[atomicbob]

SE input 4XF output 30 ohm part 1 of 3

Liquid Platinum THD+N THD nth harmonic distortion (A04) FFT 0dBu 30R load

Liquid Platinum THD THD+N vs Freq 0dBu 30R

Liquid Platinum 1 KHz spectrum Left and Right 0dBu 30R load

Liquid Platinum 50 Hz + 7000 Hz spectrum Left and Right 0dBu 30R load

Liquid Platinum 600 Hz + 1700 Hz spectrum Left and Right 0dBu 30R load

Liquid Platinum IMD spectrum Left and Right -16dBu 30R load

Liquid Platinum residual noise spectrum Left and Right A=0dB 30R load

 

[atomicbob]

SE input 4XF output 30 ohm part 2 of 3

Liquid Platinum amplitude - phase - gain (A01) 30R load

Liquid Platinum signal to noise (A07) 30R load

Liquid Platinum THD+N THD nth harmonic distortion (A04) 30R load

Liquid Platinum Crosstalk (A08 A09) 30R load

 

[atomicbob]

SE input 4XF output 30 ohm part 3 of 3

Liquid Platinum Frequency Response and Interchannel Phase pg 1/2 30R load

Liquid Platinum Frequency Response and Interchannel Phase pg 2/2 30R load

Liquid Platinum Gain vs Amplitude Left 30R load

Liquid Platinum Gain vs Amplitude Right 30R load

Liquid Platinum THD+N vs Frequency Left 30R load

Liquid Platinum THD+N vs Frequency Right 30R load

Liquid Platinum THD+N vs Amplitude Left 30R load

Liquid Platinum THD+N vs Amplitude Right 30R load

Liquid Platinum Crosstalk Left to Right vs Frequency 30R load

Liquid Platinum Crosstalk Right to Left vs Frequency 30R load

 

[atomicbob]

SMPS - NoiseNuke - LPS comparison part 1 of 3

Please see warning about use of LPS or Noise Nuke here:
https://www.head-fi.org/threads/mon...ical-measurements.894843/page-2#post-14641335

Picture of the Audio Lab setup for Liquid Platinum LPS measurements

SE input 4XF output 30 ohm load power supply comparison

Liquid Platinum 1 KHz THD+N THD FFT 0dBu 30R load SE-4XF - SMPS supplied

Liquid Platinum 1 KHz THD+N THD FFT 0dBu 30R load SE-4XF - SMPS + Noise Nuke

Liquid Platinum 1 KHz THD+N THD FFT 0dBu 30R load SE-4XF - BK1623A LPS

Liquid Platinum residual noise spectrum Left and Right A=0dB 30R load - SMPS supplied

Liquid Platinum residual noise spectrum Left and Right A=0dB 30R load - SMPS + Noise Nuke

Liquid Platinum residual noise spectrum Left and Right A=0dB 30R load - BK1623A LPS

 

[atomicbob]

SMPS - NoiseNuke - LPS comparison part 2 of 3

Liquid Platinum THD+N THD nth harmonic distortion (A04) FFT 0dBu 30R load - SMPS supplied

Liquid Platinum THD+N THD nth harmonic distortion (A04) FFT 0dBu 30R load - SMPS + Noise Nuke

Liquid Platinum THD+N THD nth harmonic distortion (A04) FFT 0dBu 30R load - BK1623A LPS

Liquid Platinum THD THD+N vs Freq 30R load SE-4XF - SMPS supplied

Liquid Platinum THD THD+N vs Freq 30R load SE-4XF - SMPS + Noise Nuke

Liquid Platinum THD THD+N vs Freq 30R load SE-4XF - BK1623A LPS

Difference between SMPS, SMPS+NoiseNuke and LPS has negligible effect on Liquid Platinum output in the audio band.

 

[atomicbob]

SMPS - NoiseNuke - LPS comparison part 3 of 3

20181112-40 36V 56R residual noise 200mV 10uS div 20MHz - SMPS.png

20181112-41 36V 56R residual noise 200mV 10uS div 20MHz - NoiseNuke.png

20181112-42 36V 56R residual noise 200mV 10uS div 20MHz - LPS .png

20181112-45 36V 56R residual noise 200mV FFT 10Hz - 50KHz - SMPS.png

20181112-47 36V 56R residual noise 200mV FFT 10Hz - 50KHz - LPS.png

20181112-46 36V 56R residual noise 200mV FFT 10Hz - 50KHz - NoiseNuke.png

20181112-48 36V 56R residual noise 200mV FFT 10KHz - 15MHz - SMPS.png

20181112-49 36V 56R residual noise 200mV FFT 10KHz - 15MHz - NoiseNuke.png

20181112-50 36V 56R residual noise 200mV FFT 10KHz - 15MHz - LPS.png

Power supply noise differences input to Liquid Platinum are measurably different. SMPS+NoiseNuke and LPS offer lowest noise presented to Liquid Platinum.

 

[atomicbob]

Liquid Platinum LPS power supply warning!!
(also applies to use of NoiseNuke with Monoprice supplied SMPS)

Use of any power supply other than that supplied by a vendor, or exact replacement, is not guaranteed to work nor covered by manufacturer warranty. Proceed at your own risk.

Liquid Platinum is a high performance amplifier with many sound quality optimizations while maintaining DC coupling from input to output. To avoid stressing amplifier components or headphones during power on / off transitions, a combination of mosfet inrush current power management and high voltage (HV) delay timer are used. It is necessary for tubes to reach sufficient electron conduction temperature before applying HV and enabling amplifier outputs.

In the off position Liquid Platinum's front panel power switch resets timing circuits. If an external power supply equipped with a power switch is used while the Liquid Platinum front panel power switch is engaged potential for excessive component stress and possibly damage exists. This can happen at either power On or power Off cycle.

