I noticed this too, at a closer look. The question is, how much would a slightly varying noise gain from parasitic cap effects disturb the results? From the photos it is not clear also if all DUT's used the identical same cap for the measurements. If so, at least the DUT's had idential conditions.scott wurcer said:This explains a call I got the other day. Did anyone notice the unbiased and unbypassed 6800uF caps in the test circuits?
Still it is a great effort and an enthusiasm to applaud to...
- Klaus
In this type of investigation any personal comments on "how they sound" are not to be expected. Also we already know it:QSerraTico_Tico said:I sorely miss the correlation between measurements results and sound quality....
AD797, top performer, some like it, some don't.
OPA604, poor performer in this test, some like it, some don't.
Pick you choice!
- Klaus
I would be very happy if someone can inform if result in an advantage to use
those op amps into power amplifier input, say, substituting differential amplifier and maybe VAS too (not when using as error correction).
I am perceiving this as a new approach (not so need) into the most expensive and sophisticated audiophile grade amplifiers... this seems to me has advantages to use them.... well.... i think discrete may be even better, but maybe mine ignorance..for sure... as i do not know them (have not the experience building with them) and i cannot conclude nothing.
Really, i am not a data addicted...no patience enougth to read 222 pages of datasheet.... if you have some conclusion..... some audibility tests made (not charts), or some opinions about, i will be happy to listen your thougths about.
http://www.sg-acoustics.ch/analogue_audio/ic_opamps/pdf/opamp_distortion.pdf
Tem que ter muita paciência Tico tico, pra lêr tôda essa coisa...haja Seiko pra isso!...podes me dar um "diagnóstico"... tipo....isso soa bem....ou tipo "outra conversa fiada" pra vender pra boboca.
We need to find a lot of time and patience to read all this thing.... too much patience!... can you give me some "diagnosis"... some final result of audibility testing.... audio is to listen, not to read papers with graphics..they sound nothing.... can you tell me "this sound fine"...or "another bill shot to make you spend money and destroy your hopes for perfection"
I continue to believe, and this seems to me very logic, that simple is better..the most simple solutions will be always better in sonics (Nelson Pass, JLH and others prove that).... we can have, of course, a lot of surrounding auxiliary circuits, CCS, sinks, mirrors and all that stuff, to help..but inside audio chain, the most simple is much better when listening... i am watching, perceiving and testing this stuff during last 48 years..no doubts about that.... those op amps are complicated...some of them have an entire amplifier circuit, with differential, sophisticated Vas and drivers and output and a lot of "inside audio chain" circuits...in my belief "this cannot sound good!" when you can just use a single differential and a single transistor VAS..less parts distorting and producing errors, phase errors, intermodulation errors is better than a lot of circuits disturbing.
Please..someone... tell me i am wrong... this gonna be great... i will try to buy all them and test all them to check and will be happy using something better than my simple beloved discrete circuits.
How they measure says nothing to me... absolutelly nothing.... i am human and not a computer to be analising graphics...to me, a human beeing, what really interests are "how they sound".... the rest may be number competition between factory, things not interesting to us, audiophiles, humans that loves to build and to listen good music with good amplifiers, good speakers.... graphics?... nice to put into a frame or into an office... to sell products maybe, to compete between them.. non usefull to humans that loves music.
regards,
Carlos
those op amps into power amplifier input, say, substituting differential amplifier and maybe VAS too (not when using as error correction).
I am perceiving this as a new approach (not so need) into the most expensive and sophisticated audiophile grade amplifiers... this seems to me has advantages to use them.... well.... i think discrete may be even better, but maybe mine ignorance..for sure... as i do not know them (have not the experience building with them) and i cannot conclude nothing.
