Trinnov Amethyst Stereo Preamplifier Reviewed

I was introduced to Trinnov more than a decade ago when the company’s Room Optimizer was demonstrated to me through a Sherwood R-972 receiver. Now, more than a decade and hundreds of product demonstrations later, I am still very impressed with the Trinnov room correction system. Room Optimizer is now available as part of Trinnov’s own high end stereo audiophile preamplifier, the Amethyst. 

When I unpacked the solidly built, 21-pound Amethyst, I thought the rear panel looked like a computer connection panel on the left side and an audio panel on the right. Around front, it looks more like a well-finished, well-equipped audio component—with two large knobs flanking a large screen that’s offset to the right side of the faceplate. 

Before I get further into any details about the Amethyst’s specifications or Trinnov’s Room Optimizer, we should talk about your room and speaker placement. The better your room is set up to start, the better your results with Room Optimizer will be. You may have read about Trinnov’s “Remapping feature” that acoustically moves the speakers to their optimal position, but this doesn’t mean you should completely ignore your room setup and put a speaker behind you or hide it with your significant other’s favorite oriental screen. The basic principles of physics still apply even if you are wielding a powerful acoustical tool in this preamp. 

The Trinnov Amethyst has 12 inputs, including AES/EBU, S/PDIF (coaxial and Toslink), and network (Wi-Fi and Ethernet) connections. The digital inputs accept up to 24-bit/192-kHz AIFF, FLAC, and WAV files. On the analog side of the house, there are two pairs each of balanced and unbalanced inputs, one of which can be configured as an MM phono input. Analog signals are digitized at 24-bit/96-kHz resolution. For outputs, there are two each of AES/EBU and S/PDIF (coaxial) and two each of balanced (XLR) and unbalanced (RCA) analog. If you are one of the very few people who use an external clock, the Amethyst has you covered with Wordclock BNC input and output connections. The Amethyst is also a DLNA, UPnP renderer and a Roon Ready player.

What Makes the Trinnov Amethyst Stereo Preamp Special?

Trinnov’s Room Optimizer is the thing that makes the Amethyst really special. Trinnov is highly regarded by industry insiders for its room correction, but the company has also made one hell of an audio component here. Now that I’ve had a chance to use the Amethyst in my own system, I understand what the hype is about. This is a serious tool. 

In addition to traditional room correction, the Amethyst can also act as an active crossover. The two pairs of analog outputs can be figured as follows: traditional one channel of amplification per speaker, bi-amping, 2.1 bass management, 2.2 mono bass management, or 2.2 stereo bass management. Crossovers can be set semi-automatically or manually. Since the crossover system is digital, there’s a wide range of options in filter types, slopes, and even a filter designed for horn-loaded speaker systems. While this seems complex, there are easy graphical instructions to follow, and the system is capable of automatically adjusting for levels, polarity, and delay. 

If you have a turntable in your system, the Amethyst has you covered—and not with some basic, run-of-the-mill phono section. The Amethyst includes Trinnov’s proprietary HybriD system that implements the RIAA correction curve in the analog domain at lower frequencies and digitally at higher frequencies. While most of my listening was with digital files, I did listen to some vinyl, and this system did a nice job with it.

I used the Amethyst in two completely different types of rooms. One is a large living room with an open area adjacent to the right, and the left speaker is about four feet from a sidewall. It’s not ideal from an acoustic standpoint, but necessary for family traffic flow. The other room is my main listening room, completely treated with Vicoustic acoustic panels. The preamp’s versatility to accommodate both rooms was most impressive. 

Not only did I use the Amethyst in different rooms, but I tried a variety of speakers—including Focal Kanta No. 3s, JBL HDI 1600s, RBH SVTRs, and Revel F328Bes, with and without dual SVS SB2000 and SVS PB4000 subwoofers. This preamp can get along (and fix acoustical anomalies) with nearly any respectable audiophile speaker on the market today, as well as manage the potentially complex needs of subwoofers. 

As indicated above, the Trinnov Amethyst has extensive audio-calibration capabilities. To make adjustments, you need to use the Amethyst’s graphical user interface, which can be accessed by any computer or an iPad or tablet running a VNC client so that you can see the data on the smaller screen. Any laptop or computer works too. The Trinnov GUI allows access to all the typical setup materials, such as input naming, but the really interesting part is when you get into the Room Optimizer tools and presets. An added benefit to the VNC connection is that representatives from Trinnov can access your processor to assist with any setup and calibration.

