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Monoprice Liquid Platinum Headphone Amp Review

SIY

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#41
Would the so called "warmth" be distortion from tube amps? I feel like that is what it is with my Little Dot II tube amp, although it might be in my head :)
The sociology of this is fascinating. Back in the day, "tube sound" was described by people like Gordon Holt as "bright, forward, and alive." Over the years, it mutated to "warm, laid back, mellow." Someone cynical might conclude that there's no such thing as "tube sound" as a generic phenomenon.

I of course would never be cynical.
 

graz_lag

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#42
The sociology of this is fascinating. Back in the day, "tube sound" was described by people like Gordon Holt as "bright, forward, and alive." Over the years, it mutated to "warm, laid back, mellow." Someone cynical might conclude that there's no such thing as "tube sound" as a generic phenomenon.

I of course would never be cynical.
So, at the end of the day, what amp technology will render the best when playing music with serious harmonic contents ?
(Purposely added by the musicians by overdriving the valve amps, for example.)
The other components of the hi-fi chain remain the same ...
 

Veri

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#43
The sociology of this is fascinating. Back in the day, "tube sound" was described by people like Gordon Holt as "bright, forward, and alive." Over the years, it mutated to "warm, laid back, mellow." Someone cynical might conclude that there's no such thing as "tube sound" as a generic phenomenon.

I of course would never be cynical.
Some of the tube sound could stem from saturation, at least that's what Tube DSP seems to imitate. Also some gear rolls off which makes it more 'analogue'/NOS sounding.
 

SIY

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#44
So, at the end of the day, what amp technology will render the best when playing music with serious harmonic contents ?
(Purposely added by the musicians by overdriving the valve amps, for example.)
The other components of the hi-fi chain remain the same ...
If you're talking about sound reproduction (as opposed to production), the technology is unimportant. The important stuff is the result: sufficient power and stability into the intended load, flat frequency response, high input impedance, low output impedance... the usual suspects. Audio engineers can achieve that with bipolars, with FETs, with tubes, with chips, and with any combination thereof.
 

graz_lag

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#46
I have a valve amplifier.
It is on top of my record cabinet so I can look at it. It isn't currently connected to anything
Neither to the power outlet ?
 

graz_lag

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#48
... The important stuff is the result: sufficient power and stability into the intended load, flat frequency response, high input impedance, low output impedance... the usual suspects ...
So, if I am evaluating different amp technologies and all get comparable measurements of the above-said parameters, my choice is going to be based - or the most part of it as Pareto would say, on subjective considerations ... Does not it ?
Or, practically, retaining the one my ears prefer after testing the different amps in my setup.
 

garbulky

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#50
The importance is due to both cost and performance. A hybrid tube pre+solid state amp tends to be lower cost to the manufacturer while still convincing the buyer it is a tube amp at a bargain. (Of which it is neither). Performance wise solid state amps are easier to get lower distortion than tubes. So categorizing them with a tube amp category puts them on top of the heap while a nicely done actual tube amp ends up below it.
 
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SIY

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#51
So, if I am evaluating different amp technologies and all get comparable measurements of the above-said parameters, my choice is going to be based - or the most part of it as Pareto would say, on subjective considerations ... Does not it ?
Or, practically, retaining the one my ears prefer after testing the different amps in my setup.
Your choice will be based on non-auditory considerations.
 
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#52
The graphs and data posted a few months ago, over at SBAF, differs quite a bit from the OP. Is there that much difference in test outout, based off the actual measuring device, or is the difference all about how you use the machine?

That power noise, displayed in the OP, is non existent in the SBAF measurements-hence the recommendation to NOT use LPS. I won't post a link, as that's not cool to me, but I wonder why there is such a gap in measuring? Many of the reviews on this site have representative powerline noise (I am only talking about devices that have data on the same tested device), that are not present at stereophile, or SBAF. Is that just due to the newer AP being used by the amirm?

I owned one of these, and the gain structure is poor, you get very little control of the volume before it gets super loud. It's perfect for hifiman cans and other planars, though. Also there is a noticeable difference from SE vs. balanced in subjective sound quality. The power on/off button is cheap, and the tube socket clamp pretty hard, be careful with them, of you are tube rolling. I'd recommend socket savers.

