Hi everyone, my name is Bruno, I'm Brazilian.
I have a pair of Yamaha HS8 monitors, in the signal input circuit, there are 6 NJM4558M op amps, I would like to upgrade to NJM5532M because they are faster, I fear the circuit will wobble.
Will I gain sound quality?
I see that some people put OPA2134 in place of NJM4558...
Could someone more experienced give me an opinion?
A photo of the input circuit board:
![20211205_153930[1].jpg](https://www.diyaudio.com/community/attachments/20211205_153930-1-jpg.1004550/ "20211205_153930[1].jpg")
Datasshet NJM4558M:
https://www.njr.com/electronic_device/PDF/NJM4558_E.pdf
Datasheet NJM5532M:
https://br.mouser.com/datasheet/2/294/NJM5532_E-1917664.pdf
See pages 14 and 42 in the service manual.
I have a pair of Yamaha HS8 monitors, in the signal input circuit, there are 6 NJM4558M op amps, I would like to upgrade to NJM5532M because they are faster, I fear the circuit will wobble.
Will I gain sound quality?
I see that some people put OPA2134 in place of NJM4558...
Could someone more experienced give me an opinion?
A photo of the input circuit board:
Datasshet NJM4558M:
https://www.njr.com/electronic_device/PDF/NJM4558_E.pdf
Datasheet NJM5532M:
https://br.mouser.com/datasheet/2/294/NJM5532_E-1917664.pdf
See pages 14 and 42 in the service manual.
I admire your quest for a nicer sound, but I really believe that the cost/risk to benefit isn’t going to make that worth while.
I agree with that.
Yamaha designed that in a laboratory to a certain price point and quality.
Since it's a small type of common powered speaker system, if isbarbato wants to "gain sound quality", then a better system is the answer.
Too many people want to "make a silk purse from a sow's ear" and just waste their time and money.
It depends your ear taste.. NJM4558 and NE5532 are both BJT input amplifiers while OPA2134 is a JFET one.
JFET sound is more like the tube sound, BJT is pure solid state.
If your consider THD levels then OPA2134 is the best in this three but noise density is better on NE5532 side.
JFET sound is more like the tube sound, BJT is pure solid state.
If your consider THD levels then OPA2134 is the best in this three but noise density is better on NE5532 side.
4558 were used a lot in recording studio consoles, still well regarded.
Yamaha are also reputed.
Leave it alone, build a totally new unit using faster slew rate chips, but bear in mind that more than 20 V/uS slew rate is a waste of time.
Yamaha are also reputed.
Leave it alone, build a totally new unit using faster slew rate chips, but bear in mind that more than 20 V/uS slew rate is a waste of time.
I bought 12 units of the OPA2134UA made by Texas Instruments, I paid $3.53 for each piece.
I just put them in one of the boxes, I'll listen to them for a while in mono and compare, see if there are any differences.
I'm going to ask someone to position them in a random way so I can't know which one is modified, to be more honest in my auditions.
No way, 5532 is far better than opa2134.
As far as 'sound quality' concern, no comment.
Best Regards
As far as 'sound quality' concern, no comment.
Best Regards
Sure they are real?
The BB marking was changed by TI on some parts.
Also, some pre amps work at their ideal voltage ranges, simply changing them does not work, you have to check if input level and power supply voltages are suitable also.
Otherwise you will get trapped.
And also, the system you are using it with may not be high end enough to show the difference in sound quality.
The BB marking was changed by TI on some parts.
Also, some pre amps work at their ideal voltage ranges, simply changing them does not work, you have to check if input level and power supply voltages are suitable also.
Otherwise you will get trapped.
And also, the system you are using it with may not be high end enough to show the difference in sound quality.
With little modification it is possible(often) to swap op-amps. But op-amp like 5532 is quite power hungry compared to standard 4558 type.
Apparently they are real yes, they are not magnetic, the prints do not erase with solvents and the markings are compatible with a Texas Instruments document, and they work.
They are powered by +/- 15V from the 7815 and 7915 regulators.
The differences in sound are quite subtle, but there are, the highs seem more understandable, less cluttered.
The noise in the tweeter is the same as in the unmodified speaker.
Really? Remember that any opamp is a high open loop gain device whose »sound« is dominated by it's NFB. A JFET input opamp will clip as hard as a BJT one when overdriven.
The benefits of JFET inputs is quite another pair of shoes.
Best regards!
There is a guy in Israel, who is a former pilot, and does this sort of stuff in a very convincing way.
You realize later it is mostly an act.
He claims clients from the USA, who pay him to rebuild old stereos, like B & O and Arcam...
He does this, changing capacitors, op amps, RoHS to regular solder and so on.
But he insisted on metal can TIP41s, instead of putting a better MJ series transistor, which would have actually improved it.
But there are people who pay to ship their stuff from Australia, and pay Israeli rates for exotic and ultimately useless work. The rates there are at times more than Europe...
Who told you JFET sound like tubes?
Have you heard the same piece played side by side on solid state and tube amps, over the same speakers, from the same input device?
And do you know why tubes became old fashioned?
Enjoy!
You realize later it is mostly an act.
He claims clients from the USA, who pay him to rebuild old stereos, like B & O and Arcam...
He does this, changing capacitors, op amps, RoHS to regular solder and so on.
But he insisted on metal can TIP41s, instead of putting a better MJ series transistor, which would have actually improved it.
