Topping B100 Amplifier Review

[DWPress]

Why do you think these would be a good tweeter amp? My thoughts are the low distortion, and SINAD., and since I'm using the tweeter in such a limited bandwidth, it should be enough power.

Yes, that is exactly my reasoning.

I'll wait until these go on sale and have had some time in the wild. I don't expect to hear any difference between the B100 and my Hypex currently in use. But it is one of the last objective tweaks I could do to my system and I have a different use for the Hypex to eventually power one more passive sub.

 

[Old_School_Brad]

Inexperienced "wattometer" fanboy who have never used a sound level meter in their life are impressed by Useless large numbers in the same way.
But incredibly it's really simple: if a speaker put 85dB with 1 watt can put 95dB with 10W.
95dB SPL are similar to a LIVE ROCK concert!
And incredibly a speaker of that type with 10W will be working at its limit distorting surely more than 2%.
Returning to the discussion,
2 speaker can go obviously to about 88 dB SPL ar least.
So in a normal domestic room at 3 meters, you can probably have 80dB with 1W, 90dB with 10W, at least.
And if you have a 85dB speaker that you listen ad 3 meters the problem is not the amplifier... Try to guess where the problem is
And the inexperienced wattometer still have to explain to me the phantom problems of external power supplies... Really incredible.
Bottom line: if a home speaker isn't making enough noise at 10W, the problem clearly isn't the amplifier.

What’s that rough calculation based on?
Is it dBA, dBC, peak, or average levels?

Let's assume it's dBA average then, since you referred to it as similar to a "LIVE ROCK concert!"
Let's also assume 15 dB headroom for peaks, which is conservative.

• Sensitivity of the Speaker
  Let’s assume the speaker sensitivity is 85 dB at 1 watt, 1 meter. This means:
  • At 1 watt of power, the speaker outputs 85 dBA at 1 meter.
  • With every 3 dB increase in SPL, we need to double the power.
• Calculating the Average Power for 95 dBA at 1 Meter
  Starting from 85 dBA at 1 watt, let’s calculate the power needed to reach 95 dBA:
  • 85 to 88 dBA: 2 watts (doubling from 1 watt).
  • 88 to 91 dBA: 4 watts.
  • 91 to 94 dBA: 8 watts.
  • 94 to 95 dBA: approximately 10 watts.
  • So, reaching 95 dBA average SPL at 1 meter requires approximately 10 watts of amplifier power. All is well so far.
• Calculating the Power Needed for Peaks 15 dB Higher (110 dBA)
  To achieve peaks 15 dB above this 95 dBA average level (i.e., 110 dBA), we need to add 15 dB, which translates to an increase of approximately 32 times the powerof the average level:
  • 95 to 98 dBA: 20 watts.
  • 98 to 101 dBA: 40 watts.
  • 101 to 104 dBA: 80 watts.
  • 104 to 107 dBA: 160 watts.
  • 107 to 110 dBA: 320 watts.
  • Therefore, an amplifier would need to be capable of delivering about 320 watts to hit those 110 dBA peaks cleanly without distortion. (Whoopsy!)
• Adjusting for Listening Distance (e.g., 3 Meters)
  Sound level decreases by about 6 dB when you double the distance. If the listener is 3 meters away, we would experience a drop of around 9-10 dB compared to the 1-meter level:
  • To achieve 95 dBA average at 3 meters, you’d need approximately 10 dB more power than calculated for 1 meter, or around 100 watts.
  • To allow for 110 dBA peaks at 3 meters, the amplifier would need to deliver roughly 1,000 watts. (Double whoopsy!)

*I didn’t address the impact of using two speakers in the previous explanation. However, to keep things balanced, I also used a conservative estimate for dynamic headroom.
*I also didn't address what the need would be with bass-heavy program material as this is kept in dBA. dBC values might see additional 10-15 dB for the transients.

So, what can we conclude? I think it's fair to say that the true loudness and demands of a 95 dBA average level can be surprising, and it’s easy to underestimate. No offense intended -most people aren’t fully aware of just how intense that level actually is.
Oh, and naturally, we can conclude that the amplifier in question is unlikely to handle most of the demands described above.

 

[EddNog]

What’s that rough calculation based on?
Is it dBA, dBC, peak, or average levels?

Let's assume it's dBA average then, since you referred to it as similar to a "LIVE ROCK concert!"
Let's also assume 15 dB headroom for peaks, which is conservative.

