Inexpensive Electrolytic Capacitors

[C Moore]

I have an Ampeg B-25 that is gutted. The transformers are in good shape and seem to be a good fit for a tube rectified "Brown" or "Blonde" era Fender. I am on a budget (what's new) so I thought I would try some of those Radial and Axial e-caps from Mouser. They are so cheap compared to something you would get from F&T, Sprague, etc. Some of the caps I ordered were in the 87 cent range.
Am I going to be sorely disappointed by this strategy? Everything else about the amp will be "normal" where components are concerned. Mallory and Vishay coupling caps, good quality turret board, tube sockets, Switch craft Jacks, Bourns pots, etc. etc. Stuff you would see in any clone you might build from Metro, Ceriatone, Weber or whoever.
Will my cheap filter caps be "noisy", have a short life span, bad ESR, make the amp sound like a Dell Computer? What has been your guys experience, and opinions?
Thank You

[Structo]

Not sure which ones you got but I know that Weber sells some very cheap E caps.

People like Gerald Weber will tell you that the filter caps are the most important parts of the amp.

Since they basically power the amp from their stored charges.

In just about every book I have from him he complains about crappy caps with the Illinois brand being his most hated brand.

I know these things add up fast for the total cost but AES has the F & T caps at reasonable prices. I have used those in several projects and they seem to work great.

http://www.tubesandmore.com/scripts/fox ... 3=02_F%26T

[krash]

I use Xicon electrolytics and have no complaints. The 20% tolerance parts may tend to run a little on the low side. I have measured 47uF caps at more like 42uF routinely but that's certainly within the 20% tolerance. So if you NEED a 25uF then get a 33 and it'll probably measure more like 27. if you NEED a 40uF then a 47uF will do it but if it's a 50 you need, then get a 56uF, etc. Or just pre-screen them. Of course I have seen parts in 10 year old tube amps that have drifted 50%.

I have not had a failure of any of these Xicon caps, even under extreme heavy use. I also don't mind using Xicon resistors. I did notice that my Mallory 150s that I use so often are now white, and branded Cornell-Doublier.

Since I am not trying to clone amps then I could care less how these caps perform vs. some other brand that was used in some old amp. I design the amp to work with the parts I have onhand. If I need lower impedance or more capacitance or whatever, I just get the appropriate parts from what's available.

[Structo]

I agree that most of the Xicon stuff seems to hold up well.

Funny, I am usually pretty picky about measuring every component before I solder it in but I can't remember the last time I checked an E cap value.
Maybe I should......

[FYL]

Funny, I am usually pretty picky about measuring every component before I solder it in but I can't remember the last time I checked an E cap value.
Maybe I should......

Well, you should begin with a visual inspection, then perform a quick check of a significative sample. And recheck the datasheet.

For example you could get some caps with an inverted sleeve, others with either the wrong sleeve or the wrong innards. But it doesn't really matter once you've cut one in half and seen that it's a bog standard cap in a large can, now you understand why the ratings are so poor in the seldom seen datasheet.

Buuut the Atoooooooms are fuuuuul of moooooooojoooooo!

[FYL]

I use Xicon electrolytics and have no complaints.

Xicon caps are AOK.

[Structo]

Half the value on a Sprague?

So much for QC.

I have heard that before about what is inside of a Atom cap.
Anybody have a picture of that?

[jelle]

A cap half the physical size in that nice and shiny big blue housing.

[Structo]

So they have a complete electrolytic cap inside that can?

If that is true, that is BS.

Many times I have heard people complain that the Atoms won't fit under a dog house on a Fender amp.
So it doesn't need to be that big of a diameter, why do they do that?

Because bigger is better?

[FYL]

I have heard that before about what is inside of a Atom cap.
Anybody have a picture of that?

Sure:

[img:320:240]http://www.tjadamowicz.com/amps/gallery/SpragueAtom.jpg[/img]

[FYL]

Many times I have heard people complain that the Atoms won't fit under a dog house on a Fender amp.

Most fit. But why bother? There are much better caps at lower prices.

So it doesn't need to be that big of a diameter, why do they do that?

Because old caps were bulky... The TVA line is supposed to "emulate" old-style caps.

[jelle]

http://home.mchsi.com/~my_mcintosh_240/20uf_sprague.JPG
http://home.mchsi.com/~my_mcintosh_240/ ... rague2.JPG

from:
http://www.thegearpage.net/board/archiv ... 58461.html

BTW, other caps have small innards too. Apparently these caps expand when they heat up.

Dart, if you see this....look at the old CDE.

[FYL]

BTW, other caps have small innards too. Apparently these caps expand when they heat up.

Quality caps are filled to the case, as proper coupling between the innards and the aluminum can is required for proper thermal dissipation. That's why TVA caps are only rated for 65 or 85°C.

[krash]

FWIW in a former career, at two different jobs, I was somewhat of an expert on capacitors from two different perspectives. And I have come to summarize that, if it works in the circuit the way you need it to work, it's OK. For sound or other subjective things, as well as measurable performance phenomena, different types of caps, materials, etc. are all over the map and you just catch what appeals to you or works for what you need.

But generally electrolytic capacitors for filtering ripple on power supplies and offering decoupling etc., they all are just about fine. Put one in series with the audio signal and the wheat separates from the chaff pretty quick.

[Phil_S]

I'm of a mind, if it works, it works. Cheap ones can work as well as more expensive ones. Probably the thing you are paying for most in the expensive ones is duty cycle. You want 1000 hr caps or 5000 hr caps? There you go.

If you think it will take you 5 years to put 1000 hours on an amp, you don't need the 5000 hour caps. If you play 4 hours a day, every day, you will get some value with 5000 hour caps.