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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    If the LP distorts the crap out of (makes more audible) an inverted signal I don't think I want it! Audio signals are AC, it should be identical on either side of baseline. Any deviation from this is distortion.
     
    Last edited: Mar 10, 2020
  2. atomicbob

    atomicbob dScope Yoda

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    Polarity inversion is different than signal distortion. Some people appear to be sensitive to polarity inversion and others can't differentiate. Note that several Schitt DACs and a number of others include a polarity reversal button. Players such as JRiver include ability to polarity invert. An inverted polarity output will merely be the input signal upside down.

    Here is a website that offers some examples. Look at the section with 180 degree out of phase waveforms:
    http://education.lenardaudio.com/en/12_amps_2.html
     
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  3. atomicbob

    atomicbob dScope Yoda

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    Ok, I went back to see how this confusion began. @Hammy suggested potential of headphones being wired reverse polarity and that might account for the bass sounding thin. He further mentioned that Liquid Platinum highlights polarity reversal. He didn't claim the Liquid Platinum inverts polarity. It doesn't. I just ran polarity checks again to refresh my memory. What LP has is excellent channel matching and gain linearity which would account for its ability to highlight some other component's polarity reversal.

    So to be clear: Liquid Platinum does NOT invert polarity.
    Liquid Platinum does NOT distort inverted polarity signals differently from normal polarity.
    LP Distortion measurements are available HERE


    Liquid Platinum FFT and oscilloscope (Blue is input to LP, Red is output from LP):
    20200310 SigGen LiqPlat 1 KHz sine 2000mVpp FFT + Time - Blue SigGen SE input - Red LP SE 300R.png
    Output is overlaid on input so closely as to be hardly distinguishable if it weren't for a very slight gain difference. It is hard to get EXACTLY 0.00 dB gain with potentiometers.
     
    Last edited: Mar 13, 2020
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  4. Hammy

    Hammy Friend

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    I do hear the effects of inverted absolute polarity when listening with the right amp, right DAC, and right headphones. I've heard it. I know what to listen for. I learned to hear what flipping the absolute polarity does by owning a Liquid Fire, Gungnir Multibit, and LCD-2r2. With the right gear it is audible. And the gear I listed is very much the right type of gear. Flipping the absolute polarity can affect how full the bass sounds, can affect how the midrange layers and images, and can affect the perception of treble characteristics. I hear the differences mostly in the bass, a little in the midrange, and the treble differences are fleeting. The differences are there. It's quite interesting to hear how flipping the absolute polarity can change how one instrument in the midrange can end up sounding more forward than another just by flipping the absolute polarity.

    I've discovered that some people hear this more than others. I happen to be someone who hears it. I hear spatial cues and timing and layering more than I hear frequency response. I prioritize the timing and spacial cues more and imaging than I prioritize ideal frequency or smooth frequency response.

    One of the things I've found is that some amps make it easy for me to hear absolute phase differences and some amps mask those differences. The Liquid Fire and Liquid Platinum make it easier for me to hear those differences (the Fire moreso than than the Platinum). An example of an amp that makes it difficult for me to hear those differences would be the original Lyr. The Schiit multibits also make it easier to hear. The Schiit delta-sigma DACs make it less easy to hear. Good planar headphones like the Audeze LCD series make it easier to hear. Bloomy dynamics like the Fostex/Massdrop TH-X series make it difficult to hear. The Focal Utopia and other Focals also make it difficult to hear (the Utopia sounds great with clean detail, but doesn't make it easy for me to hear absolute polarity or precise imaging). I tend to equate being able to hear absolute polarity with headphones as being a planar driver characteristic more than a standard dynamic driver characteristic. Stax headphones with a good amp and good DAC can also do this. One of the things I've discovered is that systems that allow me to better hear absolute phase are also the systems that allow me to better hear imaging. If I can better hear how flipping the absolute polarity changes the sound then I'm also going to be better able to hear imaging like where a violin is in an orchestra.