The first thing you will notice when using Room Optimizer is that the microphone is a serious, highly engineered piece of hardware, with four capsules mounted in locations that differ in all three positional axes. The microphone does not come with the Amethyst but is available as a separate purchase for $850. If you are just going to set up your system once and not make further changes, you will probably want to just borrow the microphone from your dealer if they are doing already doing the initial installation. On the other hand, if you might change out speakers or make changes to the room that would impact acoustics, it may be easier to buy your own microphone.  

In just a few minutes, the built-in “wizard” runs through level settings and, if bass management is used, performs crossover calibration, then it runs a few test tones. The rest is handled quickly by the Amethyst’s built-in computer. Room Optimizer adjusts amplitude and phase in most settings, but there is a crazy amount of detail and control one can manually adjust if so desired. Trinnov will work with you if you are a little sheepish about this process. Attaining excellence through one of the company’s well-trained staff normally takes about 60 minutes to get you “custom curves.” Understand this: You do not need an electrical engineering degree to make this slick preamp get up and dance for you, and there is plenty of support available, even for the less-tech-savvy audiophile. 

The Trinnov Amethyst prepares five preset filters: Comfort, Natural, Neutral, Precision, and Monitoring (more on these later). You can keep these preset filters, you can tweak them a bit, or you can add your own presets, storing up to 29 at a time. Using the automated Trinnov Room Optimizer, you can still customize the results by applying a house curve to one or more presets. A house curve lets the user define what the target curve is—for instance, if you like the added impact of mid-bass but want your really low bass rolled off because of sympathetic rattles in your listening room, that’s an easy fix. If you want a more forward vocal range with a relaxed treble? That is just as easy to accomplish. There are lots of ways to make your audio sound the way you want. If you want to go with the full-scale electrical engineer package, Trinnov’s 31-band equalizer is just waiting for you. My advice if you’re just sticking your toe into room correction waters is to be judicious with your adjustments. If you add a big peak somewhere in your curve, there is a possibility of clipping your amps. Small, careful changes followed by critical listening will yield the best results.  The Amethyst also lets you set limits to protect your gear.

The Trinnov Room Optimizer can display graphs with amplitude, phase, impulse response, and group delay. Amplitude will likely be familiar to most audio fans, while the other measurements may be familiar to an increasing number of people that use REW or similar programs. All are important and have an audible impact on clarity and imaging. 

Why Should You Care About The Trinnov Amethyst Stereo Preamp?

• The Amethyst can optimize your audio system to achieve its full potential in your room and for your ears. Audiophiles are always looking for ways to improve their system quality, but many have been against EQ dating back to the days of Cello and The Audio Palette. That is anti-science garbage in 2022. Yes, you need a well-treated room before you pop for an $11,000 stereo preamp, but know that the days of “playing God with cables” is over. With the Amethyst, you can know exactly how your system performs in your room and how to fix it with about 60 minutes of effort. Then you can rest assured that you are getting the best performance from your system in your room. Isn’t that a refreshing concept in a hobby that has suffered from My Pillow Guy–level BS and magazines selling the “$20,000 preamp of the month club” products? That crap ends with this game-changing stereo preamp.
• If you simply cannot get your speakers positioned perfectly or if you cannot implement acoustic room treatment to the level you would like, Room Optimizer can deal with your acoustical problems in ways never really available before. I feel the urge to use the phrase “game changer.” 
• If you have two-way speakers or external subwoofers, the Amethyst’s active crossover combined with the Room Optimizer function can improve integration in ways that significantly impact the sonic results. 

Some Things You Might Not Like About the Trinnov Amethyst Preamplifier

• When discussing this product with a good audiophile friend, he commented on the digitization of incoming analog signals. I do not think anyone who is looking at a room correction processor will take major issue with that, but it is worthy of note if we’re looking for some downsides here. 
• The Trinnov Amethyst does not accept DSD files and MQA. I know the mixed feelings regarding MQA, but there’s a significant amount of MQA files out there on the streaming platforms. 
• The lack of a headphone jack befuddles me on a product at this price point. I would think there’d be a bigger demand for this feature than a phono input, but for $11,000 consumers are going to want everything.  

Listening To The Trinnov Amethyst Stereo Preamp

My critical listening was done with both the RBH SVTR speakers in a 2.0 configuration in the living room and the Revel F328Be with dual SVS PB4000s in my reference room. Of the Trinnov presets, I liked the Neutral and Natural presets best, but I modified them a little bit to add a “house curve” to fit my tastes. With 29 preset spots available, you can save many curves and switch between them to see which ones sound the best to you. 

