or if it isn’t ‘fun’ to listen to, it’s probably not for me. That being said, I can still appreciate what an iem does well and if it excels at one of those things or brings remarkable value at its price point, I can still appreciate it.

As far as music, I primarily listen to pop, synthwave, edm, 80s, rap, r&b, alternative, classic rock, and occasionally soundtrack/orchestral. I almost never listen to metal, jpop, kpop, jazz, country, soul/blues, or folk music.

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Sources & Tips

Minix Z100-0db Fanless Mini PC (FLAC & Tidal) > Audio-GD DI20HE (DDC) > Sonnet Morpheus R2R (DAC) > iFi Pro iCan Signature (AMP)

Portable: HiBy R6 III (DAP) or iFi Go Bar Gold (DAC)

A nice selection of stock tips were included, including PLUSSOUND wide bore silicone, Symbio, and Comply foam. I found the stock silicone to be a great match but ended up using my own BGVP W01 and JVC Spiral Dots. KBEAR 07 also worked well but Final Type E, I didn’t find to be a great match.

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Design & Build Quality

PLUSSOUND iems are handcrafted in California. The Volta and Sonora are tribrids with DD/BA/EST drivers. The Volta ($2500) has 6 drivers per side, 2xDD for the lows, 2xBA drivers for the mids, and 2xEST for the highs. The Sonora ($3000) has 8 drivers per side, adding 2 more BAs. Both have 6-way crossover networks.

From PLUSSOUND:

• 3D Printed Acoustic Chamber
• Polished, Anodized, cryogenically treated aluminum faceplate, body, and nozzle
• In-House designed cryogenically treated 0.78mm rhodium plated tellurium copper 2-pin with PEEK insulation
• Internal Wiring Copper XS (In-house designed cryogenically treated UP-OCC litz with proprietary PS Insulation)
• Impedance | 10 ohms @1kHz @1mW
• Sensitivity | 109 dB @1kHz (Volta) 110 dB @1kHz (Sonora)
• Frequency Response | 10hz - 40kHz
• In-house, curated Copper XL cable with exclusive two-tone y-splitter

Both the Volta and Sonora showcase PLUSSOUND's boutique craftsmanship. Each has a robust, artisanal shell with beautiful finishes and a premium feel. Volta offers a more understated elegance, while Sonora brings a modern and bold presence. Subjective, but I much prefer the Volta’s understated color vs. the Sonora’s flashy gold and red. One thing to note—yes, these feel like tanks but they are review units and I can’t say how many people have had them prior to me. The shells, especially the Sonora, are starting to show some age as you’ll see in the photos. Not many of us are chucking $3000 IEMs around but just know that the finish might show some wear if you don’t treat them properly.



Fit and comfort were excellent for me with both, despite the angles and larger nozzles, and the included accessories (especially the cable) felt very high-end and nicely-matched. While build quality is excellent, the cable is hefty and can hold some memory… this isn’t going to immediately lay flat on your desk with a quick roadie wrap.



The respective cases are also of high quality and the insert can be removed to store tips and maybe a backup cable, but there’s not enough space under it to hold a DAC. You ‘can’ squeeze a DAC in next to the cable, if you want a one case solution, just know that it’s not pocketable and probably better suited for a backpack.



The overall packaging—while neat and well-presented—doesn’t stand out to me or convey the luxury status or price point these IEMs occupy. There’s also little difference between opening a Volta and a Sonora, which makes the unboxing of the Sonora feel much less special. It’s not that the included accessories aren’t premium, they certainly are, they’re just all sort of fitted into this little box. Some people will appreciate this level of minimalism and compactness. For me, I’m more immediately impressed by an IEM like the Ice Lab Prismatica ($900), which has individual foam cutouts for each accessory, at the expense of the box being roughly twice the size.

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Sound

Bass
The bass performance of an IEM can define its identity—it's one of the most polarizing aspects, in my opinion.

