What to do with class A amplifiers to avoid some mufled treble

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I have made one using FET.... mufled too!

Aksa 55 is not mufled
HRII is not mufled
DHR Turbo is not mufled
Precision 1 is not mufled
Symassym is not mufled
Roender super amp is not mufled
GEM is not mufled

Dx Standard is a little bit mufled.... even this way better than this class A and can compete with the chip amplifier in audio quality to treble and mids...but despite bass is better into Dx Standard..it is less controled, longer than normal...less precise... less High Fidelity..lovely but worse.

And several others are not mufled too.... Quasi is not mufled too...there are many good units.

No chip amplifier is mufled... at least TDA2002, TDA2003, TDA2010, TDA2020, TDA2030, LM1815, LM3775, LM3886, LM4780, LM4701T

Class A does not sounded bad... they are fine...but i think not interesting as they are a little bit mufled, too much hot and too much low power...something not interesting.

regards folks

Carlos
 
I have tried all i could about supply

Of course, some class A addict folks will always thinK into one possibility that was not tried.

Not you... you are not fanatic to class A... you research all classes dear SandyK.

When government employees does not want to do their job they start to ask you strange things; alike watter bill paid 20 years ago.... and this to block you to advance into the bureaucracy.

The class A addict folks will find something that "I have not tried"...and this will be the reason why my amplifier was perceived as mufled.

ahahahahah.

Carlos

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Your class A is great Lineup... sorry but i have closed my class A factory for ever.

Give a try for once Lineup... assemble something and listen to know what those things sounds..... have made some... Aksa?... good one...but there are others to listen and to perceive sound... simulators do not talk..they cannot play songs.... are unable to tell you how things sounds to your ear... the only way is to assemble and to listen.

regards,

Carlos
 
hi Carlos,
i think it may be that all the amplifiers that you state are sounding ok are signifcantly higher power than the class A's you have tried, more volts availible on the higher power ones even at low volume levels. just a thought.

speakers are an important factor here, most are designed with amplifiers of at least 30watts in mind, they sound very thin with low power amps, unless designed for them.

how about a nice mosfet amp, try the J Linsley Hood 80 watt (AB),
nice sound, complex regulated power supply. this will keep that soldering iron hot for a long time.
 
Negative.... class A is ended chapter.

Thank you.

GEM has class A auxiliary but used class AB... this one i can afford.

Class A is dead and buried into my ears, brain and heart.... all my doubts was cleared by forum folks...i have submited my doubts to them and received instructions i have followed... even this way confirmed old suspections i had since 1968...it is time to finish and to search for other ideas...other kinds of class maybe... or some very modified class A

Nelson Pass uses complementary Field Effect units... i have not those parts... reason why will not try this amplifier you suggested.

I know this will be waste of time... i had made already too much about the subject.

Time to have fun with other things....maybe future Class AX...or ABX....or Class P...or whatever they call.... Class D i have already a chip and a discrete amplifier..will be waiting for something good and not too much complicated to DIY.

Of course..not your case Samuel...but the ones like class A, the ones love will always think i have not tried that one was hidden inside caves in the Himalaia protected by terrible bad indians that use poison into their arrows.... and "that one", i have not listened..will not have mufled treble.

I see you are not the addicted or fanatic and thank you by the suggestion but i decline.

To continue with that story means to return into the same road i was driving for whole life... walk into the same track and to assemble the same amplifiers once again to conclude the same once again.... not a good idea to me...and now i realise that.

regards,

Carlos
 
Carlos;

Good on you for having the guts to tell it like it is !
I am sorry to say that I tried the JLLH ClassA amplifier as a guitar amp (for that "tube sound") and was VERY disappointed.
Interestingly, I have found that a standard Lin topology amplifier with FET VAS and/or drivers is excellent, even with mediocre Darlington power transistors like the TIP142/147.

Pas de probleme.
 
C'est vrai..... people will not appreciate... a pitty that true is not good to

be said.... people felt hurt when they love their class A....of course i love too...when you have class A, assembled and go listening it is delicous, wonderfull.

But when you make comparisons things appear clearly....people does not do that and go dreaming they have the best.

So easy to find the best this way...we write "the best" over and do not look, do not listen, do not assemble, do not compare with other..of course the best will continue to be "the best".

C'est vrai...la veritè

Deceptive.... i felt that once too when i have compared with an old Heathkit.... also i felt this amplifier great when i have compared with a Sony 5.1 system.... the Class A smashed the Sony high technological monster.... depends... everything is wonderfull when we have junk around to compare...but this wonderfull can turn very bad when compared to something real good.

C'a marche...na pas arretez!