It was a great deal when it was first released, but now nearing $800, I just don't see how you can justify it.
 

garbulky

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#53
The graphs and data posted a few months ago, over at SBAF, differs quite a bit from the OP. Is there that much difference in test outout, based off the actual measuring device, or is the difference all about how you use the machine?

That power noise, displayed in the OP, is non existent in the SBAF measurements-hence the recommendation to NOT use LPS. I won't post a link, as that's not cool to me, but I wonder why there is such a gap in measuring? Many of the reviews on this site have representative powerline noise (I am only talking about devices that have data on the same tested device), that are not present at stereophile, or SBAF. Is that just due to the newer AP being used by the amirm?

I owned one of these, and the gain structure is poor, you get very little control of the volume before it gets super loud. It's perfect for hifiman cans and other planars, though. Also there is a noticeable difference from SE vs. balanced in subjective sound quality. The power on/off button is cheap, and the tube socket clamp pretty hard, be careful with them, of you are tube rolling. I'd recommend socket savers.

It was a great deal when it was first released, but now nearing $800, I just don't see how you can justify it.
Whether the power supply related noise is setup induced has been bought up before. Amir mentioned a while back about when he reviewed the Schiit Yggy that he would post his power measurements. Maybe it's posted and I haven't seen it yet. I too agree that I couldn't bring myself to get the Woo. It looks nice but with the heroic efforts like a separate power supply chassis you would want something better than a SNR in the 60s.
ASR measurements


SBAF measurements (note the spec is closer to the THD spec here)
 

SIY

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#54
There's two principal causes of power supply noise sensitivity. First is circuitry with terrible power supply noise rejection. The second is layout, especially grounding.

My bet is still on the second in this case.
 

L0rdGwyn

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#55
The sociology of this is fascinating. Back in the day, "tube sound" was described by people like Gordon Holt as "bright, forward, and alive." Over the years, it mutated to "warm, laid back, mellow." Someone cynical might conclude that there's no such thing as "tube sound" as a generic phenomenon.

I of course would never be cynical.
I am the owner of a OTL tube headphone amp, which I quite enjoy. It has been characterized as "warm", but that is related to its high-output impedance and the associated damping factor, a different topic altogether :)

I would never call it "transparent" or "high-fidelity" though. It sounds great to me, my preference, but I also recognize that it is basically a distortion effects box.

Please feel free to correct me, but my understanding of the "tube sound" was related to the 2H and some 3H distortion most associated with vacuum tube triodes? Bob Katz discussed this quite a bit in this article:

https://www.innerfidelity.com/content/katzs-corner-episode-25-adventures-distortion

Obviously these are just his subjective impressions, curious if these align at all with the literature when it comes to 2H distortion in psychoacoustics.
 
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#56
The sociology of this is fascinating. Back in the day, "tube sound" was described by people like Gordon Holt as "bright, forward, and alive." Over the years, it mutated to "warm, laid back, mellow." Someone cynical might conclude that there's no such thing as "tube sound" as a generic phenomenon.

I of course would never be cynical.
That sounds about like what I look for in a Tube, I had a chance to heard the Liquid Plat at a meet... with my HE 560 I wasn't impressed. More noise and less power than I was expecting, and the combination of the two gave the HE 560 a really loose flabby low end, but reading through this thread it looks like the PSU is the issue.

Still TBH I own a hybrid tube that sounded cleaner though I don't use the stock PSU alone, I run a power conditioner along with a "single massive stage LC filter" a genie diamond in the rough from out of SBAF. Moving on I can't say I was impressed with how the Liquid Plat performed given the price and given how a cheaper option with some very easy to acquire in line power conditioning sounded better. Tho I've not heard both units side by side in my own system yet so ymmv
 
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#57
@amirm

Would it possible to calculate, and post the SINAD rating using Balanced IN and Balanced OUTPUT.

This amp is just another amp, nothing exciting or poor, out of the 1/4" jack ( for the price). So I was curious if the "measured" performance matches my own subjective assessment, of a huge improvement running balanced in/out.

I would have liked a 2.5mm or 4.4mm for iems vs the 1/4"
 

amirm

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#60
@amirm

Would it possible to calculate, and post the SINAD rating using Balanced IN and Balanced OUTPUT
I don't have a low-noise fixture for SINAD measurement. And at any rate, have packed the unit to return to its owner. :)
 
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