(2)Topping B200 vs March P282

Alan, may be this will help in the comparison?

B200 ASR Review vs Topping Specs

They both have comparable THDN specs at 5W into 4 ohms ... 114dB vs 115dB.

Both high gains are similar 21dB vs 22dB

The P282 requires 4Vrms vs 3.9Vrms for the B200 for full power.

The P282 has an 80kHz bandwidth vs over 100kHz for the B200.

The P282 has 25A maximum (load not stated) and the B200 has 13.75A (8 ohms) and 20A (4 ohms).

The B200 can be located anywhere you want, close to your speakers vs the P282. Also the B200 offers isolation, independent supplies and near infinity crosstalk.

Two B200 units cost $1200 .... Terrible warranty, imho, compared to MA ... but the B200 has 3 XLR inputs in its favor over the MA, if that's important to you.

P282 costs $1,316.75 (5 year warranty standard) – $1,448.43 (10 year warranty extra).

proj964 wrote:
Alan, would you care to comment on how these two units compare/contrast? Is the March P282 a good choice vs two Topping B200 Monoblocks?

Hi

It's a good performer in many respects, but dont get drawn in by some of the headline numbers, or for that matter Amirs review which misses or glosses over some serious limitations and inaccuracies in the manufacturers claimed performance.

First thing to note is that the low gain setting is unusable. You need to input 12.5 volts to get it to full power. Typical DACs are 4 volts xlr and 2 volts RCA. So the low gain setting is only there to 'game" the SINAD figures.

So in real world use the 5 watt 4 ohm SINAD is about the same as the P282 which typically achieves 114dB to 115dB.

The high gain setting is OK for 4 volt XLR sources, but too low for 2 volt RCA sources. They would only get the amp to output 130 watts into 4 ohms or 65 watts into 8 ohms. This restricts the amps use to XLR sources.

Another thing to note is that the b200 power output collapses into impedances below 4 ohms, and it goes into protection with inductively reactive loads.

So you need to careful with what speakers you use the B200 with as many have impedances that Dip well below 4 ohms.

In summary, no real world improvement over the P282 in terms of noise and distortion, and its a lot less capable in terms of power and drive capability.

As @SmartOne_2000 mentioned, the Topping warranty is lacking, especially considering the concerns over Topping products reliability.

I know which amp I would choose 😉

Oh the power output measured by Amir, apart from being a lot lower than the manufacturer claims, shows the B200 to be quite limited in current output. 170 watts into 4 ohms is a current of only around 9 amps peak. Again this indicates it will struggle with lower impedance speakers.

Limiting at 9 amps also ties in with it crapping out at 85 watts into 2 ohms.

The P282 current limits at 25 amps (regardless of load).

The more I look at this the more I see discrepancies in the claimed specs.

Topping say the noise is 3.9uV (A weighted) and the SNR is 145dB. If that were the case the output voltage would be 3.9 ^ 145dB which is about 70 volts. That would equate to a power output of about 1200 watts into 4 ohms!

So, either the SNR or the noise, or both specs are clearly wrong.

Amir measures 131dB SNR which makes more sense.

Also from the graphs, the THD at 5 watts 4 ohms is about -128dB. From the SINAD of -115.4dB, this makes the noise about -115.7dB.

Therefore as output voltage is 4.475 volts, the noise (4.475 v - 115.7dB) is 7.3uV.

170 watts into 4 ohms max power equates to 26 volts output. The dB difference between 26V and 7.3uV is 131dB. This ties up exactly with Amirs SNR measurement.

So we can confidently say the Topping specs are hugely over inflated. In summary:

Power = 170 watts into 4 ohms @ 1% THD
Noise = 7.3uV
SNR/DNR = 131dB

Amir says: "No class D is able to achieve this level of performance at this time"

This is simply incorrect. Our amps match/beat this, produce many times the power output, and without shutting down into reactive loads.

So another review from Amir and ASR that misses all the salient points.

Alan March wrote:
Oh the power output measured by Amir, apart from being a lot lower than the manufacturer claims, shows the B200 to be quite limited in current output. 170 watts into 4 ohms is a current of only around 9 amps peak. Again this indicates it will struggle with lower impedance speakers.

Limiting at 9 amps also ties in with it crapping out at 85 watts into 2 ohms.

The P282 current limits at 25 amps (regardless of load).

I think their website specs are very generous. My calculated peak current was based off their specs of 80Vpp into 4R (--> 20App) and 110Vpp into 8R (-->13.75App). These numbers fell short of Amir's tests based off your calculations.

SmartOne_2000 wrote:
I think their website specs are very generous.

I would say so 🙂 :). More of a case of total BS rather than a slight over emphasis.

15% more power
87% less noise
220% more SNR/DNR

proj964 wrote:
Alan, would you care to comment on how these two units compare/contrast? Is the March P282 a good choice vs two Topping B200 Monoblocks?

I had a Topping I ordered as well as an AIYAMA via Amazon.

The topping hissed worse than a basket of snakes at a Pentacostal church revival.
I swore to myself never to look at another of their products again.

I keep the $70 USD AIYAMA, and returned the Topping for a refund.
And recently got a pair of P501s to replace the AIYAMA… not that I am expecting a lot to happen to make things better… but it should not be worse.

The one thing that mono blocks bring is the ability to put the amp next to the speaker and use shorter cables.
Some people can spend a bit of money on cables, and whether that is worth it or not, it is a fact that whatever the capacitance and inductance (and resistance) numbers are, the shorter the cable… then those numbers are smaller when multiplying them against a shorter length.

The worst 1/2 meter cable might be measuring as good as the most advanced 3-4 meter cable… (maybe??)