Monoprice Monolith Liquid Platinum Headphone Amplifier by Alex Cavalli

Discussion in 'Headphone Amplifiers and Combo (DAC/Amp) Units' started by Vtory, Apr 4, 2018.

  1. nickwin

    nickwin Facebook Friend

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    That sounds like what Im getting, where did you read this? I wonder how you would accomplish this without actually changing the amps gain? FWIW it for sure is easier to dial in the volume on this unit.
     
  2. futbutts

    futbutts Acquaintance

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    I’d guess just swapping in pentiometers with a different resistance?
     
  3. nickwin

    nickwin Facebook Friend

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    If its that simple what was all the talk about changing the gain structure being such a big deal? In other words, why were people talking about the gain in the first place if all it took was a different potentiometer?
     
    Last edited: Jul 10, 2019
  4. ColtMrFire

    ColtMrFire Writes better gear impressions than you

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    I got to hear @Joshvar 's LP and funny enough it reminded me of the Valhalla 2 I used to own, only more resolving, more slam and no sandy treble (though I felt the 6CG7 tubes fixed that particular problem in the V2). Was a step down from my T3 but if I were looking for a mid amp, this would be pretty high up the list. Wonderful tonal balance and worked really well with the Modi 3. I could see it getting pretty addicting over time.
     
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  5. MLegend

    MLegend Friend

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    Regarding gain being lower on the new units, would anyone like to conduct a simple comparison test between the old and new units? This might not be the best or the most accurate way to check this, but it's better than nothing, if anyone is actually interested.

    I currently have one of the supposedly "lower gain" units with the 1.4a output power supply with the three prong power cord. If anyone else has a balanced HD650 and a Gungnir Multibit, or any other DAC that outputs 4V, connected balanced to the older Liquid Platinum and owns an EARS measurement system then we can do a simple loudness test using the signal generator and the decibel meter.

    My volume knob is a little bit above 9 o'clock (probably 9:15), according to EARS I'm at 75.9db with the HD650 and Gungnir running balanced using a 1kz test tone.
     
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  6. dBel84

    dBel84 Friend

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    not aware of any gain changes made and no, swapping a pot out wouldn't do that unless you were smoking it , then anything is perceivable. The only change was a new supplier for the wallwarts - lower noise units but this is all relative as the first lot were chosen because of there low noise characteristics.
     
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  7. RatSalad

    RatSalad Almost "Made"

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    Can these be sourced anywhere ? I'd like to buy an extra. Mine whines sometimes.
     
  8. dBel84

    dBel84 Friend

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    Sadly not.
     
  9. RatSalad

    RatSalad Almost "Made"

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    I actually asked AC at the other place. I don't think I got a response. Is having an extra power supply to much to ask
     
  10. Hammy

    Hammy Friend

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    Or plug in LCD2 headphones and the volume knob swing becomes more useful.

    I've always considered the bigger Cavalli amps (like Fire, Crimson, Platinum, Glass) to be more designed for typical planar magnetic headphones than high efficiency dynamics. Due to gain, power, and the ability of those amps to get planars to open up and sound good. The amps have a synergy with planars. To the point that I generally feel that anyone buying the Platinum should also have an interest in planars and own one to pair with the amp. You can pair standard dynamics with it, but I find maximum synergy is with planars.

    I bought the LCD2.2 back in 2011 because of the Liquid Fire. I bought the Liquid Fire because of the LCD2.2. It would be the same for me now with the Liquid Platinum but with the LCD2 Classic.
     
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  11. Josh83

    Josh83 Friend

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    I've had the LP long enough to provide, I hope, some helpful thoughts for those considering one.

    I had the CTH as my tube alternative to the Rag and enjoyed it. It's a little fun amp. It has nice slam and is immersive, partly because the "head stage" is kind of small left-to-right and not very deep. Whether because of the small staging or not, micro details tend to get lost in the mix with the CTH and micro dynamics are also somewhat lacking. Swapping the stock tube for an NOS Amperex Bugle Boy improved the stage depth detail retrieval slightly, but not dramatically. Given these traits, I liked the CTH with wide detail monsters like HD800S, but not with the narrower, darker Ether 2. In short, the CTH is nice for the price and very engaging, but not really suitable for critical listening, IMO.