Really, i am not a data addicted...no patience enougth to read 222 pages of datasheet.... if you have some conclusion..... some audibility tests made (not charts), or some opinions about, i will be happy to listen your thougths about.
http://www.sg-acoustics.ch/analogue_audio/ic_opamps/pdf/opamp_distortion.pdf
Tem que ter muita paciência Tico tico, pra lêr tôda essa coisa...haja Seiko pra isso!...podes me dar um "diagnóstico"... tipo....isso soa bem....ou tipo "outra conversa fiada" pra vender pra boboca.
We need to find a lot of time and patience to read all this thing.... too much patience!... can you give me some "diagnosis"... some final result of audibility testing.... audio is to listen, not to read papers with graphics..they sound nothing.... can you tell me "this sound fine"...or "another bill shot to make you spend money and destroy your hopes for perfection"
I continue to believe, and this seems to me very logic, that simple is better..the most simple solutions will be always better in sonics (Nelson Pass, JLH and others prove that).... we can have, of course, a lot of surrounding auxiliary circuits, CCS, sinks, mirrors and all that stuff, to help..but inside audio chain, the most simple is much better when listening... i am watching, perceiving and testing this stuff during last 48 years..no doubts about that.... those op amps are complicated...some of them have an entire amplifier circuit, with differential, sophisticated Vas and drivers and output and a lot of "inside audio chain" circuits...in my belief "this cannot sound good!" when you can just use a single differential and a single transistor VAS..less parts distorting and producing errors, phase errors, intermodulation errors is better than a lot of circuits disturbing.
Please..someone... tell me i am wrong... this gonna be great... i will try to buy all them and test all them to check and will be happy using something better than my simple beloved discrete circuits.
How they measure says nothing to me... absolutelly nothing.... i am human and not a computer to be analising graphics...to me, a human beeing, what really interests are "how they sound".... the rest may be number competition between factory, things not interesting to us, audiophiles, humans that loves to build and to listen good music with good amplifiers, good speakers.... graphics?... nice to put into a frame or into an office... to sell products maybe, to compete between them.. non usefull to humans that loves music.
regards,
Carlos
These measurements mean a lot to me. In fact, I learned plenty already from this paper. Is it EVERYTHING that I need to know? NO. But it is useful and helpful in evaluating IC op amps. I am now releasing an all IC op amp phono stage. It is important to know subtle things about each IC, (like non-linear input stage impedance) leading to distortion.
Do they sound better than discrete Mr. John Curl?
Thanks in advance to loose some time to answer me.
For sure this data serves to select the better one to use.
I have an advanced question before select them to use... are they better than discrete equivalent simplified circuit when listened by normal, common humans?.... this is in advance to go selecting them to use watching data sheet.
Some numbers are helpfull, alike to select a wife because so tall as we are, to produce tall sons maybe...or at least not so different than your family.... good selection...but this is just one thing..marriage has thousands of factors to allow us to make a good decision... those numbers, data sheet, are alike to select wife because 6 feet high alike me...but the other more important subjects we cannot know about her... also about sonics...only distortions and measurements can't tell us the whole story.... there are some low distortion amplifiers that sounds terrible...and also there are some distorted samples really interesting.
Electronic Tubes (Valvulas) sounds great and do not measure fine.
Your answer is very important as you are a very respectable man into our communitty.... if you say they can sound better, that you have experienced that, even ONCE...i will start to use them, to search for the better one.
I have a good friend, Rabbitz, that already told me they can be good as pré amplifier to LM4780... this is something to try and explore..so.. i will assemble and test some OPA with this chip amplifier.
Of course first reason to be married is the passion, the illusion of love... this feeling is important too...to love those chips...to feel them interesting...so...there are other factors, some human feelings into the equation.... the "belief" is one of them.
I have a friend with the most ugly woman you can watch in this world...the woman is worse than a dragon drunk that has crashed against a mountain... he "belief" she is wonderfull and intelligent... when nor one nor other..but he is HAPPY with that belief.... this is crazy...but we are humans and we have human perception too... some folks perceive loud and distorted as good sound.
