Monoprice Monolith Liquid Platinum Headphone Amplifier by Alex Cavalli

Follow on post from Alex about the design of the LP

https://www.head-fi.org/threads/mon...-by-alex-cavalli.876406/page-29#post-14576892

 

Hey, SBAF, I have been able t resurrect my account. I can post here too now. I'll try to be useful.

 

Welcome back! Being active here and sharing some relevant information is very much appreciated. First question, during the break in process, or during everyday use, is it okay to leave the amp running all day?

 

Whether or not it makes sense to leave it on continuously depends, I think, on how you are using it. If there are long periods of no use I don't think there is much benefit to leaving it running and this just adds hours to the tubes and other components. If the concern is maintaining SQ from listening session to session, I think about 10 mins of warmup will do about the same thing.

It the listening sessions are closer together (and "close" is a fuzzy word here) then it may make sense to just leave it on. Just be sure it is well ventilated.

I have mentioned elsewhere that I don't think a forced break in is really needed and that normal listening sessions will do the same job over a little more time. It isn't necessary to plug in headphones if you do a long break in.

 

Liquid Crimson
Liquid Platinum
Liquid Spark
etc.

I’d venture you have already surpassed useful, as I’m certain many here would agree.

 

Interested in your thoughts as you have owned the Liquid Crimson in the past.

 

Hi Alex - Quick question for you. One nice thing about Cavalli Audio was the sure line for a repair path. This is still continued with the repair path of Avenson Audio.

If these units need a repair beyond the 1 year warranty is there a path for repair?

 

Sounds like a question for Monoprice.

 

Went ahead & pulled the trigger on this. Also grabbed a pair of Siemens tubes as I’ve found they are the smoothest 6922’s I’ve heard. Having owned a couple cavalli amps and with Alex being involved in the production of the platinum I’m sure it won’t disappoint.

 

Any impressions yet?

 

removed.

 

I was about to write that but I guess it was you who also wrote there (I didn't pay attention to the nickname). I am curious to know why....

 

Will the amp work well as a balanced pre? Are the balanced outputs controlled by the volume control?

 

Seems like the issue concerned the Liquid Spark and he posted the problem in the Liquid Platinum thread instead. Also the problem was found to be his dac causing a hum.

This is per Hansotek on the Head-Fi thread. I should receive my LP tomorrow and hope to compare it to the Gilmore Headamp Lite MK2, MCTH, and Glenn’s OTL. May take me around a week to get this done.

 

I concur. Here is his post in the LS thread confirming its was his DAC (RCA connection) was the problem..

https://www.head-fi.org/threads/mon...-by-alex-cavalli.876407/page-12#post-14561913

 

I was confusing another Monoprice amp, the Monolith by Monoprice Tube Headphone Amplifier with ESS Sabre DAC (29511)

Post #22

I sure hope this amp (the LP) is the bee's knees.

 

I have not read a manual, so this information is strictly from posts I have read on Head-Fi.

XLR is input only. Connections are XLR and RCA, for input - RCA for line-level output. If you look at the back of a MassDrop Liquid Carbon X, the connections are the same topology. But the labels are clearer on the LCX, how each connection functions:

 

XLR outputs would not be female jacks anyway. They would have to add 2 more XLR male plugs for output. I don't see many demanding XLR variable output unless you have pro/semi-pro monitors or more pro amps.

 

Just an hour of warm up and sat down for a quick listen. Using new Gungnir Multibit>balanced out to LP>ETHER 2/hd650. I had some conversations with @Hands about this amp a few months ago. I would say now that he was right on the mark when he described the amp to me. It's a wonderfully neutral amp with a splash of warmth. It pushes out detail effortlessly and throws a bigger than average sound stage. That's all I really want to say for now until I break the amp in and have to time do some critical listening and comparisons to other amps. I'll also roll in some Reflectors and Mullards that I have lying around.

Packaging from Monoprice was not good. The original amp box and fit is very good. But they then put that box in another shipping box that is roughly 35% bigger with a few bubble packs tossed in. This allows for the "whip" effect when the package gets thrown around or comes off the conveyor belt at 10 plus mph. Come on guys, pack it tight! This is too expensive to pack casually.

Gain is too high. This amp really could benefit from a gain switch. 14x is keeping me around 8-9 on the pot...not good. At this price point I really wish that they had implemented a gain switch.

Both tubes had bent pins for me. I straightened them carefully before inserting them in the sockets. It is very difficult to insert the tubes in the amp. I would be shocked if this doesn't become an issue for tube rollers. If you plan to roll tubes regularly, I'd suggest that you use socket savers from day one.

 

So, two main data points so far suggest a great design from Alex being hampered by crappy execution by Monoprice.

I know the tubes were difficult to install...did you have any issues with the sockets not being well-aligned with the chasis opening or was it strictly the sockets being too stiff/tight?