Topping B100 Amplifier Review

[misterdog]

Science?More like linguistics.
No,you go on by all means,not my gear,not my worry.

So why are you here then, still at least you are now aware of what a unity gain buffer is.

Every day is a school day..

 

[jan.didden]

Topping brought out an interesting amp. They did not put your money in a massive case and heavy heatsinks so they could bragg about continuous power rating, even if that has no bearing on actual use in music. They kept the fantastic specs and affordable pricing and concentrated on actually music use.
I believe it is a worthwhile direction. Maybe they haven't dialled in the bullseye yet, but it's a worthwhile concept.
Of course, nerds here will immediately bash it, but that's par for the course.
Like the saying we have in The Netherlands: 'what the farmer doesn't know, the farmer doesn't eat'.

Jan

 

[Sokel]

So why are you here then, still at least you are now aware of what a unity gain buffer is.

Every day is a school day..

Oh,I do like school and nice genuine components,I even photo them at the photo thread.
Yep.give me Caddock resistors and Vishay diodes all day.I won't say no.

On the other hand I will say no to an weak little thingie like that,I'm on Erin's camp,give me watts.

(So,is this the next best thing since MF's Superchargers? )

 

[pma]

I might say similar about your your test lab, that earth wire just loosely twisted - laboratory controlled conditions.

And you understand what you speak about? Very short measuring wires go to XLR twisted pair cable, driven from low impedance amp output, and I have less mains interference components than Amir. So?

Do you know what you are speaking about? I do not think so. Check with mains residuals in post #1. Yes I do not have AP so my noise floor is higher. But at least I know how to measure without pollution of the spectrum by LF interference currents. You just do not like my findings and clear expressions regarding the failure to reach the rated power and my verdict that the amp did not pass the test.
You probably even do not understand the test setup schematics, why it is done as it is.

 

[misterdog]

Topping had to correct you after your first set of flawed measurements
They only corrected you on your input wiring though.

How is anyone to belive that your version two results don't have other flaws. ?

 

[Jimbob54]

Far too much egg and other unpleasant and hard to clean substances being lobbed around this thread. Don't make me get the big mop out.

 

[pma]

You are right, but believe it is sometimes difficult to stay calm when reading the incompetent remarks. Best ignored, I know.

 

[MAB]

You are right, but believe it is sometimes difficult to stay calm when reading the incompetent remarks. Best ignored, I know.

Good work PMA, many members really appreciate your contributions, and incredible technical knowledge and experience.

So why are you still here then ?

Very childish, but that is disservice to children since many are more thoughtful and less rude and make an attempt to be correct to the point. One reason he is still here is that you appear incapable and unwilling to do the work he did, and audio products are not always what they appear to be. Funny thing, many people will inadvertently operate the amp in the same mode as PMA's first test with similar results. Your comments are incrementally more toxic and misdirected, I won't even address some of the other crap you posted.

 

[pma]

Thank you, @MAB . Such posts make me think the job is not useless, it really takes quite a lot of time to collect meaningful data.

 

[capslock]

I might say similar about your your test lab, that earth wire just loosely twisted - laboratory controlled conditions.

The sole purpose of that "earth" wire is to limit the common mode signal on the ADC. There is no need for this connection to be low impedance.

 

[KSTR]

Topping brought out an interesting amp. They did not put your money in a massive case and heavy heatsinks so they could bragg about continuous power rating, even if that has no bearing on actual use in music. They kept the fantastic specs and affordable pricing and concentrated on actually music use.
I believe it is a worthwhile direction. Maybe they haven't dialled in the bullseye yet, but it's a worthwhile concept.

That's not how I see it. What I see is that there was a marketing decision to put out an amp in that specific form factor to match their DACs, and that had to result in a crippled mono design for the sake of good looks in a Topping stack. That is the main "concept", looks.

Probably without any significant cost increase they could have made a stereo B100 with the same overall form factor and looks of the two monos stacked and have the space to use proper vertical heatsinks with vertical fins (perhaps hidden behind those slots). Probably even a common power supply would fit into that space.
The number of users that will use only one single B100 in a mono setup is most likely completely irrelevant.

