Amplifier power: Class A, AB vs D

[Waxx]

bass slam comes from a amp that can deliver a lot of power instantly. That has nothing to do with the amp class but all with the power supply. A linear is more foolproof to design, but a wel designed, powerfull enough SMPS does it better i think, because the power is regulated and way more controlled.

The pitfall is that many class d amps, even big names, don't have a powerfull enough PSU to handle that. The solution to that is simple, double or triple your power amp power and consider rated power as peak power, not as rms power (altough it technically should be it).

But this has nothing to do with the class D module, a class AB or A amp with a too weak SMPS power supply will have worse result than a Class D with a to weak psu. The class D will start pumping and cut the bass by that, the class A(B) will start distorting and maybe give dc (if you push it far enough) on the outputs that will smoke your speakers...

 

[Mart68]

LOL, look at the cost of entry?
I get the weekly AudioMart flyer and it just amazes me how much $ loss the high end buyers are willing to accept in the constant upgrade path they follow.
Six figure amps and speakers drop to half MSRP or more after a year of so. Good deals for used buyers but the losses unblinkingly accepted staggers a old lower midlevel blue collar guy like me.

50 percent is about right for the desirable brands. Although they usually start by asking for 70 percent and then, over months, drop the price.

Usually to upgrade to something even more expensive that in all likelihood will be no different in performance.

Some people have pots of money though. I know people who will redecorate and buy all new furniture every 2 years or so. Or remodel the kitchen and pay a few grand for a new refrigerator so it matches. Previous one goes to the dump in full working order.

Their money, their lives.

My favourite was a bloke on one of the extreme cargo-cult forums who was buying all the foo products before he'd even bought an amp and speakers. He freely admitted he had no money and was sticking it all on his credit card.

 

[Sal1950]

My favourite was a bloke on one of the extreme cargo-cult forums who was buying all the foo products before he'd even bought an amp and speakers. He freely admitted he had no money and was sticking it all on his credit card.

Now that's totally nucking frocks.
But each to their own..

I can’t see any advantage to those old A/B amps and many disadvantages.

Well you've got your points Keith but that kind of failure rate on a brand new amp is just wrong, and if it is truely heat related they did something wrong in the chassis design. I've got 5 30+ year old Adcom amps here (purchased used) that don't show any signs of ever being repaired and all I've ever done is set the bias and offset pots.

 

[Purité Audio]

Now that's totally nucking frocks.
But each to their own..


Well you've got your points Keith but that kind of failure rate on a brand new amp is just wrong, and if it is truely heat related they did something wrong in the chassis design. I've got 5 30+ year old Adcom amps here (purchased used) that don't show any signs of ever being repaired and all I've ever done is set the bias and offset pots.

Totally agree, Eversolo’s amplifier exploits have not been a success.
Keith

 

[Ropeburn]

My favourite is their Amp F2 model, with what looks and performs like a 50$ 3255 module from AliExpress, sold for nCore money.

 

[MasterApex]

My puirifi class D does not have the same slam as my mark levinson 536.
My benchmark ahb2 is better (slam) than my purifi class D
This is done on B&W 800D3 speakers.

I also bought topping B200 that has stellar measurement but it sounds very thin when used with B&W 800D3

Until you own or try this high power mark levinson , krell , boulder with demanding low impedance speakers , you will only see measurement but have not heard the difference.

I like many amps and collect them
Just sharing experience , not passing judgement .

 

[Buckeye Amps]

My puirifi class D does not have the same slam as my mark levinson 536.
My benchmark ahb2 is better (slam) than my purifi class D
This is done on B&W 800D3 speakers.

I also bought topping B200 that has stellar measurement but it sounds very thin when used with B&W 800D3

Until you own or try this high power mark levinson , krell , boulder with demanding low impedance speakers , you will only see measurement but have not heard the difference.

I like many amps and collect them
Just sharing experience , not passing judgement .

I've actually used quite a few "high end" Class A/B amps. No difference in "slam".
No one is attacking you, just letting you know your observation is purely subjective and anecdotal and goes against the objective data, so people are going to rightfully point that out.

 

[Chrispy]

My puirifi class D does not have the same slam as my mark levinson 536.
My benchmark ahb2 is better (slam) than my purifi class D
This is done on B&W 800D3 speakers.

I also bought topping B200 that has stellar measurement but it sounds very thin when used with B&W 800D3

Until you own or try this high power mark levinson , krell , boulder with demanding low impedance speakers , you will only see measurement but have not heard the difference.

I like many amps and collect them
Just sharing experience , not passing judgement .

So far your credibility is low as far as whether others share such experience with amp "collecting" (LOL).

 

[mhardy6647]

This last fusillade of posts has made me exceedingly curious as to the measurement parameters for bass slam.


Perhaps it's somewhere on the position, velocity, acceleration, jerk, snap, crackle, pop... spectrum?