• Sensitivity of the Speaker
  Let’s assume the speaker sensitivity is 85 dB at 1 watt, 1 meter. This means:
  • At 1 watt of power, the speaker outputs 85 dBA at 1 meter.
  • With every 3 dB increase in SPL, we need to double the power.
• Calculating the Average Power for 95 dBA at 1 Meter
  Starting from 85 dBA at 1 watt, let’s calculate the power needed to reach 95 dBA:
  • 85 to 88 dBA: 2 watts (doubling from 1 watt).
  • 88 to 91 dBA: 4 watts.
  • 91 to 94 dBA: 8 watts.
  • 94 to 95 dBA: approximately 10 watts.
  • So, reaching 95 dBA average SPL at 1 meter requires approximately 10 watts of amplifier power. All is well so far.
• Calculating the Power Needed for Peaks 15 dB Higher (110 dBA)
  To achieve peaks 15 dB above this 95 dBA average level (i.e., 110 dBA), we need to add 15 dB, which translates to an increase of approximately 32 times the powerof the average level:
  • 95 to 98 dBA: 20 watts.
  • 98 to 101 dBA: 40 watts.
  • 101 to 104 dBA: 80 watts.
  • 104 to 107 dBA: 160 watts.
  • 107 to 110 dBA: 320 watts.
  • Therefore, an amplifier would need to be capable of delivering about 320 watts to hit those 110 dBA peaks cleanly without distortion. (Whoopsy!)
• Adjusting for Listening Distance (e.g., 3 Meters)
  Sound level decreases by about 6 dB when you double the distance. If the listener is 3 meters away, we would experience a drop of around 9-10 dB compared to the 1-meter level:
  • To achieve 95 dBA average at 3 meters, you’d need approximately 10 dB more power than calculated for 1 meter, or around 100 watts.
  • To allow for 110 dBA peaks at 3 meters, the amplifier would need to deliver roughly 1,000 watts. (Double whoopsy!)

*I didn’t address the impact of using two speakers in the previous explanation. However, to keep things balanced, I also used a conservative estimate for dynamic headroom.
*I also didn't address what the need would be with bass-heavy program material as this is kept in dBA. dBC values might see additional 10-15 dB for the transients.

So, what can we conclude? I think it's fair to say that the true loudness and demands of a 95 dBA average level can be surprising, and it’s easy to underestimate. No offense intended -most people aren’t fully aware of just how intense that level actually is.
Oh, and naturally, we can conclude that the amplifier in question is unlikely to handle most of the demands described above.

I’ve owned these amps weeks now and listen to them anywhere from 1-6 hours a day average. Still haven’t had a single issue reaching desired listening levels day to day with my system driven by these B100s. KEF LS50 Metas are neither hard nor easy to drive, probably considerably average. Perhaps it’s the fact I’m using a subwoofer (SVS SB-3000), but I am not high-pass filtering to the mains, and my room is not particularly small, at 16 feet by 26 feet by 10 feet, with two permanently open (doorless) openings to the kitchen and to a hallway.

Numbers are one thing. Ownership and real experience is another. Or perhaps I simply don’t listen loudly enough to risk hearing damage (90dB or louder for more than 10 minutes at a time is solid risk for permanent hearing damage and I LIKE having ears that work).

-Ed

 

[Old_School_Brad]

I’ve owned these amps weeks now and listen to them anywhere from 1-6 hours a day average. Still haven’t had a single issue reaching desired listening levels day to day with my system driven by these B100s. KEF LS50 Metas are neither hard nor easy to drive, probably considerably average. Perhaps it’s the fact I’m using a subwoofer (SVS SB-3000), but I am not high-pass filtering to the mains, and my room is not particularly small, at 16 feet by 26 feet by 10 feet, with two permanently open (doorless) openings to the kitchen and to a hallway.

Numbers are one thing. Ownership and real experience is another. Or perhaps I simply don’t listen loudly enough to risk hearing damage (90dB or louder for more than 10 minutes at a time is solid risk for permanent hearing damage and I LIKE having ears that work).

-Ed

Ed, we've already established that there are two key factors significantly lowering your power requirements:

1. You use a subwoofer.
2. You typically listen at low volumes (as you mentioned in a previous post).

The numbers are clear, but to make a fair comparison, we need to consider equivalent scenarios, and your setup doesn’t align with the example above.

 

[MAB]

For all the others who say $600 is too much for 50W here is a beautiful example of a 12W amplifier with a 4.5 review rating.
I really don't know what else to say towards these haters...

Yaqin MC-84L Tube Stereo Amplifier Review

This is a review and detailed measurements of the Yaqin MC-84L Stereo Tube amplifier. It is on kind loan from a member and costs US $600 on Amazon. The picture doesn't do justice to the nice design of this amplifier. The transformer case in the back nicely contrasts with the chrome parts. The...

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Uh...

 

[misterdog]

Ed, we've already established that there are two key factors significantly lowering your power requirements:

my room is not particularly small, at 16 feet by 26 feet by 10 feet, with two permanently open (doorless) openings to the kitchen and to a hallway.

With one key factor significantly increasing it.

 

[Old_School_Brad]

With one key factor significantly increasing it.

Not quite. If he's seated about 3 meters from the speakers in a toed-in sweet spot, the open space will reduce some of the sound reinforcement typically provided by wall reflections, but this effect isn’t major compared to the impact of listening volume. In an open area, you lose some reinforcement of mid and high frequencies since there are fewer surfaces to reflect sound back to the listener, which can make the sound seem slightly less full or spacious. However, bass frequencies are less affected by the lack of reflections, as they are more omnidirectional and do not rely as heavily on room boundaries to maintain energy.