 

[capslock]

But are the people listening to it happy?
That's the criterium - not what we as a bunch of nerds think.

Jan

I didn't since the amp died 2 s after I had it drive 11.6 V RMS into 4 R.

Pavel has listened to a pair and had them go into protection several times with classical recordings (a few pages back in this thread). We don't know the sensitivity of the speakers or the listening level.

Over at diyaudio someone ran into similar issues, even with speakers rated at 98 dB / 1 m at 2.8 V into a nominal 4 R. He seems to like to listen a bid louder, though, just look a few posts below:

Topping B100

@acko - AHA! Makes perfect sense. Appreciated. @benb and @acko - as a relative novice to all of this... I also wonder if that's where some driver / speaker manufacturers come up with their "recommended" amplifier power. Sure, if it's 300W PMPO, I may need that for some of my speakers, but...

www.diyaudio.com

If they fix the protection circuit to actually protect the amp, it may have its use in systems with a high pass as in a sat/sub configuration.

 

[pma]

84-85 dB/2.83V/m. I posted both impedance response and AA shot of the data at which it failed. I also posted the CDs used. Go back in the thread and you will find it. About the level I am not 100% sure. Below 20V. True balanced drive. Loud but not extremely. High crest factor.

 

[EJ3]

So why are you still here then ?

To see IF there is info that it does, in fact, meet it's specs.
I am also wondering if a power supply that can put out another amp or 2 at the same voltage might solve the problems that have been observed.
Or perhaps the test was incorrectly implemented.
As to me, I have no use case for anything with that low of a power rating.
But, I am curious about it.
And, I have no reason to change anything that I have because I am happy with it.

 

[restorer-john]

I am also wondering if a power supply that can put out another amp or 2 at the same voltage might solve the problems that have been observed.

The power supply used is a DC SMPS located on the end of probably a 12ft run (2 core) of wire. A measly 38V@4A (claimed) capability, into a standard 2 pin microphone plug/socket for a "power amplifier". Right oh. That rules it out as anything even aspiring to be serious straightaway.

A quality power amplifier starts with a low impedance, low noise power supply in close proximity to the output devices. Topping threw that out the window in order to hide the cheap, noise producing SMPS as far away from the amplifier as they could. I wouldn't be surprised to discover the "performance" figures quoted in the "specifications" were derived using a completely different (laboratory) supply directly connected to the board.

But, I am curious about it.

Not worth your time.

And, I have no reason to change anything that I have because I am happy with it.

You've got a pile of classic NAD-2200s. They were one of the first to play the high dynamic power game. But they did it properly. The amplifier was a conservative rated >100wpc (all day FTC) with huge front back, left and right heatsinks, along with twin normal and HV rails able to swing 190V for dynamics and even maintain those numbers for several seconds. 400W transients- no problem. The early ones were a bit fragile, but they ironed out any issues and they are rock solid, nearly 40 years later. There's nothing you could buy today that would give you another 40 years at that level of performance for what was a bargain price in retrospect.

 

[HerbertWest]

This thread evolution is not good. B100 is what it is. It has some good inaudible features and some horrible practical features. Take or leave, anybody’s choice. If it was my verdict, I would never give my recommendation to such thing.

Thank you for the efforts put in analyzing this device, Pavel. I appreciated the insightful comments from you and from other electronics experts.

 

[EJ3]

The power supply used is a DC SMPS located on the end of probably a 12ft run (2 core) of wire. A measly 38V@4A (claimed) capability, into a standard 2 pin microphone plug/socket for a "power amplifier". Right oh. That rules it out as anything even aspiring to be serious straightaway.

A quality power amplifier starts with a low impedance, low noise power supply in close proximity to the output devices. Topping threw that out the window in order to hide the cheap, noise producing SMPS as far away from the amplifier as they could. I wouldn't be surprised to discover the "performance" figures quoted in the "specifications" were derived using a completely different (laboratory) supply directly connected to the board.

Not worth your time.

