Hi thank you fredlock .
The power of this amp is 10 Watts at 8ohm load.
And I don't have PCB layout . Because this is wireing by
single line of a diameter of 0.5mm .
(using Gold-plated OFC line + fluoric resin clothing for
electronics diy. appening the fig)
"openhearted" means like NO-NFB amp, or not suppressive ....
( Sorry for not expressible well....)
Sincerely
The power of this amp is 10 Watts at 8ohm load.
And I don't have PCB layout . Because this is wireing by
single line of a diameter of 0.5mm .
(using Gold-plated OFC line + fluoric resin clothing for
electronics diy. appening the fig)
"openhearted" means like NO-NFB amp, or not suppressive ....
( Sorry for not expressible well....)
Sincerely
Attachments
schema
http://www.diyaudio.com/forums/attachment.php?postid=1610510&stamp=1221496249
LME49710 is good!
LME49870 is better .. if you can find & buy.
Not so easy, I know.
http://www.diyaudio.com/forums/attachment.php?postid=1610510&stamp=1221496249
LME49710 is good!
LME49870 is better .. if you can find & buy.
Not so easy, I know.
HI Lineup,
There is Oxygene in Air in Japan ,too.
So I use Tin plating�@or Gold plating wire for audio .
And I useed OPamp for DC servo AD8620 , now change LME49860NA,
It's better too. Bi poler input (may be) ,but DC offset is not so large, 5mv and 8mv.
I think LME49860 is better than LM4562 . too.
So I agree (can understand) you say LME49870 is better than LME49710 .But near my city ,I can't buy.....
I guess it may be inner cascord circuit for high power supply??
Thank you!
Sincerely
There is Oxygene in Air in Japan ,too.
So I use Tin plating�@or Gold plating wire for audio .
And I useed OPamp for DC servo AD8620 , now change LME49860NA,
It's better too. Bi poler input (may be) ,but DC offset is not so large, 5mv and 8mv.
I think LME49860 is better than LM4562 . too.
So I agree (can understand) you say LME49870 is better than LME49710 .But near my city ,I can't buy.....
I guess it may be inner cascord circuit for high power supply??
Thank you!
Sincerely
Hello turnA_zpoint,
A question to you regarding your feedback (just so I can try to understand what you are doing):
Looking at the AD8620 opamp, it looks like the inverting terminal input is the combination of the scaled down output voltage, and the input voltage summed together.
It looks like the input to the noninverting terminal of the AD8620 is a combination of the integrated sum of the scaled output and input.
Am I correct so far?
I'm sorry if you explained this before, but can you explain the purpose of this kind of feedback (that uses both the input voltage and the output voltage) over a "normal" DC servo opamp feedback (that only uses the output voltage) to cancel out DC offset at the output?
Many thanks to you for posting your schematics!
A question to you regarding your feedback (just so I can try to understand what you are doing):
Looking at the AD8620 opamp, it looks like the inverting terminal input is the combination of the scaled down output voltage, and the input voltage summed together.
It looks like the input to the noninverting terminal of the AD8620 is a combination of the integrated sum of the scaled output and input.
Am I correct so far?
I'm sorry if you explained this before, but can you explain the purpose of this kind of feedback (that uses both the input voltage and the output voltage) over a "normal" DC servo opamp feedback (that only uses the output voltage) to cancel out DC offset at the output?
Many thanks to you for posting your schematics!
turnA_zpoint said:
Same for me. If I wanted to buy LME49870 or LME49860 (dual).
I can not. Can not find anyone in Sweden sell LME49870.
... not many in EUROPE!
About your circuit.
Your feedback arrangement is so complicated, I do not understand
But what would you say is the difference in result
- using your way to correct signal, using negative feedback
- using 'normal' global negative feedback
Is there any better quality in the resulting output that you want to have?
And what is this quality?
Harmonics dist spectrum? Level of intermodulation dist? Level of THD?
.... why use your complicated amplifier correction ....
.... instead of normal old fashion feedback ....
because for me
the normal FB is so much easier to implement
Lineup
regards
here you have one SEARCH for Part in STOCK
there are several hits
but not all those sellers REALLY have in stock LME49870
http://www.ic2ic.com/search.jsp?sSearchWord=LME49870
Most hits are from HongKong & China
there are several hits
but not all those sellers REALLY have in stock LME49870
http://www.ic2ic.com/search.jsp?sSearchWord=LME49870
Most hits are from HongKong & China
Digikey in Japan
looks like having 110 pieces In Stock of LME49870
http://jp.digikey.com/scripts/dksearch/dksus.dll?Detail?name=LME49870MA-ND
looks like having 110 pieces In Stock of LME49870
http://jp.digikey.com/scripts/dksearch/dksus.dll?Detail?name=LME49870MA-ND
Hello south-america.
What in this special circuit is so great, Carlos?
What are the benefits you can see?
I still haven't figured this out.
The man is a clever young man from Asia. Very clever!
