[Holypal]

Positive after last night's session. Had about 16 hours burn-in on the LP and 140 on the Elex (balanced) at the time. Right now my standard of comparison is an Auralic Taurus Mk II. I listened for about 3 hours. Bass is quite solid and highs are just a touch recessed right now. It seems like it is taking shape so to speak. Nice tonality on very forward piano and aggressive tenor sax and they also have nice weight to them. It is evolving from initial quick listens earlier and I am sure it will continue to do so. Not night and day (as the amp sounds quite nice right now) but more in the way of refinement.

By slightly recessed highs I am using a track by Flim & The BB's titled "Room With A View of You" off their "Tunnel" album as an example. There is a glockenspiel part that repeats after the chorus and it's a bit more prominent on the Taurus. This was one of the first CD's I bought and has been in regular rotation for me since the mid 80's. That part was one of the first things that sold me on CD's.

After having the thermal protection circuit kick in once while running a very challenging burn in disk with Fostex TH-X00 connected via TRS it has not happened again but I have had balanced Elex connected. Volume was set at between 9 and 10 o'clock when running the burn in and listening. I do not crank the volume.

By way of full disclosure I am in my 60's and have very mild tinnitus. The latter is variable so it can impact each listening session differently. I won't be doing a back and forth comparo between amps. I'll run my HD600 balanced tonight.

I am enjoying the amp. I did not buy it hoping it would exceed the Taurus in all areas but rather to have two different perspectives and synergy. No regrets so far.

I noted Alex's comment on the SMPS providing more than adequate power but I am curious about added noise versus an LPS. It would appear that any LPS efforts are being left to aftermarket vendors. I completely understand the sacrifices needed to achieve the price point. I could never afford a Liquid Crimson. Also understand the point about dissipation as this is a very small enclosure and the top in front of the tubes is quite warm when running as it is. This is a very carefully thought out design that required some serious tightrope walking and balancing of conflicting needs. I am glad Alex made this effort.

Any thoughts on tube rolling? The tube socket requires a lot of pressure to seat the tubes and wonder if the unit is voiced with the included Electro Harmonix 6922, which is not a bad tube at all.

Could you make a comparison between LP and Taurus Mk II?

 

[runeight]

Regarding tube rolling, I suggest that if you are not ready to buy expensive NOS 6922s, first try the Genalex Gold Lions (gold pins). They are more expensive than the EHs, but they have a slightly different sound signature.

 

[sahmen]

Liquid Crimson --> Liquid Platinum II

If you haven't seen this, please go here:
https://www.head-fi.org/threads/mon...-by-alex-cavalli.876406/page-28#post-14575341

To squeeze a balanced Crimson into the Platinum sized box at 1/4 the price requires several engineering changes.

1. Power output - Today's headphones are, in general, more efficient than when the Crimson was designed. While back then 4-5W might have been a necessity, today it is not. Most (but not all) headphones will run happily to ear-splitting levels at much less power. Thus, the first engineering change is to reduce the power output. Not by than much, but by enough to be practical. This includes going to a balanced topology which reduces the rail voltages considerably.

2. Power supplies - there simply isn't enough room for a big transformer and linear supplies in the box and on the board. The only possible solution is an outboard supply, in this case for efficiency an SMPS. Then, this SMPS is used to create all of the needed supplies - LV rails, Housekeeping, HV and Heater.

The HV and Heater supplies are made with small DC-DC converters. These are efficient, small, and perfectly suitable for the constant low current requirements of the tube portion of the circuit. Some would claim that linear supplies would be better here even if they provided less voltage. I would disagree. The Platinum HV supply makes over 100V to place the 6922 at a very good operating point. The CTH, to note, also has a 100V HV supply instead of a lower voltage linear one.

Thus, the very big Crimson linear supplies are replaced with very small and/or outboard supplies which are all super efficient. This reduces the power demands of the amp a lot and the power dissipated by the non-audio components.

