capacitor re-cap maddness Blue ESR meter  alternate type capacitors? St receiver - Page 1
Forum section: electronics / repair

author: TheNewLab
author_rank: Frequent Contributor
timestamp: October 17, 2022, 12:16:05 am
content: Hey all,Recently I bought the Blue ESR meter (from Anatek?) and and LCR meter. I kind of went crazy using the Blue ESR. As I have learned the issue was bad power supply caps. (no volume). I got carried away and removed more than 100 caps in my joy. most the small caps and some really small ones. All of which were actually still good.My question is:What it I replace them with better type of caps. Mylar, or polyethylene, poly polypropylene or similar? There is the room to do so. I know using electrolytic capacitors are used for keeping cost down, but would another type improve the sound or functions?Would love any input!!

author: Haenk
author_rank: Super Contributor
timestamp: October 17, 2022, 07:36:05 am
content: Honestly, those electrolytic caps have probably little - if any - influence on the sound, nor on the functions. Replacing them will be pointless, unless they are defective or way out of spec.Good electrolytic caps are not really cheap - but they offer way larger capacity over e.g. film caps, combined with way smaller size. If you are going to replace 100 electrolytic caps by film caps, your workbench will be covered under a pile of caps. So that is not going to happen, and pointless anyway.It might be possible to marginally increase the sound performance, but only doing so by exchanging caps will result in probably no audible difference. Other parts (and the construction itself) have way more influence.If you have already narrowed the issues to the power supply, replacing a handful of caps is OK IMHO. But also check other parts. And be careful of high voltage.

author: wraper
author_rank: Unknown
timestamp: October 17, 2022, 07:50:58 am
content: Don't fix what ain't broken. Using film or other type of caps instead of electrolytic may cause problems in some cases. In the vast majority of cases there will be no improvement in function. And even if there is in some cases, most likely it will be unnoticeable to the user.

author: TheNewLab
author_rank: Frequent Contributor
timestamp: October 18, 2022, 04:30:51 am
content: Thanks!When I said "madness" I really meant it. Quickly tested each one. and any doubt, I removed it.Maybe more likedesoldering madness...I recorded each cap/location in a notebook then dumped all the caps right away, (C'mon! I was brash, and clueless with a new toy!) I ordered the matching power E-caps and then set the project aside for years. The e-caps I foolishly removed back then were quality brand. I now know they were good. back then it was like I was obsessed, on a mission to find those "bad caps" and remove them. Even if the slightest weakness.Thus why I asked. I wanted to know If I can just use what I have in stock (good poly-caps), and avoid using the cheap e-cap assortment bags that I stock. I would be happy.Thanks for mentioning the audio quality issues, since It was in my head, but I was not clear about saying that.In my head, I actually had two questions.First: Do I have to use same e-caps, (sub 25v)? or,will changing out the small e-caps to poly-caps make anything worse? all polys are 50v or 100v rated way over 16v to 25v, and there is space to fit them.Second: can I tweak the audio quality? I am thinking about how those sub $100 XLR microphones can be modded by simply changing one e-cap to a poly or tantalum. (MXL and Behringer) and then they become "nose hair" quality, "Neumann U47-like" audio quality recordingsI ended up not being very clear about either.I think I will just do the following:1.) Power supply and large E-caps will be replaced with the same.2.) For all the small-value ones, I'll just use the poly-types I have in stock.I just want to get my stereo back up and running. I'm exhausted from everything being so political. Too toxic and no humor..too serious. I need some serious music and art therapy: And finding new ways to get myself into trouble through electronics!!!Thankx all!!mic mod links:Can no longer find the details of complete DIY design and the variety of mod improvements possible, but the MXL 990 is a classic and has multiple levels of mods to improve sound It looks like this DIYing has become a new industryhttps://microphone-parts.com/collections/mod-kitshttps://www.pinterest.com/sailingandmusic/diy-microphones/https://www.pinterest.com/pin/729301733414534287/?mt=login

author: wraper
author_rank: Unknown
timestamp: October 18, 2022, 12:21:09 pm
content: There may be some slight improvement if electrolytic caps are replaced with film caps in audio signal path. Using polymer caps may break the circuit as they have about 100 times higher leakage current. They are only good for power rails with high ripple current.

author: Haenk
author_rank: Super Contributor
timestamp: October 18, 2022, 01:27:19 pm
content: Quote from: TheNewLab on October 18, 2022, 04:30:51 amThat's not on the level of "cap swap", but rather replacing the whole electronics. Sure, exchanging the whole electronics of an amp with something 5x as expensive is likely to improve the amp.Again, just replacing some components is rarely necessary and helpful.