Monoprice Monolith Liquid Platinum Headphone Amplifier by Alex Cavalli

Good to hear, I was a little spooked before I bought because there are a lot of reports of units dying, but might just be a lot sold.

I have everything hooked up to a UPS anyway because this is for my PC desktop setup.

 

I bought my LP at launch I have going on 600 hours on it in 21 months. Best amp I've been able to get so far. I don't have any issues with the volume or balance. I think a lot of people plugging 32 ohm things into it will magnify any issues if there is any at all. Main cans are 6xx and lcd2. I have had the power go out on me a couple times and once even plugged it i while it was on DERP. No issues still.

 

I've tried a bunch of amps with the HD800 & a few w/ the HD820 and the Liquid Platinum is the best I've heard for the HD8xx series by far. It's exactly what I was looking for - still neutral sounding with tons of detail, solid bass, good mids - but without the treble glare of typical solid state amp. Small form factor & balanced too which is what I needed for this PC desktop setup. Was also going to check out a v280 but so happy with LP I canceled the order, which I definitely was not expecting considering other stuff I've heard under $500.

If they released a "PRO" version with more premium materials (neutrik XLR jacks, premium volume pot, upgraded internals & PSU, etc), maybe nicer fascia - but still in same form factor and balanced - I'd buy it @ $1299. The XLR jacks is my biggest complaint, the front one for headphone especially is so damn tight.

 

The front XLR jack on my unit is REALLY tight. Does any one else have this?

I mean its tight to the extent I gotta hold the unit and yank the plug out; it comes out but it takes an abnormal amount of force compared to usual. The inside ring of my XLR jacks have a couple of places that look like friction points that are rubbing against the unit - seems like the two corners of the top notch of the female 4 pin xlr plug are biting into the metal a bit. Both sennheiser OEM 4pin XLR cables. I thought it might loosen up but it doesn't seem to be.

 

Mine was like that as well when I first got it. It got to the point where I could no longer unplug the jack, so I just left it plugged in 24/7. A year later, when I needed to unplug the jack, it came out without a lot of struggle. I'm not sure if it just needs to be unplugged in an exact way or if it just loosens over time.

 

My XLR jack is snug but slides home with a nice click almost. Seems to have held up well, I swap between HD6xx and LCD2 a lot over the last almost 2 year.

 

I don't see the point of a more expensive pro version unless the pro version gets the LP to sound much much closer to the Crimson and Fire. Otherwise the extra cost for a Pro LP would be just more money to achieve not enough sound quality improvement. Especially if you can buy a used Liquid Fire for less.

I think of the LP as being 95% of the Liquid Fire or Liquid Crimson if you think of those percentage increments as being more and more difficult to achieve as you get closer to 100%. Or consider it 90% of the LF or LC if you think of those differences as being somewhat more linear. The point is that the 5% or 10% difference in audiophile terms is a doozy. That difference is the difference between an audiophile considering it a $1K worthy amp and a $3K worthy amp. So unless the more expensive pro version can jump that gap I wouldn't consider it worth it.

What I really like about the LP is that it gets the Cavalli amp sound I love down to a price that it is practical to others and is a price I can finally recommend systems to others without making significant apologizes for the cost. 5-10 years ago it would be a system like a LF or LC at $3K, an expensive DAC for the right synergy at $1.2K to $3K (Gungnir MB, Ygggdarsil, used Berkeley Alpha, or similar), and a LCD-2 or LCD-3. A $6K to $8K system that you likely wouldn't be able to audition before forking over the money. Now we've got the LP that comes close enough and good similar DACs that aren't as expensive and a lower cost version of the LCD-2 (the Classic). Now that recommended system is a $500 Liquid Platinum, Bifrost 2 at $700, LCD-2 Classic at $800. Total system at $2K new and close enough (but not equal) to the sound qualities of that $6K to $8K system of 5-10 years ago. So that is great. I can recommend a system that is only $2K that is 95% of my $6K system, while realizing that last 5% is a doozy. That is awesome. But I still know the LP is not up to the sound qualities of the LF, LC or LG.

 

It's a quality of life thing. Like, I have to wrestle to get the headphone jack out and I can hear and see metal scraping on the plug its so tight, its actually scraping up my headphone XLR jack on the inside. Apparently that's not out of the ordinary from other owners input. Plug doesn't go in and out normally like it does with a neutrik. The volume knob and buttons feels cheap. And it doesn't look the part considering how great it sounds. This all somewhat reduces the enjoyment of the amp even if the sound quality is unbeatable.

The size, form factor, and balanced I/O is awesome, better than the liquid crimson for my purposes. But it could really use a nicer faceplate, connectors, buttons, pot, etc.