3. Power Dissipation - the confines of the new box and lack of external heatsinks demands much lower power dissipation. This is partly accomplished with the new supplies. It is also accomplished by reducing the idle currents in the output devices significantly. Whereas the Crimson's output devices burnt almost 5W each at idle the Platinum's output devices burn less than 1/2 per device. The Platinum's outputs are cooled through the board making it possible to get it all in this small enclosure.

4. SMD vs Through Hole - the Crimson was nearly entirely hand-assembled through hole components (expensive). The biggest change in the footprint of the Platinum is its use of SMD components. They are vastly smaller, don't compromise the performance, and are auto assembled dramatically reducing the manufacturing cost.

All of these 4 engineering changes working together are what makes it possible to offer the Platinum in its small box at the current price point.

@runeight : Thanks for outlining these engineering changes. Given how substantial they are or seem to be, though, they've led, almost naturally to another pressing question in my mind, one which I have been initially hesitant to ask, because of its potential sensitivity. However, I cannot help considering it to be an important question, and I am quite likely not the only one who is being nagged by such a question. After a couple of hours of mulling it over, I have come to the conclusion that the best approach would be to go ahead and just ask it, offering you the opportunity to address it (or not) in any way you're most comfortable with...

So here goes :

What changes in the sound signature or quality of the crimson (however minimal) were you anticipating from this process of shrinking it down into the smaller Platinum's box, and to what extent has the end result met your expectations?

Okay, it sounds as if I am cheating by asking two questions instead of the promised one. However, in my defense, I just see anticipation and results as two parts of the same question, if you see what I mean.

Your thoughts about this question would definitely be appreciated, as usual.

 

[runeight]

@runeight : Thanks for outlining these engineering changes. Given how substantial they are or seem to be, though, they've led, almost naturally to another pressing question in my mind, one which I have been initially hesitant to ask, because of its potential sensitivity. However, I cannot help considering it to be an important question, and I am quite likely not the only one who is being nagged by such a question. After a couple of hours of mulling it over, I have come to the conclusion that the best approach would be to go ahead and just ask it, offering you the opportunity to address it (or not) in any way you're most comfortable with...

So here goes :

What changes in the sound signature or quality of the crimson (however minimal) were you anticipating from this process of shrinking it down into the smaller Platinum's box, and to what extent has the end result met your expectations?

Okay, it sounds as if I am cheating by asking two questions instead of the promised one. However, in my defense, I just see anticipation and results as two parts of the same question, if you see what I mean.

Your thoughts about this question would definitely be appreciated, as usual.

No probs. I had expected this question. I cannot give you a perfect answer though.

From circuit topological point of view, the Platinum is exactly a Crimson, only balanced. I expected it to sound pretty much like the Crimson does. And I think it does. It just doesn't have quite the same output power. Close, but not the same.

I don't happen to have a Crimson at hand so I cannot due a strict A/B. This will have to come from others who might eventually have both. I think Hansotek did a little bit of memory comparison in his review.

 

[sahmen]

No probs. I had expected this question. I cannot give you a perfect answer though.

From circuit topological point of view, the Platinum is exactly a Crimson, only balanced. I expected it to sound pretty much like the Crimson does. And I think it does. It just doesn't have quite the same output power. Close, but not the same.

I don't happen to have a Crimson at hand so I cannot due a strict A/B. This will have to come from others who might eventually have both. I think Hansotek did a little bit of memory comparison in his review.

Thanks @runeight : it strikes me as if you are saying that you do not expect or see any important deviations in Sq performance, moving from one unit to the other, and I find that to be very reassuring, as someone who has a platinum being shipped to my destination as we speak...

So thanks again, for addressing this question,

 

[runeight]

Thanks @runeight : it strikes me as if you are saying that you do not expect or see any important deviations in Sq performance, moving from one unit to the other, and I find that to be very reassuring, as someone who has a platinum being shipped to my destination as we speak...

So thanks again, for addressing this question,

They should be similar, but only those who have both can do the direct comparison to hear the differences. Keep in mind that the Crimson was a $3k amp. The Platinum does make those engineering choices I described above to achieve its size and price point.