Charles
 
Hi, Carlos,

To find out the problem, we can start by measurement. Can you get an FFT/spectrum analysis of "muffled amp+loudspeaker" and "non-muffled amp+loudspeaker", where the loudspeaker is the same unit, using pink noise?
It can be done with Audio Control RTA, or soundcard+microphone (like behringer ECM8000). Maybe we can start by seeing what the difference is.
 
Already found out the problem dear Lumanauw

The problem was "mufled"

My speaker is linear (more or less...no one is perfect)

I have no more doubts about.... no more research about.

thank you all by the nice help and contribution...this thread reached the target... i have asked, had doubts...have tested, using suggestions, and have realised that my old time suspections were rigth...now i have absolutelly no more doubts and no need to more research about...really mufled.... not bad sound...i said mufled.... audio perceived shows less treble to a linear speaker (almost linear) and headphone...listened with me (57 years old), my daugther (11 years old...young ears) and 2 folks of this same building (18 and 22 years old).

This is nothing we cannot compensate, adjust, increasing treble a little bit or reducing bass a little bit .... well.... adjustable thing...but deceptive to me....as Class A already has the problem of low power.... already has the problem of high power consumption and high temperature..... has some dinamics problem too...some thermal noise and also has losses of treble!.... for my taste is too much.... this is terminal for class A amplifiers into my ears, brain and heart.

I am very satisfied with this thread and help received from many folks, and I have informed my conclusions, so, i asked for help and paid giving back informs about what i have perceived...very fair i think....if others has their own doubts, i suggest them to research the way i did with help of others..and do this better than i did, having a method, an organized plan to do that.

There's no other way... we have to realise those things by ourselves, not to believe what others say..have to assemble to tweak, to test and to compare, and to do those things for years long and many units...then we will be able to conclude.

If the guy has a method, organized work with the aid of instruments, the one can realise those things faster than i did.

I would like to remember folks that your honor and inteligence and qualities are not connected to have or enjoy or not to enjoy a class A or other class of amplifiers... and the fact that i feel deceptive with class A will not change your love for this kind of amplifier... i hope you all enjoy your amplifiers and be happy with them...if Class A, B, AB, H, D or other class you discover and elect as good for you.

Problem was mine, personal...i felt mufled and asked what to do?

People said...i have tested..found mufled...so....it is really mufled... a long time i have perceived that..needed confirmation...

Related my needs and will.... this thread can stop here..unless folks have things to continue conversations about....not because of me guys...i am satisfied...if you want...go ahead between youselves.

thank you,

regards,

Carlos
 
I still state
that there is nothing that say one Class A
would have less good diskant than any other Class.
If anyone give me a good logical reason, then we can start talking.

As I said, there can be amplifiers of any Class,
most of them of course Class AB, that have bad Diskant.
Simply because majority of all amplifiers are Class AB.

burbeck agree some with me:
speakers are an important factor here,
most are designed with amplifiers of at least 30 watts in mind,
they sound very thin with low power amps, unless designed for them.


We see often loudspeakers have one recommended Power Watt intervall:
Recommended amplifiers: 20-100 Watt

I think these factor is the most important for sound:
1. Quality of Speakers
2. How well Power Amp can drive your Speakers
3. Your Music what you listen to. Rock and Classical are different

As I also said, most amplifiers have electrical qualities way above even the most Hi-End Speakers you can buy.
Perfectly linear speakers exists, but they are very high priced
and often run with some form of Room Correctional system.
You know when you calibrate the phase and frequency curve for the listening room,
before you start playing your music.

And not 2 JLH, for example, are built same way.
There are as many Class A amps.
I am sure Majority would have excellent treble!


Those who will agree with you mufled Class A theory are those that are not 100 % happy with the treble sound.
I good guess there are many more not happy with thier Class AB treble!

The rest will be happy and silent busy enjoying music with Class A 😉
If Nelson Pass drops in here, and starts complaining with Class performance,
I will give it one ear, though.
Because he would probably have logical explaination,
along with his subjective listening impression.
And some measurement with diagrams.



Lineup - regards
 
Re: Already found out the problem dear Lumanauw

destroyer X said:
....as Class A already has the problem of low power.... already has the problem of high power consumption and high temperature..... has some dinamics problem too...some thermal noise and also has losses of treble!.... for my taste is too much.... this is terminal for class A amplifiers into my ears, brain and heart.
Carlos

I find it strange that you find the trebles muffled. My first amplifier was a Class B and with lots of experimenting and listening tests it evolved to a full class A amplifier. I still have the older versions and can tell you that the SQ of my class A amps are much better in every aspect.

