tlf9999 said:
The CD format had a very clear main target, and that was assumed by Philips: to provide the classical music lovers a format that allowed them to listen to their music without noise.
Some may not remember, didn't follow it, don't now or are just too youg. Maybe it's your case, [whatever]999999999999...
It was obvious that Philips wanted to and would primarily satisfy this audience.
Philips stressed to point this out, and on the first couple of years there was only one music genre on CD: classical.
Those were the first clients of CDPs and discs.
Some immediately sold their entire vinyl collection.
And some sadly found out later that a real musical experience has no direct relation to... SNR.
Yeah... I have 4 different versions of Aksa Amplifier with PCB design :S ... And the complete version!
And The board design, the secrets, the number of the transistors, all! All of Aksa!
The frist schematic who Carlos put in where have 4 problems to the complet schematic!
I can't speak more... Sorry...
And The board design, the secrets, the number of the transistors, all! All of Aksa!
The frist schematic who Carlos put in where have 4 problems to the complet schematic!
I can't speak more... Sorry...
From the viewpoint of a guy who likes to read the threads on
this forum and mainly tries to learn something technical about
amplifiers and other stuff, I've been pretty annoyed lately with
the wandering going on in all the threads.
For example, if this thread is about the AKSA amplifier and all
the technical considerations close to it (not to speak about
Mr. Dean's desire to show averybody his schematic) all of a sudden
the postings derivate to the history of CD ( and all its vague
nuances), the negativism of certain opinions and other more
than ridiculous assertions that soon or later make me sleep
without even the effort to fight that state of mind.
Com'on guys there are other threads in this excelent forum to
express our opinions, why conspurcate the threads with stuff
that is merely irrelevant to the particular subject?
There was a time (not too long ago) I told somebody that
I would quit to spend time in this forum because it was getting annoying, people were wandering all the time, being vague
about this or that and most of all not contributing anything
positive to the subject.
I think this only makes the forum to go down the hill and
nothing is gained by its members.
I came back reading the forum (almost all the subjects) because
this is like a desease, you can't live without it once you got the
vice. I like it, but at the same time I find it boresome very often just because of these facts.
So, let's get direct to the subjects, do some contribuition to the
specific thread and do not wander with surperfluous comments.
Oops! I think I'm invading the role of the moderator!
But it's my opinion though and I bet some people will desagree with it. But that's life, what the heck!
this forum and mainly tries to learn something technical about
amplifiers and other stuff, I've been pretty annoyed lately with
the wandering going on in all the threads.
For example, if this thread is about the AKSA amplifier and all
the technical considerations close to it (not to speak about
Mr. Dean's desire to show averybody his schematic) all of a sudden
the postings derivate to the history of CD ( and all its vague
nuances), the negativism of certain opinions and other more
than ridiculous assertions that soon or later make me sleep
without even the effort to fight that state of mind.
Com'on guys there are other threads in this excelent forum to
express our opinions, why conspurcate the threads with stuff
that is merely irrelevant to the particular subject?
There was a time (not too long ago) I told somebody that
I would quit to spend time in this forum because it was getting annoying, people were wandering all the time, being vague
about this or that and most of all not contributing anything
positive to the subject.
I think this only makes the forum to go down the hill and
nothing is gained by its members.
I came back reading the forum (almost all the subjects) because
this is like a desease, you can't live without it once you got the
vice. I like it, but at the same time I find it boresome very often just because of these facts.
So, let's get direct to the subjects, do some contribuition to the
specific thread and do not wander with surperfluous comments.
Oops! I think I'm invading the role of the moderator!
But it's my opinion though and I bet some people will desagree with it. But that's life, what the heck!
Dear Mod_Evil,
Increasing the value of Miller cap will improve stabilty (and decrease high freq response of the whole amp). If you decrease the value, the stabilty will become worser (but the high freq response will be better).
