Best Sounding Class D?

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CleanCopperz

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Feb 12, 2022
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This one looks good and it is probably cheaper and it can be upgraded. True mono btw.

I think I am choosing between the two Bench and and Nord....
 
Hi,
The AHB2 is not class D. Just in case you were thinking you were purchasing a Class D amplifier. It is class AB. One of the best there is too.

Regards,
Shadders.
Some would appear to imply it is Class H, whatever that is...
"At its heart the AHB2 has a switching power supply, which explains its diminutive size: it’s a Class H design rather than Class D because it features a Class AB output stage"
 
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shadders

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Nov 19, 2009
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Some would appear to imply it is Class H, whatever that is...
"At its heart the AHB2 has a switching power supply, which explains its diminutive size: it’s a Class H design rather than Class D because it features a Class AB output stage"
Hi,
The OP had concerns that power usage may be an issue, so class D was selected.

The majority of the power used in idle of a class AB amplifier is the output stage, and in use, there is much more power wasted than a class D amplifier.

Regards,
Shadders.
 
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CleanCopperz

Well-known member
Feb 12, 2022
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Hi,
The AHB2 is not class D. Just in case you were thinking you were purchasing a Class D amplifier. It is class AB. One of the best there is too.

Regards,
Shadders.
Have you read the whole thing?

“Unlike power-hungry class-A amplifiers, the AHB2 achieves a power efficiency that rivals that of a Class D (switching) power amplifier”

so thats definitly ok because it is around the same efficiency.

I ordered the silver rack version :)

EDIT: Sorry I replied a little late. Just saw the other replies. But efficiency has always been my concern. Also the HEAT. I cant stand a unit being hot. My computer is enouhg :)
 

CleanCopperz

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Feb 12, 2022
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PROTECTION CIRCUITS
  • Fully Electronic, No Relays
  • Mute Sequencing
  • Distortion Detection
  • Short Circuit Detection
  • Over Current Detection
  • Over Temperature Detection
  • SOA Detection (Output device safe operating area)

  • No relays, is that a bad thing?
 

Pedro2

Well-known member
Nov 29, 2010
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Have you read the whole thing?

“Unlike power-hungry class-A amplifiers, the AHB2 achieves a power efficiency that rivals that of a Class D (switching) power amplifier”

so thats definitly ok because it is around the same efficiency.

I ordered the silver rack version :)

EDIT: Sorry I replied a little late. Just saw the other replies. But efficiency has always been my concern. Also the HEAT. I cant stand a unit being hot. My computer is enouhg :)
It is, but I need the cream the cheese the floating sound in my room when I connect my atc scm40:)
Just read the Stereonet review of the Benchmark and it’s very positive. One question, though. Isn’t the combined cost of the Benchmark + SCM40 close to the SCM40a?
 

shadders

Well-known member
Nov 19, 2009
462
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PROTECTION CIRCUITS
  • Fully Electronic, No Relays
  • Mute Sequencing
  • Distortion Detection
  • Short Circuit Detection
  • Over Current Detection
  • Over Temperature Detection
  • SOA Detection (Output device safe operating area)

  • No relays, is that a bad thing?
Hi,
The final arbiter is whether you prefer the sound.

There is a MOSFET based output switch which is low impedance and is used on an output stage of the amplifier. This is used if the relay option is not used.

Else, the quote you have is no relays, but that is part of the protection circuit. So, given that the amplifier is class H, then the variation in power supply voltage may be the mechanism to protect the output stage should there be a fault condition.

It is not a bad thing to have no output relay since the purists will prefer the direct conductor connection. If they use a MOSFET based solution, then you could be exchanging the impact of no relay for the impact of the MOSFET solution.

Since the amplifier performs admirably, and i have yet to see any comments from an hifi buff who claims they don't like the relay sound, then don't worry about it.

Regards,
Shadders.
 

CleanCopperz

Well-known member
Feb 12, 2022
144
13
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Just read the Stereonet review of the Benchmark and it’s very positive. One question, though. Isn’t the combined cost of the Benchmark + SCM40 close to the SCM40a?
It is but not efficient tha A model. I will hate myself wasting energy on the A model forgetting it overnight vs the 1watt AHB2 uses

EDIT: class A/B is 25% efficient. Thats alot of money/energy wasted.

in theory this means the active model use:
150W LF, 60W MF, 32W HF = 60*2 = 120watt idle

also when listening to more efficient amps is lower wattage.
 
Last edited:

CleanCopperz

Well-known member
Feb 12, 2022
144
13
95
Hi,
The final arbiter is whether you prefer the sound.

There is a MOSFET based output switch which is low impedance and is used on an output stage of the amplifier. This is used if the relay option is not used.

Else, the quote you have is no relays, but that is part of the protection circuit. So, given that the amplifier is class H, then the variation in power supply voltage may be the mechanism to protect the output stage should there be a fault condition.

It is not a bad thing to have no output relay since the purists will prefer the direct conductor connection. If they use a MOSFET based solution, then you could be exchanging the impact of no relay for the impact of the MOSFET solution.

Since the amplifier performs admirably, and i have yet to see any comments from an hifi buff who claims they don't like the relay sound, then don't worry about it.