Your other complaints about class A, "low power", mine are 220W rms in 8 Ohm, high enough for me 😀, "high power consumption and high temp", well then that’s the price for good sound, "thermal noise and losses of treble", my speakers have a sensitivity of 90dB, 1W and I have to put my ear right in front of the tweeter and have to listen carefully to hear noise, I experience no loss in treble, in fact it has cleaner, more open natural trebles than any other amp I've used before.

So to me it's not called Class A for nothing. 😉

André
 
Mr.Burbeck;

I am aware that the JLLH is a "low-powered Class A" amplifier - perhaps you are not aware of the multitude of low-power valve amplifers that were the norm for guitar amplification...

For the record, I am a 52 year old East Indian with a MSEE who cut my teeth on valves back in the 1960's - I just happen to like playing the elektrik geetar !
 
Yep.... there are very low powered guitar amplifiers

Into many classes...even Integrated circuits are used, and factories are producing, and play loud.

There are some small ones using tubes too.

regards,

Carlos

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Class A does not means "first class"... it is just a letter as this kind of operation is intuitive and ancient.

First class can be because of fashion, price and quality...but not the case into amplifiers.... class A understood as first class is not correct, just a coincidence into the word.

Also people use to call their wives as "honey"...for sure they are not honey bees.

regards,

Carlos
 
The distortion of zero crossing created in class B and class A/B
amps may be perceived as increased harmonics/treble and
without the distortion, upper range may seem dry!?
Professional studios often use devices to add harmonics, etc.
to liven up commercial release pop recordings.
 
To the ones have not readed the entire thread,

to the ones have not understood me, i would like to explain that i am not the Class A enemie.

Class A is the best sonics possible into audio amplifier since the early begining of audio till our days.

But, there are evaluations we do about.... some folks thinks the negative sides are the "price to pay" for the excelent audio quality....i think it is in excess.

I do not want to assemble class A anymore, or to research into this class of amplifiers, will not build them but will not dennie to visit a friend that has one and invite me to listen together.... i just give up as i found mufled.

What means mufled?

- Means into my bad english and poor language, something that sounds alike had the high frequencies attenuated or absorved, or reduced.... this into HUMAN PERCEPTION ... and this is different compared to measurements.

There are flat amplifiers that does not sounds flat...also there are unflat amplifiers that seems flat...first because ambience, your home, your speaker, you years, your ceiling, your floor, your walls, your furniture and your BRAIN that adjust things for you passed a couple of seconds (or minutes into some folks evaluation)

I felt that class A need some treble...some more treble into the reproduction..the audio perceived by humans (not measurements)

Also i told you that this can be correct using tone controls, or adjusting speaker, or removing carpets... well.. studying and taking care of your room acoustics.

I would like to inform that my amplifier is flat, or almost flat as others (they are absolutelly NOT flat)..it is an old Sansui (1980) with some drivers refursbished and the crossover keept original, the exception was the fourth driver..the super high frequency that started into 15 kilohertz and i have reduce as it is difficuld to have 15 kilohertz into the music (only into harmonics)...

My ears are fine... also i have tried young folks and my 11 years daugther.. result was "mufled" to them too... so...nor my ears and nor my speaker.

My room is almost empty, has a bed and a computer and the floor is ceramics...i have not carpet into the walls and the cloth that cover the window is ligthweigth (bath towels because my wife has never finished the correct things to put into the place)...so...my room is not high frequency absorsive..it is high frequency reflecting environment, and this INCREASES high frequencies instead to reduce.

Also i have told i have perceive that down the sixties, also that i have assembled and listened many class A, also that i have listened Industrial Class A units and that ALWAYS i have found them mufled...since i had 18 years old when my ears were fresh and young.

I would like to ask guys, please, to read the entire thread in advance to post things.... this will avoid misunderstandings and will reduce the thread beginner work to go explaining things already posted.

Please read...sometimes english is your language...easy to you...try to imagine how hard is to me to explain details in English that is not my native language!.... please... a little effort would be very nice..... i know the majority use to read entirelly.

É um saquinho isso.... gente aterriza aqui sem ler e comenta besteiras como se não ouvesse lido.

"It is very boring those things....there are folks that lands here alike someone that jumped with parachute, and old style parachute never know were to fall exactly...so....by a destiny accident landed here...readed four posts..the last pages and goes talking wrong things that shows clearly have not readed or understood"

regards,

Carlos
 
balaboo said:
Mr.Burbeck;

I am aware that the JLLH is a "low-powered Class A" amplifier - perhaps you are not aware of the multitude of low-power valve amplifers that were the norm for guitar amplification...

You can not compare low power valve amps with low power SS amps. The valve amps are deliberately driven into clipping to create an effect with electric guitars. With a SS amp it is better to avoid clipping so you need a higher power amp.
 
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