Old Capacitor How Bad Are They ? . Testing old Capacitors from a Sansui Receiver. recapping

[@soundsofthe70s73]

Nice video Michael and amazing how far some of these caps are out. I looked up the 200 and its quite an interesting little receiver. Seems like Sansui still built a nice unit even at just 5 watts and with no cut backs in the amp section.

[@MichaelYates]

Would expect this was still quite expensive back then compaired to wages

[@Mikexception]

I have my own thoughts about electrolytic capacitors in very old gear. I would expect that some 60 years ago all capcitors specially those of big values ( which were at time somehow new development after tube technology where max applicable was like 40 uF) , if only were above required by engineers values shown in schematic were used in production line. u Just having in mind Gauss curve" Because productiion was not accurate and cost much more than today then for "every case " they produced above nominal values and hoping that "too much" will be not criticized by users . , Even if value was more than 20 % but it was not affecting sounding and operation were considered fair for use. They were considerably bigger than today so it could be easy achieved by few more twists of folia . With bigger only issue is that lowest range should be upbeated, oveloading to some percents transistors when driven hrd so when replaced it could add clarity. In old stuff were used old speakers with more eficiency than today so it could be not so easy noticed. it is not explanable for me In other way how in all old devices in 95% are found above nominal. Today production is much more accurate, they are very small in compare and often values vary also in minus. In that cease it may be rejected in line because so cheap and they are often sold as spare parts by elelctronic shops. . In vintage gear only less than nominal values were not aloved due to obvious problems to operation. Projecting gear with one raw bigger value (spare due to production accuracy problems ) would provide rise of size of gear and price of elements. My way is to check operation of gear - if supply is right, no mains hum, no abnormal sounds when switched on and both chanells work exactly with same loudness and timbre it is 99% possibility that electrolytic capacitors are ok and other in solid gear are unlikely damaged. Red light is when in one channel loudness is lower .

[@helifynoe9930]

Old non-polar electrolytic capacitors can really show a difference with age. I had two 250uf caps in my old 1976 audio power amp, and now one read 440uF and the other was 370uF. The leakage was causing significant over heating of the power transistors. Once the capacitors were replaced, everything was back to being cool again.

[@jimsregaturntableshifijukebox]

Very interesting, and nicely done Michael. Another like fro me, my friend.👌 Jim🏴󠁧󠁢󠁳󠁣󠁴󠁿🙂

[@MichaelYates]

Thanks for taking the time to watch Jim, all the best Michael

[@gezparks9630]

Another youtube video of a NAD 3020 cap restoration sound comparison demonstrated a clear improvement audible over my mobile phone! Post cap replacement sound was much more focused, lively and dynamic. You dont realise what all the fuss is about until you hear it for yourself. Only problem is the professional repair cost involved !

[@gregebert5544]

As wacholder5690 mentioned below, you have to be suspicious of low-cost testers that show old caps reporting higher-than-spec values. Aluminum electrolytics have a liquid internal electrolyte that dries-out over time from leakage and venting, and that will degrade the capacitance and the dielectric. I would reform the caps by charging them to their rated voltage and check their leakage current. It wouldn't surprise me to see increased leakage. I've seen a few aged electrolytics short-out and cause other components in the power supply to overheat. As a general rule, when I scrap an electronic gizmo, I never re-use any of the capacitors and only purchase fresh ones from a reputable supplier.

[@vinyllouver9589]

I have noticed the Sansui's going up in price. There was a 441 that sold for £330 recently though a few months back could be bought for around £100. The 101 is another gaining price. Think it might be due to you and Stereo Review X praising these models

[@MichaelYates]

Think Kelvin is a big part of this. I also noticed the £330 the 441 sold for.

[@sp0001-i7g]

Nicely done, all these old caps need replacing some are way out of spec and might cause problems later on. I think you have choosen the correct value on the power supply caps as any higher you would think about changing the bridge diodes as well. In my opinion any more that 2200 would not bring anymore to the table with this little receiver. With all the values shown its no surprising it sounds a lot better. There are a lot of electrolytics that I counted to be replaced, think you are about half way through so good luck with the rest.

[@MichaelYates]

Thanks for the comment, yes think there around 30 in this receiver. I was thinking the same about the bridge rectifyer

[@shaneonpole]

Thank you for your video, very informative. May I ask what you use for your main music input source...is it vinyl, CD or Online streaming from providers such as Spotify? Thanks Shane

[@MichaelYates]

Hi Shane, I would say 90% is from CD as so cheap at the moment and the other 10% vinyl. Im not really interested in streaming I don't think its a service for me

[@marcusbridges1851]

MIchael I have a Pioneer sx6300 and it sounds a bit dull do you know how much it would cost for me to get someone to recapp it ?

[@MichaelYates]

TBH not really got much of an idea, though I did see an advert on eBay a while ago quoting £130 for a basic amp. I would expect the 6300 to be a basic amp

[@wacholder5690]

The problem with old caps is ESR and Loss. If the loss exceeds a certain range the meter will need longer and longer to catch a stable value - which results in way higher capacity. But that's a phantom value. These cheapo testers barely reflect the real condition, because they lack the ability to connect ESR and loss against the charge and discharge curve. Rule of thumb if you use this kind of tester: watch the loss factor first. Then ESR. If both of these are in the high range (above 1% loss and ESR above 1 Ohm) the detected capacity is useless. But in this case the caps are worn and out of spec and should be replaced. Figuring the capacity in a proper way requires a resonance meter that operate with AC and tests the charge / discharge against a precicion resistor. That measurement includes the ESR and loss into the equation.

