Topping B200 Monoblock Amplifier Review

[KL....]

You mean, the power supply “fins”?
As far as I can tell from Topping FAQ, the “fins” are horizontal as well:
View attachment 433718

No, what is inside, beneath the fins. Why would horizontal matter, in this case? I am asking if it is a corded SMPS unit and as such, what it could be replaced with? :=)

 

[JeremyFife]

Thank you for a highly anticipated review

This is clearly an awesomely clean piece of kit with decent power. Personally, I have no issue with the external power supplies. Perhaps because this is now playing in the Purifi / NCx500 arena I have some questions.

You said "By now, the amp was fairly warm and it seemed that it was pulling back a bit in available power" ... I wasn't sure what that meant but it sounds like the amp is not happy in heavy use? I'm making assumptions here though.

More interestingly: I'm still trying to get my head around the implications of low gain (benefits being low noise). If I understand this correctly, that low gain of 11.6dB with a nominal speaker impedance of 4Ohm and my system's max input voltage of 4v limits the maximum power output to ~60W. Is that right?

As a stunningly low noise/distortion amp with speakers that are not unusually difficult, this seems great. It's not the perfect amp for all uses, but that's probably not what it's for. Impressive offering from Topping.

Happy that my questions are answered: yes the power output at low gain is lower but that's normal and not a real world concern - that's a choice. Amirm addressed the first question, no issues, https://audiosciencereview.com/foru...monoblock-amplifier-review.61206/post-2244893

 

[BeeKay]

No, what is inside, beneath the fins. Why would horizontal matter, in this case? I am asking if it is a corded SMPS unit and as such, what it could be replaced with?

Probably with any decent e-bike battery charger brick of the same specs?

Edit: That’s all that the PS does communicate:

 

[Old_School_Brad]

That's exactly what I'm asking myself. The measured 13 watts at rest do not necessarily speak for Class AB.

Why not?

I have a 2x1100W amplifier that idles at just 30W. The B200 brick is an SMPS, and since the amplifier likely has very low bias, its power consumption remains minimal. This method isn’t a reliable way to determine the amplifier’s class.

 

[KL....]

Amps should drive, should be voltage sources, nothing more.

To add to that and to suggest.... they need to be able to deliver current to a reactive/resistor load, even more so for speakers because they are a reactive resistor/capacitive/inductive load, essentially a reactive/resistor load :=)

 

[BeeKay]

Why not?

I have a 2x1100W amplifier that idles at just 30W. The B200 brick is an SMPS, and since the amplifier likely has very low bias, its power consumption remains minimal. This method isn’t a reliable way to determine the amplifier’s class.

Was wondering as my other AB sucked 73w at idle.

 

[Sokel]

Was wondering as my other AB sucked 73w at idle.

My Class D ones consumes 36W idle each, 0.4W in stand by.
Idle consumption is by no means a class indicator.

It COULD be a power indicator on occasion,nothing more.
I give far more importance to the stand-by one than the idle, at the end of the day most modern amps go to stand-by with the trigger or their (even better) audio sense circuit after some given minutes.

 

[WillBrink]

If I understand it does not meet it's 200w claims at 8 ohms, and power actually dips at 4 ohms? That does not seem typical amp behaviors. Otherwise the measurements seem outstanding. At that price, something has to give.

 

[Old_School_Brad]

My testing takes nearly an hour of constantly banging on the unit including a warm up period. And power was not "reduced." It just varied a few watts, some of which may be due to algorithm interaction in AP.

I wasn’t criticizing the design of the cooling plates, other than that the fins technically should be vertical -I was simply explaining why their orientation could potentially matter. And based on your comment in the review, it seemed like heat did, in fact, lead to a reduction in power.

While your suite of tests may take nearly an hour, the amplifier likely isn’t under high load for that entire duration. That’s why I pointed out that, to properly assess the thermal design, the cooling plates need to be fully saturated. Only then can we determine whether proper fin orientation would make a difference. Whether or not it matters in practice, with normal real use, might be questionable.

Just to clarify; I am not suggesting that you should expand your tests to include thermal testing.

 

[Old_School_Brad]

Was wondering as my other AB sucked 73w at idle.

That would be due to a completely different design.

With some notable factors including the power supply, the number of BJTs or MOSFETs, and the quiescent current.

 

[KL....]

That's exactly what I'm asking myself. The measured 13 watts at rest do not necessarily speak for Class AB.

Why not?

I have a 2x1100W amplifier that idles at just 30W. The B200 brick is an SMPS, and since the amplifier likely has very low bias, its power consumption remains minimal. This method isn’t a reliable way to determine the amplifier’s class.

Yes, I thought that the ClassA offset bias would be minimal (<100mV, especially after the Class B/B100), very low mV, but 13 watts does not suggest minimal. Although that could be the corded SMPS, itself, and not the B200. Does anybody know what ClassA offset bias setting is?

 

[Old_School_Brad]

Yes, I thought that the ClassA offset bias would be minimal, very low mV, but 13 watts does not suggest minimal. Does anybody know what ClassA offset bias setting is?

The 13 W also accounts for losses in the power supply, so it’s not a reliable way to determine the amplifier's class -let alone the amount of A/B bias. Additionally, bias isn't a single fixed value, it varies across different designs.

 

[KL....]

The 13 W also accounts for losses in the power supply, so it’s not a reliable way to determine the amplifier's class -let alone the amount of A/B bias. Additionally, bias isn't a single fixed value, it varies across different designs.

Yes, that could be the corded SMPS, itself, and not the B200.
For the B200, does anybody know what ClassA offset bias setting is?

 

[B.A.T.]

Would a PSU with a higher current capability increase the amp’s power output into lower impedances? Or is it possible that the amplifier design would not be able to take advantage of such a PSU?

Good observation, of course it's possible. That's another problem that Topping should take into consideration with a more powerful PSU in the future. At this point, technically this is the most desirable factor that should change and it stands for the vast majority of Topping's amplifiers. Otherwise, respect for the design!

 

[KL....]

Probably with any decent e-bike battery charger brick of the same specs?

Would that be your recommendation? The B200 noise figures are a Work of Art. Can you clarify your post further?

 

[BeeKay]

Would that be your recommendation....

Nope. That clearly would be a Topping spare part. It meant that in any very desperate case a standard SMPS meeting the specs could be a workaround. Try at your own risk.

 

[howard416]

Which appears to be a non issue here… by a long shot. Why is this still a thing? Even my usual engine rebuilding forums aren’t this pedantic.

I'm only pointing that out. I have no dog in this fight.

 

[totti1965]

Amps that are (claimed) stable down to 2 Ohms without catching fire are audiophile bragging rights gear. I admit I like the idea of an amp that has that juice on tap. I have no doubts I could happily live with the Topping amps with the speakers and size of the room I have.

Well, I think it is just some technical differences which do not have necesseraly have something to do with good or bad sound.
Some braggers out there? Maybe.

 

[KL....]

Would that be your recommendation? The B200 noise figures are a Work of Art. Can you clarify your post further?

Nope. That clearly would be a Topping spare part. It meant that in any very desperate case a standard SMPS meeting the specs could be a workaround. Try at your own risk.

Thank you for clarifying :=) It really was necessary, wasn't it?

 

[BeeKay]

Thank you for clarifying :=) It really was necessary, wasn't it?

Yes and no There was an Amazon lab power supply (80 bucks) suggested in a parallel thread. Pretty sure we wouldn’t notice a difference. I would not expect the Topping brick to be any special.