Volta: The Volta approaches bass with a refined, articulate demeanor rather than the raw impact favored by bassheads. Its sub-bass extension reaches ‘just’ low enough to give weight to genres like synthwave or ambient electronic, but it never intrudes into the midrange. Instead, the bass is tight, controlled, and clean—ideal for modern pop tracks such as The Weeknd’s "Blinding Lights," where the kick has presence but remains a supportive element rather than dominating the mix.

Bass speed and precision are where the Volta shines. The dual DDs (for a double dose) produce a nuanced texture: you can clearly discern the decay of bass strings in classic rock tracks or the smooth glide of an electronic sub-bass in synthwave staples like Kavinsky’s "Odd Look."

However, even with EQ, the Volta doesn’t metamorphose into a bass monster, though the low end does sound fuller. You can add more warmth, but it still lacks the visceral impact of more bass-centric sets like the Campfire Trifecta. In the case of the Volta, this restraint ensures that complex mixes remain uncluttered and transparent.

Sonora: By comparison, the Sonora embraces a more robust bass character. Its isobaric dynamic drivers excel at delivering fuller bass while maintaining excellent texture. The mid-bass is more forward, giving electronic dance music and pop an infectious drive: tracks by Daft Punk or Calvin Harris come alive with nice energy.

Yet, this power doesn’t sacrifice control. The Sonora’s bass remains remarkably tight, with minimal bloom that could muddy the mix. There’s just enough warmth bleeding into the lower mids to enhance body without compromising clarity. A well-mastered track maintains its separation: you can distinguish between a synth bass line and the punch of a snare drum even in fast-paced alternative music or densely produced pop.

With a bass shelf, the Sonora will give you a little more low end at the expense of some clarity, so I opted for no EQ in most of my listening. Its default bass tuning already offers good depth and punch for everyone except bassheads, aligning well with energetic genres without additional tweaks.

Ultimately, the Volta appeals to listeners who prize precision and speed in their bass, ensuring midrange and highs remain uncolored. Versus the Volta, the Sonora caters to those who crave a deeper, more satisfying rumble without excessive bleed.

Mids
The midrange is where much of the soul of a track resides. It’s where vocals live, where most instruments sing, and where emotional nuance emerges.

Volta: The Volta’s midrange is perhaps its most captivating attribute. There’s a rich and organic texture to vocals that feels effortlessly natural. The Volta presents vocals with depth and nuance. It’s not overly forward, nor recessed—just placed tastefully within the mix. The lower mids carry enough weight to give electric guitars and synths proper body without muddying the overall clarity. You’ll hear the lush strum of acoustic guitars and the rasp of a vocal line without strain.

Midrange timbre is a strong point for the Volta. It feels lifelike, with smooth transitions from lower to upper mids. There's never a harsh edge or artificial sharpness. Piano or strings resonate with realism—making the Volta ideal for ballads, acoustic tracks, and more emotional content. The upper mids are gently elevated but never aggressive, which avoids sibilance while still giving vocals air and lift.

In tracks like Fleetwood Mac’s “Dreams” or Coldplay’s “The Scientist,” the Volta lets the vocals breathe and gives acoustic instrumentation space to resonate. It doesn’t push detail in your face; instead, it invites you in.

Sonora: The Sonora’s mids are more energetic but slightly less warm. There’s a bit more upper mid push, which makes vocals more forward and energetic. For modern pop—like Ariana Grande, Daya, Ed Sheeran, or Dua Lipa—this tuning adds vibrancy and presence. The vocals are a little more front and center, adding some intensity to upbeat tracks.

Sonora’s midrange still carries excellent detail and instrument separation, but it leans more technical than emotional. In songs with dense arrangements, the Sonora can dissect layers with a good level of precision, making it a solid choice for busy mixes.

With electric guitars, synthesizers, and complex percussion, Sonora excels. It’s slightly less forgiving of poor recordings than the Volta but offers more clarity when the content is there. Ultimately, the Sonora's mids are tuned for excitement and presence, while Volta’s mids are tuned for emotion and realism.

