Anyone know what type of caps I have?

[sounder]

Looking through my parts bin for alternative decoupling input cap came across big brown approx 1.25"x .75" 4.7uF caps marked "475K 100JS" Anyone know what these are and if so, would they be better than my marginal non polar metal can electrolytics. My bass seems to be rolling off and am curious if it is the input cap.

Thanks,
David

The building stage is definable, the tweaking is never ending.

[JOE DIRT®]

sounds like you got some oldies there....if ya have a spdt switch hanging about and you know the caps are good do an AB comparison....as I often say "one never knows"

DIRT®

[sounder]

Originally posted by JOE DIRT®
sounds like you got some oldies there....if ya have a spdt switch hanging about and you know the caps are good do an AB comparison....as I often say "one never knows"

DIRT®

Thanks Dirt thats a good idea. Do you know where to find a range of quality caps in Toronto?

[Squalish]

Don't use electrolytics for any kind of signal coupling, be theiy black gates or not. If you can get it in anywhere near the same capacity, use quality either metallized polypropylene or film/foil polypropylene. If the cap is that big, it's probably some kind of film cap, an electrolytic of reasonable voltage ratings would be tiny. Try it out.

[sounder]

Originally posted by Squalish
Don't use electrolytics for any kind of signal coupling, be theiy black gates or not. If you can get it in anywhere near the same capacity, use quality either metallized polypropylene or film/foil polypropylene. If the cap is that big, it's probably some kind of film cap, an electrolytic of reasonable voltage ratings would be tiny. Try it out.

Thanks Squalish,

I did put the caps into the input circuit and things have MOSTLY improved. I did some research and it seems they are a poly. film as you say with a fire resistant finish which makes them look like a large piece of candy.

Anyhow, the electrolytic was definitely lacking in bass but the highs were incredibly defined..if not slightly tinny. With the film caps, there is much more bottom end but the highs seem a bit undefined with a tendency to hiss the s's. This may all be a little vague but I am really convinced that the decoupling signal cap is paramount in setting the colour of the sound in the IGC. Although the "candy" cap is an improvement, it's not right yet with the bass being a little flabby.

Any suggestions on signal cap types and their influence on sound?

David

[Squalish]

The conventional logic on certain other boards I frequent is that the best cap in the signal path is no cap in the signal path(the caps are used to take DC out of the signal before it gets amplified, if you don't have a 'hot' source, a jumper could be a major improvement), barring that, from best-worst

teflon
polypropylene
polycarbonate
polystyrene
polyesther
-
-
-
-
electrolytic

Look up the article 'picking capacitors' by walt jung, that should have some of the info you need.

Keep in mind that this is a big generalization, there are big differences between capacitors made of the same material, and some of the unique composition "electrolytic" caps may occupy the spaces above the generic lytics. Furthermore, even in the same line, capacity makes a big difference and voltage rating makes some difference.

If you like, for whatever reason, the sound of both of them, try parallelling them, you might prefer it, and it's unlikely to hurt anything just to try it.

Teflon caps are definitely a niche market, one that doesn't have well-known manufacturers. One of the primary places they are sold is on ebay. I would just use polyprop film.

[sounder]

Thanks Squalish for the info, I'll give the parallel thing a try, will the doubling of the capacitance matter?

[Tony]

Looking through my parts bin for alternative decoupling input cap came across big brown approx 1.25"x .75" 4.7uF caps marked "475K 100JS" Anyone know what these are and if so, would they be better than my marginal non polar metal can electrolytics. My bass seems to be rolling off and am curious if it is the input cap.

looks like you have a 4.7ufd 100volt cap there, the 'k' after 475 is the tolerance, better if you post a picture so we know for sure...