Listening volume and distance are more influential on perceived loudness: sound pressure levels decrease by about 6 dB with each doubling of distance from the speakers in open air.

So, while open areas slightly reduce overall reinforcement, the difference will be subtle compared to what’s controlled by listening volume and positioning.

 

[pma]

I have the B100 on my test bench. When measuring THD vs. level at 1kHz/4ohm, the amplifier repeatedly shuts down at 8.8V, i.e. 19.36W.

Measured with STEPS with 300ms bursts followed by 100ms pause. Thus, I am voting poor. There is no wonder, it is a linear amplifier and physics rules, there is no chance to dissipate heat from such a miniature box. Again, a toy, not an adult amplifier.

 

[Old_School_Brad]

I have the B100 on my test bench. When measuring THD vs. level at 1kHz/4ohm, the amplifier repeatedly shuts down at 8.8V, i.e. 19.36W.

View attachment 408599

Measured with STEPS with 300ms bursts followed by 100ms pause. Thus, I am voting poor. There is no wonder, it is a linear amplifier and physics rules, there is no chance to dissipate heat from such a miniature box. Again, a toy, not an adult amplifier.

That doesn’t look promising for a continuous RMS/FTC power output. -Unsurprisingly, I might add.

 

[antcollinet]

I have the B100 on my test bench. When measuring THD vs. level at 1kHz/4ohm, the amplifier repeatedly shuts down at 8.8V, i.e. 19.36W.

image snipped

Measured with STEPS with 300ms bursts followed by 100ms pause. Thus, I am voting poor. There is no wonder, it is a linear amplifier and physics rules, there is no chance to dissipate heat from such a miniature box. Again, a toy, not an adult amplifier.

Ouch - that is less than 1/4 of the short term power measured here. Over what period does your test run?

 

[pma]

I will test more. FYI - 50 Hz stepped sine and the amp shuts down at 5W. When trying to measure with a scope, it is almost impossible above 10W as the amp shuts down after few seconds. Maybe a wrong piece? I do not think so, distortion is very low, it is just a protection circuit action to save the amp from second breakdown. What a piece of s..t! I will post more later. I suspect Topping to design just for @amirm 5W chart top. And it starts purchase hystery, then. Someone must place warning here.

 

[capslock]

That is very disappointing. If it were to shut down after a few minutes of continuous test signal, I would understand, but after a few seconds?

 

[pma]

It is because of the so much undersized heatsink. And maybe the uC protection circuit setting? Anyway, it runs hot after a while with the sine input.

Some more measurements:

50Hz THD vs. level (shuts down at 5W)

IMD CCIF 19+20kHz at 2W/4ohm (very nice)

Distortion at 4W/1kHz/4ohm (at my measurement limit)

THD vs. frequency at 3.5W/4ohm @BW90kHz

Overall, it makes a very nice 5W amplifier, if I was to specify its power.

 

[Bleib]

I have the B100 on my test bench. When measuring THD vs. level at 1kHz/4ohm, the amplifier repeatedly shuts down at 8.8V, i.e. 19.36W.

View attachment 408599

Measured with STEPS with 300ms bursts followed by 100ms pause. Thus, I am voting poor. There is no wonder, it is a linear amplifier and physics rules, there is no chance to dissipate heat from such a miniature box. Again, a toy, not an adult amplifier.

Ouch, I wonder if PA5 II behaves in any similar manner

 

[Sokel]

20 W @1kHz and 5 W @ 50Hz,not bad for a 105dB sens, horn.
Anything below that though...

 

[totti1965]

This is not good. Hopefully Topping has to say something about these issues! My personal Black-Friday-Desaster 2024.
Why can´t they do any good at first try???

 

[Sokel]

This is not good. Hopefully Topping has to say something about these issues! My personal Black-Friday-Desaster 2024.
Why can´t they do any good at first try???

It won't be long till the new FTC rule will be in effect.20 days or so.

Topping will,say.And they will say price.Heatshinking is not about the items themselves.
Is the logistics of weight,size,shipping,etc.

I imagine that something with the ability to dissipate the heat dictated by physics will look silly though with an external supply.
And there,comes the other matter,certifications.

And so on...

 

[pma]

In my opinion, thermal management is the issue. I can imagine an extruded Al heatsink covering the top of the box. Made from nicely anodized aluminium. But we are not here to advise the Topping engineers, they should have done the job.

 

[totti1965]

Perhaps @amirm should promote the Review of @pma to the top of the review site! People must be warned.

 

[capslock]

Well, maybe PMA received a unit without thermally conductive grease. I cannot imagine too small a heatsink will result in thermal shutdown within seconds. It takes like a minute or more for the fins of the heat sink to reach thermal equilibrium. I am also pretty sure that in Amir's testing, loads above 5 W were applied for extended periods of time.

So let's wait and see.