You've got a pile of classic NAD-2200s. They were one of the first to play the high dynamic power game. But they did it properly. The amplifier was a conservative rated >100wpc (all day FTC) with huge front back, left and right heatsinks, along with twin normal and HV rails able to swing 190V for dynamics and even maintain those numbers for several seconds. 400W transients- no problem. The early ones were a bit fragile, but they ironed out any issues and they are rock solid, nearly 40 years later. There's nothing you could buy today that would give you another 40 years at that level of performance for what was a bargain price in retrospect.

I was thinking of something that might cause me to pull my pair of NAD 2100's (running bridged mono [which will handily do about 1/2 of what a 2200 will do] {my 2100's are also resto-modded by Peter of QuirkAudio}) out of my mother's ADVENT 300 system (using the Pre outs, not the internal amps) and a DUAL 1229 TT.
Obviously, this B100 unit is not it.
For those unfamiliar with the NAD 2200, here is a partial of Amirm's test of one of my units:
Note the differences in the frequency response plot and the SINAD.
They are both better when you run it using the LAB INPUTS (that is true whether you are running bridged mono or not) :

NAD 2200 Vintage Amplifier Review​

Wow, we have one kilowatt of power coming out of this amp in short duration!

I was surprised that the frequency response was not flat but was relieved to see later in the thread that this is due to insertion of low and high pass filters. So here is the frequency response with Lab input that doesn't have such a filter:

Response now (in green) as it should be, ruler flat to below 10 Hz, and well extending past the 40 kHz limit of this measurement.

I figured the filters may be adding some noise/distortion so re-ran the dashboard again:

Distortion doesn't change but if you look at the noise floor at 20 Hz, it is down by some 10 dB. That improves SINAD a couple of dBs, making the amplifier stand out even more!

Zoomed:

And signal to noise ratio:

Conclusions
Nice to see innovation like this from equipment that is over 30 years old! Shame on manufacturers that produce amplifiers for much less power, more distortion and higher prices these days. No, you don't get a fancy case here and sheet metal is strictly budget category. But you are not going to sit on the amp. The guts are where it matters and NAD 2200 delivers.

NOTE: the output relay on stock 2200 gets corroded and fails over time. There are videos and DIY threads on how to upgrade the relay there to fix the problem. The unit tested here has that fix. Other than that, there are not reports of many other reliability issues even though NAD products are often said to be less reliable than other brands.

Overall, I am happy to recommend the NAD 2200. I almost gave it the highest honors but given the upgraded nature of the test unit, and the fact that used amps may have issues, I avoided that. But you could have easily pushed me to give it the golfing panther.

 

[capslock]

The power supply used is a DC SMPS located on the end of probably a 12ft run (2 core) of wire. A measly 38V@4A (claimed) capability, into a standard 2 pin microphone plug/socket for a "power amplifier". Right oh. That rules it out as anything even aspiring to be serious straightaway.

A quality power amplifier starts with a low impedance, low noise power supply in close proximity to the output devices. Topping threw that out the window in order to hide the cheap, noise producing SMPS as far away from the amplifier as they could. I wouldn't be surprised to discover the "performance" figures quoted in the "specifications" were derived using a completely different (laboratory) supply directly connected to the board.

They have the same concept on the PA5, PA5 II (Plus), PA7 (Plus). The connector is an aviation connector, but cable and connector feel flimsy for the 4 or 6 A they must carry. The PA7 has a three pole connector, but they use only two pins (I suppose to keep PA5-owners from plugging it into the smaller amp). Yet the PA7 delivers up to 190 W per channel in Amir's testing:

Topping PA7 Plus Amplifier Review

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. 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...

www.audiosciencereview.com

I have used the PA5 for loudspeaker testing including running inefficient sub drivers such as the XXLS12 to max excursion with LF sines to measure harmonics. I believe it uses exactly the same power supply as the B100. So with the PA5 being able to deliver sustained sine power, this does not seem to be an issue with the power brick or the connection.

 

[pogo]

I don't have PowerCube measurements for you due to aforementioned aggressive protection circuit, not allowing me to measure peak power.

For the future:
Is there a way to approach this slowly?

 

[Old_School_Brad]

For the future:
Is there a way to approach this slowly?

Practically speaking, what’s the intended goal of this approach? After all, musical dynamics aren’t exactly "slow."