Guitar Amp Grade Capacitors ???

[Steve Conner]

Also for the umpteenth time... There's nothing wrong with cheap Asian capacitors! They're used by the billion in consumer electronics.

If anything, I'd trust them more than boutique ones made in small quantities, the large manufacturing volume gives them a chance at consistency. But what you do have to beware of is bad batches that were scrapped by the manufacturer. Sometimes they get pulled out of the dumpster and sold to hobbyists on Ebay.

Axial electrolytics are on the way out, but high voltage radial ones are still extensively used in switchmode power supplies, which are a more arduous environment than any guitar amp.

I don't know of any current production Asian caps that go above 450V. For the higher voltages you're best to use two 350V ones in series.

[MWJB]

I don't disagree Steve, but I'd also point out that until the provenance of the caps in question is established, we have no reason to suspect that they are not mass produced with acceptable consistency.

For me personally...it's not an issue, being in the UK, I will fit US made caps if that is what a customer wants, but I can pick up Euro made caps easily & cheaply enough in the values I mostly use & I am perfectly happy to use Asian caps, especially in situations where their typically smaller physical size might be relevant...I just don't see any benefit to aimless speculation & rumour mongering.

[Steve Conner]

I totally agree! I've used a lot of cheap off-brand caps like "HL" and "Suntan", and never had any trouble with them. I get them from Rapid Electronics, because they're pretty cheap, about £3 for a 100uF 450V part.

If you want to pay extra for something, look for 105'C rated caps. It gets pretty hot inside a "tubes down" combo.

The only caps that ever gave me cause for concern were, ironically, some large Rifa inverter-grade ones (£15 each!) I used as filter caps in a hi-fi amp. After several years they started to show some white crusty deposits around the vent plugs. But they still seemed to work fine, so I left them in there, they have now been running 10 years.

[guitician]

I thought that electrolytic caps were obsolete??? Who would put a part in an amp that is sure to fail in a pre-determined time....oh that's right.... manufactures looking to sell next years model....

It cant be because of tone.....caps don't have tone......

[mooreamps]

I thought that electrolytic caps were obsolete??? Who would put a part in an amp that is sure to fail in a pre-determined time....oh that's right.... manufactures looking to sell next years model....

It cant be because of tone.....caps don't have tone......

Electrolytic caps can last a long time. One way is to keep them charged by putting the stand-by switch after the cap. This technique was used by Fender in some of their vintage equipment.

caps don't have tone ????? wanna bet ??


-g

[guitician]

You thought I was serious...lol

Seriously.....tone is in the ear of the beholder

[bob p]

Also for the umpteenth time... There's nothing wrong with cheap Asian capacitors! They're used by the billion in consumer electronics.

I disagree. Cheap caps are one of the main reasons that today's consumer electronics fail after a short service life.

Unlike yesterday's consumer electronics that were made to last 20 years and could be repaired to last another 20 years, today's consumer electronics are designed to fail after a short lifespan and to be discarded not repaired. More often than not the reason for failure is low quality capacitors.

I've had some bad experiences: expensive flatscreen TVs and cheap DVD players both fail through the same mode -- cheap capacitors. Here's an example: my $30 DVD player. It used cheapo, no-name Chinese caps in the PSU, and as soon as it was out of its 12-month warranty it died due to PSU cap failure. My neighbor had the same problem. We had both bought DVD players at Christmas time. The two players were different brands, but looked alike and shared identical guts. Troubeshooting them took a few seconds because once I popped the hood I could hear the PSU caps hissing. Both had died because of failed PSU caps. Both were easily repaired with a single $0.25 cap.

You know the story -- these things would have lasted 20 years if they had used a decent quality cap instead of the cheapest cap that would last through the warranty period. Because the manufacturer is too cheap to use a $0.03 cap, you have to pay $30.00 to buy a new device. Few people can accomplish the $0.25 repair.

I've had the exact same problem with electronic metal halide ballasts. Cheap caps cause system failures, and because the ballasts are potted they're non-serviceable / disposable items. Your only option is to throw the dead one away and repurchase a $150.00 replacement. Cheap manufacturing and short lifespan effectively eliminates the theoretical cost savings of electronic ballasts when they die during a short service life. Instead of repurchasing another expensive ballast, hoping that efficiency will save you money over time, its cheaper to run an old-fashioned magnetic ballast. Although they're a bit less efficient, they last forever because you can repair them by replacing the caps.

Sometimes I feel like I'm taking one step forward and two steps back.

[guitician]

Also for the umpteenth time... There's nothing wrong with cheap Asian capacitors! They're used by the billion in consumer electronics.

It's all about their INITIAL QUALITY!

[mooreamps]

You thought I was serious...lol

Seriously.....tone is in the ear of the beholder

Hey. Don't mind me. I'm just a lowly rocket engineer..... But, I will be in Florida next week when we prep my spacecraft for launch in June.


-g

[Steve Conner]

Cool, maybe it'll get to 100 feet this time.