During one late night measurement session while fairly tired I neglected to follow standard lab procedure of powering off Unit Under Test (UUT) before switching the lab linear power supply off. I realized my lapse in procedure immediately. Upon following correct power up procedure, UUT off, then Lab supply on, I noted the tubes were glowing without engaging Liquid Platinum's power switch. Once engaged, timing circuits behaved correctly and the amp was verified to perform as expected. Unfortunately the power management mosfet had shorted Source to Drain.

Since that event using the proper power up procedure I have not experienced any issues with my Liquid Platinum other than tube heaters are on whenever the external power supply is powered. Listening evaluations still result in auditory delight.

Here is a power off discharge measurement comparing the supplied SMPS with a Zero Zone 65W LPS. The SMPS stores very little energy and is down to zero volts in approximately 100mS. Zero Zone LPS has big capacitors, as expected and requires approximately 4 seconds to discharge; 40x longer. Liquid Platinum power management has been designed to work optimally with the supplied SMPS. During the 40x extra time unpredictable circuit behavior may occur, such as mosfet S-D melting into a short.

Proper procedure for power on:
1. verify both external power supply and Liquid Platinum power switches are in OFF position
2. switch ON power supply
3. switch ON Liquid Platinum

Proper procedure to power off:
1. switch OFF Liquid Platinum
2. wait for a few seconds
3. switch OFF power supply

NEVER switch power ON or OFF to external power supply while Liquid Platinum front panel power switch is in the ON position.

Once the mosfet is damaged, the unit is likely to operate as expected. However, even if the mosfet becomes damaged, continue to follow proper power On / Off procedure described above. This is very important for proper operation of HV timing circuits.

Power up / power down sequences have been with us since the beginning of separate components for stereo and pro audio:
Power up
1. Source on
2. Preamp or Mix console on
3. Outboards (processers) on
4. Amps on

Power down
1. Amps off
2. Outboards off
3. Mix console (preamp) off
4. Source off

Failure to follow sequence may result in unpleasant loud noises and damage.

It is enough of an issue that pro audio types have rack sequencers when allowing less knowledgeable users operate complex racks. See this Furman product as an example:
https://www.furmanpower.com/product/15a-standard-power-conditioner-sequencer-M-8S

If using a switched power distribution or conditioner, I would still practice turning off amps first and on last as per procedure.

The Liquid Platinum has been designed to work with the provided SMPS. Consider the following data:

During power interruption the SMPS discharges rapidly (green line.) The amp is designed to work at 36Vdc. When the voltage is lower than operational design point, stability of operation cannot be guaranteed, true of any electronic component during power interruption and why UPS exist. So consider the time spent between say 34Vdc and 1Vdc. With the SMPS there are 100mS of potentially unstable behavior and the violet line depicts possible energy delivered. It is a tiny amount in the graph's lower left corner.

Now consider the LPS discharge (red line) which requires 4000 mS to discharge. The blue line depicts amount of potential energy delivered during power interruption. Clearly there is more time for the circuit to be potentially unstable and far more energy available. This is not desirable. So I would recommend only using any LPS or Noise Nuke if willing to either follow the power sequence procedures, use a UPS if worried about power outages or willing to take risks. This applies to all amps, not just the Liquid Platinum.

 

[atomicbob]

reserved 23/24

 

[atomicbob]

reserved 24/24

 

[omniweltall]

Thanks for taking the time to do this @atomicbob

 

[glitch39]

thanks, @atomicbob . Very, very detailed technical review. Given we'd already heard (or read) of the sonic reviews, this makes me think the Cavalli LP is a winner.
Too bad Monoprice is jacking up pricing because of the positive reviews

 

[atomicbob]

Too bad Monoprice is jacking up pricing because of the positive reviews

I think the price increases are more from Trump's Tariffs on China manufactured electronics than anything else.

 

[Thenewbie76]

Bro, I am like really lost at trying to understand this charts . I am a total newbie at the audiophile world. Just quick question , I wanna know if you would think this is meant for me. I am trying to find my 1st tube amp for my sennheiser hd 600 and ZMF aeolus which both have 300 ohms.Its small for a tube ,I can change the sound to be more brighter or warmer by changing tubes .Do you think the amp can do this and since it's a hybrid amp does it still offer that tube signature. My other amp I use is the THX AAA 789 AMP which is a solid state and super neutral.Would the liquid platinum be a good tube amp to add to my collection?

 

[Gauss1777]

@Thenewbie76 Bro, I have an HD600 too, with this headohone you can't go wrong with the Bottlehead Crack, however you must build it, it is easy and a lot of fun. it has very detailed instructions. With the HD 600, sound is sweet, not neutral, midrange and below bass it's full bodied and addictive. I don't think an hybrid can match it, I'm very tempted to get this Liquid Platinum, but then the CrackATwoA it's about the same price, so I simply don't justify one more in my priorities. it's all about to play the game to trying different things if you want to spend and enjoy music, so just buy however your heart point to. From what i read the LP matches nicely with the HD600.The HD600 is very versatile, with different amps you can use it in just about anything. for Classical and music like Norah Jones, Katie Melua, Alicia Keys, Barry White, Lounge: The Crack; for maybe Metal, Rock and Electronic (and anything else) the Liquid Platinum. I use the Crack for anything most of the time, you just have to have one with the HD600.

 

[Thenewbie76]

@Gauss1777 That is good to hear, but I am kinda scared of a D.I.Y , alot of people have told me if I wanted a tube amp I should get the bottlehead crack and If I can't do D.I.Y I should get the darkvoice or the little dot mk3. I will continue doing research