But what in his circuit, would you say Charlie of Brazil,
is better than your Dx-Amp simple ordinary global negative feedback?
I am sure you can tell, Destroyer X.
As you say you have seen how great his schematic is
But if I am mistaken,
I will wait for turnA_zpoint to tell me & others not fully as clever.
Lineup clever audio circuits
.
What in this special circuit is so great, Carlos?
What are the benefits you can see?
I still haven't figured this out.
The man is a clever young man from Asia. Very clever!
But what in his circuit, would you say Charlie of Brazil,
is better than your Dx-Amp simple ordinary global negative feedback?
I am sure you can tell, Destroyer X.
As you say you have seen how great his schematic is
But if I am mistaken,
I will wait for turnA_zpoint to tell me & others not fully as clever.
Lineup clever audio circuits
.
Hello,
Same as lineup, I don't really get the point. Why use an opamp (boo) in the regular feedback loop? There is other ways to invert the signal. And then what is the purpose of the jfet follower between the opamp and the input pair if you use an opamp? Why not just attack this pair differently to get all the signals with the right polarity? The rest of the amp is quite classic so not much can be said.
Same as lineup, I don't really get the point. Why use an opamp (boo) in the regular feedback loop? There is other ways to invert the signal. And then what is the purpose of the jfet follower between the opamp and the input pair if you use an opamp? Why not just attack this pair differently to get all the signals with the right polarity? The rest of the amp is quite classic so not much can be said.
I am sorry folks... i would like to explain you advantages and disadvantages
But this circuit is too much complex to my understanding.
Will wait the nice Japanese, to teach us some.
You see how delayed we are..... only Janeman can understand how this works....maybe another one (you).... the entrance of this guy is a big benefit to us.
Some forum members, the ones has the "big knowledge", do not use to teach us things, they go discussing inside their own big brains group ... and, sometimes,...they left something scape from their own censorship.. and those things we can use.... i use those things to learn.... thanks some of them are vain and proud.... when nervous, trying to show themselves as "big brains"...then they talk too much, and let us colect some grains of wise.
I hope this guy is a nice teacher, and has the good will to teach us, to explain us the way this circuit operates, i can understand less then 40 percent, and even those things "understandable" by me, are really very clever.
Ask the man folks.... carefull not to challenge the guy.... assume the humble position and do not ask:
- "What this has in special?".... what seems someone knows everything, meaning the circuit is common, standard, old, already completely know, poor, cheap, ridiculous and you may be in another higher level of development... someone superior that had understood everything... when we both know we don't..... well.... at least i don't!
If you know.... go ahead... explain us!
regards,
Carlos
But this circuit is too much complex to my understanding.
Will wait the nice Japanese, to teach us some.
You see how delayed we are..... only Janeman can understand how this works....maybe another one (you).... the entrance of this guy is a big benefit to us.
Some forum members, the ones has the "big knowledge", do not use to teach us things, they go discussing inside their own big brains group ... and, sometimes,...they left something scape from their own censorship.. and those things we can use.... i use those things to learn.... thanks some of them are vain and proud.... when nervous, trying to show themselves as "big brains"...then they talk too much, and let us colect some grains of wise.
I hope this guy is a nice teacher, and has the good will to teach us, to explain us the way this circuit operates, i can understand less then 40 percent, and even those things "understandable" by me, are really very clever.
Ask the man folks.... carefull not to challenge the guy.... assume the humble position and do not ask:
- "What this has in special?".... what seems someone knows everything, meaning the circuit is common, standard, old, already completely know, poor, cheap, ridiculous and you may be in another higher level of development... someone superior that had understood everything... when we both know we don't..... well.... at least i don't!
If you know.... go ahead... explain us!
regards,
Carlos
Rtarbell
Lineup
Destroyer X
Darian
I'm sorry that the UPload is late.
(Time difference..)
Lineup ,Thank you for
"Digikey in Japan looks like having 110 pieces
In Stock of LME49870"
I made the material of the explanation.
Though it might be insufficient because
it hurried up.
If there are an uncertain point ,
Please point it out.
files are 4 parts ,so I wil 4times up
Regards
Lineup
Destroyer X
Darian
I'm sorry that the UPload is late.
(Time difference..)
Lineup ,Thank you for
"Digikey in Japan looks like having 110 pieces
In Stock of LME49870"
I made the material of the explanation.
Though it might be insufficient because
it hurried up.
If there are an uncertain point ,
Please point it out.
files are 4 parts ,so I wil 4times up
Regards
Ok, I get it now but is it worth this "double modulation" from the input from the specification point of view? I guess you get 6 dB more of open loop gain so it's theorically 6 dB less of distortion too. The downside is that you have to use an opamp in the signal path... And for the DC nulling it's a clever idea. Still I never had the idea to fight these 10 to 20mV remaining after a standard DC nulling. Congratulations on this original design.
Hi! Darian
Thank you very much! . I'm grad .
(1) "double modulation" is just you say ,I think.
I want to prepare at high frequency(10Khz) feedback gain ,
many even a little. I feel effect hearing piano .. only my feeling.