    The LP is a step up across the board. It stages deeper and wider and has better micro dynamics and detail than the CTH. Compared to the Rag (not a fair comparison), you're trading some plankton and macrodynamic for the LP's smoothness, but you're not really trading anything moving from the CTH to the LP (except for the fact that some people might subjectively prefer the CTH's more immediate, but less detailed, sound).

    It probably depends on one's budget and preferences if the move from the CTH to LP is worth it. It is for me. I don't really differentiate between critical listening and fun listening, and I tend to change headphones, not amps, if I want a more "fun" listen in terms of sound signature.

    My only criticism of the LP is that my unit's knob (a newer unit, with the new power supply, bought during the Amazon sale) also has a little play in it. Debating exchanging it, but not sure if it's worth the effort.
     
    Last edited: Jul 18, 2019
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  12. MLegend

    MLegend Friend

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    My unit is the newer version with the new power supply and the volume knob also has some play, so you might be wasting your time sending it back for a replacement.
     
  13. nickwin

    nickwin Facebook Friend

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    I can second this. I returned one of the old version units that had some minor play in the volume knob (I returned it for other reasons), and the current version replacement has the exact same play.
     
  14. captkirk

    captkirk Khan's BFF

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    Loaner Impressions - Liquid Platinum


    For the sake of these impressions, I used both my listening locations comparing the Monoprice Liquid Platinum (LP) with the Massdrop Cavalli Tube Hybrid (CTH). Please note that my CTH is fed using a Zerozone LPS, not the stock “switcher”. My Schiit Jotunheim (Jot) is an earlier build, less warm though fully “baked-in” sound.

    Mac Mini > Eitr / Modi Multibit > MCTH+LPS
    DigiOneSig / SFD-1mkii SE+ > Jotunheim rev.1

    Impressions and comparisons were made using the @LFF closed headphones, T50 modded planars, the Paradox and Slant. For the sake of simplicity, I’d liken their tonality most similar to the HD-600 and HD-650 respectively.
    On looks and form-factor:

    I hate the look of the LP. It looks like a frumpy sibling of the USS Defiant. That said, it's better looking IRL and is well-built and small. Size is about the same as the CTH. It gets way more hot than the CTH though, so placement may be a consideration for some. Tube swapping was easy, volume tracking was smooth. No noise to the volume pot, where my CTH has a nice scratchyness to it.

    [​IMG]

    As others have mentioned, the LP sounds clean, has very good detail retrieval and resolution, is powerful with a fairly balanced tonality.

    I would agree with @Josh83 on many of the observations he found on the comparison between the CTH and LP, to the point that unless you need the extra power, or have a source that favors it’s balanced output v. SE, then it would be tough to justify the added cost of the LP as I find the CTH to be nearly as capable for roughly a third of the price. As with all things in audio-land, the small percentage of sonic difference usually costs more $$$.

    That said, for my needs, the added power was a welcome addition. Where the CTH provides a decent amount of drive for my planars, the LP has better driver control and brings a solid amount of weight and heft to the experience. Where the CTH sounds snappy and articulate, the LP slams.

    Comparing the LP to my Jot, the differences become more apparent. The Jot is more forward and has less delineated layering. It’s engaging, but less immersive. Both resolve well, offering the same sense/amount of plankton. The Jot excels in respect to bass detail and dynamics; sounding tight, hard hitting and clean, compared the LP’s somewhat more rounder and diffuse presentation. For softer acoustic tracks, the LP/Paradox combination was killer. Good driver control mixed with better staging, micro-dynamics, and detail. For faster, more hard hitting pop music, the Jot/Slant combination reigned supreme. Better speed and better slam for a more energetic sound.

    On tubes:

    I found the stock Elecro Harmonix tubes adequate, but I preferred the NOS Telefunken that @sheldaze included. They opened up the soundstage, sounded less dynamically compressed, had better treble extension and air (without getting nasty), and added a bit of weight to the bass (at the expense of a slightly looser sound).

    I couldn’t tell if the LP responded more to rolling than the CTH, or if the added resolve and detail retrieval just made the difference more apparent. Either way, the TFKs were a welcome change to an otherwise decent sounding amp.

    I found that I rather enjoyed the LP, more for the difference it provided with the Jot over how it compared the CTH.

    Thank you @sheldaze for the opportunity to demo the amp.

