Topping B200 Monoblock Amplifier Review

[Liberal Democracy]

I know its page 43 and I'm a fine one to talk but can we please try and keep posts in review threads on topic .

There's 2 main reasons for this ..,

1. It helps support us , keeping content relevant to the OP for the thousands of visitors who come here for these reviews.

2. Often Intriguing and valuable content gets lost in the wrong threads , we all miss out if we hide great content in the wrong threads .

So if you find yourself stumbling into a different area , make a new thread . That's helps everyone. One can search If it's been discussed before but I don't expect that , we can merge content easily. Some socialising/ chat is fine, just keep a eye on yourselves.

 

[Jim Taylor]

I know its page 43 and I'm a fine one to talk but can we please try and keep posts in review threads on topic .

There's 2 main reasons for this ..,

1. It helps support us , keeping content relevant to the thousands of visitors who come here for these reviews.

2. Often Intriguing and valuable content gets lost in the wrong threads , we all miss out if we hide great content in the wrong threads .

So if you find yourself stumbling into a different area , make a new thread . That's helps everyone. One can search If it's been discussed before but I don't expect that , we can merge content easily.

 

[Mort]

rather than relying on 'something someone said on the internet'.

Though when the friend who bought my Yamaha amp later heard my Benchmark AHB2 he immediatly bought one, as the difference to him was obvious.
As a photographer, he works at pixel levels of accuracy.

Within minutes of each other.

 

[antcollinet]

We've had this discussion countless times in this forum. You don’t need a special activ converter. With the proper cable/adapter, you can use the pseudo-balanced connection—or an impedance-balanced connection if you add a resistor.


No reason to complain—just get the right cable and use High Gain mode.


The amp has a floating ground due to its double-insulated PSU, so all the leakage is high impedance at low frequencies. And if you're worried about HF leakage, just add some ferrite clamps and use a quality cable with a low-impedance shield.


Just get a cable like this and be done with it:
(or if you spend this kind of money amps alone... also get a proper balanced DAC with it)
View attachment 435475
View attachment 435474

Correct way to connect an nCore XLR amp to an RCA source

Hello, I am wondering if there is a safe way to do this, since most solutions I have found on the internet are about the connection of the xlr terminals to the internals of the amp, or something. I want to connect the nc400 to an old unbalanced tube pre amp. Will something like this be ok...

www.audiosciencereview.com

Which is fine - but not perfectly balanced, and doesn't solve the voltage/gain topic.

 

[antcollinet]

As a photographer, he works at pixel levels of accuracy.

What on earth does this have to do with uncontrolled listening comparisons of audio equipment?

 

[Lambda]

Which is fine - but not perfectly balanced, and doesn't solve the voltage/gain topic.

Like most outputs are not perfectly balanced. And its fine. so fine its not even noticed in the review on ASR.

Q. How is impedance balancing audio different from normal balancing?

Would impedance balanced and electronic balanced audio provide exactly the same noise reduction as regular symmetrical...

www.soundonsound.com

And the "Voltage gain topic" is another non issue since this amp hits closes to full usable power with a 2V rms signal.

Nothing is ever "perfect" but if you obsessed with Perfection uses Balanced.
if you just want it to work fine. this amp in High gain with the mentioned cable is just fine.

 

[babadono]

It is for me.

ever try the THAT Corp 1646 "OutSmarts" line driver? Excellently performing IC. SparkFun used to make a little breakout board using these. I was really sad to see them stop making them.

 

[amarsicola]

Without wanting to discredit Topping, I tend to use a diagram like this (this is for Phones) for my internal evaluation that would show absolute peak values for SINAD with Topping, but would be in the middle range for load stability and absolute power.


View attachment 435275

I think Purifi would achieve top values in almost all areas.

While I agree with your overall evaluation, the low level of distortion for any given frequency of the Topping is something never seen before, the race with Purifi is quite entertaining and beneficial for the industry

 

[antcollinet]

And its fine. so fine its not even noticed in the review on ASR.

That is comparing (proper) impedance balancing with both impedance and differential signalling as far as I can see.

The problem with the cable is it doesn't implement "proper" impedance balancing. The "output" impedance of the hot and cold signals is different by whatever the output impedance of the unbalanced interface is (the "cold" signal essentially has zero output impedance where the "hot" will have whatever the output impedance is.

