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. Ksorota

    Ksorota Friend

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    I have been able to successfully swap out the stock LP pot for an Alps RK27 50k (10k and 100K) on a couple of units, its not necessarily an easy swap, and does require some modifications to the front plate, but it can be done and does make a nice improvement.

    I agree though, the easy solution is to use an external volume control like a sys, or a pre-amp.
     
  2. Azimuth

    Azimuth FKA rtaylor76, Friend

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    Any DIY'ers know where to source a TKP 4CP601C-A50K?

    It seems like the perfect size. I am not sure it would be a drop in replacement for the stock pot, but it sure seems much smaller in size than an Alps RK27.

    The only decent replacement I found from Mouser is this one:

    https://www.mouser.com/ProductDetai...s/P094N-FC15AR50K?qs=56eeD6vBg8hYVbSth/lqcQ==

    It is conductive plastic. Not sure of the quality however if it is any better than stock.
     
  3. Jer925

    Jer925 Rando

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    I was not using the Yamaha receiver tape output or anything, only going to CD input.
    but the idea is similar, just seems that I need to have everything switched on so the load seen by the CD and headphone amp is correct and the distortion goes away. I still think the sound is a little worse whenever hooking something to the output of the LP.

    I did mention I was going to use the SYS in reverse. I did some research and you cannot control volume in reverse, it the knob at full. if you trim the volume in reverse it shorts the source device and possibly cause damage. So don't do that.

    Looks like I just need to get a preamp if I want to use both speakers and headphones.

    I am noticing my planar headphones from Monoprice is a little louder on the left side and the LP is a little louder on the right it sounds perfect when used together. :confused:
     
  4. Jer925

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    I bought one of those cheap "braided" balanced headphone cables to try out the balanced output on the LP.
    The ones with clear wires braided together that seem to dominate the lower price range..
    The treble is really forceful and vocals become sibilant and shouty. But the mid range and soundstage seems compressed.
    It took away the specific "warm" LP sound and it sounded more like the THX 887. I didn't even bother trying it on the 887.

    I went and looked at the description and noticed it was silver plated wires.. I noticed silver plated wires seem to not have a copper purity and actually cheaper to make and they are on the market everywhere.

    I finally bought another one with high "N" copper (they can claim anything) and my preferred LP sound is back. I wouldn't say copper is neutral but it is natural sounding? No offense to anyone who liked the silver sound, just what I listen to and the source doesn't seem to work out.


    I previously I was using 12 to 1 o clock in SE. Now with balanced is at about 11 o clock max.. I was wondering what's a good knob position to leave it at if I get a pre amp?
     
  5. muckyfingers

    muckyfingers Rando

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  6. Jer925

    Jer925 Rando

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  7. muckyfingers

    muckyfingers Rando

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    They have pretty good customer service, I’d email and ask them to price match and return the difference, since you haven’t even had it 30 days.
     
  8. Jer925

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    I have done a test between SE and Balanced headphone outputs (back to back) and the SE sounds better to me.

    The balanced seems to have a signal very hot but there is more distortion at loud volumes. I can only use it around 10-11 o clock.

    It could be an issue with the balanced cable but I tried 2 different cables, both silver and copper. On the SE cable the power is more "mellow" and works really well with the knob around 12 or 1 o clock. It sounds really good, really normal. The balanced cable I got from Amazon they are relatively low priced, it seems really light gauge and limp, it may not be a good comparison to my "stock" unbalanced cable.

    Would it be because I am using unbalanced source (RCA input) it is better to keep the output unbalanced as well?
     
  9. Jer925

    Jer925 Rando

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    double post
     
  10. Azimuth

    Azimuth FKA rtaylor76, Friend

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    It is back up to $399.

    Still...that is a great deal. I think the ones they have been dumping on ebay have been slightly higher than that. I bet they all have channel imbalance issues related to the volume pot.
     
  11. Jer925

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    Previously I mentioned there was distortion in the headphones whenever I hooked up the headphone amp and receiver together to the same source.
    I tried the pass through and also to the fixed volume output of my preamp.

    I ended up using a 3.5mm to RCA cable to my receiver and plug it into the LP when I want to listen to speakers. And it sounds fantastic with plenty of volume to drive the RCA input of the receiver. The LP works as a stereo preamp that way and I found no loss of dynamics.
     
