Topping B100 Amplifier Review

[pma]

Level stepped sine is exactly the method to approach slowly to the rated power. The result was shown in my test. And it was shown here how “slowly” it rises. Post #950 and #952.

 

[mike70]

Level stepped sine is exactly the method to approach slowly to the rated power. The result was shown in my test. And it was shown here how “slowly” it rises. Post #950 and #952.

Your test is very valuable and in any case should be refuted with science, not with personal opinions.
Have you done the same test with the Purify / Hypex implementations?

 

[pma]

Purifi (with 2x46V power supply)

1ET400A amplifier test review

You may also like to visit my HomePage where you will find more tests and also the NC252MP tested according to IEC60268-3

Pavel Macura audiopage

description

pmacura.cz

 

[mike70]

Purifi (with 2x46V power supply)

1ET400A amplifier test review

You may also like to visit my HomePage where you will find more tests and also the NC252MP tested according to IEC60268-3

Pavel Macura audiopage

description

pmacura.cz

I'm not an electronic engineer or with a deep knowledge about electronics.
Briefly (to stay on topic) ... these amps seems to be aligned with the specifications and decent alternatives to good classic class AB amps.

 

[pma]

I'm not an electronic engineer or with a deep knowledge about electronics.
Briefly (to stay on topic) ... these amps seems to be aligned with the specifications and decent alternatives to good classic class AB amps.

Exactly. Especially the Purifi 1ET400A, it has much cleaner ultrasonic spectrum than the NC252MP and during the tests I have never experienced the amplifier shut down. It stays cold even at full power (with sufficient heatsink). To me, better choice than class AB with same power rating.

 

[Saponetto]

I should -seriously- start thinking to try some of these "new wave" amplifiers.
Currently using some old, power-guzzlers AB or tube amps, and I'd like to see minor amount on my monthly energy billing.

 

[capslock]

I should -seriously- start thinking to try some of these "new wave" amplifiers.
Currently using some old, power-guzzlers AB or tube amps, and I'd like to see minor amount on my monthly energy billing.

Class D has great efficiency at high output power, but that is not your typical home use case.

Both the switch mode power suppliers (unregulated and regulated) as well as class D modulators have an idle power consumption on the order of 5 - 15 W.

Conversely, unregulated linear power supplies typically have a very low idle power consumption. It is mostly the bias current of the class AB that determines the idle power consumption. Depending on the rail voltage and whether you just want some or optimum bias, that will be between 5 and 50 W per channel.

 

[Saponetto]

@capslock Thanks for this info!

 

[miero]

OK, thanks. I replied them with a request for a clarification on the actual power output capabilities.

I received a response from Topping with annotated "THD+N Ratio vs. Power" graphs on Balanced input, that were already available on their website. Not surprisingly, they provided nothing new that we didn't already know.

Regarding the 38 volt and 4 ampere power supply. Inside B100 there are 8 capacitors, probably CapXon 220uF 25V, 105 dg. C.
Because of 25V rating I assume they are connected in parallel as four pairs in a series. So the overall capacitance there could be 440uF 50V.

And in comparison with internal photos published at Audiophonics the IRF5210 was moved from the PCB above these capacitors to the main PCB between these capacitors and under the power connector.

 

[Sokel]

I received a response from Topping with annotated "THD+N Ratio vs. Power" graphs on Balanced input, that were already available on their website. Not surprisingly, they provided nothing new that we didn't already know.

Regarding the 38 volt and 4 ampere power supply. Inside B100 there are 8 capacitors, probably CapXon 220uF 25V, 105 dg. C.
Because of 25V rating I assume they are connected in parallel as four pairs in a series. So the overall capacitance there could be 440uF 50V.

Color of the photo is tricky,it seemed blue-ish to me and thought they were Nichicon.
So,only the green MUSE is Nichicon,ok.

 

[capslock]

I received a response from Topping with annotated "THD+N Ratio vs. Power" graphs on Balanced input, that were already available on their website. Not surprisingly, they provided nothing new that we didn't already know.

Regarding the 38 volt and 4 ampere power supply. Inside B100 there are 8 capacitors, probably CapXon 220uF 25V, 105 dg. C.
Because of 25V rating I assume they are connected in parallel as four pairs in a series. So the overall capacitance there could be 440uF 50V.

And in comparison with internal photos published at Audiophonics the IRF5210 was moved from the PCB above these capacitors to the main PCB between these capacitors and under the power connector.

