Can somebody help me identify these caps?

[sweetbeats]

The first one is labeled "1H 331K". The second is labeled "1H 101J"

I want to replace them.

How do I determine capacitance and voltage rating on these things, and what kind of cap are they??

[evm1024]

polystyrene 330 pf and 100 pf

Very nice for audio - perhaps the best sounding.

331 = 33 * 10^1

101 = 10 * 10^1

102 would be 10 * 10^2 or 1000pf

http://www.elecraft.com/Apps/caps.htm

Polystyrene caps are easily messed up by solvents and heat...No acetone or long time with the soldering iron.

[sweetbeats]

Thanks Ethan!

So is there no voltage standard for these, and why?

And am I correct that this would be a suitable replacement for the 100pF cap?

[evm1024]

Sure those poly caps would work. You might want to consider Wima polypro caps or mouser.com offers polystyrene.

How many do you need? Surplus Gizmos has polystyrene inhouse....

[sweetbeats]

Mouser doesn't have the right values, at least not that I could find.

Can you link me to the WIMA caps?

Or Surplus Gizmos could be cool...I'll get an inventory tonight.

Thanks!

[evm1024]

Here are the mouser numbers for 100pf and 133 pf polystyrene caps - don't let that they are axial bother you.

23PS110
23PS133

wima mkp2 poly caps could do well as well.

--Ethan

[sweetbeats]

So I just gotta bend the leads around on the axials then right?

[evm1024]

Originally Posted by sweetbeats

So I just gotta bend the leads around on the axials then right?

Works for me and not all uncommon. The only trick to it is that one of the leads (on all caps) goes to the outer foil and one to the inner foil of the wined. Given the choice you want the have the long lead go to the outer foil and that goes to the most noise resistant trace/pad (hint look for a dot or some such)

But, gosh who am I giving this info to! Forget I wrote that - don't go overboard - no no stop! Put that soldering iron down!

[sweetbeats]

You lost me...

Not hard to do...

[sweetbeats]

There aren't that many needed overall:

qty (1) 27pF (i.e. 270)
qty (1) 39pF (i.e. 390)
qty (21) 100pF (i.e. 101)
qty (4) 220pF (i.e. 221)
qty (12) 330pF (i.e. 331)

[sweetbeats]

I've been Googling this evening...

Mouser only has 2 of the 5 values I need, and I'm having trouble finding them elsewhere.

Anybody know of a good source for the above listed polystyrene caps, or do I look for an alternative type of cap?

[Minion]

Why would you want to replace them?? they are good caps and should last a lifetime , I have used them many times (those Polystyreme (Styroflex) are hard to find these days) and are great caps and you will be hard pressed to find a replacement cap that will sound noticeably better.....


Cheers

[sweetbeats]

Huh!

Well...I assumed that after 25 years they'd need replacing like other caps. Am I wrong in that assumption? Plus I've got a couple that look funny because some mouse used the PCB for a toilet. Should I not worry about it?

It looked like this prior to cleaning:

[Minion]

Theoreticly Poly and Polystyrene caps should last indefinately as long at they aren"t dammaged by heat or a corrosive liquid.....

I have re-used Poly caps that were over 40 years old (Orange drops and Tropical fish and Polystyrene) and they worked as well as new Caps and many were salvaged from equppment that had been badly dammaged from moisture and heat....

Electrolytics wear out because they use a chemical Dielectric that breaks down over time were Poly type caps use a Plastic/Polystyrene or a metalized film that doesn"t break down....

The Polystyrene caps in your pic look like they are in pretty good shape, in better shape than some caps I have re-used...

Cheers

[sweetbeats]

Huh!

Well okay then...mebbe I don't worry about those...the outside of the one in the pic after cleaning was corroded a bit...but I think the innards look okay. I'll have to take a closer look. The rest throughout the whole mixer look just fine.

[evm1024]

I agree! Electros and anything that drys out or degrades. In polystyrene you can see the foil inside.

Originally Posted by Minion

Theoreticly Poly and Polystyrene caps should last indefinately as long at they aren"t dammaged by heat or a corrosive liquid.....

I have re-used Poly caps that were over 40 years old (Orange drops and Tropical fish and Polystyrene) and they worked as well as new Caps and many were salvaged from equppment that had been badly dammaged from moisture and heat....

Electrolytics wear out because they use a chemical Dielectric that breaks down over time were Poly type caps use a Plastic/Polystyrene or a metalized film that doesn"t break down....

The Polystyrene caps in your pic look like they are in pretty good shape, in better shape than some caps I have re-used...

Cheers