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#1
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opamp
Hi
Which opamp is good for Marantz 63KI CDP Opa2604 seems harsh to me A S Goh |
#2
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"A S Goh" wrote in message
Hi Which opamp is good for Marantz 63KI CDP Opa2604 seems harsh to me Learn how to do DBTs and have your years opened. |
#3
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In article , "Arny Krueger" wrote:
"A S Goh" wrote in message Hi Which opamp is good for Marantz 63KI CDP Opa2604 seems harsh to me Learn how to do DBTs and have your years opened. I would imagine there are very few that could set up, or want to set up a DBT, to listen to their components under their conditions. DBT is not a factor. greg |
#4
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"GregS" wrote in message
In article , "Arny Krueger" wrote: "A S Goh" wrote in message Hi Which opamp is good for Marantz 63KI CDP Opa2604 seems harsh to me Learn how to do DBTs and have your years opened. I would imagine there are very few that could set up, or want to set up a DBT, to listen to their components under their conditions. DBT is not a factor. Unbiased is. Some years ago we set up a series of TL074 op amp circuits in cascade, to see how many stages it took to obtain positive results in an unbiased listening test. We quit at 20, I think it was. we took it to the AES and let anybody who wanted to, to try the same test. Same results. |
#6
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"Denis Sbragion" wrote in message
6.1 Hello Arny, "Arny Krueger" wrote in news:-LSdnRS3_vWJso7eRVn- : ... Some years ago we set up a series of TL074 op amp circuits in cascade, to see how many stages it took to obtain positive results in an unbiased listening test. We quit at 20, I think it was. we took it to the AES and let anybody who wanted to, to try the same test. Same results. used as buffers, i.e. with 0 dB gain? No my recollection is, gain of about 10 dB with complementary dividers in-between. |
#7
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Hello Arny,
"Arny Krueger" wrote in : No my recollection is, gain of about 10 dB with complementary dividers in-between. thanks, this makes the result even more interesting. Bye, -- Denis Sbragion InfoTecna Tel: +39 0362 805396, Fax: +39 0362 805404 URL: http://www.infotecna.it |
#8
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"Denis Sbragion" wrote in message
6.1 Hello Arny, "Arny Krueger" wrote in : No my recollection is, gain of about 10 dB with complementary dividers in-between. thanks, this makes the result even more interesting. Try it yourself! |
#9
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Hello Arny,
"Arny Krueger" wrote in news:Q5idnd6bfYejoIneRVn- : Try it yourself! no need, I trust your results. It wasn't an ironic comment, when I sat that the result is interesting I meant exactly that. No more worries about using many op-amps in series, even when they are not the best available, like the TL-074, let alone when better op-amps are used. I think there should be a database of such tests. They provide precious informations, often buried within a lot of unrelated informations all around Internet. Bye, -- Denis Sbragion InfoTecna Tel: +39 0362 805396, Fax: +39 0362 805404 URL: http://www.infotecna.it |
#10
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"Denis Sbragion" wrote in message
6.1 Hello Arny, "Arny Krueger" wrote in news:Q5idnd6bfYejoIneRVn- : Try it yourself! no need, I trust your results. Thank you. Most of the work was done by some friends of mine - David Clark and David Carlstrom. It wasn't an ironic comment, when I sat that the result is interesting I meant exactly that. No more worries about using many op-amps in series, even when they are not the best available, like the TL-074, let alone when better op-amps are used. In the "listen for yourself territory" here are some worked-out examples: http://www.pcabx.com/product/index.htm Note, some of these products fall flat on their face in the first iteration, others in 5, others not even in 20. I think there should be a database of such tests. They provide precious informations, often buried within a lot of unrelated informations all around Internet. It turns out that the modern audio world has a goodly number of examples of sonic transparency or something really pretty close. A representative or inclusive list could be a lot of work. |
#11
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A S Goh wrote:
Which opamp is good for Marantz 63KI CDP I had the great learning experience of being on an opamp listening panel some time ago. A CD was made with excerpts of recordings that had passed through some of the possible ways of combining several opamp stages in it and sent to each participant, who then listened blind and submitted a written evaluation. The opamp deployment in the contraption in question was changed in accordance with the panels preference. Interestingly the chosen setup differed from what people would have chosen in advance based on each their experience with the tested opamps. I was informed what was what because some of the tested opamps came from my modding component drawer. To my surprise I had rated what used to be my pet hate prior to that experience second on some of the examples rather than last, as I had expected I would. It was a very good learning experience. Opa2604 seems harsh to me It would appear that it is then not well suited for the actual application. It has a very high input impedance - so I am told - and that generally makes it well chosen as the first external opamp seen by the DA converter. I am however not an electronics wiz-kid, so do check this with someone who knows more than I do. My subjective impression is that it has the same kind of treble shine the Ultimo DV 38/20A had, ie. that it may come across as overbright, but not harsh. Is it oscillating? There are a gazillion other things to look into prior to replacing opamps in quality products and one should carefully consider whether the possible improvement by modding something outweighs the risk of breaking it in the process. Not all "atypical" opamps are just dumped into a PCB for cost cutting reasons, they may have specific properties that are vital for the total circuit. It is strongly recommended to actually understand the PCB prior to modding it. You are probably well aware of this, but other people reading this may not so be. A S Goh Kind regards Peter Larsen -- ******************************************* * My site is at: http://www.muyiovatki.dk * ******************************************* |
#12
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Hi Peter Larsen
Thank you for your detailed explanation Yes, opa 2604 sounds bright. I should not say harsh. There is no oscillation. I have since put in OPA 2132 and found that there is some improvements. The treble is lighter and transparent It costs twice as opa 2604 Any other ways which you I can improve on this CD63KI A S Goh "Peter Larsen" wrote in message ... A S Goh wrote: Which opamp is good for Marantz 63KI CDP I had the great learning experience of being on an opamp listening panel some time ago. A CD was made with excerpts of recordings that had passed through some of the possible ways of combining several opamp stages in it and sent to each participant, who then listened blind and submitted a written evaluation. The opamp deployment in the contraption in question was changed in accordance with the panels preference. Interestingly the chosen setup differed from what people would have chosen in advance based on each their experience with the tested opamps. I was informed what was what because some of the tested opamps came from my modding component drawer. To my surprise I had rated what used to be my pet hate prior to that experience second on some of the examples rather than last, as I had expected I would. It was a very good learning experience. Opa2604 seems harsh to me It would appear that it is then not well suited for the actual application. It has a very high input impedance - so I am told - and that generally makes it well chosen as the first external opamp seen by the DA converter. I am however not an electronics wiz-kid, so do check this with someone who knows more than I do. My subjective impression is that it has the same kind of treble shine the Ultimo DV 38/20A had, ie. that it may come across as overbright, but not harsh. Is it oscillating? There are a gazillion other things to look into prior to replacing opamps in quality products and one should carefully consider whether the possible improvement by modding something outweighs the risk of breaking it in the process. Not all "atypical" opamps are just dumped into a PCB for cost cutting reasons, they may have specific properties that are vital for the total circuit. It is strongly recommended to actually understand the PCB prior to modding it. You are probably well aware of this, but other people reading this may not so be. A S Goh Kind regards Peter Larsen -- ******************************************* * My site is at: http://www.muyiovatki.dk * ******************************************* |
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