Ban wrote:
jimi wrote:
Hello,

I have Marantz CD6000 (not KI not OSE) and PM7000 amplifier. I'm
wondering about replacing NJE2114 in CD.

I found infos that LcAudio changed AD825 to AD8066 in theirs upgrades.

http://www.lcaudio.dk/ad8065.htm

I think about OPA2604, AD8620, OPA627, OPA2134,AD8066 in CD6000. 2604
and the others is popular and well-known opamp in parameters,
amplications, sound, disadvantage and advantage. But what about new
AD8066. What is 8066 in application and sound; in bas,mid, high; have
it some emphasizes or some minuses ? Which is the best op-amp to
upgrade to achieve natural, warm sound, no emphasize in middle and
treble, no pain, no fatigue tone ? Have you ever some experiences
with changing op-amps in CD player ?



Thank you very much for all answers and suggestions

Best Regards

jimi

Hi Jimi,
I couldn't find the NJE2114 data, but the AD8065 doesn't seem a very good
replacement for high-end Audio.
It is a high frequency fet opamp and probably good for ultrasound
applications. But the very high noise corner at around 7kHz raises the noise
from 7nV/sqrtHz to 35nV at 100Hz and even 120nV at 10Hz.

It appears that the spec'd 7nV/rt-Hz noise floor starts at 20KHz! Below
that the noise goes much higher, not much good for audio.

Even an old NE5534
or OP27 have the noise corner below 10Hz and have there only 6nV/sqrtHz. If
we interpret these diagrams rightly we can assume that very low frequency
popcorn noise is at least 20 times higher in the AD8065. Another problem
might arise from layout, because these high freq amps are prone to
oscillations and overshoot especially in those pin headers. If you want to
upgrade, take an OP27 and solder it directly on the PCB. First of all know
what you are doing, don't waste your money for these overpriced modules.

Secondly the maximum supply voltage is only +/-12V, whereas the NE5534 has
+/-18V or even +/-22V maximum. So in some circuits they will let out smoke.
:-(

That page is made by idiots, who have no idea about engineering and just
cite some meaningless numbers from datasheets. I do not speak the language,
but I know German, French , Italian, Latin and Portuguese, so I could mostly
understand what was written.

In general, most modders have no idea about electrical engineering.
Anyone who does not have the proper equipment (like spectrum analyzers
and distortion analyzers) or expertise and thinks he can outdo the
original designers by replacing parts (active and passive) in CD players
or other electronics is dreaming. Why buy the original product if you
think the design is not good enough?


ciao Ban
Bordighera, Italy