It is hard to ask people things alike i am asking...people has not courage to answer and have not competence (skilled enougth, know how enougth, live expertise enougth...experience enougth)..... reason why, i am directly asking John Curl directly.
I hope you are not "connected" having good friends into chip amplifier factories or something political problem to tell me things frankly..... please... will keep secret and write to me your evaluation directly if needed... secrecy guaranteed.... and post the political scape here.
panzertoo@yahoo.com
regards,
Carlos
Thanks in advance to loose some time to answer me.
For sure this data serves to select the better one to use.
I have an advanced question before select them to use... are they better than discrete equivalent simplified circuit when listened by normal, common humans?.... this is in advance to go selecting them to use watching data sheet.
Some numbers are helpfull, alike to select a wife because so tall as we are, to produce tall sons maybe...or at least not so different than your family.... good selection...but this is just one thing..marriage has thousands of factors to allow us to make a good decision... those numbers, data sheet, are alike to select wife because 6 feet high alike me...but the other more important subjects we cannot know about her... also about sonics...only distortions and measurements can't tell us the whole story.... there are some low distortion amplifiers that sounds terrible...and also there are some distorted samples really interesting.
Electronic Tubes (Valvulas) sounds great and do not measure fine.
Your answer is very important as you are a very respectable man into our communitty.... if you say they can sound better, that you have experienced that, even ONCE...i will start to use them, to search for the better one.
I have a good friend, Rabbitz, that already told me they can be good as pré amplifier to LM4780... this is something to try and explore..so.. i will assemble and test some OPA with this chip amplifier.
Of course first reason to be married is the passion, the illusion of love... this feeling is important too...to love those chips...to feel them interesting...so...there are other factors, some human feelings into the equation.... the "belief" is one of them.
I have a friend with the most ugly woman you can watch in this world...the woman is worse than a dragon drunk that has crashed against a mountain... he "belief" she is wonderfull and intelligent... when nor one nor other..but he is HAPPY with that belief.... this is crazy...but we are humans and we have human perception too... some folks perceive loud and distorted as good sound.
It is hard to ask people things alike i am asking...people has not courage to answer and have not competence (skilled enougth, know how enougth, live expertise enougth...experience enougth)..... reason why, i am directly asking John Curl directly.
I hope you are not "connected" having good friends into chip amplifier factories or something political problem to tell me things frankly..... please... will keep secret and write to me your evaluation directly if needed... secrecy guaranteed.... and post the political scape here.
panzertoo@yahoo.com
regards,
Carlos
Attachments
i think the measurements help provide feedback on the quality of the design/designer: for example, were 2nd, 3rd, etc. order effects considered and addressed, etc.
this data can help weed out parts that may not be worth your time to consider for a particular application or point you towards parts that you may want to focus your attention on.
this data can help weed out parts that may not be worth your time to consider for a particular application or point you towards parts that you may want to focus your attention on.
QSerraTico_Tico said:Then may I ask what is the use of these measurements for audiophiles?
Not bad Scott, but I do see some higher order, and I still want to offset output bias with a fet in order to reduce it. What is it with this high impedance drive distortion? I have to look at that more closely. I have been comparing the 797 with the 1115 and you are winning so far, except for price.
What really gets me down is when a low noise op amp can't drive a reasonable value feedback resistor without a lot of extra distortion.
Also, Scott, you should check out the low noise instrument thread and give them some help. Just look at the input stage and you will understand. I think that the feedback should come from the IC designer, for best effect.
What really gets me down is when a low noise op amp can't drive a reasonable value feedback resistor without a lot of extra distortion.
Also, Scott, you should check out the low noise instrument thread and give them some help. Just look at the input stage and you will understand. I think that the feedback should come from the IC designer, for best effect.
"Releasing an all IC phono stage"
This answers everything.
Political commitments require some care about comments posted into free, open International forum, in special when people is famous and must be carefull when open the mouth to comment about those things... providing evaluations and diagnosis.