Regards,
Shadders.
I am not qualified enough to understand what you mean, but somehow I got the feeling that the amp is secure enough not to damage my speaker😂

I just hope it doesnt blow my speakers one day.

Thank you alot for the explanation🙏🙏🙏

Its better sound quality to not have relays?
 

Pedro2

Well-known member
Nov 29, 2010
67
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18,545
It is but not efficient tha A model. I will hate myself wasting energy on the A model forgetting it overnight vs the 1watt AHB2 uses

EDIT: class A/B is 25% efficient. Thats alot of money/energy wasted.

in theory this means the active model use:
150W LF, 60W MF, 32W HF = 60*2 = 120watt idle

also when listening to more efficient amps is lower wattage.
Sorry… forgot about the power consumption aspect! I know that you’re probably way down the ATC passive road now, but did you not consider any class D active speakers?
The reason I ask is that there are some superb examples out there - I currently use a pair of Hedd actives and I’m sure their type 20s would give the SCM20a a good run for the money!
Having said that, I’m sure that your new set up will sound absolutely brilliant. Enjoy the music 👍
 

shadders

Well-known member
Nov 19, 2009
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I am not qualified enough to understand what you mean, but somehow I got the feeling that the amp is secure enough not to damage my speaker😂

I just hope it doesnt blow my speakers one day.

Thank you alot for the explanation🙏🙏🙏

Its better sound quality to not have relays?
Hi,
The Benchmark will not damage your speakers given its protection system.

Is it better to not have relays ?

If the output stage protection is solid state (MOSFET) then there may be a sonic impact (subjectively).

If the output stage protection is a relay then there may be a sonic impact (subjectively).

If the output stage protection is neither solid state (MOSFET) nor relay then there is no sonic impact (subjectively).

Without a circuit diagram, then it impossible to state if there is any impact.

I would not worry about it, since no one has ever complained about a relay sound. It truly is, out of sight, out of mind.

Regards,
Shadders.
 

CleanCopperz

Well-known member
Feb 12, 2022
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Ok I see. I still need to explain why I didn´t choose the Active model. You can actually get the active model for less than what I have paid(atc scm40+ahb2) I think.

The upgrade path. I hear mostly the upgrade from scm7 to 11 is better than the upgrade from 11 to 19...price wise...I needed to jump up to the SCM40 passive model to feel the difference for the money.

So this is where the efficiency challange came in for me. Not only are AHB2 a lot more efficient, it saves me from always to having to shut them off because of very low idle energy.

My concern issue was this:
View: https://www.youtube.com/watch?v=6B2MQ1AQc4k


The issue was actually the DAC:
View: https://www.youtube.com/watch?v=Xlq8YBPYdag


But I don´t know. Any idea?
 

shadders

Well-known member
Nov 19, 2009
462
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19,270
Ok I see. I still need to explain why I didn´t choose the Active model. You can actually get the active model for less than what I have paid(atc scm40+ahb2) I think.

The upgrade path. I hear mostly the upgrade from scm7 to 11 is better than the upgrade from 11 to 19...price wise...I needed to jump up to the SCM40 passive model to feel the difference for the money.

So this is where the efficiency challange came in for me. Not only are AHB2 a lot more efficient, it saves me from always to having to shut them off because of very low idle energy.

My concern issue was this:
View: https://www.youtube.com/watch?v=6B2MQ1AQc4k


The issue was actually the DAC:
View: https://www.youtube.com/watch?v=Xlq8YBPYdag


But I don´t know. Any idea?
Hi,
If you read the comments, the issue was DC on the output of the DAC causing the pop sound, nothing wrong with the amplifier.
Regards,
Shadders.
 

CleanCopperz

Well-known member
Feb 12, 2022
144
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Hi,
If you read the comments, the issue was DC on the output of the DAC causing the pop sound, nothing wrong with the amplifier.
Regards,
Shadders.
Yeah thats the weird part. How the DAC makes the pop sound...

i just found out that the SCM40A uses only 40watt in idle, so it is 80w and not 120w....in total

...Also I hear that more people confirm the active to be better. I hate this feeling
 

shadders

Well-known member
Nov 19, 2009
462
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Yeah thats the weird part. How the DAC makes the pop sound...
Hi,
It seems that the DAC output is DC coupled, and the amplifier input is DC coupled too.
i just found out that the SCM40A uses only 40watt in idle, so it is 80w and not 120w....in total

...Also I hear that more people confirm the active to be better. I hate this feeling
The ATC active speakers have class AB amplification. Whether one is better than the ohter, then from a technical perspective, active is better than an amplifier and passive speaker with a crossover setup. It does then come down to subjective preference.

Regards,
Shadders.
 
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nopiano

Well-known member
i just found out that the SCM40A uses only 40watt in idle, so it is 80w and not 120w....in total

...Also I hear that more people confirm the active to be better. I hate this feeling
The active is clearly better. I’ve heard them alongside each other at a friend’s house, and he was using an ~£8000 Audia Flight integrated amp to power the passives. I own the passives and they’re a terrific speaker. But the active is more transparent and sounds more relaxed too.

If I had £7400 to spend on a power amp and speakers the actives are an easy preference.
 
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