Westminsterlab Quest preamplifier review

The WestminsterLab Quest solid-state preamplifier is the latest addition to the portfolio of this unique and highly interesting high-end audio company. Following the extremely positive debut of WestminsterLab electronics with the introduction of the REI Class-A power amplifiers I reviewed here, the Quest follows the same uncompromising path that anchored by REI.

Here is the breakdown of all the important features and what makes the WestminsterLab Quest very different from the beginning.


The ultimate aim of the Quest is to create the perfect preamplifier to accompany the Rei and the cables lineup. With the Quest, WestminsterLab completes the complete high-end audio loom between the source and pair of speakers. Setting out to push the boundary, it redefines how a preamplifier can contribute to the system and the ability to extract every bit of potential from both the recorded music and the music reproduction system.


During the inception of the project, the WestminsterLab team endlessly question the role of the preamplifier in an audio system and constantly challenge whether a preamplifier is absolutely necessary for a system and what qualities the added stage can bring or may bring to the outcome. They've begun with a fresh start to investigate the relationship between the source and the amplifier. Every section of the preamplifier has been looked at thoroughly to see how every single part could be improved and also what kind of synergy can be extracted from each and every part.


Not all experience that was gained from developing UNUM and Rei could be transferred to the Quest. As High Current & High Voltage signals behave very differently to Small Current and Low Voltage signals which the Quest handles. Everything has to basically start from scratch from how the signal is handled, the route it goes through, the types and materials of resistors and transistors, etc. It is a completely fresh start from the ground up.


For both Rei and UNUM amplifiers are a fully balanced design, it is obvious that WestminsterLab prefers balanced architecture and surely the Quest is featuring full balanced architecture. For the Quest preamp, WestminsterLab has taken this concept even further by using a rarely adapted dual-mono full balanced design. 

From the input selection relay, input circuitry, volume control all the way to the output driver circuitry, both left, and right channels are completely isolated, bringing an exceptional channel separation to the Quest to preserve the finest and most delicate musical information.


The power supply of the Quest provides the fundamentals to the extraordinary musical performance. With 10 separate power rails, they provide the highest possible separation between different channels and for different parts and modules within the unit,

Different rails are designed specifically to the needs of different sections of the particular part due to the varied needs and conditions, ensuring ultra low noise performance to deliver the micro dynamics and details within the music. An extra and separate transformer and power supply are dedicated to the non-audio section. In some parts, 2-stage linear regulation is adapted to exert more control on the regulation for some ultra-sensitive components within the Quest.

The O type transformer used in the Quest provides even higher efficiency than usual toroidal and a cleaner, purer, faster power due to its different iron core design.


Signal attenuation is one of the main functions of a typical preamplifier. There are many different ways to attenuate the signal - optical coupler, autotransformer, resistor ladder, etc, and each of these solutions has its ups and downs and may heavily impact the behavior and quality of the sound.

After extensive listening test and lab analysis, Leung and his team have chosen a shunt type stepped resistor network solution. The 4 channels of 64 steps precision resister network and ultra-low noise relays have their own dedicated power regulator and power supply. WestminsterLab engineers have also kept the control logic as minimal as possible, an LED display with remote control function only. It further minimizes any possibility of interference.


The overall ground design and grounding scheme can hold a significant impact on the overall performance of the system, especially for tiny signals like the Quest handles. Tremendous effort has been put to design the grounding of the Quest and a new grounding scheme - Hybrid Grounding was developed. Hybrid Grounding allows users to switch between two grounding modes on the fly to configure their Quest specifically for their system and look at the grounding scheme as a whole.


WestminsterLab has gone to the end of the world and taken extensive measures to protect the fragile signals going through the Quest. Metal absorbs radio interferences from the environment and these interferences then convert to electrical noise and magnetic disturbance which affect the whole system.

Therefore, extensive use of carbon fiber as shielding materials was adopted inside out, instead of the usual copper or aluminum braids and foils, which does not generate any magnetic fields and unwanted eddy current, and amazingly in return, it rejects interferences without absorption in nature. It also provides very high stability over environmental changes and extreme rigidity which gives low resonance and vibrations.

