Beginniner's Capactior Size/Value Question

bmsulliv · 24th May 2008, 08:13 PM

I'm in the process of replacing some caps in a pair of salvaged speakers (Rectilinear Mini III's). One of the caps is supposed to be rated at 87uf. The original is about 1" x 1/2". I couldn't find an exact 87uf cap on PartsExpress so I ordered a 90uf, just to see how close it would be. When I received the new cap I was shocked to see that it measures about 4" x 2". That seems like a huge change in volume for only a 3uf difference. My knowledge of circuits is pretty rudimentary but I'm looking to change that. Any ideas? Thanks.

dave_gerecke · 24th May 2008, 08:57 PM

Greetings, The difference in value of the capacitors is small enough that it shouldn't affect the size in this case. I suspect that the reason for the large difference in size is that the caps are made with different dielectric materials. If you buy a film cap made with polypropylene or teflon as a dielectric, they are larger than a non-polarized electrolytic for a given capacitance and voltage rating. Hope this helps.

Peace,

Dave

P.S. chances are that you will notice differences in the sound between the new and old caps. That is if you had a chance to listen to the speakers before you started on the repairs.

24th May 2008, 08:13 PM	#1
bmsulliv diyAudio Member Join Date: May 2008	Beginniner's Capactior Size/Value Question I'm in the process of replacing some caps in a pair of salvaged speakers (Rectilinear Mini III's). One of the caps is supposed to be rated at 87uf. The original is about 1" x 1/2". I couldn't find an exact 87uf cap on PartsExpress so I ordered a 90uf, just to see how close it would be. When I received the new cap I was shocked to see that it measures about 4" x 2". That seems like a huge change in volume for only a 3uf difference. My knowledge of circuits is pretty rudimentary but I'm looking to change that. Any ideas? Thanks.

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Volume (size) Question	nukaidee	Multi-Way	8	5th February 2009 12:59 AM
Size dilemma question?	tadiam	Solid State	8	14th December 2007 07:12 PM
Enclosure size question	Flyin11	Car Audio	15	19th November 2007 09:42 PM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

24th May 2008, 08:57 PM	#2
dave_gerecke diyAudio Member Join Date: Dec 2007 Location: Vermont	Greetings, The difference in value of the capacitors is small enough that it shouldn't affect the size in this case. I suspect that the reason for the large difference in size is that the caps are made with different dielectric materials. If you buy a film cap made with polypropylene or teflon as a dielectric, they are larger than a non-polarized electrolytic for a given capacitance and voltage rating. Hope this helps. Peace, Dave P.S. chances are that you will notice differences in the sound between the new and old caps. That is if you had a chance to listen to the speakers before you started on the repairs.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)