Just purchased a Marantz 2100 Tuner Want to upgrade it :)

Discussion in 'Marantz Audio' started by jeffdewe, Sep 5, 2017.

  1. jeffdewe

    jeffdewe New Member

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    Hi I always liked the looks of Marantz and finally purchased my first one, Yes I'll be removing that tape residue. I'm pretty good with a soldering gun and this tuner looks great but being 30'ish yrs old it should be recapped, Also I would like to improve the frequency response for 30hz and lower it to 20hz if possible and improve the distortion levels etc. So I figure why not start a thread on the rebuilding/upgrading of this tuner. Its being mailed to me today so I probably won't have it until Friday or maybe early next week. So what capacitors do you recommend ?, What else should I replace to improve the sound quality etc. Just give me some ideas and maybe links so I can get a grasp on this. I've recapped an arcade asteroid motherboard before so I have some idea what's involved. But you guys are a lot more seasoned than I am so I'm looking for a bit good of advice.
    Thanks
    Jeff
    2100.jpg
     
    Last edited: Sep 7, 2017
  2. avionic

    avionic " Black Knights " Subscriber

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  3. jeffdewe

    jeffdewe New Member

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    Yes it looked nice so I went for it :) Always wanted one and this one already has the LED's and he cleaned up the box and added some feet from another Marantz receiver.
     
  4. rBuckner

    rBuckner Luv 2 Restore Subscriber

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    I believe FM broadcast is limited to 30-15,000 Hz. There can be subcarrier signals below 30Hz that you don't want to reproduce. I can't remember what is sometimes used down there though, argh! Above 15KHz is the stereo pilot tone of 19kHz and there's traps in the tuner to drown that out. Other than that you'd just be amplifying any noise present. So I wouldn't recommend any mods to expand frequency range. There are mods like using different crystal filters in the IF section. Look for a tuner enthusiast website, maybe asking tuner guru 'PunkerX' what forums are out there.
     
  5. jeffdewe

    jeffdewe New Member

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    Hi thanks for the insight but your right and wrong, Fm can and is broadcast down to 20Hz not 30 and yes 15kHz is the cutoff, Tuners like Carver, Techniques and a couple others go down to 20Hz, Actually I think Marantz makes one also. I like the idea of different crystal filters, my Pioneer sx-D7000 is Quartz Synthesized and that is one of the best radio sounds I have ever listened to, If I could ever get that Marantz to sound like that I would be a happy Man :)
     
  6. rBuckner

    rBuckner Luv 2 Restore Subscriber

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    Yes, it can go down to 20Hz. I meant "limited" as in by the broadcaster for program audio. I had heard there are signals between 20 and 30Hz used for signaling or triggering.

    The crystal filters I mention was in error though, I should have said ceramic filters. These are for removing the 10.7Mhz Intermediate Frequency that comes out of the tuner front end. Nothing to do with crystals so sorry for the false hope!
     
  7. catrafter

    catrafter Marantz Specialist Subscriber

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    While the tuner may go down to 20Hz, I believe the lowest frequency that may be broadcast by an FM station is 30Hz.
    Perhaps an FM radio station engineer could chime in on this.

    Tom
     
  8. Bert 1100

    Bert 1100 Super Member

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    this is a tuner, not a receiver :deal:
    And a beautiful tuner ! have fun :)
     
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  9. I LIKE MUSIC

    I LIKE MUSIC Super Member

    General FM radio 101.

    Not exactly. They pass, not remove the IF signal from the mixer to the FM detector where it is converted from modulated RF to audio.


    upload_2017-9-7_15-1-21.png

    In the hobby of FM broadcast band DXing (trying to receive very weak, very distant stations), the IF filters may be changed to more narrow bandwidth filters. This can improve the receiver or tuner's reception ability with regard to weak signals and adjacent channel performance at the expense of audio quality.

    On the other side there are those that may replace the stock IF filters with wider bandwidth to help to improve audio quality at the expense of weak signal and or adjacent channel performance.

    Not all IF filters are ceramic. Some, especially in older gear are tuned (adjustable) transformers/inductors. The 2100 uses ceramic IF filters.

    Other modifications to the RF chain may include modifications to the RF front end and or the mixer/local oscillator.

    In the audio chain, capacitor replacement is not uncommon, including changing capacitor values. Some replace/"upgrade" transistors/integrated circuits.

    To the OP, what is your technical background and what test equipment do you have?

    Depending on your desired level of modifications and your goals, some will be much more than the "plug and play" parts replacement common on AK.

    A good, careful and accurate alignment is never a bad idea.
     
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  10. rcs16

    rcs16 Super Member

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    You can always look at the 2130 as it was TOTL at that time, it used SAW IF filters in both IF paths with a separate detector for the metering.
    It is no small feat to re-design a FM tuner, as above says, first is to have the knowledge and also the equipment before you attempt to improve on what the original designers had done.
    Even older narrow IF filters paths do not have enough rejection of strong adjacent carriers and post detection filtering sometimes can not reject IBOC subcarriers.
    "my Pioneer sx-D7000 is Quartz Synthesized and that is one of the best radio sounds I have ever listened to"
    You always could put the D7000 IF, Quad detector and PLL stereo decoder sections into it? I think the sx-3900 is almost the same.
    Adding the quartz lock PLL tuning system is a big job,requires adigital disply etc.
    I would think that the 2100 maybe more sensitive than the D7000.
     
    Last edited: Sep 12, 2017
  11. drew_t

    drew_t Well-Known Member

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    I'm going to bump this thread to ask: is changing out some/all of the electrolytic capacitors in one of these (which seems to be working OK, other than that the pointer is a bit misaligned) a good idea, a bad idea, or, an "eh, it depends -- how bored are you?" kind of proposition? No sign of leakage, bulging or other abnormalities that I can see. Is there a chance that replacing any of them might affect the calibration of the unit? I definitely don't want to do that; the procedure for re-calibrating it outlined in the service manual calls for practically a lab full of equipment (none of which I have).


    Marantz 2100 guts 2.jpg
     
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  12. jeffdewe

    jeffdewe New Member

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    I also would like to know that answer also :). I really like the sound of that tuner, The only issue I find is that sometimes the station fades away, like it doesn't stay locked into position.
     
  13. ChrisMarantz

    ChrisMarantz Super Member

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    In my experience (having worked on 60 or so tuners) replacing capacitors (other than in the power supply - possibly) has little or no effect on performance. Generally it will not effect the alignment of the tuner (however, there are so many designs it's difficult to generalize)

    A cleaning and a full and careful alignment will usually yield the most noticeable improvement - far beyond any capacitor replacement - Chris
     
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