440 µF is not exactly an ample local buffer, but maybe enough if there is sufficient capacitance residing in the power brick.
Did you take your B-100 apart to make that picture? Would you care to peek under the PCB that sides alongside the heat sink and maybe also peek underneath the heat sink?

 

[FERCSA]

440 µF is not exactly an ample local buffer, but maybe enough if there is sufficient capacitance residing in the power brick.
Did you take your B-100 apart to make that picture? Would you care to peek under the PCB that sides alongside the heat sink and maybe also peek underneath the heat sink?

I'm sure the picture was taken through the vent hole from the other side. I can see the same on mine.

 

[Sokel]

if there is sufficient capacitance residing in the power brick.

Judging by the similar in power Xbox's PSU at this teardown,there are a couple of big-ish caps in there (if they are similar)

 

[Old_School_Brad]

440 uF capacity at 38 V amounts to a negligible amount of power reserve. 16 W for 20 ms. assuming full specified charge. It's definitely dependent of the power brick.

 

[pma]

I received a response from Topping with annotated "THD+N Ratio vs. Power" graphs on Balanced input, that were already available on their website. Not surprisingly, they provided nothing new that we didn't already know

If I were the customer, I would rather ask them according to which standard they specify the rated power. And I would recommend to OEM assemblers here (@boXem , @Buckeye Amps , @Audiophonics and others) to make such specifications as well. You will need to do more testing, but it is a necessary part of the job and business.

FYI, I have not received a reply to my email I sent to Topping support on Wednesday, yet.

 

[miero]

From the B100 spec. sheet:

Output Level @4 ohm: 56Vpp => 19.8Vrms => 98W @4 ohm
Output Level @8 ohm: 66Vpp => 23.3Vrms => 68W @8 ohm
alternatively
Output Power 83W @8 ohm THD+N<10% => 25.8Vrms => 72.86Vpp

All this with a power supply providing 38 volt DC?

 

[pma]

Again and again, it is a BTL output. With 1x38V PSU, you may get about 36W/4ohm with a SE topology and 144W/4ohm with a BTL topology under almost ideal conditions.

This is all unimportant. Ask them according which standard they specify the rated power. Everything else is unimportant, just a chat.

 

[mike70]

I should -seriously- start thinking to try some of these "new wave" amplifiers.
Currently using some old, power-guzzlers AB or tube amps, and I'd like to see minor amount on my monthly energy billing.

i have done that with Purify ... and no regrets
subjective general sound quality difference with my class AB? none ... but ... higher power (from 70 to 200 watts 8 ohm) gives me:
- a llitle more headroom, with subjectively more "clarity" at higher volumes and bass at low volumes
- since many years ago i want to have maggies ... now i have the power to that kind of speakers

I think a comparable class AB with 200 watts at 8 ohms have 3x price tag, easily.

 

[misterdog]

​

The power supply used is a DC SMPS located on the end of probably a 12ft run (2 core) of wire. A measly 38V@4A (claimed) capability, into a standard 2 pin microphone plug/socket for a "power amplifier". Right oh

GX 16 Series

Number of Contacts	2 Pin	3 Pin	4 Pin	5 Pin	6 Pin	7 Pin	8 Pin	9 Pin	10 Pin
Contact Arrangement
Rated Current	7A	7A	5A	4A	4A	4A	4A	4A	4A
Rated Voltage	125	125	125	125	125	125	125	125	125
Withstand Voltage	1500	1500	1500	1500	1500	1500	1500	1500	1500
Insulation Resistance	1500	1500	1500	1500	1500	2000	2000	2000	2000
Contact Resistance	3	3	3	3	3	3	3	3	3
Panel Cut-out	16	16	16	16	16	16	16	16	16
Contacts OD	2.45	2.45	2.45	2	1.15	1.15	1.15	1.15

The GX aviation connector is a circular connector used for power and avionics in the aviation industry. It's a multi-voltage connector used in marine equipment, avionics, and soldering stations.

 

[transformer-coupled]

Better than Purifi and 3e audio PFFB dual mono (subjective review meets measurements)
I got a pair B100 yesterday from Zococity.es and its sounds great with that have 5 ohm minimum impedance 91db sensitivity speakers , clean detailed, all with high gain always, with my transformer volume control line stage it sounds great so far very high resolution and neutral caracther very transparent not fatiguing sound very nice, hope it has long live!!!!