Should I be concerned about these F&T caps?

[Junior Little]

Hey all,
I ordered some 10uF 500V F&T caps on eBay. I didn't realize until after I hit "Buy Now" that they were coming from Japan. Realizing they were going to take a while to get to me I went ahead and purchased some from AES. However, for the same value cap they are completely different in size...did I get duped, or, is this size difference to be expected? I certainly don't want any unnecessary problems to arise if I use them in a circuit.

 

[radiocaster]

Is the bottom one of a different tolerance?

 

[Junior Little]

Not sure about the tolerance. It's not marked anywhere on the cap.

 

[radiocaster]

I think you can download spec sheets from them, I've done it before. They usually have a whole range on them (those could be different ranges) and they sure have the sizes and model numbers listed.

 

[schmee]

Japanese stuff is usually really good. I see variations in size even all from AES over time. Audiophile rebuilders love Nichicon Japanese caps. In my mind "bigger is better" but I have no logic to back it up other than often more expensive caps are bigger.

 

[24 track]

F&T caps are high quality and I have had spectacular success with them, I use them exclusively for all recapping if I can get them .

I even tried to get the distibuter to set me up an account ,unfortunately the quanities i would need to buy would be impractical

 

[ahiddentableau]

It's possible that one cap is older than the other, and the machining for that type of cap changed at some point in the last several years. So it's at least possible that both of them are legit and as they should be, they just look very different for some other reason. Maybe somebody around here has more experience with their history and can help.

I totally get your reluctance to use them, though. When I see stuff like that it always makes me think of those fake ATOM caps that were just an empty case wrapped around a cheap chinese axial that was going around the forums a few years ago.

 

[Nickfl]

What do the end caps look like?

 

[2L man]

I think that bigger one has smaller internal resistance?

 

[Junior Little]

What do the end caps look like?

 

[Junior Little]

F&T caps are high quality and I have had spectacular success with them, I use them exclusively for all recapping if I can get them .

I even tried to get the distibuter to set me up an account ,unfortunately the quanities i would need to buy would be impractical

Yep, I love F&T caps and use them on all repairs and most of my builds. Great quality product. Never came across this large of a size disparity. Likely no problem, but it threw me a bit.

 

[Paul G.]

Maybe I am letting my old Typography background slip out, but look at the zeros on the 500V marking on the tiny cap. They're not aligned and one of them is the letter "O". Now look how clean and straight they are on the bigger cap.

You can measure it, and use it, but I'm assuming the little one is not actually an F&T.

 

[Junior Little]

Good eye @Paul G. !!
Now it really makes me wonder about these caps...I'll likely use them with an eye toward caution. Still, it makes me feel like I was duped.

 

[tubelectron]

Yes, The F&T caps are reliable. I use them in nearly all my project amps.
That said, the 10µF that I bought in Europe were 450V and of the smaller size that you pictured :

https://www.tube-town.net/ttstore/f-t-10-f-450-volt-axial.html

The 10µF/500V are not listed, though.

-tbln.

 

[Junior Little]

Yes, The F&T caps are reliable. I use them in nearly all my project amps.
That said, the 10µF that I bought in Europe were 450V and of the smaller size that you pictured :

https://www.tube-town.net/ttstore/f-t-10-f-450-volt-axial.html

The 10µF/500V are not listed, though.

-tbln.

The size specified on the web page is exactly the size of the smaller cap. I'm thinking they are the 450V and not 500V as advertised. Thanks for the info @tubelectron!

 

[mabinogeon]

That smaller one looks tiny! I think I'd be afraid to use it... but that's just me.

Here are three F&Ts I have in the parts bin right now:

Ft

• mabinogeon
• Dec 6, 2020

 

[milocj]

The size specified on the web page is exactly the size of the smaller cap. I'm thinking they are the 450V and not 500V as advertised. Thanks for the info @tubelectron!

I wonder if they got the wrong shrinkwrap on the smaller set and got the 500v stuff by accident? That may also explain the misaligned text if the 450v wrap is normally smaller diameter.

 

[King Fan]

My brain gets several conflicting ideas when I think about this:

Well, F&T caps do come in oddly big or small sizes when compared to other F&Ts of different value.

And how could you make money by faking capacitors for guitar amps? Would it be like counterfeiting $2 bills -- not worth that much, and not wanted in much volume?

But is there a chance you could if your labor were cheap enough? In China or somewhere?

So... (I don't know how many you ordered of course) leaving the more dubious one in the 'spares' box is win-win; you didn't waste your money ("no no, dear, I may need that in the future") but you don't have to put it in an actual amp anytime soon...

 

[Junior Little]

Hey @King Fan, that was my thought exactly: why counterfeit something of such little value, unless - as you say - there's a sales volume effect. Makes little sense to me.
However, after getting the feedback from the wonderful members of this group, I have become convinced that they are of a lower max VDC rating than advertised (post #15). Whether or not they are actual F&T caps under the wrapper, I have yet to reach a conclusion.
But your point is well taken. I only ordered 4, so not much money invested. I doubt they'll ever go in a spot requiring 500VDC, but downstream placement is a possibility. I'll probably use them in my own builds and not for repairs for somewhat obvious reasons: if they fail on me, no big deal. If they fail on a repair job, I lose clients. Word of mouth advertising is how I've always operated and I'm not going to put what meager reputation I have on the line for something I perceive as (possibly) sketchy. At least I'll be able to sleep at night!
For now they're going in a Valco 6150 build and we'll see what happens...

 

[BobbyZ]

I remember seeing a post by someone not that long ago, a few years maybe, that F&T caps have gotten smaller. I tend not to have any laying around when I order more, so I've never done any side by side comparisons.