Yamaha CX-1 Thread

Discussion in 'Yamaha' started by Bratwurst7s, Sep 30, 2017.

  1. Bratwurst7s

    Bratwurst7s In The Frying Pan Subscriber

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    So today While waiting and bored I built up a bridge rectifier out of Vishay SBYV27-200 ultra fast/soft recovery diodes. I haven't decided for sure if I'll be doing this mod or even if I'll be using these diodes or Schottky diodes but I was bored and wanted to see what it would look like. I'm also toying with the idea of finding some heat conductive/electrically non-conductive epoxy and potting the thing to a small heat sink. Anyway, to pass the time here's a few photos...

    DSC04647.jpg DSC04659.jpg DSC04660.jpg DSC04661.jpg DSC04662.jpg

    Cheers,
    James
     
  2. Bratwurst7s

    Bratwurst7s In The Frying Pan Subscriber

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    A couple more...

    DSC04663.jpg DSC04664.jpg DSC04666.jpg DSC04671.jpg DSC04672.jpg

    Not exactly a work of art but it was fun and only took a few minutes.

    Cheers,
    James
     
  3. Karl vd Berg

    Karl vd Berg Super Member

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    I like it, definitely worth a try. And the SBYV27-200 are excellent rectifiers, I used them too.

    Other rectifiers used were the VSB2200S.
     
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  4. restorer-john

    restorer-john Super Member

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    All Yamaha units using the Alps motorised input selector will eventually succumb to the same issues- poor/intermittent contact, channels dropping out and/or different levels etc. The internal silver plated contacts simply oxidise and no amount of your favourite cleaner will help.

    The component is an absolute pain to remove, dismantle and properly repair as they are unobtanium as NOS. But, it can be done and is worth it for some of their models- CX-1 included. Most of the big DSPs/RXVs and AXs that used the selectors are not worth the time or the effort to do it properly.

    Step 1. Before going crazy replacing caps, I would do preventative maintenance on the input selector. This has the potential to improve the performance and reliability of your CX-1.

    Step 2. Test the unit and see if it meets spec. If it does meet spec, leave it alone.

    Step 3. With your bench test results (freq sweeps, scope plots, THD, S/N, residuals, channel balance etc) in hand, you can make informed decisions on what to repair, upgrade or improve.

    • I would also not be touching the Fujitsu Takamisawa relay- unless it is faulty. It is a low signal level, 100milli ohm contact resistance, inert gas-filled unit, designed to switch ultra low level currents reliably (0.01mA), with silver-palladium contact surfaces. Some random relays you use for high current gate motor controllers are completely unsuitable in this application and they will degrade the performance of the CX-1.
     
    Last edited: Dec 22, 2017
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  5. Bratwurst7s

    Bratwurst7s In The Frying Pan Subscriber

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    I've used the SBYV27's in 6 or 7 CD players now and really like the results. Interesting that you would suggest the VSB2200. As a backup plan I bought some VSB3200's. I haven't used them before but thought that they looked interesting. The 2A 2200's were out of stock so I bought some of the 3A version.

    Cheers,
    James
     
  6. Bratwurst7s

    Bratwurst7s In The Frying Pan Subscriber

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    Hi John,

    About the rotary selector switch. Agree. I've owned an AX-1090 since '98. As with most units that use those rotary switches mine started having contact problems about 3 years ago. Spraying with Deoxit at that time has been successful in my case. But you raise a very valid point and I have an AX-890 sitting here that is waiting to have that switch replaced. Coincidently I just today found and bought a NOS replacement for my CX-1 as a backup (P/N: VP917000). It won't get here until after the 1st week of January but at least I found one.

    Concerning elco replacement. I'm not getting into the debate about replacing 20 year old caps. Just not going there. The parts have been purchased, and will be replaced. There is really nothing more to discuss there.

    Concerning the relays. I understand your point about not using the Finder relays that I originally talked about. Bad choice. The ones that I bought from Mouser are an exact replacement RY-12W-K. It remains to be seen if I do replace them but at least the parts that I have on hand are the correct parts. Since they are the same part that's used in my DCD-2700 CD player I actually bought 6 of them.
    https://www.mouser.de/ProductDetail/Fujitsu/RY-12W-K/?qs=pc5iSNpyspZCkKjXcqIUqw==

    CX-1 Input_1.jpg CX-1 Input_2.jpg CX-1 Input_3.jpg CX-1 Input_4.jpg

    Cheers,
    James
     
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  7. restorer-john

    restorer-john Super Member

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    Great find on the CX-1 rotary switch. :)

    I also have several units floating around here that need my attention on rotary switches, including a AX-570 and and an AX-1070. Nice amps apart from that selector. And, I thought it was really cool at the time when I was selling them new back in 1990/1... Little did I know, I would be fixing them 20+ years later...