Furthermore, many signal handling relays in the Quest feature a soft start mechanism, different sections within the unit are isolated and compartmented, making sure that the cross-interference is minimized.

For customers who want the best of the best, they can choose to purchase the extended carbon fiber option which adds another layer and barrier of carbon fiber shielding inside the unit.


At the back of the unit, there are two slots where users can insert expansion modules in the future. These sockets are designed to provide flexibility to design modules to add more input functions to the unit. For now, there is an RCA input card, and in the future, there may be a phono input card or even a digital input model.


By reducing unnecessary components and simplifying the schematic another advantage in the flexibility in designing the layout of the PCB was gained. This flexibility enabled WestminsterLab to design the layout to minimize the interference between signals and power supplies. If possible, signals often run perpendicularly to each other, even if not, they would run as further away from each other as possible to reduce unwanted interferences.


The ethos behind the industrial and electronic design of the Quest echos with the WestminsterLab tradition. 

Keeping unnecessary features and ornaments to the minimum brings the purest musical and user experience to your living room. No fancy color display, UV meter, or any distracting items. Prepare to rediscover your music.


Sometimes exceptional high-end audio products require a recalibration of our fundamental listening criteria, and the WestminsterLab Quest preamplifier triggered a far more unceremonious evaluation and emotional impact than expected. 

The special and outstanding quality of the Quest preamplifier stretched from track to track, album to album. Below are some music references that address in detail some of these specific and special sonic qualities.

The calmness and vivacity of Patrica Barber's Bye Bye Black Bird lingered long after listening, and everything was spot-on with Quest at all times. 

It was interesting to hear how well the Quest handled Barber's voice without pushing the sibilance into the brittle realm, which happens too often with solid-state preamps, regardless of price. 

The Quest's coherent inner core presented Barber's emotional scenery with rich fundamental harmonic quality, holistically incorporating the primary colors without the sonic glare or scent of tint.

Barber's sublime tale, coupled with a sumptuous musical narrative, unfolded with the WestminsterLab Quest preamp as the sonic arc of the journey.

But tonal and notes clusters were not the only things that stood out with the Quest. A greater expansion in space and time was immediately established with the upbeat and groovy "So Groovy" by Manu Katché from the album Playground.

The Quest let the groove and dynamic rhythm unfold with refreshing spontaneity. The variably and ever-changing beat was effortlessly locked with the tempos without drifting off during complex passages. 

The bass and the entire lower register were handled prominently without any none of the artificial dynamic congestion. 

Neither metallic percussion nor brass instruments are easily rendered smoothly on "So Groovy," and any imbalance in the system causes the song to fall apart and char the overall tonal contour. Not so with the Quest. As with the REI power amps, everything was balanced and operated at the golden epicenter.

Quest's micro and macro dynamic unfolding were top notch and the energy level was kept vigorous at all times. The high-octane dovetailing of JMJ & Richie's "Free La Funk" (PFM Remix) was an instant affair!

"Free La Funk" can decipher any dynamic inconsistencies that might appear with the introduction of a new and unfamiliar part of the high-end audio chain. 

Impressively, the WestminsterLab-Quest preamp reproduced JMJ & Richie's composition without falling into cauldron realms but presented a crucible quality by not only handling the demanding dynamics expertly but also accomplishing to unleash the song's perplexed and origami-like nature with higher-end mass and dynamics.

WestminsterLab profound truth quality was unquestioned with the opening track "Starlings" by Vijay Iyer Trio from the album Break Stuff. "Starlings" obviously showed the true nature of Quest's inner core, working far from the split-mindedness effect or steamroll character too easily attributed with too many preamps on the market, whether tube or solid-state. 

WestminsterLab Quest preamps resolve sonic reality with distinct nuanced dynamic diversity and by handling the general excellence, instantly recalling momentum and stitching together a greater degree of interactiveness than usual. 

The same higher-grade resolving was evident with the rendition of individual notes. They were not artificially stacked, but necessarily separated from each other allowing the minuscule decays and delays resounding properly.

Many high-end audio preamps, regardless of their respective prices, handle this particular characteristic imperviously and in the complete absence of extraordinaire. 

