Hi guys,
I donate most of my free time repairing music instruments for a rock n roll high school for kids in AZ. I recently took on a bass amp repair that is on a tight deadline and I'm kind of stuck. I have a cap that burned off on the tube side of the preamp. Easy enough repair, but turns out the cap has a number that I haven't seen before and I can't find anything on line about it. The number is 474J 100N. The 474J is no problem I knnow what that is. Its the 100N that has me confused. Any insight would really---REALLY be appreciated. I gotta have this thing on stage on the Forth! Thanks!

 

Do you have a make and model? Some of the members here are expert in looking up manuals.

 

Hello,

Can you post a picture of the capacitor?

The capacitor probably is 470000 pF or 470 nF 5 %.
The voltage is probably 100 volts, the temperature range is -55 to 70 degrees Celcius.

See this page for more info:
http://wiki.xtronics.com/index.php/Capacitor_Codes

This is a page found at the EDUCIPEDIA on component codes:
http://www.educypedia.be/electronics/datacomponent.htm

Bertus

 

Wow! Thanks for the fast replys! I'm taking a picture right now. in the mean time the Make/Model is Hartke 2115 combo (2000 series head and 1 15" speaker in same cabinet.) I've emailed and called Samson/Hartke and they won't give me the time of day.

 

ok sorry about the poor pic quality, my camera is ancient.

 

Hello,

The quality of the picture is good.

The capacitor is a ceramic 470 nF 5% 100 Volts one.

The one in the link could be a replacement:
http://www2.mouser.com/ProductDetai...GAEpiMZZMuAYrNc52CMZHHhQwZhJs%2bRyhF5WHfWgvc=

Bertus

 

i can't thank you enough for the help!!!!

 

Actually, that looks rather like some old silver mica caps that I have. However, the ceramic should do just fine; this isn't an RF application.

 

Hello,

Afther having a second look at it, SgtWookie is right.
It is a silver mica capacitor.
For an audio application the ceramic I showed you will be OK.

Bertus

 

I would say it is NOT a silvered mica capacitor but a Mylar one.

A silvered mica capacitor of this capacitance will be very large in size. Also the 100V rating does not seen common with SM capacitors. Why use a silvered mica capacitor in an preamp when a Mylar one can do, with one tenth of the cost?

Usually Mylar capacitor are green but i have also seen brown and occasionally the color shown in the photo posted above.