Topping PA7 Plus Amplifier Review

[Urib]

This is a review and detailed measurements of the Topping PA7 Plus stereo class D amplifier. It was sent to me by the company and costs US $549.
View attachment 279972

The PA7 Plus is stylish with firm switches that have nice action. You can select power on/off or trigger input. In addition, you have a choice of balanced or RCA inputs:
View attachment 279973

Yes, there is a monster external power supply. It provides a whopping 52 volts at 6.5 amps! I really like the staggered speaker terminals as it allows even the largest speaker connectors to fit in there without interference. Other derktop amplifiers use much tighter spacing.

The amplifier has large vents on the back, sides and bottom. In use the left side got firmly warm but nothing concerning.

Note that there is a non-Plus version (PA7) that has lower power and lower cost ($449).

Topping PA7 Plus Measurements
Let's start with our usual measurements starting with balanced input:
View attachment 279974

As you see gain is medium level at max volume at nearly 20 dB. SINAD lands in our excellent category and even sneaks into our top 20 best amplifiers ever measured:
View attachment 279975
View attachment 279976

RCA input shows more ground currents and noise but still holds its own:

View attachment 279978

But note that gain increases substantially to 26 dB.

Noise performance is extremely good:
View attachment 279979

We are talking about near state of the art DACs at full power!

Multitone shows off the very low distortion:
View attachment 279980

Excellent channel separation is achieved despite the very small enclosure, beating vast majority of amplifiers I test:
View attachment 279981

An interesting filter is implemented which sharply reduces load dependency:
View attachment 279984

I take that 0.7 dB to get load independence.

Let's get into our power measurements:
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191 watts with very low distortion into two channels is fantastic for such a small amplifier. Here is the same with 1% THD:

View attachment 280167

Even at 8 ohm you have lots of power:
View attachment 279983

Note how the noise floor competes with Purifi reference amplifier and even its distortion! It is just short of its power.

There is more distortion at higher frequencies but below 1 kHz, it is extremely good:
View attachment 279985

Reactive Amplifier Power Testing
I tested the PA7 Plus using the PowerCube reactive load that simulates both capacitive and inductive loads as to better match behavior of a real speaker. Response at 4 an 8 ohm was excellent:
View attachment 279986

I could even get it to work with 2 ohm but one out of two times it would go into protection and stay there.

Conclusions
Even though the PA7 Plus is based on a commercial amplifier IC, it is clearly that significant engineering optimizations have gone into the design to produce such a low noise and distortion amplifier. The package is excellent and power supply quite hefty to enable very high power output (nearly 400 watts combined at 4 ohm!). Yes, you have a big brick to hide but the amp itself remains quite small on the desk. You could even use it in a main system if you leave the volume set and use the DAC or a pre-amp with a remote.

I am happy to add Topping PA7 Plus to my recommended list.

Note: amplifiers are some of the least reliable audio gear due to high currents and voltages involved. I short circuited the PA7 Plus and while it created a large spike, it nicely went into protection and recovered. Still, if you are risk averse, you may want to wait a bit to see what the reliability turns out to me.

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As always, questions, comments, recommendations, etc. are welcome.

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Why no remote?

 

[3dcnc]

Why no remote?

for desktop you don't really need it. The partner L70 headphone amp, is also a preamp with a remote. In theory IMO you should get better results with the preamp digital volume control. It is a resistor ladder config. I have ordered one, has not arrived yet.

I appreciated its simplicity . good sound with basic control. rather than average sound with loads of features.

using it with small triangle Borea BR02
speakers and REL sub.

I would say it gets better after many hours of use. ( some say that is just a myth)

 

[3dcnc]

Why no remote?

Well today the L70 preamp, headphone amp arrived. with remote
Plugged into the Pa7 topping amp. Straight away the amp became louder and more dynamic/detailed , but not all in a good way. For my speakers - at least
I believe in burn in- especially D - amps. I will give it a few weeks ( many hours).
The signal from the preamp is definitely stronger than from the Denfrips Aries 2 DAC via xlr or my other DACs via RCA
It almost seems it has put a "sharpening filter" on details. I can hear much more details.
I will keep as ref headphone amp, but wont probably use as a preamp.
At the moment, i prefer the xDuoo TA-20 Plus class A tube headphone amp.

 

[Basilderat]

I have a Topping stack E70/L70/PA7. What is the best way to control gain for the best SNR? Should I use the L70 preamp to control gain and have the PA7 switched to bypass mode as a power amp, or should I set the L70 for no attenuation (pass-thru) and control the gain with the PA7 set to volume control? I was told that for the best SNR to run full signal to as late in the chain as possible?

