Topping B200 Monoblock Amplifier Review

[misterdog]

Why do loudspeaker manufacturers not state the amperage required for their products, if that is the most important value?

 

[voodooless]

Why do loudspeaker manufacturers not state the amperage required for their products, if that is the most important value?

Required to do what?

It's not that simple. It's similar to the power handling number. Usually, this is only about thermal handling with a crest factor applied). That doesn't at all mean that you can't destroy your speaker with that same power.

 

[dcolak]

You seem determined to twist data to suit your opinion.

Trying to justify your stance by an argument to authority (@terryforsythe 's spreadsheet) is specious. I have high regard for @terryforsythe but I think he favours my position more than yours. You need to prove your point. The amount of SPL contributed by a second speaker is not the same in all cases. The contribution typically ranges from around +3 dB to + 6dB. Heck, if you listened to only one frequency and were positioned at a null (i.e., completely out of phase), a second speaker could be detrimental.

In the calculations I showed, I used +3dB for the contribution of the second speaker, not +6dB.

Your grasp of electronics is tenuous. You attempt to sow confusion when you pretend that I (or others) are treating speakers as resistors. We talk about speaker impedance, not speaker resistance. A basic tenet of speaker impedance is that it varies with frequency. In my example, I used 2 ohm as the impedance value; it can't dip much below that before it's simply a short!

I've concluded that you're not interested in learning, or in facts, and are just trolling by promoting a foolish and indefensible idea.

"adding a second speaker increases SPL between +3 dB (for incoherent/out-of-phase sources) and +6 dB SPL (for coherent/in-phase sources)" +6dB, out of phase, incoherent will give you between 0 and 1dB.

Saying 7A would be enough to give you 100dB peaks at 3m is simply wrong.

Let's say speaker is 88 dB / 1W / 1m, nominal 8Ω speaker at 3m distance.

Needed voltage for that peak: 143W@8Ω=33.8V RMS (your ~7A were for 8 ohms)

If the speaker dips to 2Ω at that moment: I=33.8/2=16.9A RMS

Peak current: 16.9×1.414=23.9A peak

Power into 2Ω: 33.8^22/2=571W

So the B200 would need to deliver about: 17 A RMS / 24 A peak / 570 W into 2Ω

That’s way beyond what I’d expect from the B200. Nice ad hominem, by the way.

Typical class AB, even vintage, like NAD C370 can provide that current, even when they are rated with lower wattage.

 

[dcolak]

If @dcolak uses the wrong type of RCA to XLR adapter cable is it feasible that he could halve the power available to his speakers and thus get a wrong impression of the B200's capabilities?

Capabilities are always the same. Whether you use enough input voltage to get the max output depends on you, the user.

We're discussing the max output available, it's not great.

 

[NTK]

Power into 2Ω: 33.8^22/2=571W

So the B200 would need to deliver about: 17 A RMS / 24 A peak / 570 W into 2Ω

Completely irrelevant for the most of us that don't have speakers that have impedance that dips to 2 Ω.

 

[Bleib]

It also depends on where it dips to 2ohm

 

[-Matt-]

Here is my attempt at making sense of these calculations...

Using the Benchmark calculator:

We can see that to achieve the 210 W RMS power that @amirm measured this required 7.25 A RMS or 10.25 A peak.

We have the following power values (taking the 0 degree resistive case):

8 Ohms, 160 W RMS
4 Ohms, 210 W RMS
2 Ohms, 84 W RMS

I can try to estimate the power at 3.2 Ohms by linear interpolation and get:
3.2 Ohms, 159.6 W RMS

My speakers (Kef R7) dip to 3.2 Ohms. They have 88dB 1W at 1m sensitivity.

Benchmark also have a caculator for the music peak spl level. Let's see what hitting reference level of 105 dB spl peak, at my listening distance of 3m, in a normal room, would take:

It takes 101 W RMS to achieve 105 dB spl peaks. However, this calculation is for 8 Ohms.

We can work out the equivalent power requirement for 3.2 Ohms as follows:

101 W x 8 Ohms = 808

808 / 3.2 Ohms = 252.5 W

Which, unfortunately the B200 can't quite manage.

In the same manner we can calculate the 8 Ohms equivalent power of the 159.6 W that we estimated previously...

159.6 W x 3.2 Ohms = 510.72

510.72 / 8 Ohms = 63.84 W

If we enter this value back into the Benchmark calculator we get the following:

So even at the worst case 3.2 Ohm dip, the B200 should be able to generate 103 dB spl peaks.

As long as I listen at -3dB from reference level (or lower), the B200 should be able to cope. Good enough for me.

 

[bozodidthedub]

Thanks @amirm.

DAC solved
Amplifier solved
Cables solved

Now only left with speakers, arguably.

(What are your DAC and cables solutions?)

 

[Cool Runnings]

(What are your DAC and cables solutions?)

My 2 main audio set ups using Topping D70 Pro Sabre and Wiim Ultra (streamer + DAC). Cables (various types of RCAs, power cords, optical etc) tend to be mostly in the $20-$100 range from a mix of sources including Amazon Mogami cables.

