TigerScent Posted December 24, 2011 Posted December 24, 2011 I have been doing extensive mods/cap rolling on some equipment, and enjoying the sonic benefits, however, I find it disturbing that the cap life of good audio caps like Elna Silmic II's and Nichicon Muse and others is only about 1000hrs. I dont want to keep resoldering a whole set of caps in an amp every 12 months or so... Does anyone have any ideas or practical experience in extending the lifespan of audio caps? I can think of cooling (ie: putting a fan in the case) and using higher rated voltage caps....Possibly making a round heatsink might work???
LogicprObe Posted December 24, 2011 Posted December 24, 2011 Keeping them cool and using higher volatage ratings will extend the life of any cap. Where'd you get the 1000 hours from?
TigerScent Posted December 24, 2011 Author Posted December 24, 2011 Keeping them cool and using higher volatage ratings will extend the life of any cap.Where'd you get the 1000 hours from? ...on various forums etc..., and if you do a google search for audio caps lifespan etc..., you find out its usually about 1000hrs life span on boutique caps...
LogicprObe Posted December 24, 2011 Posted December 24, 2011 I'm having trouble believing that. You'd think that the more you pay, the longer they'd last!
pete_mac Posted December 24, 2011 Posted December 24, 2011 1000 hours is correct for most boutique caps, and this is based upon 85 degrees temperature. As a rule of thumb, the lifespan of an electrolytic doubles for every 10 degrees reduction in operating temperature. This means that in real-world situations where you are not running equipment 24/7 at high temperatures, boutique electrolytic caps will last MUCH longer than the specified lifespan figure suggests.
Nigel Posted December 24, 2011 Posted December 24, 2011 (edited) No expert, but i recall reading that some/most caps tend to burn holes in their films over time and that one typr 'repairs' itself. I presume that one's properties would last longer ??? Caps is an area where there is likely to be as much BS as there is fact. Is there any reliable doco written for laymen ? Edited December 24, 2011 by Nigel
TigerScent Posted December 24, 2011 Author Posted December 24, 2011 1000 hours is correct for most boutique caps, and this is based upon 85 degrees temperature.As a rule of thumb, the lifespan of an electrolytic doubles for every 10 degrees reduction in operating temperature. This means that in real-world situations where you are not running equipment 24/7 at high temperatures, boutique electrolytic caps will last MUCH longer than the specified lifespan figure suggests. ...so really, installing a fan drawing cooler air into the chassis over/near the caps area is likely to be most effective/practical.
TigerScent Posted December 24, 2011 Author Posted December 24, 2011 No expert, but i recall reading that some/most caps tend to burn holes in their films over time and that one typr 'repairs' itself.I presume that one's properties would last longer ??? Caps is an area where there is likely to be as much BS as there is fact. Is there any reliable doco written for laymen ? ...yes, that happens, but everytime this occurs, the cap loses its tolerance and is less accurate to specs... ...I have googled a fair bit... some, but still not too much info out there...
TigerScent Posted December 24, 2011 Author Posted December 24, 2011 Keeping them cool and using higher volatage ratings will extend the life of any cap.Where'd you get the 1000 hours from? yeah, I always go for higher voltage rates where possible...ie: 63 or 100v instead of 50v etc...
skippy124 Posted December 24, 2011 Posted December 24, 2011 I dont know of any simple on line doc that explains all the ins and outs of caps and their various applications, suffice it to say that there are many many different types of caps for different applications (including self healing film caps). 1000 hours is the min rated lifetime quoted for electrolytics, and it goes up from there. A couple of quick points - 1. Heat is one of the biggest determinators of any components operating life, rule of thumb is the cooler it operates the longer its potential lifetime. 2. Electrolytics are rated for life at max operating voltage, ripple current and temperature. A reduction in any of these parameters in actual operating conditions will extend the rated life. As Pete noted, a 10 deg C reduction in operating temperature results in a doubling of operating life, so an 85 Deg C rated cap will have a 2000 hour rated life at 75 deg C, 4000 hours at 65 deg C, 8000 hours at 55 deg C etc.... and this is stlll at rated voltage and ripple current. 3. Electrolytic capacitors operating in the signal path normally are operating at low ripple or AC currents , thus extending the rated operating life over caps in operating in say power supply filtering where much higher ripple currents are experienced. Cheers John
TigerScent Posted December 24, 2011 Author Posted December 24, 2011 I dont know of any simple on line doc that explains all the ins and outs of caps and their various applications, suffice it to say that there are many many different types of caps for different applications (including self healing film caps).1000 hours is the min rated lifetime quoted for electrolytics, and it goes up from there. A couple of quick points - 1. Heat is one of the biggest determinators of any components operating life, rule of thumb is the cooler it operates the longer its potential lifetime. 2. Electrolytics are rated for life at max operating voltage, ripple current and temperature. A reduction in any of these parameters in actual operating conditions will extend the rated life. As Pete noted, a 10 deg C reduction in operating temperature results in a doubling of operating life, so an 85 Deg C rated cap will have a 2000 hour rated life at 75 deg C, 4000 hours at 65 deg C, 8000 hours at 55 deg C etc.... and this is stlll at rated voltage and ripple current. 3. Electrolytic capacitors operating in the signal path normally are operating at low ripple or AC currents , thus extending the rated operating life over caps in operating in say power supply filtering where much higher ripple currents are experienced. Cheers John ahhhh, now that is making sense...., so, using higher rated caps in the power supply ie: 105 degrees with a more robust type cap...., would be the go, ...in addition to installing an intake fan, if the unit does not have one. ...I like using Silmic II's and Nichicon Muse caps, for signal path, but what are hi-Q robust caps that can be used in a power supply??