But there are people who pay to ship their stuff from Australia, and pay Israeli rates for exotic and ultimately useless work. The rates there are at times more than Europe...
Who told you JFET sound like tubes?
Have you heard the same piece played side by side on solid state and tube amps, over the same speakers, from the same input device?
And do you know why tubes became old fashioned?
Enjoy!
This phenomena, or perception, of "tube sound" of solid state from people, while widely critisized, is in reality grown in the same bucket of delusions as are capacitor-changing, and other dreamed-up tales of audio fantasy.
It's been passed around for decades on the internet, like that infamous Christmas fruitcake that nobody wants.
Let's be real here.... honestly.
While different products have different "voicing" properties due to individual design, these things are not something that can be justifiably labeled as being something that they're not.
Because to insist that they are is like taking a fundamental and established scientific formula like Ohms Law and twisting it around to make it suitable to one's own tastes.
And that is simply a rediculous idea.
It's been passed around for decades on the internet, like that infamous Christmas fruitcake that nobody wants.
Let's be real here.... honestly.
While different products have different "voicing" properties due to individual design, these things are not something that can be justifiably labeled as being something that they're not.
Because to insist that they are is like taking a fundamental and established scientific formula like Ohms Law and twisting it around to make it suitable to one's own tastes.
And that is simply a rediculous idea.
You should decide what the tube sound is.
If it is an old AM radio, the sound is dull and lifeless compared to a FM radio here. Dynamic range, clarity, frequency response, the higher frequencies...solid state FM wins hands down.
And in the tube days, all you had was LPs, which were replaced by compact cassette, then CDs.
Each was successively clearer.
So like Wise above says, there is a lot of snake oil going on about the tube sound.
There are people like Tubelab here, who actually design and make tube amps.
But believe me, tube amps are not even 0.1% of the market in terms of units sold.
And what is your problem, why are you after the dull sound of hot tubes?
Does your source give you an output that you think sounds better through a tube amp?
What is it?
If it is an old AM radio, the sound is dull and lifeless compared to a FM radio here. Dynamic range, clarity, frequency response, the higher frequencies...solid state FM wins hands down.
And in the tube days, all you had was LPs, which were replaced by compact cassette, then CDs.
Each was successively clearer.
So like Wise above says, there is a lot of snake oil going on about the tube sound.
There are people like Tubelab here, who actually design and make tube amps.
But believe me, tube amps are not even 0.1% of the market in terms of units sold.
And what is your problem, why are you after the dull sound of hot tubes?
Does your source give you an output that you think sounds better through a tube amp?
What is it?
Here's a fact that I'll pass along to anyone who believes that tubes sound "warmer" or different some solid state....
A friend stopped by, who was inclined to often discuss audio, his ears are "tuned in" to high-end audio.
I have a decent system, nothing too fancy, and the ability to switch from a solid state amp to a tube amp with the flick of a switch.
With a CD playing as he walked in, and seated in the "sweet spot" in my living room, I asked him to listen and tell me which amp was feeding my speakers.
The only interruption was a trivial split-second of the switch choosing the amps, nor did he know which amp was connected.
He chose the solid state amp numerous times as being "tube sound".
Claiming it sounded "warmer".
When I told him of the results, he just stared at me with nothing to say.
I rested my case. 😎
I can only state what I have read in Elektor years ago . They said "tube sound" has more of the even harmonics , less oneven , and that sounds "warmer" / pleasant . JFETs are like that too. I don't know if that is really true , but it stuck with me and influenced me to prefer JFet opamps over bipo's . (and their low input current / noise) .
A tube is having electrons passing through a larger gap between electrodes than in solid state, so the sound is actually distorted by that, if you compare the phase shift between input and output at different frequencies, the response will not be flat.
The other factor may be the reserve power from linear supplies with huge capacitor banks.
So the sound is warmer, actually more distorted than solid state.
But both issues have long since been addressed by different solid state designs, and in any case the response has to meet RIAA, DIN and other standards.
So we are now getting diverted to the old tube v/s solid state debates.
Personally, when I made a phono pre amp, I took the circuit from the service manual of my Kenwood set, which specified a 5532 or 6556. I had to change the input and output resistors to get a proper sound level, as I used a TL072 in place of the 5532 specified.
The user is happy, but the pitfall is that blindly changing op amps is not practical.
In conclusion, if you are happy, do the other channel.
But comparing solid state to tube is a waste of time. Been done countless times already.
The other factor may be the reserve power from linear supplies with huge capacitor banks.
So the sound is warmer, actually more distorted than solid state.
But both issues have long since been addressed by different solid state designs, and in any case the response has to meet RIAA, DIN and other standards.
So we are now getting diverted to the old tube v/s solid state debates.
Personally, when I made a phono pre amp, I took the circuit from the service manual of my Kenwood set, which specified a 5532 or 6556. I had to change the input and output resistors to get a proper sound level, as I used a TL072 in place of the 5532 specified.
The user is happy, but the pitfall is that blindly changing op amps is not practical.
In conclusion, if you are happy, do the other channel.
But comparing solid state to tube is a waste of time. Been done countless times already.
The natural progression of the original RC4558 family is to a RC4560, finally to RC4580, TI says in the RC4580 datasheet it is similar to a LM883, NE5532, something to try out perhaps. RC4580 is actually cheaper than a NE5532, imagine that. OPA2134 holds a premium price by comparison, will your ears really know the difference between them all, is the real ?