Power limit, over current limit, protections, temperature limit
Protection to short circuit, protection to overtemperature, to overcurrent, to over voltage, to under voltage.
All that stuff killed sonics...there's no protection against not perfect sonics.
If you accept to adjust 10 watts into your average power you gonna be very happy with your chip amplifier...nothing will produce more nice sonics (exception is high end a little bit worse than good solid state designs)...but DO NOT try to have power.
Those "toys" were made to be small, simple, cheap and very good...not to give you power.
I am talking about AB amplifiers...Class D is another story.
Carlos
Protection to short circuit, protection to overtemperature, to overcurrent, to over voltage, to under voltage.
All that stuff killed sonics...there's no protection against not perfect sonics.
If you accept to adjust 10 watts into your average power you gonna be very happy with your chip amplifier...nothing will produce more nice sonics (exception is high end a little bit worse than good solid state designs)...but DO NOT try to have power.
Those "toys" were made to be small, simple, cheap and very good...not to give you power.
I am talking about AB amplifiers...Class D is another story.
Carlos
rhythmdiy said:
A chip amp that is capable of 50 watts will deliver the same current as a SS amp of 50 watts. A lot of the chip amp projects seen on this forum are poorly done, with undersized smoothing caps and other "boutique" BS that will undermine its good performance. Who would build a serious solid state amp with the equivalent of board decoupling caps for smoothing and current reserve?
Build it properly, with the right components and then have a listen. Come back and say there is no tight bass...
I "sort of" agree with your statement.. Many a THX certified sub-
woofer systems are powered by bridged chipamps, and sound good... BUT a SS amp without SOA protection will on
occasion produce transients that are unhindered by any
protection adding more to the "punch" . With the exact same
PS (40-0-40 - 20k uf), A dx original or symasym would
pound the "u know what" out of a 3886..
OS
ostripper said:
Not with the same power supply. This I know because I have built quite a few chip amps. The spike protection will not have any effect under normal operating conditions. A good power supply, good hearsink to guard against overheating (and engaging the spike protection) and sticking with good practices design for amps in general will give excellent results.
For low power applications, they are very hard to beat.
Re: Re: why bass is tight and controlled on SS than chipamps like lm3886?
well then If I want to build a chipamp bpa then how much capacitance is required to get as good performance as SS.. I mean in terms of Bass
as Its said over and over in amps like Jeff Rowlands and 47 labs gain card amps its said its ultimately good for mids and highs but in order to get right bass how much capacitance should be used per channel? 100,000ufd? is enough? with 6 chips in BPA?
what about the damping factor? how well a chipamp controls the 10 inch woofer? I just had a doubt about it... can u guys please help me out... in deciding which one to go with it....
MJL21193 said:
well then If I want to build a chipamp bpa then how much capacitance is required to get as good performance as SS.. I mean in terms of Bass
as Its said over and over in amps like Jeff Rowlands and 47 labs gain card amps its said its ultimately good for mids and highs but in order to get right bass how much capacitance should be used per channel? 100,000ufd? is enough? with 6 chips in BPA?
what about the damping factor? how well a chipamp controls the 10 inch woofer? I just had a doubt about it... can u guys please help me out... in deciding which one to go with it....
Good replies.
My thoughts are there is no magic here, the chip amps are just very good circuits with heaps of constant current sources and very tightly matched devices. The distortion is good at low power. They hit the headlines with the Gaincard which used undersized ps caps which of course gave the bass a different quality (lean and fast) than most discrete SS amps they were compared with. Any SS amp would have the same sound with small caps.
If you say it's a chip amp without knowing what power supply is running it you can't say much about how it will sound. Within their power and current limits there are no aural penalties that I can hear when compared to a discrete bipolar amp. If a chip amp has bad bass it is not the fault of the 'chip'.
Edit I have used 10,000uF per rail, depends on your speaker's impedance and behaviour .Also the transformer size, VA and regulation is a big factor.
My thoughts are there is no magic here, the chip amps are just very good circuits with heaps of constant current sources and very tightly matched devices. The distortion is good at low power. They hit the headlines with the Gaincard which used undersized ps caps which of course gave the bass a different quality (lean and fast) than most discrete SS amps they were compared with. Any SS amp would have the same sound with small caps.
If you say it's a chip amp without knowing what power supply is running it you can't say much about how it will sound. Within their power and current limits there are no aural penalties that I can hear when compared to a discrete bipolar amp. If a chip amp has bad bass it is not the fault of the 'chip'.