Decky Posted December 24, 2011 Posted December 24, 2011 This might help to shed some light on the problem http://www.illinoiscapacitor.com/tech-center/life-calculators.aspx Life os a capacitor is a function of voltage and temperature. 1000 to 3000h ratings stand for maximum operating conditions only.
Batty Posted December 25, 2011 Posted December 25, 2011 Not had to replace any caps in my 1995 Copland ................ so far.
TigerScent Posted December 25, 2011 Author Posted December 25, 2011 This might help to shed some light on the problemhttp://www.illinoiscapacitor.com/tech-center/life-calculators.aspx Life os a capacitor is a function of voltage and temperature. 1000 to 3000h ratings stand for maximum operating conditions only. ...clearly, the same as for PC case..., good-cool-airflow....ie: fans etc ... ...or even, the best way to extend the life of ones audio equipment is to operate it from a coolroom or refridgerator...?!... [...I think ORP would agree, since he suggested operating his turntable in an aquarium to reduce the noise floor...(I wonder if he took to the idea of doing so with his CD/DAC, for a more analogue-induced-effect ??...we are somewhat concerned about him; no sign of him anywhere...)]
andyr Posted December 25, 2011 Posted December 25, 2011 (edited) ...I like using Nichicon Muse caps, for signal path ... I suggest electrolytics should never be in the signal path - only in the PS or as DC rail smoothing caps. Just FYI, I keep my power amps on 24x7 (except when I go away). I installed my 6 x AKSA Lifeforce/Soraya monobloc modules about 4 years ago ... so that means 8,700 hrs x 4 - and there is no sign of any trouble. Then again, AKSA amps, at most, would get to 30 deg on a hot day (inside the case). I think it's tube amps or Class A amps with high bias that suffer from heat stress (and so have shorter electrolytic cap lives). Regards, Andy Edited December 26, 2011 by andyr
TigerScent Posted December 25, 2011 Author Posted December 25, 2011 (edited) I suggest electrolytics should never be in the signal path - only in the PS or as DC rail smoothing caps. hmmm, interesting...thanks ...I was just replacing the type that was in the amp, with the same type from the Silmic II range, and using Nichicon Muse when there is no Silmic II option. I found the Nichicon Muse FW (so far) gives quite good results in the extra large output caps ... however, I have not tried other options. Maybe Cerafine? ...what are you suggesting I replace electrolytic caps with ?? Cheers Edited December 25, 2011 by TigerScent
andyr Posted December 25, 2011 Posted December 25, 2011 ...what are you suggesting I replace electrolytic caps with ?? Replace electrolytics in the signal path (or as shunt caps to earth in the signal path) with film caps. They will be much larger (physically) so you'll have to be inventive, in terms of fitting them in! Regards, Andy
LogicprObe Posted December 25, 2011 Posted December 25, 2011 Replace electrolytics in the signal path (or as shunt caps to earth in the signal path) with film caps. They will be much larger (physically) so you'll have to be inventive, in terms of fitting them in! Sure, electrolytics are used because you can get more capacitance out of a smaller package. There's no real alternative for power supply caps though.
