KLH SCx3 General Info

[poolguy]

I've had these speaker for a year or so and finally getting around to repairing the.  If anyone has any information / history on these it would be appreciated. I have replaced all the foam, capacitors, and resistors.  Looking for potentiometers now. Thanks 

[JKent]

Wow! I’ve never seen those before but there’s some info on the Research Ten series in the library here.

edit: oops sorry. Nothing in our library but do a google search for KLH Research Ten series.

Did you take pictures of the crossovers?

Those speakers should not need new pots . If they are anything like the ones in other KLH speakers all they need is a shot of Deoxit (and they are unobtainium).

Kent

[poolguy]

Yeah the post are shot. I don't know what type of environment they were  in.   Cleaned with air and used Deoxit, no help.  Sometimes a good thump works though.?  Added a couple of pix of the original crossover.  There are two inductors mounted to the cabinet as well.  I'll be interested to see how they sound when finished

[JKent]

Those look like the infamous A-P pots used in AR speakers. Never saw them in KLH. Guess standard L-pads should work 

How are those resistors? One looks scorched. If so, I’d replace them too.

[ra.ra]

38 minutes ago, JKent said:

Those look like the infamous A-P pots used in AR speakers. Never saw them in KLH.

This was my exact thought when I saw the A-P pots. I think two new L-pads will probably fit side-by-side, but you also may want to make the effort to try to clean/restore these original pots.

[poolguy]

I did try to clean the pots with no luck.  Blew them out w light air, then Deoxit  and still no good.  I had a couple of capacitors and resistors that were burned and  replaced all.  I  did find schematic  from KLH,  and after a lot of searching with some help I found the 5ohm pots.  Hope to get around to replacing them soon.  I was curious though.... can you replace the pots with an L-pad?  The 5ohm pots were a challenge for me.  I wasn't sure exactly what I needed when it came to all the different configurations.  So it looks like you guys know the history... what's the story with the A-P pots?

klh_research_ten_SCX3.pdf

[RTally]

Do a search on cleaning AR pots. Your pots look very similar. Spraying DeOxit is not enough. They have to be disassembled to clean the corrosion from the contact surfaces. The general procedure is to remove the spring clip holding the halves together. The metal part is soaked and then brushed to remove the corrosion. A bit time-consuming, but it restores the pots to functioning again.

[JKent]

Video:

http://actionmovies24h.com/wake-up-dead-ar-4x-speakers-by-cleaning-the-rheostat_HGNP7-k7EeQI.html

and here's a thread:

 

[poolguy]

Great info..... thanks guys.  I'm not sure what the story is on these speakers.  Research Series may mean they loaded them up with all the spare parts laying around and did some "research" to see how they would sound. I finished one (w new 5ohm pot) and wasn't impressed.  I listen to OLA's and BA100's in my primary system and  imo these speakers don't compare.  I'll finish the other one this weekend and give the a try for a while to see how they sound.

Mark