Decapitating my Eden World Tour

[Pabloaguas]

Well, with my WT800 having been made in 1994, these caps are at least 32 years old. Rather than doing the standard 'wait for the caps to take out the unobtainable Sankens', I decided it was time for some preventative maintenance, starting with the power board and output boards first.

So, removed the caps... and they are absolutely dead, with many measuring way out of spec. Basically they are turning into resistors at this point.

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

 

[agedhorse]

You might think 32 years would be time, but in reality that's an absurd assertion given the real (not urban internet mythology) data.

Got me laughing though... those caps (especially the NCC/UCC caps) will outlast the amp itself, as will the power resistors. I don't believe that ANY or all those electrolytic caps tested bad. I find MAYBE one or two failing caps a year (generally due to another failure that reverse biases it) and I repair over 100 amps a year every year and have been doing so for a very long time. Those film caps have a life expectancy of around 100 years, maybe much more.

Maybe at 50 years, but good luck!

 

[Pabloaguas]

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.

If your approach with customer amps is to replace only the one obviously failed cap and send them on their way, that’s a perfectly valid service philosophy.

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.

r

 

[agedhorse]

THAT guy, huh?

My customers get their amps fixed right the first time, the repairs are guaranteed and they stay repaired.

This is on amps that I designed between 10-35+ years ago so I know the reliability history and so do many players here on TB. In fact, understanding the reliability and aging metrics is a major part of my day job.

But of course you are right, you win. I have no idea what I’m doing so I’ll leave this BS to those more qualified. Sorry I offended you.

You might want to replace all those screws too, I hear that the steel gets all tired, and such…

 

[logdrum]

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

 

[Pabloaguas]

Look Andy, with all due respect, nobody asked you to swoop in and “correct” basic physics for a DIY project that’s already on the bench. When a guy with 58,000 posts lectures that electrolytics don’t really wear out and then, in the same breath, talks about repairing his own amps that are a few years old, it doesn’t exactly inspire confidence. From where I’m sitting, your comment comes off less like helpful technical input and more like condescension from a shop tech who can’t resist talking down to DIYers. I find it pretty concerning that someone in the repair business would publicly argue that aging caps aren’t really a thing, because that’s exactly the kind of mixed message that makes players distrust repair shops in the first place. If you’re here to share experience, great—but fake laughter at community members' real-world measurements and ears doesn't count as appropriate use of a forum.

Look Andy, with all due respect, nobody asked you to swoop in and “correct” basic physics for a DIY project that’s already on the bench. When a guy with 58,000 comments on TalkBass alone lectures that electrolytics don’t really wear out and then, in the same breath, talks about repairing his own amps that are only a few years old, it doesn’t exactly inspire confidence. From where I’m sitting, your comment comes off less like helpful technical input and more like condescension from a shop tech who can’t resist talking down to DIYers. I find it pretty concerning that someone in the repair business would publicly argue that aging caps aren’t really a thing, because that’s exactly the kind of mixed message that makes players distrust repair shops in the first place. If you’re here to share experience, great—but fake laughter at community members' real-world measurements and ears doesn't count as appropriate use of a forum.

Both of the big cans I can actually measure are pretty much toast and actually toast. The other 4 big cans don't measure on my LCR meter due to the size.

Many of the smaller caps measuring at half of their capacitance - the grey ones should be 1000uf, and the green one should be 100uF, but the theta is -57.8 degrees, which is a replaceable cap in my repair book. These green and grey caps help hold the bias, and when they go from being a capacitor to being a resistor, they take expensive, unattainable Japanese transistors with them, which is why you will see so many members here with failed channels on their world tours.

So I’m glad I trusted my own meter and did the work myself instead of dropping this WT800 at a random desert-rat “swap one cap and send it home” shop.

 

[Element Zero]

 

[leonard]

I bet many a Mesa amp and cab have been bought because @agedhorse freely shares his knowledge here.

 

[mmon77]

Look up ESR and get back to me.

Andy knows way more than you do.

Also, I would trust a "DER EE" meter far less than I could throw it.

 

[JamesGrant]

OP - you’re being very rude. Read AgedHorse’s original message, he’s not telling you what to do - he’s saying what his experiences and what he would do. And he’s not being an arsehat about it.

This is an interesting thread, we all might learn about cap tolerances measurements and measurement techniques. By the way, on two of those pictures the meter reading looks suspicious given the values. But the value I’d trust looks about ok.

Thanks for posting the pics, interesting.

 

[baxter_x]

You might want to replace all those screws too, I hear that the steel gets all tired,

Thanks for the advice, I'll make a new post soon about that.

 

[Pabloaguas]

So ironic that Andy would say that. I DID replace a standoff screw that is aluminum and had been bent. Replaced with steel.

But the bigger irony here, is that someone claiming to be a hundred-amplifiers a year tech, would not know the difference between tired capacitors and, well, steel screws.

 

[Pabloaguas]

Look up ESR and get back to me.

Andy knows way more than you do.

Also, I would trust a "DER EE" meter far less than I could throw it.

Everyone knows that caps wear out. It’s a fact.

Did you take a moment to look up DER EE before throwing it? Look it up and get back to me moń

 

[Pabloaguas]

It’s wild how posting ESR measurements of 30-year-old electrolytics causes more turmoil here than the actual failing caps.

I’m restoring an amp instead of treating it as disposable, I shared real data, and somehow that triggered a small army of emotional gatekeepers.

For the record: caps age, test equipment exists, and people are allowed to fix their gear without seeking permission from whatever priesthood has appointed itself in this corner of the internet.

If the idea of someone maintaining a classic Eden threatens anyone’s worldview or business model, that’s a personal crisis, not a technical one.

I’ll be over here actually working on the amp.

 

[mcnach]

So ironic that Andy would say that. I DID replace a standoff screw that is aluminum and had been bent. Replaced with steel.

But the bigger irony here, is that someone claiming to be a hundred-amplifiers a year tech, would not know the difference between tired capacitors and, well, steel screws.

Dude, did you step on a Lego when you got up this morning?

 

[dontvex]

If somebody replaces the caps on their 32 year old amp and the pulled caps test bad for the most part, then doing a cap job is absolutely called for. It is at that point the right thing to do if you want your equipment to be reliable and to sound as intended by the designer. No two ways about it IMHO.

And yes, I've seen caps in amps that test good after 50+ years, but with the OP's amp that is obviously not the case.

I'm all for basing the decision to do a cap job on a case-by-case basis instead of preemptive replacement after X years. The OP took all the steps to make this decision an informed one.

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".

 

[JamesGrant]

So ironic that Andy would say that. I DID replace a standoff screw that is aluminum and had been bent. Replaced with steel.

But the bigger irony here, is that someone claiming to be a hundred-amplifiers a year tech, would not know the difference between tired capacitors and, well, steel screws.

Whoosh

 

[ceetee]

Quite entertaining.

 

[mmon77]

Everyone knows that caps wear out. It’s a fact.

Did you take a moment to look up DER EE before throwing it? Look it up and get back to me moń

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.

 

[poochiecheeks]

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.