The Surprising Truth About Old Capacitors

we took a taxi hi everyone just a quick video here to report on something surprising some of you may find useful or interesting today I was working on an old Dinoco pas 3x preamp I'm restoring it's in pretty good shape but apparently got plenty of you says all the 12ax7 tubes tested as barely breathing the preamp dates back to 1971 so at almost 50 years old I assume that along with the tubes all the coupling capacitors would need to be replaced as well I started by making a quick drawing of the two PC boards showing the positions alignment and values of the caps I plan to replace for fun I tested the first one I removed for leakage and was amazed to find that it tested perfectly I then tested it for capacitance and again it was spot-on I removed five more capacitors from the boards and every single one tested perfectly at that point I determined that all of the capacitors on the board I had planned to replace were not of the paper variety but of a newer mylar style similar to today's modern capacitors i scrapped all plans of replacing them and decided to reinstall the ones I removed and not bother testing the rest if there are any problems once the restoration is complete I'll troubleshoot components on an individual basis instead of doing a blanket replacement speaking of blankets hi tayt to make a blanket statement that all capacitors that look like these are reliable and don't need to be replaced I did a little research on these black cat caps made by Cornell Dubilier and I couldn't find any consistent information about how they're made they appear to be mylar but that doesn't mean all black cats are they may be but again I've read too much conflicting information to be absolutely certain black beauties are another type of capacitor made by Sprague which seemed to bring similar confusion the point of this video really is that you should test capacitors before blindly replacing them even if you've read otherwise the exception would be pastors that are clearly made from paper such as these much older wax paper caps if you see these you really are going to be better off just replacing them and any tests you do will very likely show their leaky or out of spec ceramic caps are generally fine but if your device isn't working correctly a ceramic cap will occasionally be to blame so don't be surprised if you run across a bad one and of course electrolytic caps should always be tested as there's a higher likelihood of failure there all of the electrolytic sin my TAS 3x will be replaced along with the selenium rectifier I'd also caution you not to buy or use capacitors because of some supposed sonic benefit some people pay ridiculous money for capacitors even crappy old wax paper ones because they mistakenly believe they'll make things sound more transparent or pure and that's just baloney if two capacitors measure the same they'll sound the same don't be fooled into buying new old stock capacitors because someone told you they possess some magic antique sound if you have old capacitors that test as new use them and if they test poorly replace them and when buying capacitors get new ones of a high quality from a reputable manufacturer and seller capacitors don't possess magic sound qualities but there are genuine differences in tolerance build quality temperature ratings voltage ratings and longevity and if any of these things cause a capacitor to be out of spec for the circuit unpleasant audible problems can be created well time for me to get back to restoring the PAS 3x look for a video in the future where I'll show its restoration in complete detail the PAS 3x will be part of a 60 70 s - putting together which will include a Dinoco st 70 I built a Dinoco FM 3 tuner I'm going to build this modified Thorens turntable and a pair of Dinoco 825 speakers all of which will also be featured on my channel to stay updated please subscribe and click the bell and if you liked this video give it a thumbs up I'll see you soon

Channel: Flux Condenser Vintage Audio Electronics

Views: 18,101

Keywords: Replacing capacitors, Black cat capacitors, Black beauty capacitors, Which capacitors need to be replaced, Should capacitors always be replaced, How to replace capacitors, How to test capacitors, Capacitor leakage, When should capacitors be replaced, Audiophile capacitors, Do capacitors sound different, Old capacitors, Antique capacitors, Should I replace all the capacitors, How to fix antique radios, dynaco, pas-3 preamp, do capacitors sound different, st-70, fm-3

Id: EdTV1_8esgY

Length: 4min 24sec (264 seconds)

Published: Mon Jul 29 2019