Treble
The treble region is where so much of the perceived air, sparkle, and detail of a recording lives. A well‑tuned treble can transform tracks from merely listenable to truly immersive, revealing textures and microdetails that lie hidden beneath the surface.

Volta: On my first listen, I noticed that the Volta’s treble is intentionally smoothed out—which lends to its non‑fatiguing, laid‑back signature. The lower treble carries essential vocal and instrumental presence, yet the Volta presents these frequencies with restraint. Sibilance is essentially non‑existent and mixes are never harsh or grainy. This makes the Volta forgiving of aggressive recordings, ensuring that longer listening sessions are comfortable.

Continuing up, there’s just enough energy to keep percussion and cymbals alive, though you’re not going to get much shimmer or sparkle. In classic rock tracks, the ringing of hi‑hats and the snap of snare drums had some clarity, even if they weren’t laser‑sharp.

As for air and spaciousness, this is where the Volta shows its most relaxed tuning. There’s a roll‑off, so airy reverb tails on synth tracks (e.g., Kavinsky’s “Odd Look”) are present but never overly prominent. For modern pop’s edm‑inspired drops, you feel enough atmospheric shimmer without it sounding synthetic or piercing.

At the highest frequencies (at least from what I can still hear), many of us simply want an impression of extension—fundamental harmonics and breath around instruments. The Volta provides a sense of openness here, but it’s subtle. It won’t expose every microdetail in a recording, though it manages to maintain the illusion of air, supporting a cohesive tonal balance.

Sonora: Where the Volta opts for smoothness, the Sonora chooses clarity and sparkle. Its EST drivers deliver lower treble with more immediate presence. Vocals feel livelier and more forward—especially female vocals. In modern pop tracks like Sia’s “Chandelier,” the breathiness has more texture, and sibilance, while still controlled, sits closer to the foreground, giving edge without harshness.

In the mid‑treble, the Sonora reveals fine percussion details which help create a sense of excitement. This region is tuned to preserve detail and transient speed. You hear stick hits and subtle slate‑room ambience that some IEMs smooth over.

The upper treble on the Sonora is where it truly shines. It is well extended, imparting an airy halo around instruments. On synthwave’s soaring leads and modern pop’s layered vocals, you feel reverb tails lingering, imparting a three‑dimensional shimmer. This makes tracks sound larger and more holographic. However, on already bright or poorly mastered songs, the extra treble can verge on fatigue, especially at higher volumes.

Summing the two up here, the Volta is relaxed, smooth, and non‑fatiguing. It prioritizes comfort and long‑listening use, ideal for listeners sensitive to sibilance or who value a holistic tonal balance. If you like to listen loud, this is the one I’d get. The Sonora, in comparison, is detailed, airy, and sparkly. It prioritizes resolution and excitement. It’s more ideal for those who want to uncover nuances and enjoy an expansive, glittering top end. If you don’t find treble fatiguing and want something more fun or energetic, get the Sonora. But if you listen moderately loud, these can cause fatigue… we have different tolerances so take what you will.

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Soundstage & Imaging
Soundstage and imaging are often what separate great IEMs from extraordinary ones. They provide the spatial context that makes music feel immersive and multidimensional.

Volta: The Volta’s soundstage isn’t massive in width, but what it lacks laterally, it makes up for in some verticality and depth. Vocals feel like they rise and hover just above your head, while bass elements sit firmly below. This vertical expansion adds a unique dimension to orchestral pieces and live recordings.

Depth is another strong suit. Instruments are layered with nice front-to-back positioning. This lets you clearly distinguish background vocals from lead singers, and secondary instrumentation doesn’t collapse into a mix. It maintains a well-structured stage where every element has its place.

However, it’s important to note that this precision doesn’t come with a wide-open feeling. The Volta feels like an intimate room rather than a grandiose concert hall. For genres like jazz or acoustic, neither of which I’m hugely into, I can see this being a plus. But for those seeking a massive, out-of-head experience, it may feel constrained.

