twinbugles Posted June 23, 2008 Share Posted June 23, 2008 Greetings. I would like to update my '81 khorn AA xovers...or, at least replace the old caps. How can I find out what value the old caps are?? Thanks all for your time....[H] Quote Link to comment Share on other sites More sharing options...
Deang Posted June 23, 2008 Share Posted June 23, 2008 The two caps in the tweeter circuit are 2uF. The value sitting between input and the #5 tap on the autoformer is 13uF. Quote Link to comment Share on other sites More sharing options...
Islander Posted June 23, 2008 Share Posted June 23, 2008 Replacing the caps is a good idea. Fresh ones will sound better. Here's the AA crossover schematic: Quote Link to comment Share on other sites More sharing options...
Daddy Dee Posted June 24, 2008 Share Posted June 24, 2008 Yeh. I think you are getting good advice here. You'll think you've got new speakers with fresh caps. There are other possibilities for mods beyond that, but I'd suggest just enjoying your new sounding Khorns for a while before thinking of doing anything else. Quote Link to comment Share on other sites More sharing options...
twinbugles Posted June 24, 2008 Author Share Posted June 24, 2008 Thank you all for taking the time to send me this info. I agree with the incremental approach: just changing caps with some hi-grade caps (Sonicaps or Solens, or...?) and enjoy it for now...then after I get rich and famous (or cash in my stash of beer bottles a few times) I can spring for some ALK or BC xovers. Is there any reason for me to continue with the AA xover? I understand it provides tweeter protection from excessive power....but I currently drive the Khorns with a modded Dynaco ST70 (Maybe 30 watts), and will be building a flea powered SET after I cash in LOTSA beer bottles. Quote Link to comment Share on other sites More sharing options...
Islander Posted June 24, 2008 Share Posted June 24, 2008 The AA crossover should be ideal with your electronics. Some of the steep-slope crossovers soak up a bit of amplifier power. Replacing the caps will bring your crossover back into original spec, so you can hear how an AA crossover was actually designed to sound. Before thinking of a different crossover, I'd consider a pair of BEC's CT125 tweeters. They sound noticeably clearer than the K-77s and are a closer match for output between individual drivers, typically within 1dB or less, while K-77s, especially old ones, can vary as much as 2-3dB. Quote Link to comment Share on other sites More sharing options...
tigerwoodKhorns Posted June 24, 2008 Share Posted June 24, 2008 Thank you all for taking the time to send me this info. I agree with the incremental approach: just changing caps with some hi-grade caps (Sonicaps or Solens, or...?) and enjoy it for now...then after I get rich and famous (or cash in my stash of beer bottles a few times) I can spring for some ALK or BC xovers. Is there any reason for me to continue with the AA xover? I understand it provides tweeter protection from excessive power....but I currently drive the Khorns with a modded Dynaco ST70 (Maybe 30 watts), and will be building a flea powered SET after I cash in LOTSA beer bottles. I would change them to Type A's and just add fuses to the tweeter portion. You want to have tweeter protection, even with low power. I have blows fuses with 30 watt amps (from a faulty volume control on a preamp). Quote Link to comment Share on other sites More sharing options...
twinbugles Posted June 24, 2008 Author Share Posted June 24, 2008 Thanks for the input. Is there a specific voltage rating I need to look for with regards to the caps? Will 50v or 100v be adequate? Quote Link to comment Share on other sites More sharing options...
wsu99999 Posted June 26, 2008 Share Posted June 26, 2008 Does anyone have any preference on the caps? I've seen people use sonicaps a lot - is there anything out there that is cheaper but equal quality? I know that 50 bucks or so isn't too bad for 2 crossovers, but I'm sure there is another brand out there that has a really cheap price and the quality is still there. Anyone kn ow? Quote Link to comment Share on other sites More sharing options...
Blvdre Posted June 26, 2008 Share Posted June 26, 2008 Sure, the clarity caps (PX) are nice and fairly inexpensive. I'm using them in a set of passives, and they are definitely nicer than the inexpensive Solens. http://www.madisound.com/manufacturers/claritycap/px.php Edit: scratch that, I wasn't paying attention to the values required. Quote Link to comment Share on other sites More sharing options...
Deang Posted June 27, 2008 Share Posted June 27, 2008 "I've seen people use sonicaps a lot - is there anything out there that is cheaper but equal quality?" Nope. Quote Link to comment Share on other sites More sharing options...
Erik Mandaville Posted July 4, 2008 Share Posted July 4, 2008 " You want to have tweeter protection, even with low power. " I agree, and would add too that low power when pushed into clipping distortion is more often a cause of tweeter failure than clean high power. Good luck on your SET project! Erik Quote Link to comment Share on other sites More sharing options...
HarryO Posted July 4, 2008 Share Posted July 4, 2008 "I've seen people use sonicaps a lot - is there anything out there that is cheaper but equal quality?" Nope. Agreed.But...I tried out some of the inexpensive Jantzen from PE on my AA's and they're not bad. Not Sonicaps but not bad for $20 for 2 crossovers to my door. The values on the Jantzens are 1.8 and 12 instead of the 2 and 13. Harry Quote Link to comment Share on other sites More sharing options...
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