I did a back of the envelope calculation, using a 100ohm output impedance, and 1% matching for other impedances, and the lack of the "cold" output resistor resulted in a reduction in CM noise rejection from around 40dB to around 30dB.

Not as bad as I'd expected, but still a significant reduction. This would get worse with higher output impedance on the unbalanced output.

Of course you could add a resistor to the cable between the "cold" wire, and the RCA ring - but then you'd have to know the device output impedance to match, and the cable would then be just for that specific device.

 

[Lambda]

That is comparing (proper) impedance balancing with both impedance and differential signalling as far as I can see.

And how do you know from the review if a DAC (for example) has this?
You would not know.

Not as bad as I'd expected, but still a significant reduction.

Reduction compared to what? It’s still a significant improvement to an single ended unbalanced RCA interconnect.

 

[antcollinet]

And how do you know from the review if a DAC (for example) has this?
You would not know.

Well, I admit I'd be making an assumption that anyone implementing a balanced output knows that both hot and cold need the same output impedance, just as they'd know they need the same input impedance on inputs. I've certainly never heard of an instance where this is not the case, but I suppose it could happen.

Reduction compared to what? It’s still a significant improvement to an single ended unbalanced RCA interconnect.

In the (quick and dirty) calculation I did:

≅40dB CMRR with both input and output impedances balanced with 1% resistors at the opposite extremes of tolerance. So for each pair, one at +1% and the other at -1%.

≅30dB CMMR in the same situation but with the cold output impedance set to 0 ohms.

The assumption is that single-ended RCA has 0dB CMMR.


So - no doubt that the “pseudo-balanced" cable gives a significant benefit compared with an unbalanced cable, but loses around 10dB compared with fully impedance-balanced interconnect. I have used it myself, and quite likely in most cases where there is audible CM noise, it will reduce that to inaudible - or at least to "below annoyance". There will probably be some cases where the extra 10dB or so is needed and probably some others where even that is not enough.

EDIT : if we want to discuss this detailed "balanced interconnect" topic further, it might be appropriate to move it to the more specific thread:

Why balanced XLR needs an inverted signal?

Hello dear friends, I understand that the balanced XLR needs an inverted signal wire (pin 3) so at the end, in the mixer, the pin 3 is inverted again and summed with the pin 1. This will make any noise that got picked up in the cable to get subtracted from pin 1 and pin 3. Awesome idea! But...

www.audiosciencereview.com

 

[Lambda]

to keep it relevant to the "topping-b200-monoblock-amplifier"
What i’m saying is: there is no need for an dedicated RCA input since you can uses a adapter cable.

Using an adapter Cable can give <30dB better CMRR compared to using an unbalanced interconnect
i think we agree on this:

So - no doubt that the “pseudo-balanced" cable gives a significant benefit compared with an unbalanced cable,

So it is a no issue to uses This specific amp with an unbalanced signal source. cases closed.


CMMR is Sadly never here and and the same way its almost never tested here.

Well, I admit I'd be making an assumption that anyone implementing a balanced output knows that both hot and cold need the same output impedance, just as they'd know they need the same input impedance on inputs. I've certainly never heard of an instance where this is not the case, but I suppose it could happen.

I can assure you this assumption is wrong.
there are many "impedance balanced" devices with only one output driven.

And some have very poorly balanced impedance between hot and cold. aka. cold is just grounded and hot is just the AC coupled output of a buffer
so they are both "0Ohm" with some tolerance.

 

[KL....]

Using an adapter Cable can give <30dB better CMRR compared to using an unbalanced interconnect

Would the required electronics (such as complementary input circuit/electronics), inside the B200, provide >30 dB CMRR when using an unbalanced interconnect, especially as the B100 allows for unbalanced and achieves fabulous measurements?

 

[Sokel]

Would the required electronics (such as complementary input circuit/electronics), inside the B200, provide >30 dB CMRR when using an unbalanced interconnect, especially as the B100 allows for unbalanced and achieves fabulous measurements?

Watching lab measurements we must never forget that:

Our case may differ, by far depending the conditions.
Once again: there's no better investment of money and time than getting a way to sanity check you OWN system.

It doesn't take much and there's people here always ready to help with that.

 

[antcollinet]

Using an adapter Cable can give <30dB better CMRR compared to using an unbalanced interconnect
i think we agree on this:

Yep definitely.