    [​IMG]
     
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  15. Bill-P

    Bill-P Level 42 Mad Wizard

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    And... I received the same LP from Kirk on Friday. Just fired her up a few hours ago and here are some quick notes (first impressions):

    1. Stock tubes are somewhat... disastrous. Took me about 1 minute max before I decided to try the included Telefunkens.
    2. Telefunkens are nicer than stock tubes, but... somewhat thin and a bit shouty to me. Very good imaging, though, and gave a bit more depth to the sound.
    3. In popped the Amperex Orange Globes I've been saving for the amp and... that was it. Yes, @Hands was right. These could be "too much of a good thing" if used in conjunction with, say... HD650 and a NOS or R2R DAC. The Amperex thickened things up significantly. The contrast over the Telefunkens is very stark and amazing.
    4. Dynamics are very good with both Telefunkens and Amperex, but I think I'll give the edge to Amperex since bass hits harder and is somewhat a bit tighter.
    5. Amperex lacks the air and transparency of Telefunkens but in return, it's a more solid, thickened, warmed up, or... I shall put it this way: meatier and manlier sound.
    6. My modded HD800 + LP + Amperex is actually quite good. Thickness of HD650, airiness of HD800, and a hint of tube sweetness. Now it's no longer "too much of a good thing".
    7. Took me 5 songs and I pressed the "order" button. LP to me is basically what I've always wanted: a MCTH that has the technicality of the THX AAA.
    8. Yes, it's a bit more laid-back (more so than even MCTH), and I can agree that it does sound a bit restrained, but that's just perfect for my preference. The amp has just enough dynamics to keep me engaged, while it helps with those super sibilant tracks, even on my HD800. That's a big win.

    Now, the positive things aside, first impression is not so good with these things:

    1. Build quality is cheap. It was cheap when I first saw the casing at CanJam, and... at the risk of Cavalli frowning on me whenever I meet him next, I'll have to say this: the casing still feels cheap. Monoprice is cutting too much away here. I wouldn't have minded paying $799 or $899 or even $999 for the amp if the casing was better. Not that it's that bad (not plasticky), but... overall, it just looks and feels like nothing special considering the sound. I held down the front of the amp very carefully every time I plugged/unplugged my headphones to make sure the casing wouldn't move. I think the feet will keep the amp there, but the build didn't really inspire confidence.

    2. The included power supply looks cheap, feels cheap, seems cheap, and honestly, I wouldn't be surprised if it is cheap. Even MCTH feels like it has a higher quality PSU. This is just begging to be replaced. Again, I feel like Monoprice is cutting it too close here. Heck, the light on the brick stayed on for a whole minute after I just barely grazed the power cable against the socket (by accident). Luckily, the amp wasn't connected, and I learned to read the instructions provided in the box immediately after that. If anything, I'm not surprised if someone can damage the amp because of this PSU unit. Shame on you, Monoprice.

    3. The sockets on the board seem a bit... tight. I had to wiggle the tubes very carefully so as to not bend them (a lesson learned the hard way from dealing with the Crack), and even then, it took quite a while to get the tubes out. Swapping them back and forth was a bit of a hassle in between the super tight sockets and the slow-to-cool-off PSU.

    Despite the shortcomings, I'll still get one of these things. But... just to say, I do prefer the build quality of THX AAA and MCTH over the Liquid Platinum. And both the THX amp and MCTH are cheaper. Drop at least delivered on build quality if nothing else.
     
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  16. ChaChaRealSmooth

    ChaChaRealSmooth SBAF Gearmaster

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    I've also rolled some Telefunkens, and while I liked them I do agree with @Bill-P that they can be a bit thin. His impressions on the Telefunkens in LP is pretty spot on.

    The current tubes I run is Tungsram 6922. I'd recommend these if you think the Liquid Platinum is too laid-back. It's NOT going to make it a super-dynamic amp by any means (I mean, come on, it's just rolling tubes to dial things in), but it does definitely help. Bass in particular gets much better (better impact, better pitch differentiation). I think it's a little wetter sounding than the stock tubes, but unsure. Treble extension is similar to stock.
     
    Last edited: Jul 24, 2019
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  17. Hammy

    Hammy Friend

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    Have you tried the Gold Lion E88CC/6922 new production tubes in comparison to the Tungsram 6922?
     