    On the caps, we restorers all replace- we have to do so for long term reliability, especially on paid gigs, but I always benchmark the unit before and after. That way, I can see any real improvements or the lack of. That is not a conversation most people around AK are prepared to have.

    The CX-600/800 and 1000 may be a few years older, but have solid state switching, albeit in less aesthetically pleasing designs and have proved to be considerably more reliable haven't they?
     
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  8. Bratwurst7s

    Bratwurst7s In The Frying Pan Subscriber

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    Well, I'm not so far along skill wise that I have the ability to bench check a unit. Not to mention a limited budget for buying test equipment. I'm still very much in the early part of the learning curve. I do however check and document the values of the old caps AND the new ones. One reason that I've been using less and less of the Nichicon FG's is that in values 220µF and higher they have been consistently been testing low, often 10%+ low. So if I'm changing caps as a PME I don't see the point of starting out lower than nominal. The Panasonic FC and UCC KYB have on the other hand been consistently testing pretty nominal.

    Considering the rotary vs individual switches. Replacement rotary switches with gold contacts are still available here, at least in 7 and 9 position versions. I'm having a hard time finding them in 6 position types. In fact I have a 9 position one here that I bought by mistake. I haven't done enough amps to really get a feel for what is best, but on the other hand as long as I can find replacements there is a steady stream of AX type amps on ebay for very reasonable prices because of those rotary selectors. I've been very happy with my 1090 over the years. I like the way the AX-(x)x50 and up are built.

    Concerning the CX-600/800/1000. I've only had my hands on one CX-600. And I haven't been completely successful in bringing it back to good order. I've managed to repair all of the original issues (with a lot of mistakes along the way) but I've created a problem of my own that I haven't solved yet. I got so frustrated that I had to set it aside until I learn more and have some other things out of the way. It has been a good learning experience and I haven't given up on it, but it has to wait. In some ways I like the solid-state switching and in some ways I think that it adds it's own set of complex problems. And they still have all of those single switches that oxidize.

    Cheers,
    James

    edit: btw, I have no problem with discussing testing, and am working on trying to learn more. The last 4 years of getting started with this as a hobby has been a lot of fun and very educational. It's only the point of doing PM (or not) or re-installing 20 yo components that I don't see the point of discussing. Sorry if I was curt or asswipeish. My apologies.
     
    Last edited: Dec 22, 2017
  9. zaibatsu

    zaibatsu Active Member

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    Since there's a discussion brewing here, it's been my experience that for original capacitors (particularly larger ones) which do measure within spec (obviously not always the case), their ESR will often be lower (and thus ripple current rating higher) than the exact-value (capacitance and voltage) modern replacement. This makes sense to some extent, as ripple value has some proportionality to surface area / size. On top of this, many new capacitors measure below-spec in capacitance by 10-15% (a cost-cutting initiative rather than coincidence, I suspect). Obviously this doesn't apply to original capacitors which have degraded.

    In my experience, the best solutions for these problems are:
    1. Increase the voltage rating of the replacement, with the knowledge that in many cases it's not an "upgrade", rather somewhat a necessity to maintain factory-new ripple values. My conclusion is that "new caps being smaller due to superior modern technology" is somewhat misleading, the measurements seem to agree. Fitting a capacitor with a similar physical size to the one removed is a good rule of thumb IMO - which often involves jumping up a voltage rating or two.
    2. If the model of capacitor chosen offers small capacitance steps, jump up a rating and measure what you're putting back in. 20% over is better than 10-15% under in my book. I've found some brands/models are worse than others on this front, but if you get into the habit of measuring everything, you get a feel for what to order next time.
    I think the solution isn't to avoid recapping - but rather to be more conscious of what we're recapping with.
     
  10. Bert 1100

    Bert 1100 Super Member

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    Thank you Zaibatsu for the insight, very interesting !
     
  11. Bratwurst7s

    Bratwurst7s In The Frying Pan Subscriber

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    With these comments in mind today I started testing the some of the caps that I bought. The test quantities are admittedly low but interesting nonetheless. All caps tested are fresh out of the package from Mouser in the last week except for a few cases which I'll note as I go.

    Panasonic FM, 100µF/50v, 10 pieces.
    Lowest/highest µF = 103.7 / 104.9µF. Average = 104.5µF.
    Lowest/highest ESR = 0.05 / 0.07 ohms. Average = 0.056 ohms.
    Lowest/highest vLoss = 0.6 / 0.7%. Average = 0.62%.