  12. dBel84

    dBel84 Friend

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  13. Pancakes

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    Just another data point: bought the LP during the crazy $293 sale and had really bad channel imbalance. It's been sent back for exchange. My unit was the later revision with the larger tube sockets. Long story short, looks like they're still using the same shit pots - no change.
     
  14. Jer925

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    Hey guys.. I wasted much time buying different balanced headphone cables from Amazon in $40-$60 range, they have crappy sound quality, sounded is worse than SE cable that came with my headphone. When you turn them just a little loud these cables distort. It's like the wire is bottom tier quality or had bad craftsmanship. I returned them and continued using the SE for weeks, but the balanced headphone cable is still on my mind.

    I had some 3.5mm extension cable around and I know they sounded good. I already have the correct end on the headphone side, so I decided cut it and solder it to a Neutrik connector. How hard could it be right?
    I started chopping off one end and was met with colored wires that have no insulation! It turns out they are called enamelled wires and need to burn it off and tinned first. It took a while soldered them on and then realized the barrel is not supposed to be on the wire side! Backed the choke and barrel off the 3.5mm side but can no longer reinstall. Had to drill out the choke, in the end it had tech braid and heatshrinks looked like something you custom ordered. About $30-$40 in parts and audio grade solder into it.

    But after the whole fiasco of DIY a cable the LP sounds really good now, no more distortion and I can say it sounds better than the SE output now. I tried it with the LP and THX DAC Amp both makes the headphone sounds amazing.

    With a pre-amp and using balanced out I do not think it need the knob 1:30. Listening for distortion and harshness I feel the LP perform better around 11 o clock with the balanced output. IMO.
     
  15. jnak00

    jnak00 Friend

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    I jumped on the $293 deal a few weeks ago and finally go this amp yesterday. Mostly it sounds good, but where is the bass? This thing hits like a limp noodle. I'm using Bifrost 2 as my DAC, Aeolus for headphones, balanced in and out. There's just little or no slam compared to Asgard 3. Will this improve as the tubes burn in?
     
  16. HotRatSalad

    HotRatSalad Friend

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    I've never noticed more slam out of Asgard 3 than LP. Had them both since they launched, Asgard 3 does good down low more than it's price tag for sure though.
    I found the biggest difference in bass awesome sauce was when I heard Starlett, even with HD650 I had more perfect bass than I thought was possible. I use a Bifrost 2 also and just got Aeolus.

    Valhalla 2
    SW51+
    Asgard 3
    Liquid Platinum/3F
    DNA Starlett

    in order for bass amount and if quality then SW51+ moves up to LP on the list !
    I use JJ gold pins on LP, like them best out of EH stock and genelex gold lions.
     
  17. jnak00

    jnak00 Friend

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    With Asgard, I can feel the bass impact in my ears and head. Not so with LP, at roughly the same volume. It wasn't something I was specifically looking for, it just jumped out at me as I was listening.

    I do tend to listen at low-ish volumes. Just under 9:00 on LP, and a little lower still on Asgard on high gain. Maybe higher volumes would fill in the bass on LP. And the amp and tubes are brand-new, so maybe some more runtime will help.
     
  18. Jer925

    Jer925 Rando

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    The bass on mine is there from day 1. It has slightly higher bass than THX amps. It has not changed.
    I will also say the unit sounds better after an hour once warmed up.
     
  19. Hammy

    Hammy Friend

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    The Liquid Platinum and other Cavalli embedded hybrids have more space and layering and depth than the Asgard 3 and similar amps. The LP is able to actually present bass with layering and imaging depth. If the bass in the recording is mixed a little layered back then that is the way the LP will play it. I find it neat to have bass that can layer and separate. Allows me to better hear what the bass player is doing or hear what kinds of effects are used on the bass.

    If the bass always slams then there can be no subtle and layering. Just like with brickwalled recordings, if everything is loud there can be no quiet.
     
  20. jnak00

    jnak00 Friend

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    Yes, as I listen more, I think that's it. The bass on LP is very clean, textured, and nuanced. The Asgard is less refined but hits harder.
     

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