Decapitating my Eden World Tour

[Gervais Cote]

The parts that eventually need replacement are the electrolytic capacitors as they lose ESR, tantalum capacitors as they may fail short and some resistors IF they show any signs of overheating.

Electrolytic capacitors usually have a tolerance of +/- 20% so taking a reading of its actual value doesn’t mean much. Leakage or a swollen top might indicate the end of its life though.

 

[dontvex]

I actually did. And I don't trust the AI response that Google returns when I look something up.

I'll keep my Flukes, Simpsons and HPs thank you very much.

Happy for your nice collection but neither Fluke nor Simpson do currently produce a LCR meter and the HPs are definitely overkill for the discussed application.

So, what you got? HP4263B? Fine, now you have one more least significant digit to know your cap is bad. Congrats.

Hint: OP is not working in a lab or in the industry, so horses for courses.

 

[Jazzdogg]

Wow! What a thread! Our @agedhorse is revered on TalkBass for reasons that the OP, whom I have never heard of, is apparently unware of.

I will continue to trust what Agedhorse says, and I am doubly glad that TB has an ignore function.

 

[S-Bigbottom]

Has anyone here yet recapped their old World Tour? I would think at 32 years it would be time.

Whether your caps are faulty or not does not matter to the discussion, it is the "Hey caps get old so we all should replace them. Are you replacing your old capacitors?" in your last sentence of the original post that is being addressed.

Replacement strictly due to age was brought up, that was addressed. To me, replacement of capacitors due to age is the intended topic of this thread.

Rather than doing the standard 'wait for the caps to take out the unobtainable Sankens', I decided it was time for some preventative maintenance,

 

[TonyP-]

Drama aside
is there any way to know for sure "this amp needs all the caps replaced" aside from features starting to fail on the amp? I see people replace components on 80s Boss pedals like its some marvel mystery oil fix for perfect tone.

That was my thought as well…

It’s easy to be rude and defensive online…
Thank you @agedhorse for your input as usual.

 

[Oldtimer]

Andy means well and maybe hard to believe maybe due to the tone but he is saving you a lot of headache. and money.. His main concerns are, no one gets electrocutes or cause a fire, not waste money - specially cabs and caps, repairs clarify myths, when it comes to amplification and applied electrical engineering in audio. Why he does it in this forum, I have no idea. Guy is not a salesman even though he works for these companies and because he is blunt, he may even turn off potential buyers . Just remember that the top poster on talk bass does even post about gear and the 56K post you highlighted most of that have been very helpful to people.


My SWR bass 350 is also old older than what you have and was really used hard and the only wear item are the input jacks and the fx sends. It is used in a rehearsal loud setting at least once a week, It is not actually at my house but at a friend's rehearsal space and he has a jam that is loud almost every Thursday and maybe Friday if he is not gigging.. Your Eden is better quality and newer, so it is very reasonable to suspect that they are not as bad.

I had a tech who like Andy follows troubleshooting procedures (he worked at Sandia National laboratories ) and possibly 99 out of 100 tube amp repairs do not require capacitor replacement. An amp tech that rarely goes into cap job mode is a very good tech.

Anyway if you still would like to go initially as planned, the guy from Analog man said that there are so many counterfeit old parts, something you should research . Good luck

I would love to know your amp tech! I assume in New Mexico. Do we, possibly, know each other? I'm in Edgewood. You can PM me. To keep this relative to the discussion, Andy went through my Streamliner 900 last year and it was quick, reasonable, and updated. Thanks Andy!

 

[agedhorse]

Most manufacturers give 15 years as an absolute limit for the life of their electrolytic caps. That includes uprating for lower temperature operation. I'm aware manufacturers want to sell their product, so yeah, let's double that conservatively to thirty if you want. In the light of that, I wouldn't want to call the thought of a cap job after 30+ years "urban internet mythology".

If you were to do the math, you would discover that this is utter hogwash with many examples of products outside the audio industry that directly refute this claim in practice.

in the telecom industry, there are amplifiers and switching logic systems that run 24/7 for decades. Same applies to many commercial and industrial control products, including linear and switching power supplies.

Within the audio industry, there are products with decades long trouble-free life spans that are used throughout airports, convention centers, movie theatres, malls, etc.

It’s all about proper designs and doing the calculations to quantify the limitations and lifespan. It’s not just about age, it’s mostly about the construction technology, operating hours, ripple current, temperature, polarization voltage and a few other variables. This is exactly why a cap rated for 1000 hours/105C can last over 100k hours under different conditions.

Drama aside
is there any way to know for sure "this amp needs all the caps replaced" aside from features starting to fail on the amp? I see people replace components on 80s Boss pedals like its some marvel mystery oil fix for perfect tone.

Testing of the circuit reveals impacts on performance.

When testing a group of components that very rarely fail and all the measurements indicate failure, the very next step is to verify that the meter itself is correct. A common techie failure is to replace a bunch of components only to discover that the battery in the meter was low! (Yeah, it happens)

The parts that eventually need replacement are the electrolytic capacitors as they lose ESR, tantalum capacitors as they may fail short and some resistors IF they show any signs of overheating.

Electrolytic capacitors usually have a tolerance of +/- 20% so taking a reading of its actual value doesn’t mean much. Leakage or a swollen top might indicate the end of its life though.

Capacitors CAN fail, but assuming they are all bad when my experience data shows that this generally isn’t true is what I am getting at. Especially the film and ceramic caps which almost never fail.