    Panasonic FC 100µF/50v, 10 pieces.
    Lowest/highest µF = 94.2 / 95.6µF. Average = 95.1µF.
    Lowest/highest ESR = 0.15 / 0.18 ohms. Average = 0.16 ohms.
    Lowest/highest vLoss = 0.7 / 0.8%. Average = 0.71%.

    And a couple of UCC KYB 100µF/50v (I only have 2).
    110.2µF, 0.09 ohms, 0.6% vLoss.
    109.8µF, 0.08 ohms, 0.6% vLoss.

    I don't have any Nichicon in 100µF/50v to directly compare but have some ca 6 month old 63v, 10 pieces.
    Lowest/highest µF = 101.5 / 103.3µF. Average = 102.24µF.
    Lowest/highest ESR = 0.07 / 0.09 ohms. Average = 0.079 ohms.
    Lowest/highest vLoss = 0.7 / 1.0%. Average = 0.79%

    More later,
    James

    edit: I forgot to show the ripple current rating on these, and since this one is for the power supply that might apply. Best to worst in that regard...
    FM: 870mA
    KYB: 620mA
    FC: 615mA
    FG: 255mA

    I guess that I'll be using the FM caps.
     
    Last edited: Dec 26, 2017
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  12. Bratwurst7s

    Bratwurst7s In The Frying Pan Subscriber

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    Nichicon FG 330µF/25v, 4 pieces.
    Lowest/highest µF = 297.2 / 301.3µF. Average = 299.8µF.
    Lowest/highest ESR = 0.09 / 1.0 ohms. Average = 0.95 ohm.
    Lowest/highest vLoss = 1.8 / 2.0%. Average 1.9%.

    Nichicon KZ 330µF/25v 2 pieces, ca 6 months old.
    287.9µF, 0.05 ohms, 1.0%.
    289.2µF, 0.04 ohms, 1.0%.

    I think that I might be looking at ordering some FC & FM for this value. It irritates me that I didn't do so before.

    Nichicon KL 470µF/35v, 4 pieces.
    Lowest/highest µF = 454.3 / 459.4µF. Average = 465.5µF.
    Lowest/highest ESR = 0.9 / 1.1 ohms. Average = 0.1 ohms.
    Lowest/highest vLoss = 0.6 / 0.9%. Average = 0.675%.

    Panasonic FC 470µF/35v, 10 pieces.
    Lowest/highest µF = 439.9 / 452.9µF. Average = 447.2µF.
    Lowest/highest ESR = 0.05 / 0.06 ohms. Average = 0.56 ohms.
    Lowest/highest vLoss = 0.9 / 1.3%. Average = 1.01%.

    Also disappointing. Why am I buying new caps that measure low?

    Cheers,
    James
     
  13. Bratwurst7s

    Bratwurst7s In The Frying Pan Subscriber

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    Panasonic FC 1000µF/10v, 10 pieces.
    Lowest/highest µF = 1013 / 1034µF. Average = 1023.1µF.
    Lowest/highest ESR = 0.06 / 0.07 ohms. Average = 0.069 ohms.
    Lowest/highest vLoss = 1.1 / 1.2%. Average = 1.12%.

    Nichicon FG 1000µF/10v, 2 pieces ca 1 year old.
    819.7µF, 0.06 ohms, 2.17%.
    817.5µF, 0.06 ohms, 2.4%.

    Cheers,
    James
     
  14. Bratwurst7s

    Bratwurst7s In The Frying Pan Subscriber

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    Nichicon KL 2200µF/25v, 10 pieces.
    Lowest/highest µF = 2435 / 2483µF. Average = 2452.6µF.
    Lowest/highest ESR = 0.03 / 0.07 ohms. Average = 0.47 ohms.
    Lowest/highest vLoss = 0.9 / 1.3%. Average = 1.12%.

    Panasonic FC 2200µF/35v, 12 pieces. I bought these from an unknown-to-me outfit in the UK through Amazon. Strictly a backup as the caps that I ordered from Mouser showed 16 weeks backorder at that time. (Now those are showing week-2 2018 delivery). I have no way of knowing how old these caps really are. It will be interesting to compare them with the Mouser caps later.
    Lowest/highest µF = 2062 / 2094µF. Average = 2076µF.
    Lowest/highest ESR = 0.04 / 0.05 ohms. Average = 0.049 ohms.
    Lowest/highest vLoss = 0.9 / 1.2%. Average = 1.15%.

    Panasonic FC 2700µF/35v, 10 pieces. Bought as a backup/upgrade possibility for the FC 2200µF/35v.
    Lowest/highest µF = 2622 / 2747µF. Average = 2694.2µF.
    Lowest/highest ESR = 0.02 / 0.06 ohms. Average = 0.31 ohms.
    Lowest/highest vLoss = 1.2 / 1.6%. Average = 1.48%.