[@MichaelYates]

Thanks for the thoughts on these type of meters, I only really use this meter for testing transistors and pinouts. I will have to look around for a decent one. Though must say I am very pleased with the results so far maybe down to the sound signature of the caps I used so far.

[@wacholder5690]

@@MichaelYates If you don't repair stuff as a professional these little testers are some 100 percent better than nothing or the usual "guesswork" with a resistance meter. I use them myself for getting a quick overview. But as noted: the capacitance value alone is worthless if loss and ESR are too high, since the test bases on the time measured for charge and discharge with a comparatively small voltage and charge current - which is heavily influenced (or falsificated) by the other two. 🙂 A good indication on your video is, that the deviation of the capacity measured vs. that printed on the component grows bigger and bigger with the rise of the losses. A truely dead capacitor shows either a short (shows resistor symbol instead of capacitor) or no capacity (shows capacity symbol but with minimal capacitance). A capacitor "out of range" has bigger losses and ESR in first place - which renders it useless for filter or transfer applications. Shorts couple DC or trip a supply fuse and an open one eliminates the signal ... or causes hum if used as a DC-filter cap. Residing in Germany I repair antique hifi-stuff on a regular basis, since my job as a computer field engineer is just swapping parts in first place. And I truely miss the "solder actions" I had to do when I started back in the mid-80s.

[@HillsWorkbench]

@@MichaelYates I'd like to know the model name or number. This unit is superior in that it tests ESR first.

[@MichaelYates]

@@HillsWorkbench Hi I cannot see a model number on unit but here is a link to one on eBay www.ebay.co.uk/itm/354632424567?_skw=transistor+tester&itmmeta=01JBM4VAH6QN70PA5G78EFJX27&hash=item5291bd5c77:g:MZ0AAOSw3wlkBq8Z&itmprp=enc%3AAQAJAAAA8HoV3kP08IDx%2BKZ9MfhVJKmpQnXoqhXRr87aSpEv8IXkuLhQaPHXlZCdgxf%2BojrnMyWgrjzQAsrnKxtkmSFKr60Rzsn4Ue7VtNOaw3wHcbSvIgkVRsYoI5dYWU%2FNE42asqhQR%2FRmCGBVBmIks4p7cMHdvneMSuNvNBZ2Cc3kaJGZkzyRmznYKmZDo4Q0fNf8niI%2BdB%2F791WNkZRkLeTx3khU6zbj%2BkqrYJOJuAFVOHtWSAoJj04cOcCGoY8VFvUAloyBpanPyltunVh7fmRPoMDWqztXE2%2B5T8QpwioYKTgHgawXVPw2CydVn3u6LQ8DGA%3D%3D%7Ctkp%3ABk9SR5ip7YTdZA

[@paulborodea4957]

I saw many people using radial leaded capacitors for smoothing like these 1000uf in your Sansui. Why you do not use snap-in type which are better for this application. The ripple current is better, you can choose the right diameter and stop using foam arround the capacitor body.

[@MichaelYates]

Thanks Paul for a good question. I used the 2200uf radial ones as they were just sitting in my parts drawer. If I did not have them to hand then yes I would have ordered some snap in ones I think they look a lot better clamped in nicely and as you say the ripple current is a little better. The ones I put in seem to be doing a good job though a little untidy. ps just subbed to your channel

[@jedi-mic]

Try a 470uF 250 volts capacitor on the other side of Bridge rectifier where it comes from the transformer. I would up the capacitors to 4,400 but use two in parallel 2200. That should be fine especially with the 470 cap having a small value on the transformer protecting it from in rush current. Check the transformer when you turn it on from cold it doesn't get hot! if you're going to go higher values you need to really use a thermistor or slow start circuit like if you're gonna run 20,000 or Plus what capacitors did you use code?

[@soundsofthe70s73]

Mic, I have a little look at the receiver and the diagram and for what I can see it has the 2x1000uf just after the rectifier so was wondering what the 470uf would be doing? also its only got a dinky little transformer and would the 4400uf be to much for it. I am only a novice but I find asking questions is the way to learn.

[@jedi-mic]

@@soundsofthe70s73 the reason for the 470 or lower, is you protect the transformer from rush current when you have bigger capacitance, when you put it on? the capacitors draw a lot of current because of the capacitance, and that puts strain on the transformer till they charge. Also it gives you some filtering from the transformer to the rectifier stage. you can put a x2 or x1 0.47uF 250V safety capacitor across it as well probably visible, you're not going to get much rush current at 4,400uF I just say if you're going up to over 20,000uF could be an issue!! if it's a very small transformer. You start it up listen for Hum you shouldn't really hear any more than normal that could be an indication that your straining it and the heat.

[@soundsofthe70s73]

@@jedi-mic Thank you for your reply. I now understand

[@MichaelYates]

Thank Mic for your advice on the upgrades. I will keep these in mind I have just found some of the other caps I require and should be how to finish the reaccping over the weekend. As for part numbers all I know is they were Rubicon caps and not got the order notes as had them a good while in my draw. looking at some I have in front of me they are 105c 1943 PET on them if that helps

[@larcat3148]

Is that a non polarised plastic / polyester film type cap ?

[@BenState]

What frequency are you testing?

[@MichaelYates]

I was just generally listening to some cd's before and after the part recapp

[@paulziminskin2ghr282]

Too much talking..

[@MichaelYates]

Sorry Paul I do waffle