First look for a 'Rifa' mains filter cap as these are notorious for splitting and stinking. The smell is totally overpowering but often there is smoke as well.
Beyond that it could be anything...
Beyond that it could be anything...
thanks guys,
the owner just mailed me that the resistor stinks... but not that much the caps... i'll ask him to take better pictures, so that i can see better,
thanks again will get back to you guys
the owner just mailed me that the resistor stinks... but not that much the caps... i'll ask him to take better pictures, so that i can see better,
thanks again will get back to you guys
the main filter is on a small print, i can see the back of it, but not the rifa cap itself...
the owner is dropping it off at my place, so that i can look for myself. he made a close up of the resistor and it looks fried. i wonder why that would go. never seen a resistor overheating without a reason.
the owner is dropping it off at my place, so that i can look for myself. he made a close up of the resistor and it looks fried. i wonder why that would go. never seen a resistor overheating without a reason.
Attachments
There is something gungy on the resistor but the resistor body itself doesn't look discoloured.
I wouldn't like to say on tbh. It would help to perhaps see what the resistor does on the circuit. There looks to be bit of discolouration on the pcb at the left, but not at the right.
Could something have been spilled into it?
I wouldn't like to say on tbh. It would help to perhaps see what the resistor does on the circuit. There looks to be bit of discolouration on the pcb at the left, but not at the right.
Could something have been spilled into it?
Change all the electrolytics in both the preamp and power amp their old enough to start giving trouble, the resistor could be part of the power supply and a bad electrolytic cap is overheating it. And yes it could have something spilled into it, but use this opportunity to get ahead of future trouble.
both the power amp as preamp is coming over.
i have a capacitor and esr measuring tool.... i will measure the caps...
it could makes sense to change them all; they are at least 19 years old...
anyone with advice on what to replace them with ? just looked around
nichicon dubilier mundorf ... 5000uf/63v (for the preamp) double for the power amp.
what with the other caps ? diodes ?
oh yeah: i think the resistor looks to be right behind an input, anyone who knows where to find the shematic... i have been looking for it
thanks guys
i have a capacitor and esr measuring tool.... i will measure the caps...
it could makes sense to change them all; they are at least 19 years old...
anyone with advice on what to replace them with ? just looked around
nichicon dubilier mundorf ... 5000uf/63v (for the preamp) double for the power amp.
what with the other caps ? diodes ?
oh yeah: i think the resistor looks to be right behind an input, anyone who knows where to find the shematic... i have been looking for it
thanks guys
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If the caps are 10000/63, I still have a decent supply of these original Densen´s.
PM me if you need any 🙂
PM me if you need any 🙂
hi guys,
the preamp has left the building. all the resistors you see on the first post photo are input resistors of 301 ohm directly after the cinch connectors. they all measured 301 ohm.
the first two had some brown fluid under them. i desoldred one leg of each, i wanted to see how the underside looked... they looked fine, (i left them one leg loose, cause the owner only uses 2 inputs).
i put a bit of toilet paper on the brown stuff and i was surprised that it soaked up immediately as a fine brown fluid. it must have been there for at least 15 years (it is the first time the amp was opened up..
a few questions arise
1)what was it ? (must been something that can stay fluid and not evaporate within 15 years) has to be some kind of oil; to me it remembered me of some very fine chain oil.
2)why the smell: the resistors don't heat up, or was the fluid acting as a conductor and heated up ?
(still it's strange, since it is an input and the input signal is not that powerfull... so i checked what was connected: a MF X-CAN preamp tube... and that was doing just fine, voltage was fine, no DC..... so not really an aswer to what caused the "heating up" of the fluid...
i checked all the caps too,and they were fine, very fine; so i left them in there. i guess that within 5 years i might change them in this preamp and the poweramp (which all looked fine)
11.26mf 0.18ohm Vloss:2.6%
11.39mf 0.17ohm Vloss:2.3%
10.83mf 0.18ohm Vloss:2.9%
10.84mf 0.18ohm Vloss:2.6%
11.12mf 0.18ohm Vloss:2.6%
11.01mf 0.17ohm Vloss:3.3%
12.09mf 0.16ohm Vloss:2.9%
12.17mf 0.18ohm Vloss:2.6%
i got a mail from a member who would sell original densen caps (he got them via a danish diy site...)
i had mailed densen to ask what could overheat those resistors and this is the answer (very kind people i must admit)
the cause for the heating of the resistor can be several, but it might have something to do with the capacitors being old. Over time they dry out and get slow at charging and de-charging We recommend have them changed about every 10-15 years.
It could also simply be as a result of an overload.
If you wish we can sell you the parts, but I can't guarentee this will work in the long or even short term, as there might be an overlying issue.