The tolerances are quite wide on electrolytic caps, which is why measuring them and declaring them “failing” CAN be false conclusion, it’s more about the performance in the circuit. Just the act of removing the cap (resoldering and tugging on the leads) can damage the cap.

Tantalum caps are a little different, their failure mode is often leaky or short circuit due to the chemistry of the cap. When they work, they are great, but when they fail, it’s mostly random and short circuit. I don’t use them for that reason.

In the hobby and DIY world, it’s easy to resort to relying on urban myths, if all the cool kids are saying/doing it, it must be right. Same dangers as AI, garbage in, garbage out.

 

[agedhorse]

I see people replace components on 80s Boss pedals like its some marvel mystery oil fix for perfect tone.

By the way, thank you… this is a good example of my reference to urban mythology… all the cool kids are doing it so it must be necessary!

 

[agedhorse]

I would love to know your amp tech! I assume in New Mexico. Do we, possibly, know each other? I'm in Edgewood. You can PM me. To keep this relative to the discussion, Andy went through my Streamliner 900 last year and it was quick, reasonable, and updated. Thanks Andy!

Did it require any caps replaced?

 

[Oldtimer]

Did it require any caps replaced?

You would know! It was there for the LED replacements.

 

[Andy Marshman]

I am a believer in reliability that's born out of preventive maintenance - in all industries. I've been guilty of wholesale cap changeouts when likely there weres some components that did not need replacing. I can live with that and I trust that the amps were more reliable for having done it. I don't own, or feel the need to use, an instrument to test capacitor specs and tolerances.
I respect the experience and helpful guidance that Aged Horse has provided on this forum. He's also shot down (quickly) many myths and
B.S. concepts that people have asked about.

 

[2saddleslab]

A mind, much like a parachute, is best used when open. The OP has received the best possible advice. Be a shame to waste it.

 

[agedhorse]

I am a believer in reliability that's born out of preventive maintenance - in all industries. I've been guilty of wholesale cap changeouts when likely there weres some components that did not need replacing. I can live with that and I trust that the amps were more reliable for having done it. I don't own, or feel the need to use, an instrument to test capacitor specs and tolerances.
I respect the experience and helpful guidance that Aged Horse has provided on this forum. He's also shot down (quickly) many myths and
B.S. concepts that people have asked about.

You have repeated one of the greatest fallacies in industry… reliability is born out of preventative maintenance.

In reality, reliability is designed into (or out of) a product. It’s exactly the same as the often quoted statement that reliability is all about testing and QC… you can’t QC reliability into an inadequately designed product no matter how hard you try.

 

[Nuisance]

Oh, it’s that guy.

The “100 amps a year on the bench and 58,000 posts on TalkBass” guy. I honestly don’t know how many hours are in your day, but hey, respect for the multitask.

^^^^^THIS is why we can't have nice things.

We are blessed to have @agedhorse (and a few other pro engineers, luthiers, and players) on this forum. Please don't run our experts off with stupid, ignorant statements.

 

[logdrum]

I would love to know your amp tech! I assume in New Mexico. Do we, possibly, know each other? I'm in Edgewood. You can PM me. To keep this relative to the discussion, Andy went through my Streamliner 900 last year and it was quick, reasonable, and updated. Thanks Andy!

Rick Heinzeltman but he stopped last year. If he would do it again. I'll DM you. I will contact or meet him. I will DM

 

[darev]

 

[Root 5]

Oh, it’s that guy.

The “100 amps a year on the bench and 58,000 posts on TalkBass” guy. I honestly don’t know how many hours are in your day, but hey, respect for the multitask.

Just to clarify: I didn’t wake up one morning and decide “internet myths say 32-year-old caps must be dead.” I was living with a very noisy, flat-sounding amp that’s known for this as it ages. So I pulled the original caps, put them on an LCR meter, and found that not only the generic ones but at least one of those Nippon Chemi-Cons were measuring like resistors with a side of capacitance—high ESR, low C, ugly dissipation. That’s not mythology, that’s what’s actually in this WT800.

I’m not claiming every Eden on the planet needs a recap or that all electrolytics self-destruct at 32 years. I am saying that when my caps measure like that, and the boards are already out, I’m going to replace them and drop in some nicer bits (yes, including Ashton Perry–wound resistors while I’m in there) rather than hope that all of the generic caps magically get younger.

If your experience is that most of these survive 50–100 years, cool.


My experience is that the parts in front of me are cooked. I’ll trust my meter and my ears on my own amp.

You can win the internet; I’ll settle for my WT800 actually working the way I want it to.








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lol! You don’t know who agedhorse is, do ya?

 

[sawzalot]

This thread has made my day. Nothing better than watching someone clearly trying to provoke an angry emotional reaction get schooled by quiet competence based on science. I learn a lot from these threads.

 

[winston]

Yeah, must be backwards day… first time in the 30 or so years I’ve been on the internet that some brilliant individual suggested that having real-life experts generously sharing the actual fruits of their professional experience with a community is a very very bad thing!!

^^^^^THIS is why we can't have nice things.

We are blessed to have @agedhorse (and a few other pro engineers, luthiers, and players) on this forum. Please don't run our experts off with stupid, ignorant statements.

 

[agedhorse]

This thread has made my day. Nothing better than watching someone clearly trying to provoke an angry emotional reaction get schooled by quiet competence based on science. I learn a lot from these threads.

That’s exactly my intent, I receive a lot of messages asking for real world education rather than just parroting the same old internet BS. For me, it’s a form of paying it forward (at least to those who have an interest in learning.