Monoprice Monolith Liquid Platinum Headphone Amplifier by Alex Cavalli

This isn’t normal. My units been running for 2 hrs. & it’s luke warm at best. This is also the first time I’ve used the balanced outs on my Yggdrasil. A considerable improvement. Looks like I’ll be upgrading my big boy setup soon

 

Ugh...mine is hottest along the sides and bottom edges (that's what she said). How about yours, lukewarm at those locations also?

 

Yes, it’s a non-issue. Maybe try elevating the amp a bit?

 

I may have to grab a thermometer gun from Amazon. The amp continues to sound very very good, especially with the 650. I'll do a quick comparo with the t4 (from memory) soon.

 

I received mine last Friday. Hooked my Gungnir Multibit balanced to it and connected a pair of Fostex THX00 and started a burn-in disc (mix of XLO and others) on repeat. After a couple of hours the protection circuit kicked in. Per Alex Cavalli that is DC offset protection. I switched to my Elex connected balanced and have been running the amp with my burn-in disk for 12 hours every day since without issue and do a 4 hour listening session each night. It does get hot all over and I have plenty of ventilation space but I am really driving the amp pretty hard.

Enjoying it so far. I am a lower volume level listener and it does have plenty of gain as I rarely get past 10 o'clock with the Elex.

 

Mine gets warm on the sides and bottom but not hot enough to be alarmed, pretty typical for an amp temp IMO.

 

The amp sounds the way it does because it is DC coupled with no global feedback . Gain is set by the tube mu, without changing the design ( and sound ) to provide gobs of negative feedback, you are limited by the characteristics of the 6922 tube. and no, this is not an invitation to start tube rolling other types of tubes for which this amp was not designed.

EDIT:
discussed with Alex - amp does use some global feedback, enough to control but not so much to drain its life

a tip for changing tubes - rock gently side to side with an overall upward force - don't just yank it out.

..dB

 

Liquid Platinum surface temperatures - hard data: 40 ± 4 °C
after 2 hours power on time.

Left side


Top surface


Right side


EH6922 plate temp


Front surface


Liquid Crimson top surface for comparison


Lyr3 top surface for comparison


There is nothing here that causes me any concern.
Some 2A3 amps achieve much higher temperatures.
Some tube plate temperatures can rise to 300 °C

 

Thank you for using °C! And confirming this isn't a big deal before it got out of hand.

 

atomicbob is truly Audiophile Batman. He's got all the cool gadgets.

 

Monoprice Liquid Platinum packaging:



I did mention that the outside package wasn’t damaged. On the other hand if it’s tossed around in won’t look as pretty.

 

My LS was in a more oblong box with more packing pillows. Seems like a waste of packing space.

 

Just some thoughts based on Liquid Crimson.

1) Liquid Crimson runs hot. Probably just about as hot, and it’s kinda made out of heat sinks.
2) Liquid Crimson has a bunch of gain as well. I use a Freya as an overgrown stepped attenuator, balanced in from a Gungnir Multibit a1, se out to the Liquid Crimson. I also used a Sys for a while and it worked great.

With balanced in, probably the xlr attenuators are the way to go. As for the temperature, 104 won’t really burn anything, but you will pull your hand away pretty quick.

Anyway, not sure I added much to the discussion other than the complaints are similar with its predecessor, and pretty minor.

 

a guide to amp temperature from the man who demands heat from his amps

 

Bonus points to the eagle eye that can identify what DAC I’m using for Liquid Platinum run-in.

 

Heh...he uses the "how long can I touch this before I pull my hand away because Imma ' bout to get burned" method as well. I've been using this scale for years. Maybe we should call it the Pass Hot Scale.

Either way...it still seems not as hot as original Schiit Asgard. I'd call it a PHS of 2 or Bloody Hot. I have one I'll send you.

 

@bazelio posted this a year or so back. Hot enough to fry an egg.

 

Egads! Remind me to wipe any loaner gear from hands down really well.