Sonora: The Sonora trades some of the Volta’s vertical precision for a wider, more expansive soundstage. The horizontal spread is immediately noticeable. Instruments pan further out, vocals are a touch more central, and reverb tails stretch a little longer. This creates a more holographic effect, especially with genres like synthwave or modern electronic pop where sound design is space-driven.

With Sonora, you get a greater sense of everything happening around you. On tracks like Kavinsky’s “Nightcall” or Lady Gaga’s “Rain On Me,” the width envelops you more, and instruments rarely overlap in undesirable ways.

Imaging is still accurate, but not as pinpoint as the Volta. There’s a little more diffusion in the presentation. This softens the edges a little, which works well for lush, layered tracks but might reduce perceived precision in leaner arrangements.

Where the Sonora excels is in delivering a more immersive, exciting listening experience. When paired with the right song, that’s when I feel like this IEM commands its asking price. The extra air and sparkle up top also help create a greater sense of openness, which contributes to the wider soundstage.

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Noise Floor
On my iFi Pro iCAN Signature, HiBy R6 III, and iFi Go Bar Gold, the Volta and Sonora both revealed a noise floor on medium or high gain during quiet passages, but switching to low gain improved the background significantly.

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Final Thoughts
Both the PLUSSOUND Volta and Sonora are beautifully crafted, sonically refined IEMs with unique personalities. The accessories included are of high quality, especially the cable—this isn’t some $30 courtesy, and it’s nice to see more manufacturers include premium cables with their offerings. Because of its thickness and weight, it’s not going to be to everyone’s liking. I’d like to see PLUSSOUND offer an optional version of these IEMs with a cheaper cable at a reduced price so that we can go out and use our own.

From my perspective, the Volta is the better choice for listeners who want smoothness, vocal intimacy, and natural timbre in a relaxed package. If you like to listen loud or for longer periods, this is the one I’d recommend of these two.



The Sonora steps up with more dynamic punch, a wider stage, and better detail retrieval. This is the more exciting IEM by a longshot, and a better fit for those who listen to pop, edm, or enjoy a livelier tuning with more bite, like myself.



These are two different flavors of high-end sound. And honestly, they complement each other surprisingly well in a collection.

Thanks to Christian at Plussound and Sebastian Chu for arranging this tour for the Volta and Sonora, Plussound’s 3rd generation IEM (FYI: The first being an earbud type IEM that use to show for sale on Plussound's website, many feel the Allegro was Plussound's first IEM)
Typical of Christian’s work with Plussound’s cables and his attention to detail of how subtle changes in materials and formats make a huge change in sound, this level of work is again apparent on the new Sonora and Volta IEMs.

I wanted to join this latest tour as until recently my daily driver IEM was the Plussound Allegro, so there was a lot of interest on my part to see how the Plussound IEM line has evolved from the Allegro, Plussound’s 2nd generation IEM.

I’m going away from the “Pro’s/Con’s” format usually done on these showcase reviews because there are 2 products, and it will be easier covering each and contrasting the differences, and comparing to the Allegro.

While billed as being less bulky than the Allegro, I never found the Allegro to be bulky. While it was a large IEM it was comfortable in my ear.
Both the Volta and the Sonora were slightly smaller (thinner front to back, with a less bulbous backside lying against the concha of the ear) and were about the same comfort for me as the Allergo, but both are still much bigger than some IEM’s currently out there.

Like the Allegro, both the Volta and Sonora were very TIP sensitive. Changing from one tip to another has a dramatic change to the sound. I was also looking for a tip that I could use on both IEMs to remove another variable for this write up
Like the Allegro I went through quite a few tips and similarly the same 2 came up as for me the best in sound quality.
Tips utilized on both the Sonora and Volta were:
Plussound Silicon
Plussound Symbio
Plussound Comply
Azla Crystal (OG/V1)
Azla Xlastic (OG/V1)
Divinus Velvet Std Bore
Divinus Velvet Wide Bore
Eletech Baroque
Pentaconn Coreir Brass
Pentaconn Coreier Aluminum
Spinfit W1
Spin Fit 145
I quickly eliminated the Divinus Velvet std bore and both the Brass and Aluminum Pentacon Coreir tips.
The Std velvet killed too much of the sound on the Volta, but were OK with the Sonora, the Corier tips for me were not comfortable to wear with the Volta or Sonora.

