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Post by petet on Jul 5, 2020 14:45:34 GMT
Hi folks, I'm a newbie here, and I guess like others got here by looking into an issue... I've had my X-cans for a few years, bought from the bay, and it's been fine till the other day when listening it lost the music behind a wall of noise. After turning it off and letting it cool down, it sounds great again for a while, maybe an hour, then the noise starts up and the music is barely audible. I've taken a look inside and it has obviously had some upgrades done previously... from looking on here I can tell it has upgraded volume pot, phones jack, caps, sockets etc Thinking it might be a valve.. I've chucked a couple of new Teslas in as a test, but no change... I'm hoping someone here will recognise the symptoms and maybe know the fix..? Many thanks in anticipation... Pete    |
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Post by PinkFloyd on Jul 5, 2020 20:13:27 GMT
Hi folks, I'm a newbie here, and I guess like others got here by looking into an issue... I've had my X-cans for a few years, bought from the bay, and it's been fine till the other day when listening it lost the music behind a wall of noise. After turning it off and letting it cool down, it sounds great again for a while, maybe an hour, then the noise starts up and the music is barely audible. I've taken a look inside and it has obviously had some upgrades done previously... from looking on here I can tell it has upgraded volume pot, phones jack, caps, sockets etc Thinking it might be a valve.. I've chucked a couple of new Teslas in as a test, but no change... I'm hoping someone here will recognise the symptoms and maybe know the fix..? Many thanks in anticipation... Pete Hi Pete, Your pics arent showing mate. Mike. |
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Post by petet on Jul 5, 2020 22:55:06 GMT
Ah... That'll be access permissions then... As they show up for me. Right, try again... Having burnt half my flikr pics so as to upload some more, it seems the tapatalk app can use phone gallery pics... Hoorah.! Why didn't I think of that before.! Hope all good now....    |
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Post by PinkFloyd on Jul 6, 2020 11:20:10 GMT
Hi Peter,
Are the small yellow caps (10uF) Nitai non polar types?
Mike.
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Post by petet on Jul 6, 2020 17:05:59 GMT
Hi Peter, Are the small yellow caps (10uF) Nitai non polar types? Mike. Hi Mike, Yes indeed they are... Well spotted - I had to wait till I got home from work to confirm. I notice there's some heat discoloration of the board at TR102 and 202... Is that normal.? (I've no electronics training or real experience...) Whilst looking I did discover a loose solder joint on the line in ground connection, now re-soldered. Cheers, Pete |
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Post by PinkFloyd on Jul 6, 2020 19:28:58 GMT
Hi Pete, The reason I asked if they were Nitai non polar caps is because the only yellow non polar caps I have ever come across are Nitai and they are the low end of the food chain when it comes to caps  The ONLY 10uF caps that should be Non Polar types in the X-CANS are C103 and C203 (these are the input coupling caps) the rest of the 10uF caps should be bi-polar types (C111 / C110 / C211 / C210 / C109 / C209) Looks like somebody (hopefully not me!) has fitted non polar caps in all of the 10uF positions. I don't reckon that is causing your sudden dropout from music (for an hour) to distortion though. I would be looking at the capacitors on the upper PCB (power board) seems that one or more may be going into failure mode and going high ESR intermittently...... what that means (in very simple easy to understand language) is your car battery is fine for an hour and then a gremlin kicks in and decides to impede the flow of current by introducing resistance to the flow of current. Bottom line, it's one (or more) failing capacitors on the power board that is causing this "one hour dropout" phenomenon. Physical signs are usually a bulging capacitor..... the tops sometimes start to show signs of bulging..... but I can't see the tops of the caps as they appear to be covered with felt pads...... remove those felt pads and have a look at the state of the tops of the caps. I, personally, would recap the entire amp...... it's not expensive, that would definitely do the trick and would ensure the amp was good to go (and sound better than it EVER did) for another 30 years Pete. You're photos are not too clear (try macro mode next time) but I can see that the opamps are in DIP 8 sockets...... the stock NE5532 opamps are soldered direct to the PCB so the opamps in your amp are also not inkeeping with the stock build....... My guess, from looking at them through a rose tinted glass, is they are either OPA2132 or OPA2134? Please confirm. Anyhoo..... I'll stop waffling on (I'm starting to bore the f**k out of myself). Mike. |
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Post by petet on Jul 6, 2020 21:50:18 GMT
Yawn, yawn...😁
Yes the opamps are BB opa2134s
It seems the issue may have been the dry solder on the line in... It's been running fine since I did that - I always test after any change - years of working in engineering and IT..!!
But I'd still be very happy to upgrade the caps to the best suited as there's no point doing half a job, luckily I believe you might be able to help out with suggestions and supplies on that front?