Edit I have used 10,000uF per rail, depends on your speaker's impedance and behaviour .Also the transformer size, VA and regulation is a big factor.
Internal limiters inside chip amplifiers can kill your sound quality
I have studied some and have burned 6 chips.... many models used into testing.
I found sound great if you decide to listen them 1/4 to maximum power...never reaching the maximum.
Here you can see a video showing the crossover noises when the protection enters... when you reach the maximum the over current protection enters... listen the real thing happening.
By the way, there are 70 small videos into Youtube...just type Dx Amplifier and enjoy a lot of small video tests and local pictures if you like that stuff.
http://www.youtube.com/watch?v=34pYSsYNXa0
If i was someone that could accept power around 10 watts i would quit my search on good amplifiers...chip would be more than enougth..in special LM4780 is very good (despite mine gone in flames to the hell).... also the treble is not perfect but very good.
They use all needed sophisticated aided subcircuits without any kind of economy... all differentials, current sink, voltage and current regulators, stabilizers, compensations, mirrors, fets and all needed stuff having matched parts and precision internal resistances...non inductive things, small patches inside... all we can dream when doing discrete...so.... could be better than discrete if size was not so small and protections killing sonics.
The old Sanyo STK had good sound and not those limiting things... the result was they could burn but while operating had nice sound...all technologie is inside...modern circuits...last developments and discoveries are inside those chips....but the need to be reliable, the need not to burn, the need to be cheap, the need to be very small...all those decisions are killing sonics.
Potentially they could be the maximum possible quality...but market does not accept small reliability...so.... factory is protecting...now you have long life and less perfect sonics.
Carlos
I have studied some and have burned 6 chips.... many models used into testing.
I found sound great if you decide to listen them 1/4 to maximum power...never reaching the maximum.
Here you can see a video showing the crossover noises when the protection enters... when you reach the maximum the over current protection enters... listen the real thing happening.
By the way, there are 70 small videos into Youtube...just type Dx Amplifier and enjoy a lot of small video tests and local pictures if you like that stuff.
http://www.youtube.com/watch?v=34pYSsYNXa0
If i was someone that could accept power around 10 watts i would quit my search on good amplifiers...chip would be more than enougth..in special LM4780 is very good (despite mine gone in flames to the hell).... also the treble is not perfect but very good.
They use all needed sophisticated aided subcircuits without any kind of economy... all differentials, current sink, voltage and current regulators, stabilizers, compensations, mirrors, fets and all needed stuff having matched parts and precision internal resistances...non inductive things, small patches inside... all we can dream when doing discrete...so.... could be better than discrete if size was not so small and protections killing sonics.
The old Sanyo STK had good sound and not those limiting things... the result was they could burn but while operating had nice sound...all technologie is inside...modern circuits...last developments and discoveries are inside those chips....but the need to be reliable, the need not to burn, the need to be cheap, the need to be very small...all those decisions are killing sonics.
Potentially they could be the maximum possible quality...but market does not accept small reliability...so.... factory is protecting...now you have long life and less perfect sonics.
Carlos
This one i am "burning"... playing with this toy
Sounds very good....but it is funny, can pump 25 watts into 4 outputs ... 25 RMS each output (Automobile CD player from Sony).... nice sound...but it has small size..imagine to dissipate 160 watts (all channels pumping maximum power... this may be the consumption) using the small metal tab?
The result was controled...power was controled by heat sensors...automatic control...when your car is 35 degrees celsius, when under the sunligth, hot weather..power goes to 3 watts each channel..ahahahahah!
I am trying to burn it...it is beeing hard to do that...protection works fine.
The designer was clever..you switch on when cold and pumps delicious sound..tigth bass.... a good "demonstration"..and when you start to feel happy the power was already reduced slowly and you do not perceive that...so..you continue happy!
Carlos
Sounds very good....but it is funny, can pump 25 watts into 4 outputs ... 25 RMS each output (Automobile CD player from Sony).... nice sound...but it has small size..imagine to dissipate 160 watts (all channels pumping maximum power... this may be the consumption) using the small metal tab?
The result was controled...power was controled by heat sensors...automatic control...when your car is 35 degrees celsius, when under the sunligth, hot weather..power goes to 3 watts each channel..ahahahahah!
I am trying to burn it...it is beeing hard to do that...protection works fine.
The designer was clever..you switch on when cold and pumps delicious sound..tigth bass.... a good "demonstration"..and when you start to feel happy the power was already reduced slowly and you do not perceive that...so..you continue happy!