I found the sound to be quite different in the following ways when I rolled the tips on both IEMs
Plussound Silicon – As with the Allegro, the bass took an immediate hit sounding thinner despite having a good seal. The highs sounded veiled, and for the Volta went immediately shrill for me.
Plussound Comply – I’ve not had good luck with comply tips, and no difference here. I still attribute this to the small but long bore size of the Comply’s. Bass was again killed off, sound became immediately mid centric.
Plussound Symbio – Different than the Allegro, which these were the worst sounding on the Allegro, for the Sonora and Volta, it was of the better sounding tips from Plussound, but still far from my ultimate choice
Azla Crystals – For sometime these were my tips of choice for Allegro, and did well with both Volta and Sonora. Bass cleaned up and had better presence, mids were more neutral, highs became more cohesive with the mids. Great sound
Azla Xlastic – similar to the Crystal tips, but less comfortable fit wise, and on odd harmonic in the mid highs made them not as easy to listen. On the Volta created a uncomfortable peak with the mid highs which made it a bad choice to use on both.
Eletech Baroque – Improvement over the Azla Crystal tips. Better bass/sub bass, while keeping the mids the same. Highs gained a little clarity.
SpinFit W1 – Very comfortable fit wise, mids and highs gained clarity but the bass response was cut back vs. Azla Crystal and Eletech Baroque. Great for someone wanting to enhance mids to be a little more forward and attenuate the highs
SpinFit 145 – Nothing bad, but nothing standout either. Similar bass profile as the W1

Doing some back to back between the Azla and Eletech eartips, I found the sound enhancements stayed the same between Volta and Sonora when using the Eletech Baroque tips vs with the Azla Crystals, where the Volta gained a little more energy on the Highs which caused me to have to not use similar volumes. Decided to use the Eletech Baroques for the rest of the listening time/tests to keep things to just the differences of the 2 IEM’s

Cables.
Now with the Allegro this IEM seemed to like cables that are Silver or Silver Hybrid.
With the Volta and Sonora shipping with the new Copper XL Plussound cable, I put that cable onto the Allegro. It seemed to be OK with it, but not at its best.
This had me then look into doing some cable rolling to find a cable all 3 IEM’s could use so I could again keep the differences in sound to just the IEM
Rolling through a number of cables I have on hand. Tthough I really wanted to put into the mix some cables members of the Watercooler thread who are near me had, but decided against it and used just what was on hand – I also wanted to try and use a Plussound Cable which I have many versions of, as this is a Plussound sponsored tour.

Another consideration I had to stay with what I had on hand, was to stay with a copper based cable or copper blend cable (many of the newer cables are mainly silver based), as during my pretesting of both using cables that were silver based, the Volta did NOT respond well, going sibilant and shrill to my ears. It preferred copper or copper with gold, or Palladium platting. The Sonora was fine with and even excelled with silver in the cable. Because of this, I scratched cables that had silver as a main component off the list to use. This also meant the Plussound PPH and Eletech Sonnet of Adam which were my go to cables on the Allegro might not be the best for this testing.
These are the cables I rolled onto the Sonora and Volta (prices are MSRP)
Plussound Copper + $999.00 (the coaxial stock cable that comes on the Allegro)
Plussound Hybrid+ $1299 (Coaxial Silver + Coaxial Copper mixed cable)
Plussound Quad Copper X8 $1600 (Copper, Silver Platted Copper, Gold Plated Copper, Palladium Plated copper)
Plussound Copper XL $800 (the Stock Cable for Volta and Sonora, 18AWG copper)
Plussound PPH (Palladium Platted Hybrid) X8 $3500 (Palladium Plated Copper, Palladium Plated Silver)
Eletech Ode To Laura $2799 (3 types of UPOCC copper)
Eletech 5th Ode $3499 (Copper, Gold Platted Copper, OCC Graphene)
Eletech Aristotle $749 (2 types of copper - OCC copper, Oil Soaked Crimson OCC copper)
Eletech Sonnet Of Adam $2799 (Gold Platted Copper, Gold Plated Silver, Silver Gold Blend)

