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Modding Altec Lansing MX5021 speakers

Discussion in 'Audio, Video & Home Theater' started by RejZoR, Jun 17, 2017.

  1. RejZoR

    RejZoR

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    Ok, I've decided to buy Sound BlasterX AE-5 when it comes out next month and for the sake of upgrading the whole experience, I'm planning to mod my Altec Lansing MX5021 speakers. They served me well for years and since they are one of rare few with wall mount option, I'm gonna buff them instead.

    Specifically these key areas:
    - capacitors in both satelites
    - capacitors on the main amplifier
    - OP-AMP in the amplifier
    - replacement of power converter to more quality toroid transformer (allegedly, this should fix annoying hissing)

    I'm planning to replace ALL key capacitors with Nichicon Muse Gold capacitors. For OP-AMP, I was looking at BurrBrown OPA2134PA. It's considered high end and I could get one for price of peanuts. So, I'm even willing to go with something even more high end, I'm just not sure which one is appropriate since I don't know the parameters important for OP-AMPs. For capacitors, voltage and capacitance, no problem. But for OP-AMS, no clue. I also haven't opened up the AMP unit yet, unsure about the complexity of the PCB underneath. Looks fairly simple from above, but I don't know how's it below. I don't have professional solder iron, just very basic clumsy one...

    EDIT:
    I'm also wondering how to tell orientation of OP-AMPs? I'm assuming it's important how you place them in.

    I've also seen some ridiculous Orange OP-AMPs that have tiny PCB sticking out of the plug pins/base. Is that compatible with MX5021 or not? Might be willing to go crazy with OP-AMPs even up to 30€ (the BurrBrown is like 5€ with shipping). Just need to know what to pay attention to when picking them up.
     
    Last edited: Jun 17, 2017
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  2. gdallsk

    gdallsk

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    The OP-AMP's have a little notch or a small indentation on the surface that you have to align with the one on the socket:

    [​IMG]

    Same will go for the cylindrical ones, they will have the same markings on the PCB.

    Also, when choosing one, make sure to get the ones you need, be it a mono one or a stereo, otherwise, if you pick a mono one for a stereo use, it will either be too quiet or you'll get a difference in volume between the channels.
     
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  3. RejZoR

    RejZoR

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    Anything else worth paying attention when picking up OP-AMP ? Do they separate in terms of bit depth and frequency range they can work with (or work at)? I'd like to expand the frequency response, although speaker drivers are probably the most limiting factor anyway.
     
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  4. gdallsk

    gdallsk

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    most OP-Amp's operate at very similar frequencies, all they do is just boost the output signal, and colour the sound depending on their characteristics.

    The one's that I've used previously were LM4562, and LME49720, the latter being a bit more powerful and neutral, and the former a bit warmer.
    And yes, if your speakers aren't good enough, you probably won't notice the difference.
     
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  5. RejZoR

    RejZoR

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    I'm actually more looking for more detailed sound rather than warmer. But still not too detailed because that often ends up being harsh on the ears.

    Any idea on the transformer? I've read somewhere that better toroid transformer supposedly fixed the hissing with MX5021. Just yesterday, I've noticed I can actually tone down hissing noise if I lower treble/bass parameters to zero. Volume knob doesn't seem to affect it, but treble does. Doesn't eliminate it entirely, but lowers it significantly. Some say it's transformer issue, others pre-AMP overdrive. What's your opinion?

    Been using it with zero treble and bass amplification, only colorizing audio using Creative Crystalizer and EQ and the sound is... interesting. First few seconds felt like something was missing, but now it kinda sounds really detailed. Probably because treble and bass frequencies don't drive over all other frequencies. I'm assuming.
     
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  6. gdallsk

    gdallsk

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    The hissing you describe is the noise floor of the speaker system you have. I have a similar issue with my amplifier when there's literally no sound coming from the speaker but there's that annoying background hiss. I've been reading about it and people seem to recommending changing the default caps in the amp. But it can also come from the power outlet itself or the cheap cabling on the satellites.
     
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  7. RejZoR

    RejZoR

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    I've replaced thin satelitte cables with proper high end thick copper wires specifically for speakers. Good thing MX5021 have same cable ports as HiFi systems so it was a snappy replacement. MX5021 is not grounded system afaik. Never had this issue with Creative speakers in the past, essentially used on same wall socket. I do use power surge in front of everything. That should actually help afaik.
     
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  8. RejZoR

    RejZoR

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    Damn, was checking eBay for cheap OP-AMP sockets and they cost more than OP-AMP itself. Usually in 10 pcs quantity only. A bit annoying.
     
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  9. 5DVX0130

    5DVX0130

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    Search DIP8 socket...
    Pages, upon pages, and for less than $1.
     
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  10. RejZoR

    RejZoR

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    What the frigging hell!? Tried to open one satellite and at first the screw was really hard to move and then its head literally snapped off. I literally can't open it. It's like some idiot glued it together and rammed screws through the glue. Tried two screws and both snapped off. Insane. Why even bother using screws!? Got 3 others out and the last one just got the cross obliterated. Awesome...
     
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  11. RejZoR

    RejZoR

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    Ok, just ordered all the goodies.

    1x BurrBrown OPA2134PA + socket
    8x Nichicon Gold capacitors for pretty much everything
    2x 4700uF Nichicon Standard Audio (because I couldn't find any 4700uF 50V Gold's that aren't from China. I'm really not in the mood of waiting 1 month for the components. besides, the ones from Europe were actually cheaper in general.

    I think it'll be a good upgrade even if it's not the best "Gold" one. Was thinking of replacing some more stuff, but after checking the other side of PCB, I don't think my tools or soldering skills are good enough to replace others, so I'm keeping those stock. I'll already be sweating with the OP-AMP socket with those 8 pins. Pretty crowded with zero margin for error. Transformer is a big ass unit and the number of wires is a bit confusing, so I'm leaving that one out for now. If I could live this long with a bit of hissing, I can do now. Hoping to boost the quality as whole though.

    Total cost, roughly 50€ with shipping costs. Seems reasonable considering speakers were around 150€ back in the day iirc.

    It's possible it'll make literally no difference or that I'll even ruin them. But hey, it'll be a great learning experience :D
     
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  12. RejZoR

    RejZoR

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    Also noticed transformer was totally loosened up and rubber feet on subwoofer moved all the way to the edges of the sub frame XD Nothing double sided TESA tape can't fix :D
     
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  13. RejZoR

    RejZoR

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    So, the OP-AMP was first to arrive :D Just need socket for it and then I might already start working as components are arriving from different sellers.
     
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