Carlos
Attachments
Tight bass is related to speakers, speaker placement and room acoustics, not to amplifiers (and I know by the pictures the kind of speakers that you use, Carlos, they would probably be considered as useless junk by most people here).
The protections found on chip amps like LM3886 or TDA7294 are never triggered when driving a typical 8 ohm speaker load, current never goes that high.
How about exceeding voice coil linear displacement or exciting room modes? This is far more likely to happen.
The protections found on chip amps like LM3886 or TDA7294 are never triggered when driving a typical 8 ohm speaker load, current never goes that high.
How about exceeding voice coil linear displacement or exciting room modes? This is far more likely to happen.
I don't want to believe that.Eva said:
I reckon that the main limitation of a chipamp is the current output capability, even at 8ohms. This is determined by the SOAR of the chip components, the temperatures of the chip components and how the Spike protection is programmed to trigger with the varying currents/voltages and temperatures.
I agree with Eva.
If you need to play for example LM3886, which has rather high currents, to the trigger level,
then you have not a good sound system.
that is, your amplifier does not match your speakers/room size.
For a normal room and normal sensitve speakers (88-92 dB SPL)
LM3886 would be more than sufficient.
if you have speakers with low SPL (80-85 dB), you have two choices:
- Change to better sensitive speakers
- Use an adequate amplifier for your speakers.
For example Nelson Pass F4 has got less current out, than LM3886
But nobody is complaining.
Because Nelson Pass himself uses speakers with good sensitivity ( like 95-96 dB/Watt, if I recall)
and this is what he recommends, as first choice.
Such general statements like:
- Discrete transistor Amps have tighter Bass
- Tube Amplifiers has weak Bass
- Chip Amps sounds bad because of current limit protection
- Class A amplifiers has a muffled sound
... they are just not valid statements.
Truth is:
- There are Tube amplifier with wonderful strong Bass
- There are transistor amps with both weak and muffled bass
- There are chip amps with great bass
- There are Class A amplifiers with the best clarity in sound.
As well as the opposite
----------------
It has not much to do with what amplifier technique used.
A good sound system is good.
A bad sound system is bad.
Simple as that.
Ask Peter Daniel
He will tell you what a good chip amp system is like.
With the correctly setup sound chain. With well done constrution.
It is better to build 2 proper and very well designed quality sound systems.
Than to build 3000 amplifiers and get only halfway to get a good standard.
Lineup
If you need to play for example LM3886, which has rather high currents, to the trigger level,
then you have not a good sound system.
that is, your amplifier does not match your speakers/room size.
For a normal room and normal sensitve speakers (88-92 dB SPL)
LM3886 would be more than sufficient.
if you have speakers with low SPL (80-85 dB), you have two choices:
- Change to better sensitive speakers
- Use an adequate amplifier for your speakers.
For example Nelson Pass F4 has got less current out, than LM3886
But nobody is complaining.
Because Nelson Pass himself uses speakers with good sensitivity ( like 95-96 dB/Watt, if I recall)
and this is what he recommends, as first choice.
Such general statements like:
- Discrete transistor Amps have tighter Bass
- Tube Amplifiers has weak Bass
- Chip Amps sounds bad because of current limit protection
- Class A amplifiers has a muffled sound
... they are just not valid statements.
Truth is:
- There are Tube amplifier with wonderful strong Bass
- There are transistor amps with both weak and muffled bass
- There are chip amps with great bass
- There are Class A amplifiers with the best clarity in sound.
As well as the opposite
----------------
It has not much to do with what amplifier technique used.
A good sound system is good.
A bad sound system is bad.
Simple as that.
Ask Peter Daniel
He will tell you what a good chip amp system is like.
With the correctly setup sound chain. With well done constrution.
It is better to build 2 proper and very well designed quality sound systems.
Than to build 3000 amplifiers and get only halfway to get a good standard.
Lineup
I assume that the debate is about direct comparison of the 3886 based amp with another circuit solution; on same speakers and in the same room. Then the explanation given by Eva does not work.
Might sound like a paradox, but proper midrange and treble dynamics and trasient reproduction subjectively affects bass perception. It is not much about frequency response in low frequency band.
Might sound like a paradox, but proper midrange and treble dynamics and trasient reproduction subjectively affects bass perception. It is not much about frequency response in low frequency band.
Excuse me, but I can’t simply understand the point in half of those youtube videos. They show you switching the amplifier on and off repeatedly and driving some speakers with subsonic frequencies or into a condition where the internal protections kick in.