Without boring with details, as mentioned above the Volta preferred Copper, or Gold/Copper blends by far.
The Sonora did well with these type of cables (and was also good with Silver Based), as did the Allegro
It came down to the Plussound Quad Copper and the Eletech 5th Ode.
Unfortunately both of these are limited run cables and while both are still in inventory for sale, they will be harder to find. But it kept the cable enhancements similar across all 3 so I decided between these 2 cables, and I found there Volta preferred the 5th Ode more than the Quad Copper, while the Sonora and Allegro were fine with either, so chose to use the Eletech 5th Ode for the rest of my tests.
YMMV when it comes to cable choice, just wanted to lay out I was looking for minimal changes across all 3 so it really came down to the IEM’s themselves

My sources were:
Cayin N30LE Amber Pearl Edition, running in Class A, Classic Tube, Med Gain modes.
Uses the AKM 4499EQ DAC
Lotoo PAW6000 running as is ( Solid State mode) and also running Line Out mode into a Cayin C9ii also in running in Class A, Classic Tube, High Anode, Med Gain.
Utilizing the AKM 4493 DAC chip as the output
Both IEM’s responded well with additional amplification and/or gain (The N30LE or C9ii amp stages), but are easily driven with standard amplification from both DAP’s.

Music files for this testing were all FLAC files ranging from 16bit to 24 bit and 44Khz to 96Khz
Genres of music ranged from Modern and Classic Jazz, 60’s-80’s rock, 70-90s R&B, some classical and some Pop.

Now with the lead In done this is what I heard


Volta
MSRP $2499
Driver make up - 2 Dynamic, 2 BA 2 EST (6 per side)
The IEM is positioned on Plussound’s website as follows:
The overall tuning for VOLTA is crafted to offer a neutral frequency response with slight emphasis on lows and highs for a versatile listening experience that is both engaging and accurate

I found this to be mostly true, but vs the Allergo and Sonora, it had a much narrower and shallower, more concentrated and centered soundstage.
Friends who are into Electronica/Club type of music (admittedly I am not) have stated to me that they look for IEM’s with this type of profile, as they want the sound to be “in your face”. Talking to some other IEM engineers at several CanJam’s they have stated they concentrate on creating that type of “concentrated wall of sound/in your face” presentation when catering to this type of listener. The Volta seems to do this.
With Jazz recordings the mid to high transition was more abrupt With classical rock, the step from bass to mid bass had a similar abrupt step. The tuninng of the Volta might be for some who possibly look for that Narrow Stage / in your face/centered type of tuning
Not sure if Christian chose the name Volta to impart that sense of energy this IEM seems to exhibit.
Also I notice the Volta seemed to have a sweet spot when in my ear, and by making sure the angle the sound tube was properly aligned in my ear, by rotating it while in my ear backwards or forward, when aligned, the sound was much clearer, much more neutral. I did NOT have this type of placement issue with the Sonora, and never had it with my Allegro
I also think because of this emphasis of placement in the ear, and narrower stage, silver cables just don’t play well on the Volta (IMO) and it really did prefer copper cables by far
As I don’t think I am the target listener for the Volta, and given the proximity of price to Sonora and I do NOT feel I am the target listener, I’ll end my sound comments here.

Build quality was excellent, the included accessories and attention to detail did not disappoint and is what I’ve come to expect from ANY of Plussound’s products
IF what I’ve said about the Volta appeals, it is a well built and equipped IEM, that should be part of your consideration list.