Bob: Try replacing the caps in your flatscreen TV with Sprague Atoms and see how much longer they last.

[bob p]

I'm not a fan of Atoms, Steve. I don't use them. I prefer the CDE 380/381 series snap-in caps, or the CDE 550C inverter grade caps for "extreme" applications (like the supply rails on Carver amps).

There's no question that the TV would have lasted a lot longer if it had used quality caps in the first place. Its unfortunate that so much electronic gear fails today because the Chinese contract manufacturers choose to substitute inferior quality parts for high quality parts because they think the swap will go undetected. They will substitute the lowest quality part that they can get away with using. Its gotten to the point that if you buy something, you have to buy a brand-name item in the HOPE that the brand name customer will ride the contract manufacturer hard enough to assure that there's no part swapping going on. If you buy a no name item, you can pretty much bet on the fact that its got the lowest passable quality parts inside and that its going to have a short service life.

I don't have blind faith in Asian caps. I've been burned too many times.

[Diablo]

I've had the exact same problem with electronic metal halide ballasts. Cheap caps cause system failures, and because the ballasts are potted they're non-serviceable / disposable items. Your only option is to throw the dead one away and repurchase a $150.00 replacement. Cheap manufacturing and short lifespan effectively eliminates the theoretical cost savings of electronic ballasts when they die during a short service life. Instead of repurchasing another expensive ballast, hoping that efficiency will save you money over time, its cheaper to run an old-fashioned magnetic ballast. Although they're a bit less efficient, they last forever because you can repair them by replacing the caps.

Sometimes I feel like I'm taking one step forward and two steps back.

That's great to hear about electronic ballasts. I work for a company that makes steel for magnetic ballasts. We had various bigwigs in our marketing dept., who wanted us to exit the business because "magnetic ballasts are doomed" when electronic ballasts take over. I love it when magnetism wins.

[bob p]

Magnetic MH ballasts were the de-facto standard in HID lighting until being "green" got shoved in everyone's faces, and everyone scrambled to make HF electronic ballasts because they were 10-15% more efficient. I've had the electronics fail so many times its not funny. There's not much "green" in throwing out a potted electronic ballast every few years and manufacturing a new one to take its place... especially when a "tar" ballast can last a hundred years.

On a related note, the performance levels are better with mag ballasts also. I'm using MH lights for lighting a reef aquarium, and I monitor the light output with a rather pricey PAR meter. It measures the amount of photosynthetically active radiation that is produced by the lighting system. Since coral growth rates are dependent upon light delivery, there's a direct correlation between the number of u-moles of light per square meter per second and the number of grams of CaC03 that become photosynthetically calcified as coral skeletons per square meter per month. One important thing that I've noticed in using the PAR meter is that the mag ballasts produce more intense light than the e-ballasts because they're current regulated devices and not power regulated devices. Granted, people might not notice the e-ballast's dimmer light output in a warehouse application, but the amount of PAR is directly related to coral growth rates, whose variance is subjectively very noticeable in a captive reef system.

There's been a lot of EPA propaganda and marketing hype about the better relative "efficiency" of e-ballasts. Being someone who actually measures the light output (and the rate of coral growth in kg of CaCO3 per square meter per year), I don't agree with the hype. The energy savings aren't being realized in an equal light comparison. The energy savings data is intentionally skewed; part of the reason that the ballasts consume less energy is because of efficiency, but they're also designed to produce less total light. The ads sound good, but the real world results are lacking. Tell that to your marketing guys.

Of course, we see the same effect with CFL bulbs. They save energy for two reasons: fluorescent is more energy efficient, and the lights also produce fewer lumens of output than the incandescent equivalent. Not many people notice the difference, but it can be very noticeable with a reading lamp, or if you have a light meter. My house is darker now that we're using "equal wattage equivalent" CFL bulbs.

[Alex/Tubewonder]

You want to know where any component was manufactured? Ask the supplier for a copy of ROHS compliance certificate. If they can't or won't provide it then smell the fish.
Want really, really, really high quality long life high voltage electrolytics? They're made in France, be ready to cough up the Euros through your nose but the amp will outlive you and the owner without a cap job down the line. They're HERE - takes a while to browse through the site to find exactly what you're looking for like 100uF/500V radial cap 105C derated to 70C operating temperature gives >200.000 hrs life time, get better air flow, reduce temperature another 15C and get close to 500.000hrs lifetime. These caps are spec'd for mission critical avionics and space duty. (In space noone can hear you play so it doesn't matter what caps are in your amp)

[fyl]

Want really, really, really high quality long life high voltage electrolytics? They're made in France, be ready to cough up the Euros through your nose but the amp will outlive you and the owner without a cap job down the line.

Eurofarad manufactures some of the best caps around but aren't alone: check for instance the Evox/Rifa line - now part of the Kemet empire. For instance axial caps from the PEG124 series are rated for 27,500 hours @ 105°C.

http://www.kemet.com/kemet/web/homepage/kechome.nsf/file/PEG124%20Series/$file/F3304_PEG124.pdf