Regards,
P.S.: 47pF is a good compromise. If the CB-capacity of the VAS transistor is high, you can go lower with the value. If the amp oscillating, you need to use higher value. But don't go higher then 100pF.
Increasing the value of Miller cap will improve stabilty (and decrease high freq response of the whole amp). If you decrease the value, the stabilty will become worser (but the high freq response will be better).
Regards,
P.S.: 47pF is a good compromise. If the CB-capacity of the VAS transistor is high, you can go lower with the value. If the amp oscillating, you need to use higher value. But don't go higher then 100pF.
Hi,
that's the second time I have tried to access a schematic on IMAGESHACK. It does not show any detail (unreadable) and the "click on" does not work.
Mod Evil if the amp is better with a smaller Miller comp cap then the amp was over compensated in the first place, bad design or playing safe with a wide spread of component tolerances. Both indicators of poor quality.
Putting in a smaller Miller comp cap will decrease HF stability but also increase the feedback in the global regime which in turn will reduce the hi frequency distortion of the output stage. This could be the effect you are hearing. But this solution will only apply to an amp that is already over compensated. There is another mechanism that I am aware of that may make the amp sound better;- the smaller cap in the VAS stage will put less load on the previous stage (LTP?) and the easier loading may make the earlier stage perform better.
that's the second time I have tried to access a schematic on IMAGESHACK. It does not show any detail (unreadable) and the "click on" does not work.
Mod Evil if the amp is better with a smaller Miller comp cap then the amp was over compensated in the first place, bad design or playing safe with a wide spread of component tolerances. Both indicators of poor quality.
Putting in a smaller Miller comp cap will decrease HF stability but also increase the feedback in the global regime which in turn will reduce the hi frequency distortion of the output stage. This could be the effect you are hearing. But this solution will only apply to an amp that is already over compensated. There is another mechanism that I am aware of that may make the amp sound better;- the smaller cap in the VAS stage will put less load on the previous stage (LTP?) and the easier loading may make the earlier stage perform better.
My AKSA amplifier mod
http://www.kuprevicius.kaunas.lm.lt/AKSA_FINAL.jpg
It looks good in simulation (SWCAD). But how it works in real life I don't know. Now I' m making PCB for this mod. So if there are some big mistakes (amp will sound terrible or it will blow at first test )
Please, help me to correct them.
Thanks in advance.
http://www.kuprevicius.kaunas.lm.lt/AKSA_FINAL.jpg
It looks good in simulation (SWCAD). But how it works in real life I don't know.
Now I' m making PCB for this mod. So if there are some big mistakes (amp will sound terrible or it will blow at first test )Please, help me to correct them
.Thanks in advance.
I 've posted AKSA amplifier mod.
PMA,
I think you expected something different, on that image.
Here are some more different versions of mod:
http://www.kuprevicius.kaunas.lm.lt/AKSA_FINAL.jpg
http://www.kuprevicius.kaunas.lm.lt/AKSA_FINAL1.jpg
http://www.kuprevicius.kaunas.lm.lt/AKSA_FINAL2.jpg
which one is worth to try?
PMA,
I think you expected something different, on that image
.Here are some more different versions of mod:
http://www.kuprevicius.kaunas.lm.lt/AKSA_FINAL.jpg
http://www.kuprevicius.kaunas.lm.lt/AKSA_FINAL1.jpg
http://www.kuprevicius.kaunas.lm.lt/AKSA_FINAL2.jpg
which one is worth to try?
I've attached a conceptual schematic of the AKSA. Some details are missing, of course, but all detail is revealed in the kit documentation. I choose not to reveal all in a public domain; my IP, my prerogative.
I would prefer not to discuss the details of this ad insanem; this is a very simple circuit, the sound is all in the details.
Cheers,
Hugh
I would prefer not to discuss the details of this ad insanem; this is a very simple circuit, the sound is all in the details.
Cheers,
Hugh
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