 

[babadono]

My Goodness.......I use a pair of B200 to run the bass bins on my Klipsch Jubilee tri amped system. There is nothing missing, especially on recorded music that has dynamic range compressed. Where is anyone getting recorded music that requires the amperage being talked about here to handle peaks? Now live sound reinforcement requirements are another story.

 

[Chanur]

Does anyone know if these use feedback (probably)? I was watching a headphone amplifier review on the Jotunheim 3 and it barely uses any feedback and the Mjolnir 3 has a no feedback mode as well. It seems several reviewers liked the sound and they speculated it could be due to the lack of small amount of feedback. I was wondering if there has been some kind of blind testing showing if people prefer no feedback or not?

 

[SoySalsaPicante]

Does anyone know if these use feedback (probably)? I was watching a headphone amplifier review on the Jotunheim 3 and it barely uses any feedback and the Mjolnir 3 has a no feedback mode as well. It seems several reviewers liked the sound and they speculated it could be due to the lack of small amount of feedback. I was wondering if there has been some kind of blind testing showing if people prefer no feedback or not?

These use so much feedback it should be written in all-caps.

 

[Chanur]

These use so much feedback it should be written in all-caps.

That's kind of what I expected. So it makes me wonder if we would subconsciously prefer no feedback or if it doesn't actually bother us.

 

[SoySalsaPicante]

That's kind of what I expected. So it makes me wonder if we would subconsciously prefer no feedback or if it doesn't actually bother us.

It doesn’t bother me and I’m generally considered a subjectivist.

 

[babadono]

Feedback (negative feedback that is) is what makes low noise, low distortion amplifiers possible. IMHO don't drink the feedback is bad KoolAid. If you like the sound that small amounts of distortion produce like those in well designed but little or no feedback amplifiers that is a personal preference. And each person knows what they like.

 

[terryforsythe]

Does anyone know if these use feedback (probably)? I was watching a headphone amplifier review on the Jotunheim 3 and it barely uses any feedback and the Mjolnir 3 has a no feedback mode as well. It seems several reviewers liked the sound and they speculated it could be due to the lack of small amount of feedback. I was wondering if there has been some kind of blind testing showing if people prefer no feedback or not?

This correlates with a discussion yesterday in the B100 review thread. To summarize that discussion, back in 1970 someone investigated transient intermodulation distortion (TIM) and blamed it on the use of negative feedback. That interpretation became popular in the audiophile zeitgeist, and still remains to a certain extent, which affects the preconcieved biases of some people.

Subsequent investigations discovered that the real culprit is the use of transistors with a low slew rate, which now is a long resolved issue. Here is what Google AI said about the B100 (take it with a grain of salt), which is the little brother of the B200:

"The Topping B100 features a rated slew rate of ± 350 V/μs. This highly responsive "Diamond Differential" circuitry allows for extremely fast transient recovery and helps to virtually eliminate transient intermodulation distortion (TIM)."

The general concensus is that the audible differences between modern, well designed, amplifiers with low output impedance is non-existant in blind testing so long as they are not pushed beyond their power capabilities. Audible differences do arrise, however, with amplifiers having higher output impedances, depending on the speaker load. Erin's audio corner ran testing and the affect is worse with some speakers. Generally speaking, use of a high amount of feedback, and PFFB in class D amplifiers, lowers the output impedance of an amplifier, making the amplifier more consistant among different speaker loads, in addition to lowering distortion.

Could some people prefer amplifiers with no, or low, negative feedback? Perhaps, if they prefer the resulting colorations/distortion. As an example, tube amplifiers oftentimes have high output impedance, which causes additional waviness in a speaker's response (more exagerated in some speakers than with others) and relatively high distortion. But, some people prefer the sound of tube amplifiers over modern, well designed, solid state amplifiers. There is nothing wrong with that. In the end, this hobby is about enjoying the music. If someone prefers certain sound characteristics, they should continue enjoying their music the way that makes them happy!

 

[babadono]

Yes Sir...enjoyment of music is in the ear(or auditory cortex) of the hearer.

 

[Hipster Doofus]

Why buy this over a Topping Pa7 Plus? Actually you would have to buy two.

Remember... since the advent of class D the audio world has really opened up to hobbyists who like moving things around and collecting. It is not dirt cheap, but not so expensive either, especially if you collect things over a few years. And although I try to buy objectively... when I listen I almost always begin lying to myself based on price and what others have said. Then I remember again ...it's mostly about the speakers. Well, until the next bit of kit comes out next year.

AND SO IT GOES...

 

[maxchau]

You won't regret getting the B200's. They have a, dare I say it, "sweetness" that I didn't hear from the SMSL PA-X GanFET amp I used before it. And while I am currently toggling between "home-built" IcePOWER 2000AS2-HV and the Hypex Nilai 500 modules (in a dual-mono configuration), both of which offer a tremendous amount of Class-D power, neither has the sweetness of the B200. Having said that, what's keeping me from going back to the Topping's is the sheer control the DIY amps have over my main speakers (Eminent Tech LFT-8b's).

Enjoy the journey!

I also found Icepower 1200AS2 dual monos has absolute control and drives over my McIntosh XRT18s. My dual mono amps based on 3e Audio 480-1-29 are sweeter than 1200AS2 in the mid and treble.