Usual problem"Op Amps"

[aleksandar]

Hi To All.......

Ive just upgraded the opm amps into Marantz Pm 7000 and i know some burn in time need to pass in order that the new op ams start to work as they should.....
ive chaneged all the op amps inside the amplifier with OP275. The standard Op's where NJM2114D for the preamplfier, and 3 NJM 2068D and one is for the balance,other for hte tone controls"bass&treble" and the third one i supose is for the headphones or source direct but am not sure which function does it make.

The FIrst and main problem that i have is it good to change the NJM2068D with OP275 also ive seen the specification for both and OP275 i better. Or i should put some other OP amp for the function that NJM 2068 is doing. For the NJM 2114D i know that OP275 is a good replacement because i have CD6000 and inside are same NJM2114D and ive had replaced them with OP275 and the result was positive.
But my problem is with the Marantz Pm7000, what should i do for hte NJM2068D which replacement i good for them?

Also ive noticed that the right chanel heat sink i more hoter than the left which is strange, also i have to turn the volume litle more than the previous OP's the marantz had so i have the same level of power, why this hapends, or its just normaly becasue the PM 7000 was designed to work with NJM2068D and NJM 2114D?

As for the sound i feel that it get sharpyer in sense that hte vocals and hi freq sounds get more power and hte strereo image is litle better so over all from the first impresions i think is soinding good but i will see for some days to pass.

Bye Bye

[lineup]

Originally posted by aleksandar
Hi To All.......

Ive just upgraded the opm amps into Marantz Pm 7000
-----
The FIrst and main problem that i have is it good to change the NJM2068D with OP275 also ive seen the specification for both and OP275 i better.
-----
But my problem is with the Marantz Pm7000, what should i do for hte NJM2068D which replacement i good for them?
.

Replacement for OP275 .. one special operational amplifier
with transistors input

This is a very difficult question, aleksandar


What is OP275.

GENERAL DESCRIPTION

The OP275 is the first amplifier to feature the Butler Amplifier front-end.

This new front-end design combines both bipolar and JFET transistors
to attain amplifiers with
- the accuracy andlow noise performance of bipolar transistors, and
- the speed and sound quality of JFETs.

Total Harmonic Distortion plus Noise equals that of previous audio amplifiers,
but at much lower supply currents.

So, to begin with, is not easy to find a better one.

Not even the Prophets of Audio Amplifiers in our forum
can answer such query ...
This is why no one bothers to help you.
... and what status would we gain in here, by helping a total newbie with things
So, if The Top of Top can not give you an advice, who am I to try to do it
Sadly so. But the reality it is.
Yes.


Welcome to our board, mate!
To see how things work here.
lineup
PS.
.... try at our Chimp Anzee department
.... they are usually friendly and nice over there
.... and they would know better all about OP-Amps (Chips, IC)
.... in this FET department central of The World they are experts in such

[aleksandar]

Thanks for the answer lineup.

I was only wondering if the op275 is going to function good like distorsion or some other problem but for now its working about 25 hours so it had a little burn in time and i like the way it sounds also i use only OP275 in the cd player and the amplifier.

Anyway bye bye and thanks again for hte reply

Alex

[Netlist]

aleksandar,
I moved your topic to Solid State as that's what the PM7000 is. Please don't cross post in other forums.

/Hugo

[aleksandar]

Guys here are some pictures from the board where the JRC 2068DD where and now op275 is aslo this is the board where tone control, balance and source direct OPs are.

[aleksandar]

Here is the preamplifier with the volume control OP aslo now changed from JRC 2114D with Op275.

But its very strange why right chanel heat sink its little hoter than the left chanel...........maybe ive done something wrong with soldering? But it sounds OK i cant hear any problems also the volume on the right and left its equal.

Ok at very very low volume like 1 or 0.5 from 10 left chanel only plays but this is very common

[aleksandar]

Here is one more from the tone controls, balance and source direct

[aleksandar]

Here is one more from the tone controls, balance and source direct