Yes. The amplier / speaker makes a "pop" sound when switched on. Isn't this like an inherent characteristic of about all solid-state amplifiers? Do like many others and put a delayed relay switching to it.
Yes. It pops again because of the peak limiting / overcurrent protection. But what the video doesn't show for comparison are the ill effects that might happen because of the lack of peak limiting. I'd be more willing to hear a few slight pops from a speaker instead of toasting the amplifier or the voice coil of the speaker. Also, are you sure that lack of peak limiting wouldn't cause excess cone excursion, which could sound quite bad as well? Your videos seem to be quite selective in what they present and what they do not. Such bias is somewhat disturbing.
Whats the point of driving the speakers at subsonic frequencies? Nevertheless, the amplifiers seems to work fine even under that abnormal condition. Even the best drivers/amps do that "woof woof" sound when driven like that. I once experimented with a high-quality instrumentation / reference amplifier (which I could never afford in my life) driving a high-quality low frequency transducer (which I couldn't affored either) and it also did that "woof woof" thing at low frequencies. It's mostly inaudible anyway and you surely won't have it there when the signal frequency increases. Crossover distortion audible at subsonic frequencies? Of course it is. Audible at audible frequencies? I doubt it.
And what's the point of showing ill effects of improper DC offset? Condition like that should never exist in a properly designed amplifier in the first place. You can't label a chip design bad simply because some of your designs based on it failed to manage proper DC offset conditions.
Yes. The amplier / speaker makes a "pop" sound when switched on. Isn't this like an inherent characteristic of about all solid-state amplifiers? Do like many others and put a delayed relay switching to it.
Yes. It pops again because of the peak limiting / overcurrent protection. But what the video doesn't show for comparison are the ill effects that might happen because of the lack of peak limiting. I'd be more willing to hear a few slight pops from a speaker instead of toasting the amplifier or the voice coil of the speaker. Also, are you sure that lack of peak limiting wouldn't cause excess cone excursion, which could sound quite bad as well? Your videos seem to be quite selective in what they present and what they do not. Such bias is somewhat disturbing.
Whats the point of driving the speakers at subsonic frequencies? Nevertheless, the amplifiers seems to work fine even under that abnormal condition. Even the best drivers/amps do that "woof woof" sound when driven like that. I once experimented with a high-quality instrumentation / reference amplifier (which I could never afford in my life) driving a high-quality low frequency transducer (which I couldn't affored either) and it also did that "woof woof" thing at low frequencies. It's mostly inaudible anyway and you surely won't have it there when the signal frequency increases. Crossover distortion audible at subsonic frequencies? Of course it is. Audible at audible frequencies? I doubt it.
And what's the point of showing ill effects of improper DC offset? Condition like that should never exist in a properly designed amplifier in the first place. You can't label a chip design bad simply because some of your designs based on it failed to manage proper DC offset conditions.
Must be a bad design ,both versions of my "frugalamp" have
no "pop" whatsoever ,on or off. FA2 ,you don't even know it
was turned on until you hit it with a signal.. whatever
chipamp that was ,I would redesign/not use it.
No paradox, but truth . An amp's bass is always "sensed"
in relation to its Mid/HF content.The same bass drum whether
in mono with no room acoustics (from a synth) or a live
version (in stereo with room reverberations) would indeed
be perceived quite differently even with the same amp.
The live drum would sound different (better) on the amp
that could most faithfully reproduce the subtle room acoustics.
The human brain works in funny ways ,(look around)..
OS
I would not be arrogant to say Philips International does not know
The Speaker came from Philips International imported parts joined together into Philips Brazil systems...the same speaker are use worldwide.... Philips are competent folks... the speaker was selected because of performance and price for their Class D systems.... the speaker was the choice to hold the power and to reproduce audio quality considering the price range.
I am sorry very much dear Eva, if Philips has decided to use and this means "testimony of quality" i will have preference to believe on them when you offer opposite point of view.
Also i had many imported units and have used them and they were not superior anyway!
The speaker seems made in China...but what is the problem to be made in China?.... they had evoluted a lot and have superated many other countries technology... alike Japan did when i was young..and people had that idea about Japanese speakers..considering junk..... maybe the first ones.... fast they became the better ones.
Expensive does not means good.... this speaker has high complicance, does not produce noises when reproducing music.... the infrasonic is silent, not noise...SO... audio also will not have the noise together... the moving coil does not touch the iron core... ressonance is very low... does not reproduce high frequencies (good that) because it is not a full range... there's absolutelly nothing wrong with the speaker i use unless people is thinking about unobtanium.