  18. ChaChaRealSmooth

    ChaChaRealSmooth SBAF Gearmaster

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    No, sorry. I only have the Telefunkens, the Tungsram (both 6922 and PCC88; got gifted the PCC88 set), and the stock Electro Harmonix tubes. Not going to buy anymore tubes unless tragedy strikes and all my tubes break.

    Tube summary:
    • Electro Harmonix 6922 (stock): Adequate. Too laid-back for my taste. A bit dynamically flat. Stage is wide but lacks depth. Kind of boring.
    • Telefunken PCC88: Much better treble extension. Sense of space and air improved. Thinner sounding. Soundstage has more depth. More dynamic than Electro Harmonix, but presentation is still very laid-back. Transients have more impact, slightly more bass slam than Electro Harmonix, but does sound a bit looser as @captkirk described above with the E88CC (edit: I think it's more that it's a bit more bloomy down low into the low mids). Good pairing with warmer setups. More "accurate" and analytical than the others (I actually changed my mind and I do like this tube, just not as much as the Tungsram).
    • Tungsram 6922/PCC88: Thicker, richer sound with more layers (especially in bass and mids). Very dynamic and does a lot to make the Liquid Platinum less "boring" and laid-back. Bass has more slam and impact than Telefunkens. This is overall my favorite tube in the Liquid Platinum, but it's also probably the least accurate of the three.

    For those looking to roll tubes in the Liquid Platinum and want to save a few bucks and go with 7DJ8/PCC88 tubes, keep in mind that the 7 volt tubes seem to need considerably more time to warm-up than the 6-volt ones (makes sense, since the Liquid Platinum is designed for the 6-volt tubes and the 7-volt tubes will run cooler in the same amp). Also, they seem to hiss a lot when cold, but this goes away as the amp warms up. Uncertain as to exact effects on the amp, but at the very least I don't believe it's in any way harmful to the amp.
     
    Last edited: Aug 5, 2019
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  19. Hammy

    Hammy Friend

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    I've been using the Genalex Gold Lion E88CC/6922 new production tubes in the Liquid Platinum. I also use the Gold Lion tubes in my Liquid Fire. I find the Gold Lion tubes work well in both amps. Especially for new production tubes that are easy to find and buy. My primary headphones with the LF and LP are the LCD-2r2 (non fazor) and LCD-2 Classic.

    The Gold Lion tubes have a reasonably good soundstage depth without being too laid-back. Sonic density in the bass through the mids is filled in with good layering and imaging. The sound has oomph when the music does.

    However, with the Liquid Platinum I notice that the mids seem to lack the level and style of transparency or resolving that I'm after. The Liquid Fire with the Gold Lion tubes does well in that area. But the Liquid Platinum lets me know that the mids are lacking in resolution or transparency.

    My quest with tubes in the Liquid Platinum is to get more transparency and resolution in the mids while keeping the rest of the things I like.

    I plan to keep using the Gold Lion tubes with the Liquid Fire. The Liquid Fire takes four tubes. I've been getting about two years of use out of Gold Lion tubes in the Liquid Fire before the sound degrades and I replace the tubes. About $200 every two years to keep the amp going. I've shied away from expensive NOS tubes with that amp due to cost and how fast I'd go through those tubes given how much I use the amp. But with the Liquid Platinum using two tubes and as an amp that I'm not going to use as much as my Fire and Glass I could put $100+ NOS tubes in it and not burn through them too quickly.
     
  20. Bill-P

    Bill-P Level 42 Mad Wizard

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    Hm... more time with the Liquid Platinum (now that I own one) tells me it won't be that ultra transparent beast you want.

    Even with HD800 it sounds very laid back and kinda smooth... ish. I honestly haven't found any track that even remotely gets close to "sibilant."

    It is marvelous for my taste, but I can definitely say this with authority: if you're looking for transparency, moar details, moar clarity, etc... then I don't think this will ever deliver it. The amp doesn't sound like it's made for that. It's like... a grown-up MCTH, I think. Same laid-back smooth sound, just more technically capable.

    Pair it with a good ESS or AKM DAC and it's a pretty nice setup. But it won't work with headphones and DAC that already sound thick/bassy/warm. I don't find the Liquid Platinum enjoyable with my HD650 at all. THX AAA is the better amp for that headphone.
     
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