I can't see exactly which components the pictures are of, but some of these old capacitors we no longer have in stock as they were custom made for our specifications back in the days. When swapping them out we use Audio grade Nippon Chemicon capacitors which are of a newer spec and will serve very nicely as a replacement.
To be honest I recommend sending the unit to us so we can have a look at it. A Repair like this is in the neighbourhood of 3000 DKK.
i have connected the preamp in my system, and i could immediately feel the change. For my taste it puts out to much highs, the sound becomes more detailed so the first seconds you tend to hear more, but after 5 seconds fatigue gets to you. It is something i heard in the system of the owner... we both attributed to the audionote speakers (i tought they be more orientated at tubes) but in my system the same (tripath amp, with diy speakers: scanspeak revelators 8" and tweeter bookshelf). what i found is that the amp uses toshiba transistors: 2c3423 a1360 ; looked around on the internet and i'm not the only one that thinks that the highs are a bit to present.
QUESTION; i was looking for a drop in that might sound better: but that is hoping for a miracle; a drop in, in a certain topology and that has to sound better... no solution was found, but if somebody knows one: please let me know. i'll do the same.
i have add some pictures if anybody needs them.. you never know.
thanks a lot people.
kind regards
The dude abides
the preamp has left the building. all the resistors you see on the first post photo are input resistors of 301 ohm directly after the cinch connectors. they all measured 301 ohm.
the first two had some brown fluid under them. i desoldred one leg of each, i wanted to see how the underside looked... they looked fine, (i left them one leg loose, cause the owner only uses 2 inputs).
i put a bit of toilet paper on the brown stuff and i was surprised that it soaked up immediately as a fine brown fluid. it must have been there for at least 15 years (it is the first time the amp was opened up..
a few questions arise
1)what was it ? (must been something that can stay fluid and not evaporate within 15 years) has to be some kind of oil; to me it remembered me of some very fine chain oil.
2)why the smell: the resistors don't heat up, or was the fluid acting as a conductor and heated up ?
(still it's strange, since it is an input and the input signal is not that powerfull... so i checked what was connected: a MF X-CAN preamp tube... and that was doing just fine, voltage was fine, no DC..... so not really an aswer to what caused the "heating up" of the fluid...
i checked all the caps too,and they were fine, very fine; so i left them in there. i guess that within 5 years i might change them in this preamp and the poweramp (which all looked fine)
11.26mf 0.18ohm Vloss:2.6%
11.39mf 0.17ohm Vloss:2.3%
10.83mf 0.18ohm Vloss:2.9%
10.84mf 0.18ohm Vloss:2.6%
11.12mf 0.18ohm Vloss:2.6%
11.01mf 0.17ohm Vloss:3.3%
12.09mf 0.16ohm Vloss:2.9%
12.17mf 0.18ohm Vloss:2.6%
i got a mail from a member who would sell original densen caps (he got them via a danish diy site...)
i had mailed densen to ask what could overheat those resistors and this is the answer (very kind people i must admit)
the cause for the heating of the resistor can be several, but it might have something to do with the capacitors being old. Over time they dry out and get slow at charging and de-charging We recommend have them changed about every 10-15 years.
It could also simply be as a result of an overload.
If you wish we can sell you the parts, but I can't guarentee this will work in the long or even short term, as there might be an overlying issue.
I can't see exactly which components the pictures are of, but some of these old capacitors we no longer have in stock as they were custom made for our specifications back in the days. When swapping them out we use Audio grade Nippon Chemicon capacitors which are of a newer spec and will serve very nicely as a replacement.
To be honest I recommend sending the unit to us so we can have a look at it. A Repair like this is in the neighbourhood of 3000 DKK.
i have connected the preamp in my system, and i could immediately feel the change. For my taste it puts out to much highs, the sound becomes more detailed so the first seconds you tend to hear more, but after 5 seconds fatigue gets to you. It is something i heard in the system of the owner... we both attributed to the audionote speakers (i tought they be more orientated at tubes) but in my system the same (tripath amp, with diy speakers: scanspeak revelators 8" and tweeter bookshelf). what i found is that the amp uses toshiba transistors: 2c3423 a1360 ; looked around on the internet and i'm not the only one that thinks that the highs are a bit to present.
QUESTION; i was looking for a drop in that might sound better: but that is hoping for a miracle; a drop in, in a certain topology and that has to sound better... no solution was found, but if somebody knows one: please let me know. i'll do the same.
i have add some pictures if anybody needs them.. you never know.
thanks a lot people.
kind regards
The dude abides
Attachments
🙂 To may unknowns about the history of the amp to make a judgement call. I'd still say spillage of some kind was a possibility.
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