    For me the higher end Cavalli amps allow me to hear this. And the Schiit multibits allow me to hear this. Combined with the Audeze planars. It's a full system synergy thing that lets it happen.

    TLDR version: The ability of the Liquid Platinum to allow me to hear that the absolute polarity is wrong or right is a good thing. A very good thing. Only good amps allow me to hear that. Combined with a the right DAC and the right headphones. The Liquid Platinum is awesome. Only slightly less awesome than the Fire, Crimson or Glass.
     
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  5. atomicbob

    atomicbob dScope Yoda

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    @Hammy : thank-you, very well stated.

    For anyone looking to acquire a Liquid Platinum at this moment in time, monoprice is running 24.84% off:
    https://www.monoprice.com/product?p_id=33305

    Gotta love that fractional bit less than 25%. In any case this is a stonking good deal on this excellent hybrid headphone amp.
     
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  6. nickwin

    nickwin Facebook Friend

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    I wasn't suggesting that the LP causes an inversion, I'm talking about what it means if it makes inverted polarity more subjectively noticeable. If what your hearing with an inverted polarity isn't distortion of some type what is it? Audio signals are AC, the negative voltage swing is identical to the positive voltage swing and my understanding is our ears pick up on air pressure differences, not absolutes. Disregarding any type of distortion the pressure difference generated in a wave cycle is identical regardless of whether the wave begins with a compression or rarefaction. Are you assuming that the ear can differentiate a compression from a rarefaction? I'll be honest I don't understand how it would make any difference without making that assumption or bringing distortion into the equation.

    I'm not disputing what people are hearing, I'm just trying to wrap my head around why/how that would be.
     
    Last edited: Mar 12, 2020
  7. atomicbob

    atomicbob dScope Yoda

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    Your initial statement when read by those surfing our threads via search engines would tend to imply a deficiency exists with the Liquid Platinum. I wish to make certain readers are not misled.

    I am going to suggest that absolute polarity detection is facilitated by greater transparency of the LP, more faithful rendering. If a component muddies the signal then absolute polarity may become harder to detect. This is the opposite of your initial reaction, that LP would "distort the crap out of an inverted signal." From the data I presented above, both spectrum and oscilloscope displays indicate the LP produces a faithful rendering of the input signal.

    Here is some reading with arguments on both sides of polarity audibility and an audible test example.

    https://www.gcaudio.com/tips-tricks/absolute-polarity-a-prerequisite-to-optimum-performance/

    https://www.psaudio.com/pauls-posts/absolute-phase/

    https://www.stereophile.com/content/absolute-phase-fact-or-fallacy

    https://www.audiocheck.net/blindtests_abspolarity.php
     
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  8. kevlar397

    kevlar397 Rando

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    @Skyline, I have what I believe is an efficient headphone, the Grado GS1000e, and would like your thoughts on how it would pair with the LP, specifically in regards to its gain. I’m planning to pair it with a Bifrost Multibit and test it against a Lyr 3. I’ve read very positive reviews of the LP against a number of amps, including the Lyr 3, but will need to hear them for myself. Would I be able to compare them “as is” with my Grado’s, or should I plan to use an attenuator. Are there any balanced attenuators you recommend? Thanks.
     
  9. Skyline

    Skyline Double-blindly done with this hobby

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    I wish I could help, but I don't have any experience with the Grados or how they work with various amps. I'd hate to lead you in the wrong direction.

    I don't have any experience with attenuation since it hasn't been needed in my particular setup.

    FWIW, the Bifrost 2/LP combo is a good one. I'm not saying it's "better", but I prefer it over the Gungnir A2 pairing that I used previously.

    And, even though you didn't ask, a final update/change since my "review"...the stock tubes are good. I've bought a pair of Gold Lions and a pair of Amperex a-frames...they're both collecting dust at the moment as the stock tubes take up most of my ear time.
     
