• Monolith Cavalli Liquid Platinum Review

    January 23, 2019 Luckbad 8

    Today we take a look at the Monolith by Monoprice Liquid Platinum Headphone Amplifier by Alex Cavalli.

    This review has taken me longer than perhaps any other on the site. The reasons had little to do with the Liquid Platinum itself. It started with work getting super busy, but ultimately it boiled down to this: I’d worked hard to strip myself of high end audio gear to kick the habit (and to get some cash).

    Being an audiophile can become a very expensive hobby very quickly. You want the best gear, the best software, the best music. Thousands of dollars can disappear in a blink. When my 16 year old car needed to be replaced, I purged my high end gear to soften the blow.

    But that left me with a problem in reviewing the Liquid Platinum. Its little sibling, the Liquid Spark, was capably empowered by the mid-tier DACs I had access to. Listening to the Liquid Platinum, however, I knew it was capable of more than I was hearing.

    Finally, I was able to get myself an RME ADI-2 DAC again. It’s a lovely piece of kit and can deliver clean resolution to put the Monolith Cavalli Liquid Platinum to a proper test.

    I’d love to hear it with a great modern multibit DAC like the Schiit Gungnir Multibit or Yggdrasil, but you’ll have to look elsewhere for impressions of those pairings (I did get to use it with a Modi Multibit, but the resolution on the DAC seems inadequate for the pairing).

    Now that we’ve plodded through the preamble, it’s time for some impressions.


    Clean, crisp, airy. Those are some of the first impressions I get when powering the Liquid Platinum on. It doesn’t sound like a solid state amp. It doesn’t sound like a tube amp. It sounds like a hybrid, which Cavalli is the undisputed (in my book) king of designing.

    It’s not in your face, nor is it laid back.

    It does everything well. It does nothing badly. In a sense, it’s what most amplifiers aim to achieve. Clean, detailed, easy to listen to, and elegant.

    The Liquid Platinum is not an amplifier that blows you away on first listen unless you know what it has achieved. It’s not a sexy, warm tube amplifier that makes the sound wet and romantic. It’s not a sharpened detail monster that etches every note with exaggerated delineation.

    It is lovely to listen to. It delivers gorgeous detail without sugarcoating it. It is engaging without grabbing you by the collar and shaking you. It is relaxing without lulling you to sleep. It is… well, it’s a Cavalli amplifier.

    What Monoprice and Cavalli have achieved via their partnership is utterly impressive. Can you get a better headphone amplifier for under $1000? Not that I’m aware of, unless you’re after specific coloration.

    What I’m describing sounds perfect. In reality, there are some negatives, but we’ll get on to those a little later.

    I suspected that I was holding the Liquid Platinum back with my DACs. It seemed to have more to offer than my converters could provide. After getting something that provides more detail, I discovered I was indeed correct. It’s all about that synergy.

    Let’s talk about a little slice of synergy:

    Sonnet Allegro Pro USB card -> RME ADI-2 DAC -> Monolith Cavalli Liquid Platinum -> Sennheiser HD650s (with balanced cables I made throughout the chain). This rig is heavenly.

    The combination delivers a wonderful balance of detail and listening enjoyment. It’s not the world’s most detailed offering, but it’s not warm at the cost of clarity. It lets me fall into the music.

    I mentioned earlier that the Liquid Platinum is easy to listen to. This amp is not fatiguing. One of its greatest strengths is the ability to deliver a neutral, clean presentation without inducing listening fatigue. I am particularly susceptible to getting fatigued while listening to music, and I’ve never felt it with the Liquid Platinum.

    It doesn’t color the music notably, though I’d say it has a slight focus on the midrange, with a relatively smooth high end and de-emphasized rolled sub-bass.

    As far as other audiophile needs are concerned, it meets them well. The soundstage is reasonably wide and adequately deep. Again, it does everything well. It’s not going to blow away many amps that cost 3x as much, but it can certainly embarrass a number of four figure amplifiers along the way.

    The technicalities are exemplary. The sound is airy and smooth without getting swooshy or muddy. 

    I really like this thing.

    What about its looks?

    Some folks complained before the amp ever came out that they didn’t like how it looked. I think it looks really slick. The Liquid Platinum looks great in person, and it’s quite well built. It’s fairly compact for the powerhouse that it is, doesn’t get very hot, and is understated without looking boring.  

    Further Notes

    This amplifier is a balanced design. It sounds great even using a fully single-ended chain, but it sounds even better with balanced gear (particularly at the output). If you’re considering the Liquid Platinum, you should have headphones with 4 pin XLR (or a plan to make that happen–I made myself a balanced cable for my Sennheiser HD650s years ago).

    Tube rolling! The Liquid Platinum responds well to changing tubes, allowing you to gently nudge the sound toward your preferences. Equivalent tube types to the stock 6922 include: 6DJ8, 7308, Cca, ECC88, E88CC, CV2493, CV2492, E188CC, 6H23/6N23P

    For those of you who are concerned with technical measurements, rest assured that the LP measures very well. You can see atomicbob’s detailed measurements at SBAF.