 

[Sal1950]

I also bought topping B200 that has stellar measurement but it sounds very thin when used with B&W 800D3

Thin, as in lacking any thick sounding harmonic distortion?

 

[Mike_Trueman]

There are some heavy class D amps if thats your fetisch.

Marantz Model 10 is a 74lbs Purifi Class D Integrated Amplifier!
Technics SU-R1000
Technics SE-R1
...

 

[Sal1950]

This last fusillade of posts has made me exceedingly curious as to the measurement parameters for bass slam.

The feeling you get if you drop one of those monster 114lb weighted guys on your foot?

 

[Buckeye Amps]

Whenever someone brings up Class D as not being able to handle Bass duties, I often wonder what they think is powering some of the best performing Subwoofers on the market...

 

[pma]

To all members describing "bass slam" etc., I would suggest this: if you are technically capable enough, do what I did in this test. You may use your speaker instead of the resistor load to keep the conditions of your sighted listening. Or make a speaker switch and make a level matched test. Otherwise, the subjective impressions described may only be anecdotal stories.

 

[Waxx]

My puirifi class D does not have the same slam as my mark levinson 536.
My benchmark ahb2 is better (slam) than my purifi class D
This is done on B&W 800D3 speakers.

I also bought topping B200 that has stellar measurement but it sounds very thin when used with B&W 800D3

Until you own or try this high power mark levinson , krell , boulder with demanding low impedance speakers , you will only see measurement but have not heard the difference.

I like many amps and collect them
Just sharing experience , not passing judgement .

Untill you replace them with a Powersoft amps (class D pro amp), you don't know that that kind of amp drives demanding low impendance speakers even easier because they are made for it. And yes, you can measure that '"slam", it's when an amp never start to compress sound because the psu can't follow the demands by the music and creates distortion at high volume and/or pumping (volume drops when the bass kicks in).

Those demanding speakers have huge impendance peaks and so huge swings in needed power and not all amps are build for that. It's the power supply of those high power amps that makes the difference as they are build for high power and are more forgiving when driven into red (until you go to far). But a class D with an SMPS with enough power reserve does it often better than a linear psu. That is just science (until proven otherwise on scientific base). give an amp enough power juice and it will do it, and regulated switching power supply gives cleaner power (and so cleaner sound) than a linear. It's when you push it to it's limits that linear is more forgiving than an SMPS, and class AB more forgiving than class D, but that is probally the only real technical advantage.

Not that i don't have class AB amps with linear psu, but they are smaller because i don't need that kind of power at home.

 

[mhardy6647]

The feeling you get if you drop one of those monster 114lb weighted guys on your foot?

I have a sense that the jerk (fourth derivative of position) may also be a factor. EDIT: speaking of ahem-worthiness: Third derivative (position, velocity, acceleration, jerk -- I can, too, count, appearances to the contrary! ), with respect to time. Shout-out to @thewas for gently and kindly reminding me of these things!

ahem.

 

[MasterApex]

My class D amp is year 2021 Purifi Eigentakt Stereo Amplifier based on EVAL-1 .
Maybe it does not have good enough power supply so the bass slam is not as good as my Krell and Levinson ; Just like the topping B200 amp is challenged to drive B&w 800D3 , probably due to lack of peak current at below 3ohm.

I like the midrange of the current Purifi , but lacking in details and bass slam in comparison to levinson 536 when driving 800D3 speaker

I am considering new buckeye 2nd Purifi monobloc class D to see if this is better than my 2021 Purifi and also exploring this class D amp that I heard has good details like Levinson 536.

GaN-FET Amplifiers — Monobloc and dual-mono stereo DUO

 

[Buckeye Amps]

My class D amp is year 2021 Purifi Eigentakt Stereo Amplifier based on EVAL-1 .
Maybe it does not have good enough power supply so the bass slam is not as good as my Krell and Levinson ; Just like the topping B200 amp is challenged to drive B&w 800D3 , probably due to lack of peak current at below 3ohm.

I like the midrange of the current Purifi , but lacking in details and bass slam in comparison to levinson 536 when driving 800D3 speaker

I am considering new buckeye 2nd Purifi monobloc class D to see if this is better than my 2021 Purifi and also exploring this class D amp that I heard has good details like Levinson 536.

GaN-FET Amplifiers — Monobloc and dual-mono stereo DUO

Something else is amiss then as there is definitely no issue with detail or slam.

And the GaNFET Class D will perform identical to the Purifi.

 

[Palmspar]

Whenever someone brings up Class D as not being able to handle Bass duties, I often wonder what they think is powering some of the best performing Subwoofers on the market...

Use Hypex FA plate amps for my Diy subs, sound good to me.
2000w@4ohm total.

 

[mhardy6647]

PS (from earlier today) Not to be redundant, but I still wanna know the SI units for bass slam.