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Thanx Tony the pictures help.

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You are right these are the caps I would leave alone.

Polypropylene ( I called them polyprop for short)? are one of the few capacitors to have no temperature drift.? They rarely fail.

Take a look at the voltage ratings of the polyprop caps in the back of the Xpander service manual.?They are rated for much higher voltages then they would ever encounter in the Xpander?( some are rated for 1000 volts)????

and they are getting harder and harder to come by. There are alternatives but you are talking about big money.???

Also keep in mind these are precise caps used in the?tuning and filter?circuits. Replacing these with a part that is not exacty the same,?

would shurly result in tune fails.?Not to mention if the tech forgets to clean the solder rosin off the board.

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The electrolytic caps are really the only type that are going to wear out.?? So imho I would not mess with em.

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btw? the little brown bean looking cap ( Cx43)is a mica cap also hard to find and near indestructable

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Best Regards

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Karl

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???

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On Tuesday, February 24, 2015 1:40 PM, "Tony Cappellini cappy2112@... [xpantastic]" <xpantastic@...> wrote:

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[ from Tony Cappellini included below]

Thanks for the info Karl.

That battery is the exact same one in my Xpander currently.

Looking at the attached picture of my voice board

Regarding the polyprop caps- when people recap their voice boards, do they just replace all other caps except these?

Looking at the voice board, at the left most voice- are these examples of the polyprop caps C206,C207 (orange, tubular), and C212,213 (blue, rectangular) ?

What about C222? I can't tell if it is electrolytic from looking at the picture.

There is a very small number of electrolytic caps in the voice circuits,I will just replace these, but it just seem unusual not to replace

the caps that are in abundance (the polypropylene ones)

Are? there no substitutes for these? Tantalum or polystyrene?

On Mon, Feb 23, 2015 at 4:30 PM, Karl Schmeer shire03@... [xpantastic] <xpantastic@...> wrote:

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Hi Tony,

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Here is a link to the battery:

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All electrolytics will wear out with age. However the ones under the most stress ( ie..? power supply filters )? will?usually fail sooner.

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Ceramics will change their capacitance with age, but its pretty rare to see one fail.??Most of?the ceramics used in the Xpander are bypass caps to keep the power supply lines to the digital chips clean.? If they are out of?spec no one would ever notice.?

?

As far as your voiceless voices: Look at Cx49? ( I think x is the voice number )? on the analog voice board.? I have seen this cap fail?many times.?It will definetly cause a tune fail.??

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When shopping for caps look at the MTBF ( Mean time before failure) ?number.?? The larger this number the better the reliability,

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I would recommend Panasonic?as a?vendor because they list this number in their data.?

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One final note.?? The voice boards use polyprop caps for setting the VCO's and?VCF's ?frequency.? They don't look anything like an electrolytic.

but they are special caps that are hard to find?these adays.? I would?leave these alone.

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Best Of Luck?

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Karl

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On Sunday, February 22, 2015 1:16 PM, "cappy2112@... [xpantastic]" <xpantastic@...> wrote:

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Happy New Year Xpander/M12 owners,

For the sake of prevention, I want to replace the battery in my Xpander, as well as the caps

on the power supply board.

At the moment, the battery looks clean, no signs of leakage.

For those who have replaced batteries, would you post the part # and vendor information?

Are there any calibration settings that need to be backed up like on the OB-8, or does the battery just back up the patches?

C3 is showing signs of deterioration, so I will just replace all of the electrolytic caps (C1, C3, C4, C5, C6, C7,C8, C9, C15).

Do I also need to replace the non-electrolytics (C11, C1C13, etc) ? Do these degrade over time?

After I get the battery & power supply overhauled, I'll start on the voice board, and will ask for advice when I get there. I know 1-2 of the voices failed auto tune, and sound a little squarely. I'll disable the good voices so I can focus on these. I know Karl, PeWe and others can diagnose which parts are likely to be bad just from the decryption of the symptoms.

There are ceramic & other non-electrolytics on the processor board. Do these need to be replaced?

Would you post high quality brands to use for the caps, I'd rather avoid the cheap stuff.

Also, preferred vendors would be welcome. I'm OK with Digikey, Jameco, Mouser.

If there are other components that should also be replaced do to degradation with age, please suggest them as well.

Thanks for your advice!!

Tony