To me it seems that these things, the use Ics instead of discrete, are just fashion generated by the pressure of the technological moment, the use of modern things, or what is more appropriate and politically correct, in obedience to the groups that generate opinions ... then, I think, in the case, possibly some solutions are adapted to market needs .... then, very probably, is whether what is needed, not what is objectively and subjectively the best solution ... but what is more easily accepted as good or better.
The silence, in some cases, is eloquent
Thank you not to answer directly or using mail Mr. John Curl, as gave me a lot of informations... silence seems a lot to me.... in special that has a lot of respect on me.
thanks,
I will continue with my beliefs.
Carlos
This answers everything.
Political commitments require some care about comments posted into free, open International forum, in special when people is famous and must be carefull when open the mouth to comment about those things... providing evaluations and diagnosis.
To me it seems that these things, the use Ics instead of discrete, are just fashion generated by the pressure of the technological moment, the use of modern things, or what is more appropriate and politically correct, in obedience to the groups that generate opinions ... then, I think, in the case, possibly some solutions are adapted to market needs .... then, very probably, is whether what is needed, not what is objectively and subjectively the best solution ... but what is more easily accepted as good or better.
The silence, in some cases, is eloquent
Thank you not to answer directly or using mail Mr. John Curl, as gave me a lot of informations... silence seems a lot to me.... in special that has a lot of respect on me.
thanks,
I will continue with my beliefs.
Carlos
I'm in love with the Ugliest Girl in the World
Originally posted by destroyer X:
I have a friend with the most ugly woman you can watch in this world...the woman is worse than a dragon drunk that has crashed against a mountain... he "belief" she is wonderfull and intelligent... when nor one nor other..but he is HAPPY with that belief.... this is crazy...but we are humans and we have human perception too...
This is a wellknown fact.
You often see the most 'beautiful' woman (on the outside)
having some real unpleasant, short and fat, old and ugly man.
And be quite happy with this 'animal' at her side ....
Lineup
This following is one clever polemic & protest song, to
The Cult of being YOUNG & BEAUTIFUL .. at any price (even facelifts!)
Originally posted by Bob Dylan 1987 in an album I have in my collection:
also, do not forget the old halojoy topic
an intelligent twist using same message ....
UGLY Looking Amp! - but good working
Originally posted by destroyer X:
I have a friend with the most ugly woman you can watch in this world...the woman is worse than a dragon drunk that has crashed against a mountain... he "belief" she is wonderfull and intelligent... when nor one nor other..but he is HAPPY with that belief.... this is crazy...but we are humans and we have human perception too...
This is a wellknown fact.
You often see the most 'beautiful' woman (on the outside)
having some real unpleasant, short and fat, old and ugly man.
And be quite happy with this 'animal' at her side ....
Lineup
This following is one clever polemic & protest song, to
The Cult of being YOUNG & BEAUTIFUL .. at any price (even facelifts!)
Originally posted by Bob Dylan 1987 in an album I have in my collection:
BobDylan.com - Ugliest Girl
also, do not forget the old halojoy topic
an intelligent twist using same message ....
UGLY Looking Amp! - but good working
halojoy, February 2003:
Of natural causes, it is only the most "beautiful amps"
that get pictures posted. They are running the SHOW.
But surely they are only "the tip of an iceberg".
95% of All Good Great Sounding DIY-amps are REALLY Ugly.
Carlos, you have no right to commit me to an opinion about IC's vs discrete. I design with both, and discrete is almost always better. It is also more complicated and expensive. I first started testing linear IC's 42 years ago, and I have devices from that time and many hundred types in my lab as samples or for production. This 'op amp shoot-out' helps me by saving me the time and effort to make similar measurements, myself. Virtually ALL the op amps that I am now using for audio are listed in this paper.
Actually tubes would most probably have lower input resistance distortion that is in many IC's, but I don't have enough room for tubes with this design.
Actually tubes would most probably have lower input resistance distortion that is in many IC's, but I don't have enough room for tubes with this design.
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