 

[staticV3]

I have a Topping stack E70/L70/PA7. What is the best way to control gain for the best SNR? Should I use the L70 preamp to control gain and have the PA7 switched to bypass mode as a power amp, or should I set the L70 for no attenuation (pass-thru) and control the gain with the PA7 set to volume control? I was told that for the best SNR to run full signal to as late in the chain as possible?

I'd set the
E70 to 5V, DAC mode (volume control disabled), the
L70 to Low gain, -6dB for effectively unity gain, and the
PA7 to it's lowest volume.

I would then start listening to music and slowly increase the volume on the PA7 until I've reached the highest volume that I'll need.

After that, I would leave the PA7 knob where it is (maybe put some tape or a drop of hot glue on it so the knob can't get knocked out of position), then exclusively use the L70 to control volume.

Note that you can set a Safe volume on the L70 which it'll go back to when turning on or switching I/O.
That way, you can avoid unpleasant volume jumps when you start playing but left the volume too high from your last session.

 

[Basilderat]

I'd set the
E70 to 5V, DAC mode (volume control disabled), the
L70 to Low gain, -6dB for effectively unity gain, and the
PA7 to it's lowest volume.

I would then start listening to music and slowly increase the volume on the PA7 until I've reached the highest volume that I'll need.

After that, I would leave the PA7 knob where it is (maybe put some tape or a drop of hot glue on it so the knob can't get knocked out of position), then exclusively use the L70 to control volume.

Note that you can set a Safe volume on the L70 which it'll go back to when turning on or switching I/O.
That way, you can avoid unpleasant volume jumps when you start playing but left the volume too high from your last session.

Thank you, that's audiophile gold! - makes perfect sense, really appreciated.

 

[GPJ]

Just a comment FTR. Been using a brand new PA7 for the past couple of days and the performance is remarkable. Feeding it with an E70V set to pre mode (5V XLR) and the PA7 in power amp mode. Speaker are Klipsch RF7 II which are pretty efficient ........... -20dB is the point of starting to get very loud. -23-25dB is very good (80dB in 15x25 room). Power brick is just warm and amp is normally hot on bottom (nowhere near overheating) and just warm on top. I am very happy with this amplifier. Hope it lasts a while for sure because the audio performance is top notch.

 

[Chaos01]

Does anyone know what ist the damping factor from the Pa7 Plus?

 

[staticV3]

Does anyone know what ist the damping factor from the Pa7 Plus?

The PA7's output impedance has not been measured yet, therefore the damping factor cannot be calculated.

 

[tom_tom]

Hello, I have a question to users of PA7 Plus. Is Your device getting really hot while using ? I have simple setup with Wiim Pro Plus connected to it. When I forget to turn it of, even without playing music chasis is getting rather hot than warm. Is this standard behavior ? Other class D like amp I have e.g. SMSL A300 with build in PSU is not as hot normally.

 

[AzReciOn]

Hello, I have a question to users of PA7 Plus. Is Your device getting really hot while using ? I have simple setup with Wiim Pro Plus connected to it. When I forget to turn it of, even without playing music chasis is getting rather hot than warm. Is this standard behavior ? Other class D like amp I have e.g. SMSL A300 with build in PSU is not as hot normally.

I have PA5, and it also heats up quite a lot, and structurally they are similar, except in PA7 the board is turned down by the radiator, which clearly does not contribute to better heat dissipation. Personally, I installed a small cooler - and the amplifier is always barely warm. On the other hand, my personal analysis of failed devices (from other users) is as follows: the damage is mechanical rather than thermal (I think that due to frequent temperature fluctuations and varying degrees of thermal expansion of components, that is, my theory is that the devices fail not because ofdue to overheating of the components, and due to constant on/off), but I still hedged with active cooling.

And yes, most D-class amplifiers usually don't heat up like that, but specifically for PA5/PA7, this is normal.

 

[Doodski]

On the other hand, my personal analysis of failed devices (from other users) is as follows: the damage is mechanical rather than thermal (I think that due to frequent temperature fluctuations and varying degrees of thermal expansion of components, that is, my theory is that the devices fail not because ofdue to overheating of the components, and due to constant on/off), but I still hedged with active cooling.