And some have very poorly balanced impedance between hot and cold. aka. cold is just grounded and hot is just the AC coupled output of a buffer
so they are both "0Ohm" with some tolerance.

Well that sounds a bit poor.

But going back to where our conversation started, I was mainly trying to explain why someone might want to go for an active converter even though a pseudo balanced solution might give a 90% solution.

 

[antcollinet]

Would the required electronics (such as complementary input circuit/electronics), inside the B200, provide >30 dB CMRR when using an unbalanced interconnect, especially as the B100 allows for unbalanced and achieves fabulous measurements?

No - you need to carry the reference voltage (connected to ground at the RCA end) separate from the ground connection. You need a 2 wire plus shield cable connected in the correct way to be able to take advantage of the balanced inputs at the B200 end. An unbalanced interconnect does not do that.

 

[Lambda]

was mainly trying to explain why someone might want to go for an active converter even though a pseudo balanced solution might give a 90% solution.

But with an active converter, you have:

• The unbalanced connection with no CMRR between the unbalanced source and the converter +
• Noise from the active converter +
• THD from the active converter +
• (Noise from the balanced connection - the improved CMRR)

There might be an extreme case with a very long balanced cable where the THD+N of this approach is lower… but I don’t see it being the case in general.
I would argue that in most cases, it's the worse-performing solution.

 

[KL....]

Would the required electronics (such as complementary input circuit/electronics), inside the B200, provide >30 dB CMRR when using an unbalanced interconnect, especially as the B100 allows for unbalanced and achieves fabulous measurements?

No - you need to carry the reference voltage (connected to ground at the RCA end) separate from the ground connection. You need a 2 wire plus shield cable connected in the correct way to be able to take advantage of the balanced inputs at the B200 end. An unbalanced interconnect does not do that.

Thank you, yes, you are correct/right but I actually meant (hypothetically) if the B200 could accept an unbalanced RCA interconnect (like the B100 can) and had the required electronics (such as complementary input circuit/electronics) inside the B200 to receive unbalanced RCA interconnect/signal (like the B100), would the CMRR be >30 dB? Would there even be a CMRR reading/measurement, perhaps, at the completion of the inside electronics?.... apologys for any confusion :=)

 

[KL....]

We've had this discussion countless times in this forum. You don’t need a special activ converter. With the proper cable/adapter, you can use the pseudo-balanced connection—or an impedance-balanced connection if you add a resistor.


No reason to complain—just get the right cable and use High Gain mode.


The amp has a floating ground due to its double-insulated PSU, so all the leakage is high impedance at low frequencies. And if you're worried about HF leakage, just add some ferrite clamps and use a quality cable with a low-impedance shield.


Just get a cable like this and be done with it:
(or if you spend this kind of money amps alone... also get a proper balanced DAC with it)
View attachment 435475
View attachment 435474

Correct way to connect an nCore XLR amp to an RCA source

Hello, I am wondering if there is a safe way to do this, since most solutions I have found on the internet are about the connection of the xlr terminals to the internals of the amp, or something. I want to connect the nc400 to an old unbalanced tube pre amp. Will something like this be ok...

www.audiosciencereview.com

Thank you, yes/ok, this will resolve RCA to XLR issues for 90% of cases with less than <30db CMRR.

• If no shield can XLR pin1 (Earth/Ground) be unconnected. If yes, will the CMRR be the same,
• Also, can you simply tie XLR pin2 (Cold/RCA -/Return/Ground) to XLR pin1 (Ground) and pin3 is (Hot/RCA +/Signal), and achieve the same result?

 

[mr_bill]

to keep it relevant to the "topping-b200-monoblock-amplifier"
What i’m saying is: there is no need for an dedicated RCA input since you can uses a adapter cable.

Using an adapter Cable can give <30dB better CMRR compared to using an unbalanced interconnect
i think we agree on this:



So it is a no issue to uses This specific amp with an unbalanced signal source. cases closed.


CMMR is Sadly never here and and the same way its almost never tested here.

I can assure you this assumption is wrong.
there are many "impedance balanced" devices with only one output driven.

And some have very poorly balanced impedance between hot and cold. aka. cold is just grounded and hot is just the AC coupled output of a buffer
so they are both "0Ohm" with some tolerance.

To help me - are you saying rca on the source end and xlr or adapter into B200 is a good thing of necessary?