    One of the most important elements in any amplifier is its power delivery. The Liquid Platinum comes with a switch mode power supply. I realize cost and space concerns required it, but man would it have been nice if it came with a linear supply or something like the RME ADI-2 DAC does (cleans up the SMPS power after it gets into the chassis). I’ve used it with a linear power supply and the atomicbob Noise Nuke, and both improve the sound a bit. But…

    CAUTION: Using an LPS is not recommended and could damage your amp even under normal conditions and void the warranty. Here are Cavalli’s comments for more details: Link

    And for those of you who really like to look at gut shots of equipment, here’s what the Liquid Platinum looked like in not-quite-final form (posted by Cavalli at some point on Head-Fi):


    Is the Liquid Platinum perfect? Well, no. At its price point and size, some sacrifices must be made. Here are the negatives to my mind:

    The gain on this amp is pretty high, meaning you have to turn it down quite a bit to use it with many headphones. Why? Here, have a post. I initially settled on using Harrison Labs RCA Line Level Attenuators for RCA input to reduce the incoming volume and get more play in the volume knob. This is a reasonable solution, but I was eventually saved by the RME ADI-2 DAC which has excellent transparent volume control.

    The tube sockets are a little tight. This wouldn’t necessarily be a problem, but there’s not a simple way to remove the chassis top or anything, so you have limited space to work with. In other amps, I’ve broken the bases of older (really expensive) NOS tubes before trying to get them in or out of tight sockets. It makes me worry. I haven’t broken a tube yet, but I’ve also been reluctant to tube swap because I’m wary of breaking something. Note that others have reported that frequent tube swapping has caused the sockets to loosen up enough to alleviate the concerns, so they probably made the right call to start with them tight.

    I don’t love the stock tubes. The construction on my stock pair was inconsistent. I’m sure Monoprice would’ve sent a replacement pair, but I didn’t want them in any case. It would have been nice to see Genalex Gold Lion tubes like the Liquid Crimson came with. I personally swapped mine with a matched pair of 6N23P-EV tubes, but I’d really like a nice pair of Amperex 6DJ8 tubes.

    Liquid Platinum vs. Liquid Crimson

    Is this a balanced Liquid Crimson? Honestly, not quite. This is an excellent amplifier, mind you, but I’ve been chomping at the bit trying to get a balanced version of the Liquid Crimson for far less money. It didn’t exactly happen.

    How do they differ? The Liquid Platinum is a little more aggressive and dry in its presentation. The treble is a bit more delineated, which as a result means it’s marginally less smooth than the Crimson. It has a little less bottom end heft (less sub-bass extension) and isn’t quite as spacious. That said, it is a little more open and airy and when fully balanced, it delivers tremendous clarity. They’re two slightly different amps, but the Liquid Platinum is an amazing entry at its price point.

    If I wasn’t intimately familiar with the Liquid Crimson (notably, my favorite neutral amplifier of all time), the Liquid Platinum would have skyrocketed to the top of my list of favorite amps. It does nothing wrong. It also responds more to tube rolling than the Liquid Crimson, so you can actually tune it a bit toward your preferences (if I had a nice pair of Amperex 6DJ8s still as mentioned earlier, that might be the ideal pairing).

    Okay, so it’s not an improved unobtainium amplifier for less 1/3 the price. But it’s a great amp unto itself.

    How did the Crimson become the Platinum? Alex himself explains in a pair of posts:


    The Monolith Cavalli Liquid Platinum is a wonderful headphone amplifier. It is well-built, sounds great, and is priced attractively for its capability. As a well-designed embedded hybrid amplifier, it delivers some of the best of both the tube and solid state worlds.

    Beautifully neutral with a little touch of warmth. It’s open, sweet, and transparent. The more I listen–especially after going fully balanced–the more I fall for this amplifier.

    I highly recommend the Cavalli Liquid Platinum.

    It might not be everything to everyone, but it comes darn near close. And yes, it is a true Cavalli amp!

    Want to learn more about the the Liquid Platinum? Look for posts by runeight on Head-Fi and SuperBestAudioFriends. That is Alex Cavalli, the designer behind all of the Cavalli amplifiers. 

    Categories: Amp, Gear, Reviews

    8 thoughts on “Monolith Cavalli Liquid Platinum Review

    • Anh Phan Nguyen says:

      Hi ya. I’m Ash1412 on SBAF. I’m surprised you didn’t post this review over there. It’s a great review. As an owner of LP myself but without a DAC with good volume control, how did the Harrison attenuators work in your system? Did you go for the 12db or 6db ones?

    • Anh Phan Nguyen says:

      Hi I’m Ash1412 from SBAF. Surprised you didn’t post your review there, it’s a great one. As an owner of LP myself, I’m wondering how the Harrison attenuators worked for you? Did you go for the 12db or 6db ones? Did they affect sound much? Thanks

    • Petukchele says:

      The nos Siemens e88cc and Telefeunken e88cc rock in this amp

    • Aaron says:

      I know this review is now over six months old, but when I came across it I just had to leave a comment.
      After weeks (more like months) of researching I have ended up with the same (desired) chain as the one you have listed above:
      RME ADI-2 DAC -> Monolith Cavalli Liquid Platinum -> Sennheiser Headphones
      … with the small difference that I will be driving HD 800S headphones instead of the HD 650’s, great to see someone else loves this setup.
      I have yet to buy all these items but am really looking forward to it.
      Do you have any experience of using HD 800’s with this setup?
      There is a lot of debate in the forums about the ADI-2 being able to drive these phones on its own, I contacted RME directly and they said that it can drive them fine, but of course they would say that.
      For a long time the WA7 Fireflies sat at the top of my list for an amp, until I discovered the Platinum, the ADI-2 I am completely sold on.

      • Luckbad says:

        The WA7 is not a great amp from Woo. They have much better stuff, but that’s not a good bang for the buck these days. The Liquid Platinum is very good. I do not personally like the HD800 because I’m too sensitive to treble.

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