Sonora
MSRP $2999
Driver make up = 2 Dynamic, 4 BA, 2 EST (8 per side)
The IEM is positioned on Plussound’s website as follows:
This tuning approach provides a more engaging listening experience, adding a touch of excitement and sparkle to treble while reinforcing the bass impact. SONORA delivers a versatile listening experience that caters to a wide range of listeners, from audiophiles seeking detail and transparency to casual listeners who enjoy a lively and dynamic sound

Again I found this to be true.
Sonora by far had a wider range of music it played well with and sounded great with.
It had a much wider soundstage than Volta, and added more depth. Stage height was similar.
I found the Sonora to offer more layering than the Volta
I found it to be mildly V shaped, not quite W shaped in its sound presentation.
There was a nice coherency from lows to mids and mids to highs.
It was a very easy to listen to the Sonora, and it played well with all genere’s of music I threw at it. It is a very musical sounding IEM
The Sonora traded away a little clarity and pinpoint positioning to be a little more musical, and slightly warmer colored in its sound than the Allegro. The Allegro is much more reference in its sound. It has better clarity and is very precise with its instrument placement. The Allegro also had a wider, deeper and taller stage than the Sonora. The Allegro to my ears also had a little more extension to the highs taking away a little of the warmth I heard in the Sonora.
For both the Sonora and Allegro, these IEMs seemed to appreciate a little silver in the cable make up. They both responded with more sparkle and cleaner highs and an even wider soundstage with cables like the Hybrid Plus, and the PPH X8 from Plussound and the Sonnet of Adam from Eletech. This clearly differentiated the Sonora from the Volta.
The Sonora was OK with all silver or predominately silver cables, but the Sonora appreciated mixed metal cables with copper in them much more than straight silver cables. I tested this via a quick session using both Plussound’s Tri-Silver (Silver, Gold Silver Mix, Palladium Platted Silver) and Eletech’s Euclid (Silver and Silver with 2% gold). I did not include these in the cable used mention as it was a quick test that proved it was not the right cables to do extensive listening with on the Sonora.

Build quality was also excellent, the included accessories and attention to detail again did not disappoint and as mentioned previously is what I’ve come to expect from ANY of Plussound’s products
IF what I’ve said about the Sonora appeals, it is a well built and equipped IEM, that should be part of your consideration list.


Summary of what I heard between the 3.
As I kept the variables to a min of just being the IEM’s here is what I hear.
If your looking for a more reference sound in a Plussound IEM, it is the Allegro
If your looking for a musical slightly warmer sounding IEM that still offers accuracy with a wider soundstage, it is the Sonora
If your looking for a IEM that has a more aggressive sound signature, but not necessarily wide stage and a little of its accuracy traded for pace and energy, it is the Volta.
While there is nothing wrong with using the stock cable, both the Sonora and Volta did respond well to multi metal cables from Plussound that are still available such as the Hybrid + and the Quad Copper.
Similarly tip rolling is encouraged and you should consider at least auditioning with the 3 included tip choices but you may find your current tip of choice might be the right tip for you.
The Volta does represent a cost savings if the suggested sound signature is to your liking.
But IMO the better of the 2 is the Sonora.
Given Sonora’s pricing, and the sound I heard, it should be competitive with the other IEM’s in its price range, and IMO should be included in IEM’s your looking at, at a similar price currently (disregarding some of the latest releases at CanJam NY),
But if your looking for a more reference tuning with a touch better clarity in a Plussound created IEM, perhaps look for a used set of Allegro’s

If you’ve made it this far, thank you for reading my write up.
And I do want to emphasize all that I wrote above is 100% IMO, and YMMV

Thanks for the tour that organized by @Sebastien Chiu and PlusSound for providing me with the opportunity to demo Volta and Sonora. Since I haven't heard the Allegro, which is the first IEM released by PlusSound, this is also my first time hearing the PlusSound IEMs.

For the readers who do not know PlusSound, which happens to be a local company for me, it has been one of the household names in the headphone and IEM cable industry since 2012. I had the pleasure to also demo PlusSound’s recently released two cables: quad-copper custom cable and copper XL custom cable, which is used as the stock cable for both Volta and Sonora in another tour last year. PlusSound entered the IEM market two years ago with Allegro ($3,499.99), a TOTL proposal that received good review but failed to gain big traction in the market.