Having noises when reproducing low frequencies, also bellow the audible spectrum is better than have amplifiers producing clicks and pops because of crossover and protection.... what happens into infrasonic will happens also into musical reproduction when you play loud... this turns noisy and dirty reproduction into peaks.
Those chips, that has protections inside are unable to reproduce peaks without noises...and i have proved you that.... reality is reality, what folks thinks is what folks thinks.
Lineup...if you make a good effort, maybe before your death as you are old as i am... we have more 20 or 30 healthy years ahead... i think you will be able to build more tree or four amplifiers..sorry, i will build more 2 thousands, as i love to listen music and not to delirate into theories or simulators.... also i love to learn real things... differences into comparison... sorry not to be lazy about build things.
In my mind the clicks i have listened are definitive...not theories can dennie the real thing.
regards,
Carlos
The Speaker came from Philips International imported parts joined together into Philips Brazil systems...the same speaker are use worldwide.... Philips are competent folks... the speaker was selected because of performance and price for their Class D systems.... the speaker was the choice to hold the power and to reproduce audio quality considering the price range.
I am sorry very much dear Eva, if Philips has decided to use and this means "testimony of quality" i will have preference to believe on them when you offer opposite point of view.
Also i had many imported units and have used them and they were not superior anyway!
The speaker seems made in China...but what is the problem to be made in China?.... they had evoluted a lot and have superated many other countries technology... alike Japan did when i was young..and people had that idea about Japanese speakers..considering junk..... maybe the first ones.... fast they became the better ones.
Expensive does not means good.... this speaker has high complicance, does not produce noises when reproducing music.... the infrasonic is silent, not noise...SO... audio also will not have the noise together... the moving coil does not touch the iron core... ressonance is very low... does not reproduce high frequencies (good that) because it is not a full range... there's absolutelly nothing wrong with the speaker i use unless people is thinking about unobtanium.
Having noises when reproducing low frequencies, also bellow the audible spectrum is better than have amplifiers producing clicks and pops because of crossover and protection.... what happens into infrasonic will happens also into musical reproduction when you play loud... this turns noisy and dirty reproduction into peaks.
Those chips, that has protections inside are unable to reproduce peaks without noises...and i have proved you that.... reality is reality, what folks thinks is what folks thinks.
Lineup...if you make a good effort, maybe before your death as you are old as i am... we have more 20 or 30 healthy years ahead... i think you will be able to build more tree or four amplifiers..sorry, i will build more 2 thousands, as i love to listen music and not to delirate into theories or simulators.... also i love to learn real things... differences into comparison... sorry not to be lazy about build things.
In my mind the clicks i have listened are definitive...not theories can dennie the real thing.
regards,
Carlos
Attachments
destroyer X
Philips. there are many 1000 of just junk speakers around the world
using philips cheap drivers.
Philips is not the first woofers I would go for.
When building a good sound speaker. This is an understatement.
In fact Philips would come rather far down at my list of options
LM3886, LM3875, LM4780 are happily used by 1000 of DIY people.
Those that can handle them and have not your problems, destroyer X
I do not know what wrong you made?
But this I can guess: You did not put your heart to it. And gave these great chips a fair chance
You maybe stay away from useing National amp power IC
As I said .. contact Peter Daniel and he can tell you how to do, Carlos
exactly, gainphile
... and this is basically what Eva posted ... and me lineup
I see you understand the importantance of Audio Systems.
Not all things go good together.
Some like to think they know amplifiers
.... but can not understand
that Audio System is only to a minor degree about the power amplifier unit.
Lineup
Philips. there are many 1000 of just junk speakers around the world
using philips cheap drivers.
Philips is not the first woofers I would go for.
When building a good sound speaker. This is an understatement.
In fact Philips would come rather far down at my list of options
LM3886, LM3875, LM4780 are happily used by 1000 of DIY people.
Those that can handle them and have not your problems, destroyer X
I do not know what wrong you made?
But this I can guess: You did not put your heart to it. And gave these great chips a fair chance
You maybe stay away from useing National amp power IC
As I said .. contact Peter Daniel and he can tell you how to do, Carlos
gainphile said:
exactly, gainphile
... and this is basically what Eva posted ... and me lineup
I see you understand the importantance of Audio Systems.
Not all things go good together.
Some like to think they know amplifiers
.... but can not understand
that Audio System is only to a minor degree about the power amplifier unit.
Lineup
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