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  10. kevlar397

    kevlar397 Rando

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    Thanks for your feedback and honesty. I really appreciate it. To clarify, you preferred the Bifrost 2/LP combo to the Gungnir A2/LP combo? I’ll keep looking for people with attenuation experience, unless you happen to know someone? Also, thanks for the update on your tube preference. That was helpful.
     
  11. e.schell

    e.schell Friend

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  12. Skyline

    Skyline Double-blindly done with this hobby

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    Sure thing. And yes...that's correct about the BF2 v Gungnir A2 preference (at least in this setup).

    That's important to remember for the tube preferences as well. It's all about synergy. The stock tubes are a little leaner and cleaner sounding than my other sets, which works well with the BF2 and HD650 since they are both warm-leaning. Your experience with Grados could be exactly the opposite.
     
  13. Pharmaboy

    Pharmaboy Friend

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    Never heard of these devices. Which one do you use? How does it sound?

    These are microphone attenuators, and using them in a headphone audio setup strikes me as the most challenging/revealing application possible. If they do anything to the signal, you'll definitely hear it.
     
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  14. e.schell

    e.schell Friend

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    @Pharmaboy I'm using the VPD Variable inline attenuators XLR-F to XLR-M.

    You will have to use an extra set of balanced xlr interconnects (I've been using the Schiit PYST short ones) Then these attenuators go inline (which for me is Gungnir Multibit > short PYST > attenuator > xlr interconnect > Liquid Platinum). Each one has an 8 step selector, each being 6dB of attenuation per step.

    These things aren't super cheap at ~$50-$60 each (need a pair) but they are custom made on order and feel really solidly made. Have had no issues for the year or so I have been using them. I'm very happy with them and helps tremendously with dialing in volume when using low Z / higher sensitivity hp's like my Focal Clears.

    As for how they sound, I have not done any comparative testing, just bought them, installed, and never looked back. I assume they give / take very little in regards to changing the sound signature.

    If I remember correctly there is another friend ( @beemerphile ) who uses / used these and that's where I found Naiant. Not sure if beemerphile has any other tidbits to share about his experience with them.
     
    Last edited: May 17, 2020
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  15. Hammy

    Hammy Friend

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    The Liquid Platinum is a balanced amp where the balanced headphone jack is much better than the single-ended jack. The reason to get the Liquid Platinum is to use the balanced output. The single-ended jack doesn't justify the amp. If you're considering the LP your Grados would need to be converted to balanced.

    I don't have a balanced Grado. Can't test one with the LP.
     
  16. kevlar397

    kevlar397 Rando

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    Thanks @e.schell! I really appreciate you sharing what has worked for you. I saw your post explaining where you put the attenuator between your DAC and amp. I've thought of adding a preamp, and since their isn't much information in reviews or forums about attenuators and preamps, I was wondering if it matters whether the attenuator goes between the preamp and the amp or the dac and the preamp. Thanks!
     
  17. kevlar397

    kevlar397 Rando

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    Good point. Yes, I have been picking up that a piece of equipment has the potential to have a different impact to my system's overall sound than someone else's due to how each piece in system's audio chain interacts with the other pieces.
     
  18. kevlar397

    kevlar397 Rando

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    Hi @Hammy, thanks for making sure I knew this about the LP. I am planning to send my Grados back to Grado Labs to have them swap the SE cable out for a blanced one. I was glad to learn that I will still be able to use my Grados with my SE equipment by adding a balanced to SE adapter.
     
  19. Mithrandir41

    Mithrandir41 Friend

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    You

    Can
    multiquote!
     
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  20. kevlar397

    kevlar397 Rando

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    Good to know @Mithrandir41, but you could have just given me a friendly heads up.

    @Skyline @Hammy @e.schell Is this guy typical of the Super Best Audio Friends forum? I came here, because I heard it was a more positive and helpful place than the typical forums. I hope that is true.
     

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