(2)By using this DC servo,
Frequency response becoomes flat to DC .
because only inner ofset is separated and can be feedbacked .
Need not use large electrolytic capacitors for LPF ,
So can use high quality CAP (like Poripropren CAP ).
this amp use 100nF (0.1uF) , but no pole lower frequency
and flat so DC signal.
Regards!
Thank you very much! . I'm grad .
(1) "double modulation" is just you say ,I think.
I want to prepare at high frequency(10Khz) feedback gain ,
many even a little. I feel effect hearing piano .. only my feeling.
(2)By using this DC servo,
Frequency response becoomes flat to DC .
because only inner ofset is separated and can be feedbacked .
Need not use large electrolytic capacitors for LPF ,
So can use high quality CAP (like Poripropren CAP ).
this amp use 100nF (0.1uF) , but no pole lower frequency
and flat so DC signal.
Regards!
Hello again,
I say "double modulation" because you get the signal to the input jfet pair by their gates AND their sources. Even if it's not too relevent I think you may take into consideration that the 2 signals have different propagation times. It's fine if you use a very fast opamp for the inverting buffer. Still why not buffer the other signal too since you have 3 opamp units in your design and 4 would be easy to implement. It's more for intellectual matter but I feel like 2 NFB loops from the same point with different propagation times are maybe not optimal. I could be wrong. Regarding the DC feedback, I'm not sure I fully understand your theory and how you get a lower pole or something. Anyway, I looked at your website and some solidstate designs are very interesting. Are they all from you or some from japanese magazines or someone else? The traduction engine doesn't do a good job on japanese pages and that's too bad! I would like to fully appreciate it!
I say "double modulation" because you get the signal to the input jfet pair by their gates AND their sources. Even if it's not too relevent I think you may take into consideration that the 2 signals have different propagation times. It's fine if you use a very fast opamp for the inverting buffer. Still why not buffer the other signal too since you have 3 opamp units in your design and 4 would be easy to implement. It's more for intellectual matter but I feel like 2 NFB loops from the same point with different propagation times are maybe not optimal. I could be wrong. Regarding the DC feedback, I'm not sure I fully understand your theory and how you get a lower pole or something. Anyway, I looked at your website and some solidstate designs are very interesting. Are they all from you or some from japanese magazines or someone else? The traduction engine doesn't do a good job on japanese pages and that's too bad! I would like to fully appreciate it!
Hi Darian ,
I now understand ,you said.
At early step to design ,I thought it may oscillate .
So tested some phase compensation .
(Mainly down near the oscillating frequency gain enough)
But at last need not them under this condition.
About "the 2 signals have different propagation times",
the OPAMP and souce input is from same one point..
It is OPAMP and FETsource inputed same signal.
But the current feedback and the voltage feedback are different propagation times (just you say 2 NFB loops).
About this, I think, the "double modulation" is possible to think
only source follower with opamp, that input is from source.
Then one is error signal,another is able to think turbulence.
The source follower is low impedance (so this is current feedback),
OPAMP input is hi impedace ,then the influence doesn't go out easily mutually. (sorry not enough explane)
4th OPAMP ,I did not think about!
(But I have made an effort to keep simple as much as possible...)
About "lower pole or something" ,the audio signal is canceled,
then ,because it is 0 even if 0 is integrated,to put it briefly....
About "Are they all from you or some from japanese magazines or someone else?",
It is basically original. However, this DC servo etc. understand there is a person who previously hit on.
A contents made before though it was a poor English translation was up-loaded again. However, though the content becomes the previous one a little.
(Because there is a lot of capacity, it deletes once )
http://www2.plala.or.jp/puthoff/amp_HTML_ENG/
REGARDS
I now understand ,you said.
At early step to design ,I thought it may oscillate .
So tested some phase compensation .
(Mainly down near the oscillating frequency gain enough)
But at last need not them under this condition.
About "the 2 signals have different propagation times",
the OPAMP and souce input is from same one point..
It is OPAMP and FETsource inputed same signal.
But the current feedback and the voltage feedback are different propagation times (just you say 2 NFB loops).
About this, I think, the "double modulation" is possible to think
only source follower with opamp, that input is from source.
Then one is error signal,another is able to think turbulence.
The source follower is low impedance (so this is current feedback),
OPAMP input is hi impedace ,then the influence doesn't go out easily mutually. (sorry not enough explane)
4th OPAMP ,I did not think about!
(But I have made an effort to keep simple as much as possible...)
About "lower pole or something" ,the audio signal is canceled,
then ,because it is 0 even if 0 is integrated,to put it briefly....
About "Are they all from you or some from japanese magazines or someone else?",
It is basically original. However, this DC servo etc. understand there is a person who previously hit on.
A contents made before though it was a poor English translation was up-loaded again. However, though the content becomes the previous one a little.
(Because there is a lot of capacity, it deletes once )
http://www2.plala.or.jp/puthoff/amp_HTML_ENG/
REGARDS
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