The MF headphone amp I had previously looked beautiful, had a very nice volume knob, fantastic connectors on the front, and exact same size factor. It didn't sound nearly as good, but it was a joy to have on the desk and use. Given LP is $799 retail there is a lot of room to add some more "quality of life" looks and feel while still being in a reasonable price bracket for an upgraded "PRO" version. I am sure many would upgrade to this just for a nicer usability experience. How much extra could some neutrik jacks, a better pot, and a machined aluminum faceplate cost? I am sure that could be done and sold @ MSRP 1299 or less keeping all the rest the same.

In other words it sounds like a $1299 (or more) amp so why not release a version that looks and feels like one?

 

My XLR jacks (all of them) have been fine from day 1.

The tube sockets took time to loosen up, but after a year of use they are fine as well.

 

Maybe I have a bum unit then. I dropped a note on a couple of other forums and got some hits with same complaint, maybe some have bad jacks

I requested an RMA and it tempts me to re-order the v280 @1199 as I know that is built immaculately, but the size is so huge it will take up so much space on my desk

Hopefully it's not a big batch affected by this issue

 

RMA acquired though monoprice customer support sucked and tried to blame the bad jack on me somehow. I am missing it already :/

 

That doesn't make sense unless you jammed something malformed into it. Your Sennheiser cables aren't cheap and those overprived XLR plugs on them aren't cheaply made. Monoprice shouldn't be accusing you of jack shit unless you admitted stupidity or they have inspected the unit and found crayons in your VCR.

 

I'm not sure the guy I talked to even understood WTF was going on. I tried to explain him it the bad jack was damaging said expensive cables with the force needed to remove the cable, and he's asking for pictures of the jack. The jack looks fine, I sent him a picture of the scratched up $300 ch800s' XLR connector and and told him I had to wrestle it out and he still didn't seem to get it that the retention mechanism on the top of the Liquid Platinum jack was defective and dragging on the XLR cables

Then he's like "normally we don't cover accidental damage to our products", I'm like your product damaged MY product with it's cheap port and messed up retention mechanism, not the other way around. He's like don't worry we'll still replace it. Well thanks, so nice of you. Really not a good experience

Normally I wouldn't even bother with a replacement given this amp was messing up my stuff and the shite customer service rep, but it really did have a special synergy with my dac and headphones. Maybe give one more chance still PO'd tho

 

It's the only thing I don't like about the LP is monoprice. Most people seem pleased with their service and offering replacement without much hassle. Maybe you got a weirdo or something.

 

Well his name was Jimbo. So maybe, yeah, haha!

He also said something like "thank you for being a cooperative one" early on in the chat which was a bit odd. Maybe someone before me went off on him with his stellar CS skills

 

For future reference you may like to know that Avenson Audio are the official channel for out of warranty Cavalli repairs.
You could always ask them (instead of monoprice) to swap the jack for another one if it happens to you again.

I don't think anyone knows if Monoprice has a service center for repairs or if they just scrap their warranty returns.
They always just swap one for another.

 

thx for that - Yeah maybe in the future if it breaks, this jack was broken out of the box (only had amp like a week), thought it would loosen up a bit and was just a bit stiff but turned out retention mechanism was broke and scraping metal on metal on the jack every time I pulled it out (was not releasing properly)

If I did get it repaired out of warranty I'd have em install a silky smooth neutrik on there too bad I never get into soldering could just do myself.

 

Replacement unit came in, this one the front plug is much better (still not neutrik smooth, but at least not a wrestling match to get plug out). Burning in now...

 

When I had the [now traded in] BEL 6922 tubes in my LP, I noticed that there seemed to be a nearly non-audible distortion at ~2khz-3khz range. This was most noticeable in my Grado Hemp, followed by my HD820, and least noticeable in my HD700 (which happens to have a notable depression at that frequency). But I could "hear" it across all three

The best way i could describe it is feeling like someone was scratching on my eardrum, and it seemed more prominent in the right channel than the left (followed headphone R earcup when reversed); when I put back the stock tubes it went away for the most part, but at higher volumes now that I am listening for it I can still sort of feel it a bit so I am wondering if they just emphasize it a lot less. There is certain content I can put on that provokes the issue and makes it more audible, like distorted electric guitars or organs. I am not sure if this is a sensitivity my own ears have or if it is something wrong with the unit itself (i.e. like it is spitting out loads of distortion at ~2khz). I have another set of tubes on the way just to try something else, but now I am wishing I had some equipment to measure distortion to see if my LP has an issue or if I'm just sensitive to that frequency. I am sensitive to certain high frequencies but never heard a distortion quite like this as prominent as when those BEL 6922 tubes were in. If it was built a little better I'd have more faith in the unit and be more likely to blame my own ears.

 

I think the build quality of the LP is pretty good, all things considered. It's not a boutique amplifier or anything.

For what it's worth, I've spent a lot of time in the LP owner's threads and related tube rolling threads and I've never heard anyone else mention this specifically.

@atomicbob also did some pretty extensive measurements if I remember correctly, so you can track that thread down and see if it uncovers something that might explain what you hear.

I'm not saying you're crazy, but would tend to think that it's more likely something you're sensitive to rather than a fault in the equipment.