I am not certain that would be an good idea:
The MJM4558 should have a gain-bandwidth of 3MHz whereas the OPA1612 has 40-80 MHz (depending on amplification).
Swapping might (not "will") cause oscillation as the PCB and decoupling designed for the slow '4558 may not be up to the task with the much faster '1612.
But as experimenting is part of the dna in DIY - then you may try and it may work or not (advice, though: disconnect power amps and speakers to avoid damage if you should decide to test)
Cheers, Martin
The MJM4558 should have a gain-bandwidth of 3MHz whereas the OPA1612 has 40-80 MHz (depending on amplification).
Swapping might (not "will") cause oscillation as the PCB and decoupling designed for the slow '4558 may not be up to the task with the much faster '1612.
But as experimenting is part of the dna in DIY - then you may try and it may work or not (advice, though: disconnect power amps and speakers to avoid damage if you should decide to test)
Cheers, Martin
And a small followup after watching the video:
It is correct that the '4558 only has a slew rate of 1V/us.
But that will give you an unlimited peak signal (with regards to slew rate limiting) at 20kHz of around 8V - much, much more than I would expect the preamp of such a monitor to produce.
So I really think the claim about the significance of the slew rate for the attack of the sound is somewhat exaggerated.
The sound difference recorded is also close to being absurd, IMHO.
Does the recorded sound with the unchanged monitor really sound remotely as your speakers?
Cheers, Martin
It is correct that the '4558 only has a slew rate of 1V/us.
But that will give you an unlimited peak signal (with regards to slew rate limiting) at 20kHz of around 8V - much, much more than I would expect the preamp of such a monitor to produce.
So I really think the claim about the significance of the slew rate for the attack of the sound is somewhat exaggerated.
The sound difference recorded is also close to being absurd, IMHO.
Does the recorded sound with the unchanged monitor really sound remotely as your speakers?
Cheers, Martin
Hi Martin, I think you were right.
I have done this mod and have now louder white noise from the tweeter...
while turning the volume poti through certain positions my speaker starts to plop and wobble... turning the poti volume up nearing full volume, the speaker nearly got blown up...
not sure what is causing that. Having the exact same problem with both speakers.
...well, I can just let the volume poti sit on the middle position and everything works but still.... I am not sure if that mod did anything good to my speaker.
It really sounds as if the mod is not going the right direction and if you want to continue down that route, you will need to go deeper into measuring what is going on - and an oscilloscope and understanding of circuitry.
And the schematics not to forget!
If this sounds as too much for you I think my best recommendation would be to revert the changes done.
But: as I wrote in #3 - does the original sound from your speakers even remotely resemble the linked video?
Or, in other words: are the original speakers sounding bad?
Hint: I find the claims in the video outrageous
Cheers, Martin
And the schematics not to forget!
If this sounds as too much for you I think my best recommendation would be to revert the changes done.
But: as I wrote in #3 - does the original sound from your speakers even remotely resemble the linked video?
Or, in other words: are the original speakers sounding bad?
Hint: I find the claims in the video outrageous
Cheers, Martin