JA Posted December 25, 2011 Posted December 25, 2011 Yes as has already been pointed out heat and also time under load is what will contribute to reduced life in electrolytic caps. To this end consider choosing caps with lower ESR as this will result in lower internal heat genration in the capacitor. You could even consider using a metal heat shield between the caps and any "point" source of heat such as a group of power resistors etc... to help reduce radiant heat transfer or use carefully drilled holes to promote better natural convection around the heat source or the capacitors. Best JA
Zaphod Beeblebrox Posted December 25, 2011 Posted December 25, 2011 (edited) ahhhh, now that is making sense...., so, using higher rated caps in the power supply ie: 105 degrees with a more robust type cap...., would be the go, ...in addition to installing an intake fan, if the unit does not have one....I like using Silmic II's and Nichicon Muse caps, for signal path, but what are hi-Q robust caps that can be used in a power supply?? Your amplifier uses a fan to not only keep the output stage operating at the correct temperature, but also to keep electrolytic caps cool. In practical terms, the large caps in your amp will last around 20 years, whilst the smaller caps (the ones mounted on the output stages) should be replaced every 10 years or so. THEY SHOULD NEVER BE REPLACED WITH ANY OTHER CAPACITOR, unless Peter Stein has measured the specific types you want to use and has verified that they are suitable. Your amplifier was designed to use capacitors with very specific properties (they are made in Taiwan to Peter Stein's stringent specs). Use of other, even quite highly praised caps has, in the past, been shown to cause your amplifier to deliver inferior performance. For the record: The caps in your amplifier have been optimised, depending on the location in the topology of the amp. Replacing, willy nilly, with something that someone, somewhere on the internet CLAIMS is a good thing, may end up damaging the performance of your amp. As I understand it, Peter recently serviced your amp. That would, almost certainly, have involved capacitor replacement. If in doubt, ASK THE MANUFACTURER. Don't ask people who don't know anything about your specific needs. And yes, Pete-mac is correct. 85 degree C caps are uprated, at lower temperatures. They will last more than double their rated life, for each 10 degree C drop in temperature. Edited December 25, 2011 by Zaphod Beeblebrox Brain fart
TigerScent Posted December 25, 2011 Author Posted December 25, 2011 (edited) Your amplifier uses a fan to not only keep the output stage operating at the correct temperature, but also to keep electrolytic caps cool. In practical terms, the small caps in your amp will last around 20 years, whilst the smaller caps (the ones mounted on the output stages) should be replaced every 10 years or so. THEY SHOULD NEVER BE REPLACED WITH AN OTHER CAPACITOR, unless Peter Stein has measured the specific types you want to use and has verified that they are suitable. Your amplifier was designed to use capacitors with very specific properties (they are made in Taiwan to Peter Stein's stringent specs). Use of other, even quite highly praised caps has, in the past, been shown to cause your amplifier to deliver inferior performance. For the record: The caps in your amplifier have been optimised, depending on the location in the topology of the amp. Replacing, willy nilly, with something that someone, somewhere on the internet CLAIMS is a good thing, may end up damaging the performance of your amp. As I understand it, Peter recently serviced your amp. That would, almost certainly, have involved capacitor replacement. If in doubt, ASK THE MANUFACTURER. Don't ask people who don't know anything about your specific needs. And yes, Pete-mac is correct. 85 degree C caps are uprated, at lower temperatures. They will last more than double their rated life, for each 10 degree C drop in temperature. Hey Zaph, ... I totally appreciate your concern... ...however, have-no-fear....I am not replacing 'any' caps or anything in the ME 550...., except what I told Peter I would do, that is, put silver strips internally in parallel with the output leads already there, leading to the RCA out speaker terminals..., aside from that...I am touching NOTHING...., it cost me a small fortune (probably gave me a good price) to get him to do what he did, and I am not going to compromise that... ...so, I am now thinkingabout extending cap life..., so I am going to put a fan in the TC-750 and any other amp without fans....,taking into consideration air-flow characteristics etc.... ...but 'not' the ME-550 Type I... Edited December 25, 2011 by TigerScent
Zaphod Beeblebrox Posted December 25, 2011 Posted December 25, 2011 ...but 'not' the ME-550 Type I... Smart move. Whilst it is possible to make minor performance enhancements to the ME550, replacing caps is not the way to go. And of course, the biggest performance improvement possible with your ME550, is to use the correct preamp.
TigerScent Posted December 25, 2011 Author Posted December 25, 2011 Smart move. Whilst it is possible to make minor performance enhancements to the ME550, replacing caps is not the way to go. And of course, the biggest performance improvement possible with your ME550, is to use the correct preamp. O - tell me about the 'minor performance enhancements'.....??? ...yes, I am keeping my eye out for garage sales and 'cash-converters' for an ME-preamp...I remember vaguely possibly seeing an ME in one of those places years ago..., not knowing what it was....
speedgod66 Posted December 25, 2011 Posted December 25, 2011 Zaphod how much would it cost to get an ME1500 serviced and caps etc replaced and brought up to standard ?
Zaphod Beeblebrox Posted December 25, 2011 Posted December 25, 2011 Zaphod how much would it cost to get an ME1500 serviced and caps etc replaced and brought up to standard ? The ME1500 is a large, very complicated amp to work on. I would need to examine the amp to determine what needs to be done. As a VERY rough generalisation, the range of costs would be approximately: * Simple cap replacement (all small electros in both output stages + control module), bias check and adjust - $350.00. * As above + fan control repair/replacement (often required in older amps) - $700.00. * As above + full foam replacement (normally required if the amp has not been serviced in 10 - 15 years) - $1,400.00. * The above should cover almost all eventualities. Little else ever causes problems in the ME1500.
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