Illinois brand capacitors still bad?

[SoulFetish]

Were the capacitors themselves bad? Or was it just that Fender used the lower temperature 85Degree ones?

Admittedly higher ratings are better, but Sprague Atoms are 85°C rated.

85°C = 185°F

Actually, Sprague Atoms are commonly only 65°C rated!! Which is complete garbage
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[FUCHSAUDIO]

We use F&T and MOD in the shop. MOD's are a great value, most likely imported, but no reliability issues.
F&T are top of the line, a little more money, but I think they sound a touch better. We use them in vintage amps always, especially since they are often owned by cork-sniffers. We use in our tweed builds.
MOD's are great for modern Hot-Rod amps and general day to day "meatball surgery" jobs.

[TUBEDUDE]

F&T are my go to if I have to use electrolytics. Sprague blue have been superceded by newer advances in capacitors. They only maintain market share because of superstitious amp builders that can't bear the visuals of a better cap. Sprague realized this and put smaller caps inside the big blue shells to make diehards happy. If the small caps inside were not in another case they would likely enjoy a higher thermal rating.

[GAStan]

Were the capacitors themselves bad? Or was it just that Fender used the lower temperature 85Degree ones?

Admittedly higher ratings are better, but Sprague Atoms are 85°C rated.

85°C = 185°F

Actually, Sprague Atoms are commonly only 65°C rated!! Which is complete garbage
.
.
IMG_8138.jpeg

Learn something new every day. Perhaps I should have specified my Atoms are +85°C rated

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[GAStan]

Does anyone have an experienced opinion on Jupiter and/or JJ radial electrolytics?

20240601_185609.jpg

[Mark]

I think the TAD caps are pretty good too. Here are cap values and ESR. Before I replaced the old Mallory caps in the SF Twin Reverb, I measured from the negative end of the cap and its earth connection and there wasn’t any leakage current measured on my multimeter. I do wonder sometimes if it’s such a great idea to replace old caps when they are obviously in good condition, the rationale is people are looking for the sound and response from the vintage parts and I’m cutting them out and throwing them away. Of course my opinion maybe deeply flawed and if you strongly disagree please tell me your experience.

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[Mark]

Vishay caps are very good too. I got some recently any they were streets ahead of IC caps.

[R.G.]

Here's an interesting deep background article on electro capacitor quality.
https://en.wikipedia.org/wiki/Capacitor_plague
In the late-late 1990s and early 2000s there was an industry-wide plague (!!) of electrolytic capacitor failures, especially noticeable in computer motherboards, but endemic to all electrolytics. Brand name didn't matter so much as what all the capacitor manufacturers were doing in chasing low ESR. I was interested in the note that the push for low ESR might have resulted in more water in the caps. Apparently this reduces the brand-new ESR, so they look GREAT for ESR when new, but degrade faster.

For the PC industry, that has all flushed out because of the two-to-four-year life of PCs, but for guitar amps, the caps tend to stay in there for decades.

[FUCHSAUDIO]

I do wonder sometimes if it’s such a great idea to replace old caps when they are obviously in good condition, the rationale is people are looking for the sound and response from the vintage parts and I’m cutting them out and throwing them away. Of course my opinion maybe deeply flawed and if you strongly disagree please tell me your experience.

Honestly, the time factor concerns me. What does "obviously in good condition" even mean ?!?!

These parts age due to temperature, age, use, non-use, etc. I spoke with engineers at Nichicon about caps we use in service and production. The MTBF (Mean time before failure) ratings are usually 20 years at the outside, under "ideal conditions". A guitar amp with tubes is far from ideal. It's a higher temp than ambient, that's for sure. The engineer said "20 years is reasonable, beyond that is pushing your luck". I called to check the date code on a Mesa Nichicon filter cap bundle. I actually asked a friend at Mesa-Boogie who said "if they aren't leaking and measure near capacitance printed on it, they don't go". That prompted the call to Nichicon.

There are chemicals inside that can dry, and insulation that can break down. I have changed countless "good" (but old) caps in amps where other techs in the area didn't. The difference was audibly surprising. Tighter low end, more headroom, less ripple on the B+ when the amp is tested with tones into a load. There is both a sonic and measurable reason to change them IMHO.

This is my opinion.

