Cap identification....please

[Garydean]

what do they call those rectangular bypass, thin shaped capacitors, as seen in the picture enclosed. The ones I usually see are gray in color and have typical capacitor values stamped on them? I've never had to replace one, until now. The photo enclosed is a Marshall but the amp I'm fixing is a Matamp, not shown.

reads: 68nK 630, there are 4 of them on the output section of a quad EL34. Looks like someone had replace a power resistor with a wrong value, burned this cap to toast. The tube in the respective circuit is bad as well.

would a 150 .68 630V replace that? I see in Mouser they have drawings of their caps but it's hard to tell what I'm ordering. I have 150's or should I get an exact replacement?

once again....thank you

[captntasty]

Assuming we're talking about the big one at bottom of photo... does it look like this -



If so it is a Sprague Orange Drop...
68n = 68 nanofarads = .068uf (micro)
k = 10% tolerance
630v (600v)
These are pretty common in amps, some amount of mojo to them?

Assuming you're talking about the one on top... its a box capacitor. Some like Wima's, plenty of other manufacturers. Mallory makes 160 series...

When you say 150's do you mean Mallory 150's? In which case, that would sub for the Sprague just fine, but I'm not sure they have a .068uf in the right voltage
Cheers.

[drewl]

Also known as "chiclets" the value is .68uf

[Alex R]

.68uf is the one in the pic - but it sounds like the one in the amp, not pictured, is .068uf, a more typical coupling value. Confusing.

[Garydean]

Here is the actual photo of the cap in need.



also, I was wondering about those green resistors, 22R 5% 223 are the only markings I can see. What would replace those. 2 are burned.


thanks

[Alex R]

Can't quite see the markings on top of the caps.

Those are 22 ohm resistors, maybe up to 5 watt. Someone might recognise the type and give the wattage for definite. Bung in 5 watt ceramics and be sure. Or flameproof. Leave them a bit up from the board to ventilate them better, like the ones in there (ceramics usually have lugs to achieve this). It's ok to use the wires of normal types to achieve this instead of the little stands those have.

[Garydean]

the caps say 68nk 630

[Alex R]

- going to be .068uf I think. Is that K right up next to the n or is there a gap?

[Garydean]

all the characters are right next to each other, no spaces.

[Alex R]

ok - dunno what the K means, maybe a type code, but 68n is .068uf.

[Garydean]

Thanks for all your help Alex.

[captntasty]

tolerance

k = 10% tolerance

68n x .10 = 6.8n

the actual value of any given cap is going to be up to +/- 6.8n so the range will be about 61n to 75n or .062uf to .074uf. Not really a big deal but there are probably 5%, 2% and 1% tolerance caps.

[Garydean]

captntasty thanks for the info. I was able to order a few different styles whith the same values from Mouser. Hopefully I have it covered.

thanks again!!