I just want to be clear that you all are not getting a full Liquid Crimson, but perhaps something that is within reach of it.

Also, note that the Platinum measures very well. See MP website and some posts earlier in this thread.

I think we'll have to wait as the reports come in.

 

[Jim N]

Could you make a comparison between LP and Taurus Mk II?

Only indirectly in my commentary. I've had my Taurus almost 2 years and have listened to it for a few thousand hours playing a wide variety of music using 6 different pairs of headphones. It would be unfair to fully compare them now since the LP is still refining with burn-in and I have only listened to it for a few hours with only one set of cans.I want to level the playing field a bit more. I also want to get past the "new toy" stage with it.

I will be keeping both for the foreseeable future. I have nothing negative to say about the LP so far. Time will tell.

 

[sahmen]

They should be similar, but only those who have both can do the direct comparison to hear the differences. Keep in mind that the Crimson was a $3k amp. The Platinum does make those engineering choices I described above to achieve its size and price point.

I just want to be clear that you all are not getting a full Liquid Crimson, but perhaps something that is within reach of it.

Also, note that the Platinum measures very well. See MP website and some posts earlier in this thread.

I think we'll have to wait as the reports come in.

Understood. I do have a Liquid Carbon v1, and the Spark, to compare with the Platinum, but not the Crimson, so I too would be looking forward to those reports. I get the sense that comparisons under these circumstances would involve a delicate balancing act, but it is all good. I see a few exciting moments ahead.

 

[greenkiwi]

Well, I can say that I am just very excited to have this. I have been regretting missing the RMAF Crimson deal from 2015 since I saw it. I'd heard the LP in it's uncased bare form at a meet in San Francisco and kept hoping it would come out. When CA closed its doors, I was really tempted by the MD CTH, but upon listening, it didn't really do it for me. At any rate, I can't wait to give this a listen at work all next week. And I'm still a little bummed I didn't pick up the crimson for $1850... but heck, that's still 2+x the cost of the LP.

@runeight Thanks for finding a way to make this happen.

 

[greenkiwi]

Random question, what at what temp does the thermal protection kick in? I've seen it mentioned a couple times now.

And what is considered warm vs hot in terms of normal running temp for the amp?

 

[runeight]

Random question, what at what temp does the thermal protection kick in? I've seen it mentioned a couple times now.

And what is considered warm vs hot in terms of normal running temp for the amp?

Glad you asked. I've meant to comment on that.

The interrupt was the DC offset detector to protect headphones from too much DC at the output should that occur. All of my big amps had this feature. So does the Spark.

The amp doesn't have thermal protection. It does run pretty warm and so needs good free air ventilation.

 

[Jim N]

Glad you asked. I've meant to comment on that.

The interrupt was the DC offset detector to protect headphones from too much DC at the output should that occur. All of my big amps had this feature. So does the Spark.

The amp doesn't have thermal protection. It does run pretty warm and so needs good free air ventilation.

Thanks for information. I'll use the correct description. It has not occurred again and i have been running the amp continuously 12-14 hours at a shot for two days now.

I misread "protection circuit" from the Enjoy The Music review of the LP.

 

[DRHamp]

I’m unclear on the se rca outs on the back - I think I read that they are not pre-outs (no volume control) - so what is their function?

 

[Zachik]

I’m unclear on the se rca outs on the back - I think I read that they are not pre-outs (no volume control) - so what is their function?

Their function is to be able to connect to another amp. So, for example, if you have 1 DAC and 2 amps - you do not need a splitter.

 

[jsmiller58]

I’m unclear on the se rca outs on the back - I think I read that they are not pre-outs (no volume control) - so what is their function?

As @Zachik say, allows you to daisy chain two amps together so they share and can simultaneously run off of the same DAC. A pretty useful feature. Also exists on the LCX. In the case of the LCX, the LCX has to also be turned on for this feature to work correctly (not sure why). Might or might not be the case that the 789 needs to be on for the second amp to work when chained to it.