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A S Goh
 
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Hi

Which opamp is good for Marantz 63KI CDP

Opa2604 seems harsh to me

A S Goh


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Arny Krueger
 
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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.


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GregS
 
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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
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Arny Krueger
 
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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.


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Denis Sbragion
 
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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
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Arny Krueger
 
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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!


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Arny Krueger
 
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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   Report Post  
Peter Larsen
 
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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   Report Post  
A S Goh
 
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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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