Thanks for your input and advice so far...
Pete
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nando
Been here a while! 
The Frying Dutchman
Always look on the bright side of life
Posts: 393 
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Post by nando on Jul 7, 2020 18:30:17 GMT
Why would one place felt pads on caps?
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Post by petet on Jul 7, 2020 19:03:33 GMT
Hey Nando, Wasn't me, so not sure, but they didn't hold back on them... There's four or five on the board top and bottom as well... Can only imagine they're meant for mechanical damping..? Pete    |
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Post by PinkFloyd on Jul 7, 2020 19:54:33 GMT
Why would one place felt pads on caps? erm...... "guilty"  There was a trend for "skinning" caps a good few years ago and I, at the time, also thought it a good idea to "dampen" capacitors (I still do to a degree)...... the cheap felt pads were an ideal way to dampen the caps and bought about "slight" improvements to the sound quality..... there were even instances where I would mount the capacitor on butyl rubber and totally encase the capacitor with butyl rubber..... very effective but fugly! (f**kin' ugly). To this day I swear by skinned and polished caps, I skin and polish all of the caps in my personal gear, the difference is not night and day but the skinned caps deffo have the edge. I wouldn't supply a kit of parts with skinned caps for obvious reasons....... the recipient would think I was passing off crap caps...... the reason I leave the skins on is to show they are getting the real deal from day one. Totally down to the end user to decide whether or not to skin the sleeve off a cap. rockgrotto.proboards.com/thread/1667/capacitor-mystery-solvedDampening etc. was a big thing here, back in the day, the "BLOB" (to this day) is one of my best sounding amps...... strange days Nando but we were actively pushing the envelope and thinking out of the box: rockgrotto.proboards.com/thread/6843/useful-tweak |
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Post by PinkFloyd on Jul 7, 2020 20:14:28 GMT
Anyhoo, Pete.
I may have been responsible (in one way or another) for the goings on inside your X-CANS (V1) all those years ago..... I actually think I modded that amp back in 2006, there's just something about the look of it that gives me the feeling it's one of my very early ones.
I know you've got it back up and running by soldering the dodgy ground connection but, hey, this has bought back good memories mate...... PM me (message me) and we can arrange to get your V1 modded to the tits free of charge Pete.
I'll send you an email.
All the best,
Mike.
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Post by PinkFloyd on Jul 7, 2020 20:21:56 GMT
The Dubilier 470uF is the dead giveaway........ that's one of mine, guilty as charged...... must be 20 years ago? Totally NOT embarrased, it has given 20 years of good service, BUT it needs to be bought up to speed Mike. |
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nando
Been here a while!
The Frying Dutchman
Always look on the bright side of life
Posts: 393
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Post by nando on Jul 8, 2020 8:55:33 GMT
Are you just suggesting there is a lifetime warranty? 😁
These felt pads sound like hard core voodoo to me. A light pad like that could not possibly change the resonance frequency of a cap that is mechanically attached to the pcb with solder.
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Post by PinkFloyd on Jul 8, 2020 20:46:35 GMT
"Are you just suggesting there is a lifetime warranty? 😁"
No, stupid me, I was just being nostalgic..... my bad.
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Post by PinkFloyd on Jul 8, 2020 20:52:14 GMT
Are you just suggesting there is a lifetime warranty? 😁 These felt pads sound like hard core voodoo to me. A light pad like that could not possibly change the resonance frequency of a cap that is mechanically attached to the pcb with solder. |
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Post by PinkFloyd on Jul 8, 2020 20:52:54 GMT
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Post by PinkFloyd on Jul 8, 2020 20:58:49 GMT
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Post by PinkFloyd on Jul 8, 2020 21:12:22 GMT
the Head-Fi timeline is all wrong........ I didn't become a member in "2009"..... I was one of the founder members back in the day (circa 2003) and helped kickstart head-fi....... I don't want to go down that route, I haven't spoken to Jude for years, I don't want to speak to Jude BUT I am pissed off that I have been "historically" erased from "one of the founder members of Head-Fi" to a "member" in 2009.
Oh well, not a biggie.....
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Post by mrpharmacist on Jul 9, 2020 5:33:59 GMT
the Head-Fi timeline is all wrong........ I didn't become a member in "2009"..... I was one of the founder members back in the day (circa 2003) and helped kickstart head-fi....... I don't want to go down that route, I haven't spoken to Jude for years, I don't want to speak to Jude BUT I am pissed off that I have been "historically" erased from "one of the founder members of Head-Fi" to a "member" in 2009. Oh well, not a biggie..... When people ask what you do you could say you're redacted. Sounds vaguely exotic. Vaguely. |
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