    That's all for today.
    James
     
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  15. Karl vd Berg

    Karl vd Berg Super Member

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    Agree, and that's what I'm doing too, lately - whenever is possible - with new capacitors.
    An example is, by replacing an old 35V cap, if a 63V version is available and fits in diameter, then I use it.

    Indeed, in most cases one value higher than the original version won't hurt (again, in most of the cases), with some exceptions like in timing and DC protection circuits.
    But I can use, another example, a 560uF/63V cap (if available) to replace the old 470uF/35V.
     
  16. Karl vd Berg

    Karl vd Berg Super Member

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    Glad that the FM's meet the DS numbers, James. I should have mentioned these before. I started using them after suggestion by folks in some other threads recently.

    The Panasonic FR series are also very good for both PSU and/or general purpose...
     
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  17. Bratwurst7s

    Bratwurst7s In The Frying Pan Subscriber

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    They do look interesting. I measured all of the rest of the caps for this project today, along with some alternates and more. I need an hour or 2 tomorrow to work out the averages etc and I'll post the results tomorrow. A few more FM, FC, Nichicon ES and even the MKS2 got measured.

    The input selector switch arrived today. It looks exactly like the seller's photos so no new photos.

    I bought Kid Rock's new CD for Wife today, as well as Jeff Beck's Blow By Blow and John Fogerty "Revival". Time to go out front and make some noise...

    Cheers,
    James
     
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  18. Bratwurst7s

    Bratwurst7s In The Frying Pan Subscriber

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    OK. So tomorrow comes today.

    First, imho the new Kid Rock rates a solid "Good". A few songs = Good+, a few = Good-, one that he could have spared. All in all not bad. Born Free is still my favorite CD.
    I haven't listened to Blow By Blow for probably over 30 years. I'm saving that until tomorrow and will listen back to back with "Wired".
    Now John Fogerty's Revival, I give that a VG.
    Just,
    Pure,
    Clean,
    John Fogerty.

    OK. Down to business.

    I only bought 2 Panasonic FM in 33µF/35v.
    34.74µF, 1.1 ohms, 0.6% vLoss
    34.58µF, 1.2 ohms, 0.7% vLoss

    FM 22µF/50v, 10 pieces.
    Lowest/highest µF = 22.36 / 22.86. Average = 22.6µF.
    Lowest/highest ESR = 0.28 / 0.32 ohms. Average = 0.3 ohms.
    Lowest/highest vLoss = 0.9 / 1.0 ohms. Average = 0.94 ohms.

    FC 22µF/35v, 4 pieces.
    Lowest/highest µF = 22.27 / 23.27µF, Average = 22.9µF.
    Lowest/highest ESR = 0.73 / 0.76ohms. Average = 0.75 ohms.
    Lowest/highest vLoss = 1.0 /10.1%. Average 1.05%.

    Nichicon ES 22µF/35v, 10 pieces.
    Lowest/highest µF = 24.65 / 24.89µF. Average = 24.77µF.
    Lowest/highest ESR = 0.51 / 0.53ohms. Average = 0.52 ohms.
    Lowest/highest vLoss = 2.0 /2.3%. Average = 2.13%.

    FC 47µF/50v, 3 pieces.
    47.39µF, 0.68ohms, 1.0%.
    47.54µF, 0.63ohms, 1.0%.
    47.69µF, 0.63ohms, 0.9%.

    ES 47µF/35v, 10 pieces.
    Lowest/highest µF = 24.65 / 24.89µF. Average = 24.77µF.
    Lowest/highest ESR = 0.51 / 0.53ohms. Average = 0.52ohms.
    Lowest/highest vLoss = 2.0 / 2.4%. Average = 2.13%.

    Cheers,
    James
     
  19. Bratwurst7s

    Bratwurst7s In The Frying Pan Subscriber

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    Fc 100µF/63v.
    98.12µF, 0.20ohms, 0.7% vLoss.
    97.71µF, 0.24ohms, 0.5%.

    ES 100µF/35v, 10 pieces.
    Lowest/highest = 98.1 / 99.6µF. Average = 98.6µF.
    Lowest/highest = .10 / .12ohms. Average = 0.11ohms.
    Lowest/highest = 1.3 / 1.6%. Average = 1.46%.

    ES 330µF/35v, 4 pieces.
    Lowest/highest = 343.2 / 346.0µF. Average = 344.15µF.
    Lowest/highest = 0.04 / 0.05ohms. Average = 0.045ohms.
    Lowest/highest = 0.7 / 1.0%. Average = 0.93%.

    My beer ran out. The rest tomorrow.
    James
     
  20. Mark B

    Mark B Yamaha Fan Subscriber

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