Shelby Lynne came to life with Trinnov’s Room Optimizer engaged, as she serenaded me about the benefits of morning romance in “Just a Little Lovin’” (Qobuz, 24-bit/192-kHz). The Amethyst includes a button that allows you to immediately bypass the room optimization to easily perform an A/B comparison. The most immediate and profound change was the sense of increased focus. The positioning and solidity of Shelby Lynne’s voice became sharper and more solid with Room Optimizer engaged, as did the overall sense of space. There was noticeably more definition in the electric bass, too.

The introduction of David Axelrod’s famous jazz piece “Holy Thursday” (Tidal, 16-bit/44.1-kHz)also demonstrated an increase in dynamics that I was not expecting. The track starts off softly with piano and bass, then builds quickly as various instruments join in. The horns and drums, in particular, had increased dynamics and presence with Room Optimizer engaged. I was expecting the increased detail but was surprised by the difference in dynamics. While this piece sounds trippy and immersive without Room Optimizer, the processor made it even more engaging by allowing each of the many instruments to sound more distinct.

 
Lastly, I want to touch on the impact the Trinnov Amethyst has with bass performance. If you want to get the most out of the Amethyst, make sure your full-range speakers really are fully range or add a subwoofer (preferably two). Whether I was listening to the RBH SVTRs in a 2.0 configuration or the Revel F328Bes with the SVS PB4000s in a 2.2 configuration, the Amethyst consistently improved the quality of the bass. Subjectively, the amount of bass decreased, but there was noticeably more definition. With really low bass, such as in the Saint-Saens pipe organ, there appeared to be more extension. I understand that the words “less bass” may horrify some readers, but do not worry. Remember when I discussed house curves above? You can simply program your own house curve to provide the bass you want. A slight bump was enough for me.

Does the Trinnov Amethyst Stereo Preamplifier Hold Its Value?

I would expect this preamp to hold its value nicely, which is surprising because most cutting-edge digital audio components lose value quickly as the next iteration is released. This is especially true with surround processors, as new formats are released, and with video gear, when higher-resolution sources or updated HDMI connectors come to market. Since the Amethyst’s Room Optimizer is handled by an Intel Dual-Core processor, the software should be updateable for quite a while. Looking back at Trinnov’s track record, they appear to support products for a long time, rather than releasing a new model every year.  

Who Is the Competition For The Trinnov Amethyst Stereo Preamp?

While room correction can be found on just about every A/V processor, it’s still relatively rare on stereo products aimed at audiophiles, with most audiophile room correction products being computer-based filter additions to playback software.

• We will be reviewing Anthem’s STR preamplifier ($4,299), which has similar features like bass management and room correction and adds Moving Coil and DSD capabilities. But it lacks network audio playback, such as Roon. The STR uses Anthem’s own ARC room correction software thus likely folds down DSD to PCM in that process. I have used other versions of the ARC software and found it to be quite capable as have my colleagues who own/review Anthem products with ARC, but it did not provide the level of detail or control that the Trinnov system offers. It will be interesting to see how the latest ARC system compares, especially at one-third the price.    
• The T+A P3100HV ($23,000) is more of a traditional high-end stereo preamplifier with the addition of a three-band-per-channel parametric equalizer. The T+A does add a headphone output. This may be an exceptional stereo preamplifier, but if you need advance room correction or bass management, this is not the piece for you.
• If you’re already in love with your stereo preamplifier but want to add the Room Optimizer functionality, the Trinnov ST2-HiFi ($7,000) provides the same processing but omits the preamplifier/streaming features, so it can be placed between your own preamplifier and amplifier.
• NAD has some interesting integrated amps out including the M10 V2 ($2,999 retail but out of stock many places online) that look great in terms of specs and performance but also come with their own take on digital room correction. I look forward to taking a look at this product in the near future.

Final Thoughts On The Trinnov Amethyst Stereo Preamp

When first looking at the Amethyst’s specs, I was concerned about the extra A/D conversions and how other high-end preamplifiers appear to be more simplistic in design – be it on paper. But the second you engage the Room Optimizer function on the Trinnov Amethyst preamp, all of those concerns go out the window. You might be able to get similar performance with a professional calibration using the right hardware, but this is the best-sounding stereo-oriented bass management and room correction I have heard that you can take home and set up yourself. 

Every time I used the Amethyst’s bypass button to compare the sound with and without Room Optimizer, I preferred to leave it engaged. It did not matter which room or which speakers, with or without subwoofers, Room Optimizer made a marked improvement. Take the software out of the equation and this is a perfectly respectable stereo preamp, but if you are not going to use the bass management or Room Optimizer features, there are a lot of other great options to consider at or below this one’s asking price. But let’s be honest: If you are interested in the Amethyst, you are going to use these tools—and when properly implemented, they deliver one of the few audiophile upgrades that is truly transformative.