Likelyhood of older Yamaha amps needing recap or similar?

Discussion in 'Yamaha' started by Asmodeus2112, Feb 8, 2019.

  1. Asmodeus2112

    Asmodeus2112 AK Subscriber Subscriber

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    I have been getting back into Hi Fi, and would love to get some of those awesome amps I couldn't afford when they were new and I was a kid. Several for sale right now, an M-4, M-80, M-70, M-50 and a MX-1000. Cruising AK there are a lot of threads about restoring/repairing, but how typical is the need to do serious work on some of these older amps? I am quite technical, but not a repair tech. Trying to decide if i shouldn't pony up and go with newer? (I like the older stuff better though...) I picked up a C-45 from thrift and a MX-55 on CL to get started, but would like to go bigger/better.
     
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  2. Mark B

    Mark B Yamaha Fan Subscriber

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    I have many unrestored Yamaha amps from the 80's and 90's that work beautifully. I've had my B-1 and B-2 restored as a failure could take out the VFETS. If you can solder and are methodical you could recap an amplifier that was in working condition without needing to be an expert repair tech.
     
    Last edited: Feb 8, 2019
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  3. mbz

    mbz Super Member

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    Some of the amps have known problems like troublesome switches, relays, fusible resistors and corrosive component glue.
    Often simple cleaning is all that's required. Would be handy if you can handle a multimeter and are comfortable taking voltage
    measurement on a live unit, should "serious" troubleshooting be required. Others can advise which are the better M?-????
    amps to go for.
     
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  4. amr2

    amr2 Well-Known Member

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    I have restored an M-80 and a MX-1000, both are great amps.
     
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  5. DBx5

    DBx5 New Member

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    Electrolytics are limited life components. Simple answer is, yes, recap them.
     
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  6. Asmodeus2112

    Asmodeus2112 AK Subscriber Subscriber

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    Thanks, I have seen many threads here and the support form the community is excellent. I am confident I could do the work. My time is probably the biggest obstacle. Are there other amps that have VFETS? Outside of sound quality, it doesn't sound like I would be risking damaging an amp if I didn't recap for a while?
     

     

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  7. avionic

    avionic " Black Knights " F-15 Eagle Keeper Subscriber

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    M-60/65,M-80/85 ,M-2/4 , MX-1/2. The M-50/70 can be tricky if it has power supply issues.
    SONY and Yamaha.
     
  8. Asmodeus2112

    Asmodeus2112 AK Subscriber Subscriber

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    Which amp would be the best for a first recap project?
     
  9. ic-racer

    ic-racer Super Member

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    CX830 large cap.JPG
    I just like working on them, so I have way more speakers and amplifiers than I can use. If I did not like doing the work, I'd certainly go for the NEW YAMAHA stereo equipment while they still make it.

    BTW, my most recent Yamaha 'project' pictured above, required no capacitor replacements. It just needed cosmetics, calibration and deoxit. I'm listening to it right now.

    Since you already have the C-45, why not re-cap that. Record some music 'through' the preamp before you start. Measure all the old caps you removed. Based on what you find when you are done, you can decide if it was worth the time and effort.

    Those new Yamahas look pretty nice...and they don't need capacitor replacements or DeOxit.
    [​IMG]
     
    Last edited: Feb 9, 2019
  10. ic-racer

    ic-racer Super Member

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    BTW this is what you might find in your C-45. This is from my M-45. That glue is corrosive. It caused the resistor to go open circuit. I was listening to it when the resistor's axial lead finally gave way, it make quite a lot of very loud popping and banging as it made intermittent contact until I could turn it off. Scared the crap out of me, I thought it was going to explode.

    Yamaha M-45 OpenResistor.jpg
     
    Last edited: Feb 9, 2019
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  11. Asmodeus2112

    Asmodeus2112 AK Subscriber Subscriber

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    Yeah, that's a good idea to start with the C-45. I bought a C-4 and M-4 from a fellow AK'er here in ATX today. The C-4 was already recapped, but the M-4 i don't think so. It's about the journey, so we'll see how it goes. I have a newer, although near BOTL R-S500, and I don't like it's sound. The C-45 + MX55 are much nicer.
     

     

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  12. Mark B

    Mark B Yamaha Fan Subscriber

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    The C-4 and M-4 are very nice. The M-4 should be an ideal amp for a first recap.
     
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  13. Bratwurst7s

    Bratwurst7s In The Frying Pan Subscriber

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    This is imho the single most important point to inspect and correct with any Yamaha amp made before about 1990 when they changed to the white glue shown in ic-racer's post #9 above.

    A lot of other maintenance points may be optional, Sony Bond glue removal and corrosion correction is not.

    Cheers,
    James
     
    Last edited: Feb 10, 2019
  14. Asmodeus2112

    Asmodeus2112 AK Subscriber Subscriber

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    Ok, I will search for details and check my amps. M-4 and C-4 had it? C-45?
     
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  15. Bratwurst7s

    Bratwurst7s In The Frying Pan Subscriber

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    I don't have first hand experience with those control and power amps but I'm believing yes.

    How do you like your Canton Karat 200's? That's a speaker that I like a lot.

    Cheers,
    James
     
  16. Asmodeus2112

    Asmodeus2112 AK Subscriber Subscriber

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    Love the Karat 200's. I would like to experience more Canton speakers, but they are a bit scarce here. About to buy a pair of NS-1000 though. Always wanted a pair, so gonna give it a go. Figure they are marketable so can sell them if i don't like them later for about what I will pay.
     

     

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  17. Asmodeus2112

    Asmodeus2112 AK Subscriber Subscriber

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    James, since I like the Karat 200's so much, I have been looking for other Cantons. Some Ergo 80 DC's are up for sale, do you have any experience with them?
     
  18. Bratwurst7s

    Bratwurst7s In The Frying Pan Subscriber

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    Not directly.

    The Ergo 80 is the follow on to the CT 80. The CT 80 I do have experience with, a friend of mine has a pair. Which he has recently replaced with my old Karat 60's and is much happier with the Karat's.

    For my tastes the CT 80 is a little bass shy and not really a large improvement over the Karat 200, both having an 8" woofer. The CT has perhaps a little better midrange than the 200. A Karat 60 is imo a much better speaker than the CT 80, but then again imo so is a CT 800.

    With the Ergo 80 the 4" mid of the CT 80 was replaced with an 8" mid. the crossover frequency was dropped from 4khz to 3.5khz. An 8" mid is going to start to get somewhat directional at that level. You can expect that the Ergo 80 has MKT film caps on the tweeters, possibly on the upper end of the mids. But the sensitivity drops from 93.4db (CT 80) to 87.5db.

    The Ergo 80 DC (and all other "DC" Cantons) has an added crossover section on the low end of the woofers that is supposed to cut off their response just before their resonant frequency and is supposed to give cleaner bass.

    It would be irresponsible of me to disregard the Ergo 80DC because I haven't personally heard any. But they are a model that I would highly recommend listening to before buying to replace a Karat 200. And keep in mind that they will need more power to play at the same level as the older models.

    Just my opinions and in all fairness I must state that I personally much prefer the sound of closed box acoustic suspension speakers over bass reflex. So be aware that I am not completely objective.

    Cheers,
    James
     
  19. avionic

    avionic " Black Knights " F-15 Eagle Keeper Subscriber

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  20. avionic

    avionic " Black Knights " F-15 Eagle Keeper Subscriber

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    I have a C-45 here without any glue.C-4 will have some glue around the larger caps and board mounted heatsinks. The M-4 probably won't have much at all.
     
    Last edited: Feb 12, 2019

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