[maxkracht]

I have changed countless "good" (but old) caps in amps where other techs in the area didn't. The difference was audibly surprising. Tighter low end, more headroom, less ripple on the B+ when the amp is tested with tones into a load. There is both a sonic and measurable reason to change them IMHO.

This has been my experience as well, supported by comments from several clients who hadn't noticed the slow degradation until getting their amp back. 20 years is when I start to suggest recapping for preventative maintenance, though I usually don't press the issue until something is 25-30+. I truly don't understand techs who will replace one blown cap in a 40 year old amp but leave the rest...

[TUBEDUDE]

A shorted cap can take out expensive parts.

[Mark]

I do wonder sometimes if it’s such a great idea to replace old caps when they are obviously in good condition, the rationale is people are looking for the sound and response from the vintage parts and I’m cutting them out and throwing them away. Of course my opinion maybe deeply flawed and if you strongly disagree please tell me your experience.

Honestly, the time factor concerns me. What does "obviously in good condition" even mean ?!?!

These parts age due to temperature, age, use, non-use, etc. I spoke with engineers at Nichicon about caps we use in service and production. The MTBF (Mean time before failure) ratings are usually 20 years at the outside, under "ideal conditions". A guitar amp with tubes is far from ideal. It's a higher temp than ambient, that's for sure. The engineer said "20 years is reasonable, beyond that is pushing your luck". I called to check the date code on a Mesa Nichicon filter cap bundle. I actually asked a friend at Mesa-Boogie who said "if they aren't leaking and measure near capacitance printed on it, they don't go". That prompted the call to Nichicon.

There are chemicals inside that can dry, and insulation that can break down. I have changed countless "good" (but old) caps in amps where other techs in the area didn't. The difference was audibly surprising. Tighter low end, more headroom, less ripple on the B+ when the amp is tested with tones into a load. There is both a sonic and measurable reason to change them IMHO.

This is my opinion.

That’s good, this is the sort of thing I am wishing to get feedback on. There was folklore about that caps should be changed every ten years. I thought that sounded like a marketing campaign from cap manufacturers or techs wanting more income.

[Mark]

Here's an interesting deep background article on electro capacitor quality.
https://en.wikipedia.org/wiki/Capacitor_plague
In the late-late 1990s and early 2000s there was an industry-wide plague (!!) of electrolytic capacitor failures, especially noticeable in computer motherboards, but endemic to all electrolytics. Brand name didn't matter so much as what all the capacitor manufacturers were doing in chasing low ESR. I was interested in the note that the push for low ESR might have resulted in more water in the caps. Apparently this reduces the brand-new ESR, so they look GREAT for ESR when new, but degrade faster.

For the PC industry, that has all flushed out because of the two-to-four-year life of PCs, but for guitar amps, the caps tend to stay in there for decades.

The article did say this, I haven’t found the caps to have low capacitance or high ESR, I don’t know if I mentioned it, but I did measure the caps leakage current with my multimeter and it was fine.

“The capacitance should normally degrade to as low as 70% of the rated value, and the ESR increase to twice the rated value, over the normal life span of the component, before it should be considered as a "degradation failure".”

It’s common knowledge that valve were better made in the past and I wondered if the lifespan of caps was now short as most consumers devices are in waste disposal in five to ten years?

The Mallory caps in this old Twin measured well and I can’t say that the performance of the amp is better with the new F&T caps. I don’t think it’s a bad thing to replace the caps as it should ensure reliability.

[bepone]

There should be no drama around that...electrolytics working on low temperature, in everyday use can last more than 100.000h..maybe also 250.000.. so 30-50 years.. it is no miracle that amps from 70ties still working. If temperature is increased, life is shortened very much.

If elco is NOT working or staying on the shelf many years, this IS a problem.

So better run all day long than powering on every month for 1 hour

[maxkracht]

It’s common knowledge that valve were better made in the past and I wondered if the lifespan of caps was now short as most consumers devices are in waste disposal in five to ten years?

I think It is a trap to generalize like this. I carefully select high quality caps that are run well below their ripple current, voltage, and temperature rating. I also make an effort to keep them away from hot stuff whenever possible, securely attach them, don't excessively bend leads, don't keep the soldering iron on for too long, etc.. Compare my best efforts to those of a manufacturer who buys the cheapest parts they can get away with and has poor quality control. There were good caps in the past and bad caps in the past. (same with tubes) Survivors bias is also an important factor.