Topping B200 Amplifier Review [Video]

[amirm]

That’s why I specifically mentioned a complex load below 4 ohms -not as a wordplay, but as an important distinction.

It is word play. The only accurate thing you can say is that it has difficulty with 2 ohm and lower. That is the only data.

2 ohm capability goes well beyond capability of most amplifiers. You are not seeing people cry in streets over it. Reason is that their speakers are close to 4 ohm than 2.

If a speaker impedance is at 2 ohm, I would call that a broken design.

 

[Old_School_Brad]

It is word play. The only accurate thing you can say is that it has difficulty with 2 ohm and lower. That is the only data.

2 ohm capability goes well beyond capability of most amplifiers. You are not seeing people cry in streets over it. Reason is that their speakers are close to 4 ohm than 2.

If a speaker impedance is at 2 ohm, I would call that a broken design.

We can see the power drop between the 8-ohm 60° and 4-ohm 60° measurements.

4-ohm nominal speakers are quite popular and may occasionally dip lower, especially with random phase variations in the mix. If this happens, for example, in the bass region, the power output from the B200 would decrease. Since it’s a Class A/B amplifier, it isn’t immune to back-EMF.

 

[Old_School_Brad]

For a specific range of a speaker’s frequency spectrum, for example at 60 Hz, the impedance might be 4 ohms, but with a 50° phase angle, the load "seen" by the amplifier would be equivalent to a 2.6-ohm resistive load. The B200 could struggle with this, even with a 4-ohm impedance. And with struggle I mean that its power output would be reduced.

This is particularly relevant for Class A/B amplifiers.

But again, the B200 performs well within its capabilities. Just do well informed speaker-pairing.

To elaborate on my point, I’ve found a typical mid-budget amplifier, the Yamaha A-S701, which behaves as expected for a "classic" Class A/B design -its power increases with lower impedance and phase shifts.

 

[BeeKay]

Nice to have insane power at 2Ohms. How many users in the real world need that? I mean apart those with some rather exotic or badly designed speakers? We can rave on this until the cows come home. It won’t get any more useful in every days use. Let alone the amp delivers on what it is built for.

 

[Old_School_Brad]

Nice to have insane power at 2Ohms. How many users in the real world need that? I mean apart those with some rather exotic or badly designed speakers? We can rave on this until the cows come home. It won’t get any more useful in every days use. Let alone the amp delivers on what it is built for.

It’s far from being exotic or poorly designed speakers that exhibit the exact trait I’ve explained above. Unless you consider the below examples to be exotic and poorly designed.
EPDR represents the "as seen" load from the amplifier.

Spoiler: Polk R700

Spoiler: KEF Q Concerto Meta

Spoiler: Wharfedale Super Linton

 

[BeeKay]

So what are you telling me? 3 or 3.5 Ohms is a problem for this amp? Any report it failed with one of the above mentioned speakers? Weren't we talking about 2 Ohms and less?

 

[Old_School_Brad]

So what are you telling me? 3 or 3.5 Ohms is a problem for this amp? Any report it failed with one of the above mentioned speakers? Weren't we talking about 2 Ohms and less?

It could be.
What I’m trying to explain is why. You need to look at the EPDR trace to understand what the combined impedance and phase angle amount to "as seen" by the amplifier.

The areas circled below represent low impedance loads that the B200 would likely struggle to supply significant power to. They appear to correspond to 2.1 and 1.8-ohm EPDR.

How much power does the B200 output into 2.1 and 1.8-ohm loads at 0°? Around 80 W, give or take. Whether 80 W max power in the bass is sufficient for your specific use case is something for you to decide reg. program material and SPL.

 

[BeeKay]

and phase angle amount to "as seen" by the amplifier.

Point taken. When you write "the amplifier" - does this with certainty include the one we are discussing right now or would that depend on the design?

 

[Old_School_Brad]

Point taken. When you write "the amplifier" - does this with certainty include the one we are discussing right now or would that depend on the design?

It is definitely relevant for the B200, as it lacks the current reserves needed to "keep up" its power. In the example above, the 200 W amplifier would effectively be reduced to an 80 W amplifier in the bass, where power is most required.

However, as always, it will depend on individual use cases. Factors such as SPL expectations, the type of music you listen to, your typical listening distance, and EQ settings all play a role.

Don’t get me wrong; the B200 is excellent at what it does. However, some care may be needed when pairing it with the right speakers.

 

[-Matt-]

I plan on testing with them using b200. Don't need an amplifier there but for testing.

It would be great to hear your subjective listening impressions if/when you get the chance to test the B200 with your Revel Salon 2's.

Here is the impedance plot for the Revel Ultima Salon 2's (from Stereophile):

It looks as though it remains above 3 Ohms and only gets to about -50 degrees of phase angle so likely will work just fine until the B200s run out of power.

 

[Old_School_Brad]

It would be great to hear your subjective listening impressions if/when you get the chance to test the B200 with your Revel Salon 2's.

Here is the impedance plot for the Revel Ultima Salon 2's (from Stereophile):

It looks as though it remains above 3 Ohms and only gets to about -50 degrees of phase angle so likely will work just fine until the B200s run out of power.

That's an excellent crossover design that will work well with almost all amplifiers.