thr33p4c Posted March 17, 2023 Report Share Posted March 17, 2023 Hi everyone. It has been a long time since I posted on this forum. I have come a long way in my audio journey since first joining the forums here. I am now working as a full time audio technician and recently came across another beautiful set of KLH Model Fives. I wanted to take the opportunity to document a restoration from start to finish in an attempt to give back to the community that was so helpful to me when I was first getting started in audio repair. All three parts are available below: Part 1 - Dissasembly & Crossover Rebuild Part 2 - Cabinet Repair & Refinishing Part 3 - Cabinet Loading, Seals, & Testing Quote Link to comment Share on other sites More sharing options...
JKent Posted March 17, 2023 Report Share Posted March 17, 2023 Thank you! This is absolutely excellent. It should be pinned to the beginning of the KLH section and/or put in the Library. I'v done a lot of these Model Fives. Wish I'd had this reference before 😀 I'm on the road and may have specific comments later. Roy and I have been going back and forth about the resistors and maybe he'll chime in with his insights. Kent Quote Link to comment Share on other sites More sharing options...
Dogfenceguy Posted March 21, 2023 Report Share Posted March 21, 2023 Great video, thank you for the info! I have a pair of KLH 5's that were damaged with volume being turned up to high using blue tooth. I assume the caps and resistors were damaged, so I assume changing all of them out is a good start? What are the exact specs of the Mills resistors you used and the Vishay? Quote Link to comment Share on other sites More sharing options...
Quoytard Posted March 21, 2023 Report Share Posted March 21, 2023 Great video - thanks for your effort and sharing your work. Part 1 is beyond my capability but it was interesting to see how things work. I recently resurrected my 5's (actually, I relied on the knowledge, guidance, and kindness of JKent and other members of this forum - 'I' did nothing!). They sound wonderful. Looking forward to more videos from you. Do you plan to cover surround resealing and cabinet renewal/restore at some point? Quote Link to comment Share on other sites More sharing options...
JKent Posted March 21, 2023 Report Share Posted March 21, 2023 4 hours ago, Dogfenceguy said: What are the exact specs of the Mills resistors you used and the Vishay? Only the woofer resistor must be replaced and that should be 15 or 20 watts. Quote Link to comment Share on other sites More sharing options...
thr33p4c Posted March 26, 2023 Author Report Share Posted March 26, 2023 On 3/21/2023 at 2:14 PM, JKent said: Only the woofer resistor must be replaced and that should be 15 or 20 watts. Would you be able to elaborate on the requirement for increased wattage on the 5 ohm woofer resistor? I would like to add this to the next installment of the video. I am also going to add some notes about the rare but possible failure of the terminal tie strip rivets. I had one KLH Five that suddenly developed terrible bass response and I eventually tracked it down to phantom resistance between one terminal tie strip and the XO plate. I had completely forgotten about this until I reviewed some of my old documentation and CSP posts. Quote Link to comment Share on other sites More sharing options...
thr33p4c Posted March 26, 2023 Author Report Share Posted March 26, 2023 On 3/21/2023 at 12:30 PM, Quoytard said: Do you plan to cover surround resealing and cabinet renewal/restore at some point? I will be covering some cabinet restoration tips in the spring once it warms up a bit outside. I need to brush up on my knowledge with regards to surround doping but this will be covered as well. Quote Link to comment Share on other sites More sharing options...
JKent Posted March 26, 2023 Report Share Posted March 26, 2023 6 hours ago, thr33p4c said: Would you be able to elaborate on the requirement for increased wattage on the 5 ohm woofer resistor? I would like to add this to the next installment of the video. I am also going to add some notes about the rare but possible failure of the terminal tie strip rivets. I had one KLH Five that suddenly developed terrible bass response and I eventually tracked it down to phantom resistance between one terminal tie strip and the XO plate. I had completely forgotten about this until I reviewed some of my old documentation and CSP posts. I had noticed scorched, burned or cracked resistors in Fives and Twelves. Based on that I always replaced all of the 5w resistors with 10 or 12w. RoyC, who knows far more about crossover design than I isolated the culprit as the 5 ohm resistor in the woofer circuit. I’m away from home now so don’t have access to my notes or photos. Maybe Roy will chime in here. He recommended 15 or 20 watts for that 5 ohmer. I no longer advocate replacing all the resistors. They don’t normally go bad unless they are too weak for the job and that would apply to the 5 ohm 5w woofer resistor. Quote Link to comment Share on other sites More sharing options...
thr33p4c Posted March 26, 2023 Author Report Share Posted March 26, 2023 1 hour ago, JKent said: I no longer advocate replacing all the resistors. They don’t normally go bad unless they are too weak for the job and that would apply to the 5 ohm 5w woofer resistor. I would tend to agree. I simply swapped mine since I was going for a gut rebuild from scratch and wanted to start with clean terminals. Its seems like these were originally built with the capacitors going in last so in theory, it would actually be pretty easy to just desolder the original caps and leave the resistors in place. Quote Link to comment Share on other sites More sharing options...
RoyC Posted March 31, 2023 Report Share Posted March 31, 2023 On 3/26/2023 at 7:54 PM, thr33p4c said: I would tend to agree. I simply swapped mine since I was going for a gut rebuild from scratch and wanted to start with clean terminals. Its seems like these were originally built with the capacitors going in last so in theory, it would actually be pretty easy to just desolder the original caps and leave the resistors in place. First of all, very nice video and work! I have been at this for lots of years, and have restored many KLH speakers. The 5 ohm resistor in parallel with the KLH 5 woofer is exposed to more current, and is the only one I have occasionally found to be fried. The other potential KLH resistor issue is likely to be found with any "Rockwood" brand resistor (which can sometimes be found in Advent Loudspeakers as well). It is prudent to replace them whenever you find them, regardless of value, model, or placement within the circuit. Roy Quote Link to comment Share on other sites More sharing options...
thr33p4c Posted May 26, 2023 Author Report Share Posted May 26, 2023 Part 2 Posted and added to main post... Quote Link to comment Share on other sites More sharing options...
Quoytard Posted May 26, 2023 Report Share Posted May 26, 2023 Great work on restoring the cabinets - they look so good. Thanks so much for your time and effort and sharing this video! Watched it from end to end. Quote Link to comment Share on other sites More sharing options...
thr33p4c Posted June 17, 2023 Author Report Share Posted June 17, 2023 Part 3 (Final) Posted and added to main post... Quote Link to comment Share on other sites More sharing options...
Quoytard Posted June 22, 2023 Report Share Posted June 22, 2023 Outstanding! Learned so much, some of which I'll be able to apply myself. The rest? Not so sure but very educational nonetheless. Thanks - Quote Link to comment Share on other sites More sharing options...
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