The WestminsterLab Quest preamplifier has another unique feature. It can replicate and propagate the outer and inner shell of music equally well across all musical genres unyieldingly.


I'm sure you've gotten an idea of how much time went into the production of the WestminsterLab Quest preamp. The REI Class A power amps have shown how seriously Angus and the WestminsterLab team take their products, and Quest not only builds on these foundations but continues to explore the universe of micro-amplification with WestminsterLab's proprietary fully balanced topology and extremely refined circuits. 

WestminsterLab has managed to trickle the technology of a splendid REI Class A power amp without losing the essence of what makes REI such memorable ultra-high-end power amplifiers. 

I have tried Quest in many pairings, but as expected there is a certain outstanding and potent synergy with the WestminsterLab Res power amps that strengthen the dynamic synergy and allows ultra subtle feather-light nuances in music reproduction to manifest.

Quest is a contemporary high-end preamplifier that boasts the familiar analog quality deeply cherished by aficionados. In addition, the Quest operates with unique transparency that allows for an impressive level of sonic and dynamic expansiveness where it is needed and called upon. 

Regardless of price, any high-end audio product must not only form a complete great-sounding and great-performing device that can operate with the rest of ancillary high-end audio reference components. It also needs to fulfill music's essence through all aspects, and WestminsterLab Quest does just that. It always puts the music at forte. 

The Quest preamplifier does not misinterpret the original message but delivers a lucid and luminous vibrancy, always with its unique orthogonal quality. 

I'm sure it was no easy matter for the WestminsterLab team to voice this solid-state preamp, but a few of the replayed notes reveal what the driving forces behind the Quest concept were: to deliver the unadulterated music, reproduce it with no character of its own, and let the powerful inner core to unleash a majestic aural illusion. 

The Quest preamp dispenses a non-subtle, decisive difference in what sets a high-class preamp apart from a mediocre one at any moment.

By default, the Quest subsumes exceptional tonal and transient density, as well as a unique horizontal and vertical localization permitting an utterly reflexive sense of a recorded event.  

Like the REI amplifiers, the WestminsterLab Quest preamp is deliberately stripped of unwanted technical bells and whistles, thus cleverly avoiding complexity for the sake of it and consequently staying away from unwanted saturation, complexity, distortion, resonances, etc. 

With the Quest preamp, WestminsterLab continues the remarkable product output of the standout products. It's remarkable how to complete Quest is for a "first-born" preamp. 

Considering how perfected the WestminsterLab REI amplifiers were, it is easy to understand that the same dedication and effort went into the development of the Quest. 

The WestminsterLab Quest is aquarted with quality on all fronts and offers a transparent window into an infinite world of music that is neither glossed nor colored. Like the REI amplifiers, it offers an expansive platform that can deliver a grander than usual dynamic scale in an organic manner that is not easily achieved. 

The team at WestminsterLab is doing something profoundly right with the design of their products, which began with high-end audio cables, continued with REI power amplifiers, and is now topped off with the Quest preamp. I am more than happy to acknowledge the sonic excellence of the WestminsterLab Quest and the effort and meticulous dedication that went into the WestminsterLab Quest preamp with the 2021 Mono and Stereo Editors Choice Award. 

Too many times in our beloved industry the technical and exotic blurb is lost in translation when reality strikes and the product is put at the real-world test.  It is great and enlivening to see such a young team set their sights so high and deliver what is marketed. ⧉

Matej Isak


  • 22.000 USD 
  • 1000 USD - optional extended carbon pack


  • Distortion: less than 0.0001% @ 1kHz
  • ​Signal-to-Noise Ratio: more than 120dB, unweighted 
  • Input: 3 sets of balanced XLR input, 2 optional modules
  • ​Input Impedance: 51 kΩ​
  • Input Voltage: 6Vrms
  • Frequency Response: 2Hz to 100kHz, 0.1dB
  • Outputs: 2 sets of balanced XLR outputs
  • Output Voltage: 12Vrms
  • Channel Separation: more than 120dB
  • ​Gain: 6.5dB
  • ​Volume Control Range: 0 to -63dB / Mute
  • ​Dimensions: W470 x H110 x D392 mm
  • ​Weight: 13.2KG



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