Very high heat components can have dissociated solder. It appears as if crumbly looking non-shiny solder joints and there might be donut rings cracks in it too. It then usually goes intermittent and causes serious issues. I have seen this often in amplifiers running 4 Ohms when the amp is rated to 8 Ohms and also for people that run the amps very hard at high output levels as well as amps with inferior designs. To do this requires very very high heat at components on the PCB.

 

[AzReciOn]

Very high heat components can have dissociated solder. It appears as if crumbly looking non-shiny solder joints and there might be donut rings cracks in it too. It then usually goes intermittent and causes serious issues. I have seen this often in amplifiers running 4 Ohms when the amp is rated to 8 Ohms and also for people that run the amps very hard at high output levels as well as amps with inferior designs. To do this requires very very high heat at components on the PCB.

«The truth is out there»

 

[Mike_Trueman]

Hello, I have a question to users of PA7 Plus. Is Your device getting really hot while using ? I have simple setup with Wiim Pro Plus connected to it. When I forget to turn it of, even without playing music chasis is getting rather hot than warm. Is this standard behavior ? Other class D like amp I have e.g. SMSL A300 with build in PSU is not as hot normally.

Hello,
I use the SMSL AO300 direct connected to my PC with USB.

Does the PA7 PLUS + E70 Velvet sound much better connected to a PC or should i stick with my SMSL AO300?

TOPPING PA7 PLUS + TOPPING E70 VELVET BLACK PACKAGE

<h3 class="col pl-0 artdet__name line-clamp--3-12">TOPPING PA7 PLUS - Class-D Balanced Desktop Stereo Amplifier 2x300W 4 Ohm</h3><p>

www.muzix.eu

 

[Toku]

Hello,
I use the SMSL AO300 direct connected to my PC with USB.

Does the PA7 PLUS + E70 Velvet sound much better connected to a PC or should i stick with my SMSL AO300?

TOPPING PA7 PLUS + TOPPING E70 VELVET BLACK PACKAGE

<h3 class="col pl-0 artdet__name line-clamp--3-12">TOPPING PA7 PLUS - Class-D Balanced Desktop Stereo Amplifier 2x300W 4 Ohm</h3><p>

www.muzix.eu

The Ifineon MA5332MS amplifier chip used in the A300 and the TI TPA3255 amplifier chip used in the PA7 PLUS have a large difference in power efficiency. The MA5332MS is an amplifier chip that pursues low power consumption and generates very little heat.

 

[ErkyPerky]

I'm just about to buy the pa7 plus to pair with my E70. I also have a rega turntable that uses a seperate phono stage. Do you think the pa7 plus would be enough to amplify the signal? Or would i need a preamp? Preferably the L70? (even though its marketed as a headphone amp). Any replies would be appreciated.

 

[Guddu]

I'm just about to buy the pa7 plus to pair with my E70. I also have a rega turntable that uses a seperate phono stage. Do you think the pa7 plus would be enough to amplify the signal? Or would i need a preamp? Preferably the L70? (even though its marketed as a headphone amp). Any replies would be appreciated.

Absolutely nothing to be worried about, E70 will pair as well as any other DAC.
PA7 Plus will work well with any DAC/Pre with 1.9v (RCA) & 3.8v (XLR/TRS) or more.

 

[Vladetz]

I'm just about to buy the pa7 plus to pair with my E70. I also have a rega turntable that uses a seperate phono stage. Do you think the pa7 plus would be enough to amplify the signal? Or would i need a preamp? Preferably the L70? (even though its marketed as a headphone amp). Any replies would be appreciated.

You definitely need phono preamp if rega does not have a built-in

 

[Chaos01]

@amirm One question, at this graphs the distortion over 1khz is higher, at 15khz on Fosi Za3 Level. Still okay but in Relation to the Low sinad irretating for me and a questionmark to Not buy the Pa7+.

How ist the audible influence from the different distortion levels from the different frequenzes? Most AB amps have the Same distortion Levels for alls frequenzes, some class D come closer and some Like this one have big gaps between them. So what sounds better, Low sinad or equal distortion on all frequenzes? Thx

 

[staticV3]

@amirm One question, at this graphs the distortion over 1khz is higher, at 15khz on Fosi Za3 Level. Still okay but in Relation to the Low sinad irretating for me and a questionmark to Not buy the Pa7+.

See here:

Is SINAD around 5-15 KHz relevant?

I’m trying to build some active 3-way bookshelves. At this point, I need to decide for amp selection for my high frequency >2.5 KHz. I love Hypex products and will be powering the low end and midrange with hypex modules. I’m a bit hesitant about the tweeter amplification. Most newer class D...

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