Vota ($2,499.99) and Sonora ($2,999.99) are the second release from PlusSound, but with much reasonable prices. Compared to the flagship Allegro, they have the similar tribrid driver configuration but with just a smaller driver count: Vota has 6 drivers and Sonora has 8, compared to the 12 of Allegro.

The unboxing is very impressive, not in terms of Sony IER-Z1R level, but nevertheless very premium, as you can see from the carrying box and accessory pouch below.




In terms of the design, both Vota (grey body) and Sonora (gold and red body) are designed with a 6-way crossover with tribrid drivers: the same dual 10mm DDs in isobaric arrangement for low and sub low frequencies, the same dual electrostatic drivers for high and super high frequencies and only differs in the mid-range with Volta having 2 BA while Sonora having 4 BA.



Both Vota and Sonora give you a premium feeling: the sculptured shell is built with anodized aluminum from precision CNC machinery. Then the IEM body is polished and anodized with subsequent cryogenically treatment.



Both IEMs used PlusSound’s own copper XL as the stock cable, which by itself is a $749.99 MSRP premium cable.

The bore of both IEM is wide, and you need appropriate eartips to fit them. For me, one of the most satisfactory matches is with Pentaconn COREI brass tips.

Now let’s talk about my sound impression. I primarily use both IEMs from my desktop gears, which consisted of ADI-2 DAC to Flux FA10 amp or Hagerman Tuba tube amp. I also used iBasso DC-Elite dongle directly from PC. For DAP, I used Sony NW-WM1Z and NW-WM1ZM2. I find both Volta and Sonora tuned with a balanced and safe all-rounder style. Their tunings are slightly different: Volta is more neutral with a slight V shape to boost the bass and treble while Sonora is more exciting with slightly more V shape, or some may call a W shape since the vocals are not recessed.

None of Volta or Sonora is tuned with bass-head level boost, and you will not find bass as the center point of your attention. However, when you pay attention to the bass, you will find the bass is so powerful and impactful that the bass performance is not outshined by even the best TOTL IEMs in bass area. For example, I listened to Volta and Sonora side by side with Campfire Trifecta, and I didn’t find the bass from either Volta or Sonora inferior. The only difference is in the bass quantity, which is one of the tuning choices. As a matter of fact, Volta and Sonora sound like Trifecta equipped with faster and modern dynamic drivers in some tracks that I was listening to.

In terms of the mids, vocals are engaging and natural with Sonora being slightly more resolving. Again, both Volta and Sonora have the similar treble performances, which is airy without sibilance.

The soundstage and imaging of Volta and Sonora are also at TOTL level, though they are not doing anything particular to impress you such as in some of the TOTL IEMs with bone conductor driver.

The overall impression of Vota and Sonora reminds me of AK/EE Novus, which is a $4,999 TOTL IEM, and that says a lot about the value of Vota and Sonora. The safe tuning choice of PlusSound for Volta and Sonora makes them fantastic value for those who are looking for a all-rounder IEM with the performance at TOTL level but may also turn those people away if they are looking for special sauces.

Even though Volta and Sonora are tuned differently, they are not that different from my perspective. I personally prefer Sonora since it is more exciting and more engaging.

To sum up, it is very hard to find fault of Volta and Sonora, if you only want to spend less than $3k and want an all-rounder IEM without any particular strong preference, such as bass-head or treble-head, then you will be very hard to find anything better than Volta or Sonora.

Now one of the cons that I noticed is the stock cable. The cable is excellent in terms of sound performance, but it is heavy and not very flexible. This coupled with a lightweight IEM body makes the fitting an issue for me since the cable has the tendency to drag the IEMs out of my ears if I move around too much.

The music I was listening to during this demo varied from pop, classic rock, hip hop, metal, to electric. I found both Volta and Sonora handle them effortless.