May 9, 201214 yr The wires should in the first place never be near the solder points. Even if the heat doesn't get them the sharp exposed leads might. Teflon sleeve wires are recommended. I would run them along the side of the boards. If you must, use higher stands offs and secure the wires to zip ties to anchors the wires http://www.amazon.com/Zip-Tie-Mount-25-Pack/dp/B000BSJHLE I use the 3m ones. Quite a lot more expensive as compared to the normal ones but they don't come off unless you literally use a screwdrive or penknife to cut them out.
May 9, 201214 yr Thanks Victor. I have to wait for my panels from FPE and the Khozmo, which appears to be stuck in New York 2 weeks after I ordered it. I have had the amp on and off for hours without a glitch. Unfortunately, I have not been able to listen to it. I am hoping I can take it to the LA meet in August in nothing blows up. http://www.flickr.co...in/photostream/ http://www.flickr.co...in/photostream/ Edited May 9, 201214 yr by eggil
May 9, 201214 yr Nothing wrong with running the wires underneath PCB's but stay clear of AC lines and use wire with ample insulation. I also hope you aren't running the amp with the transformer sitting on the metal chassis? I would recommend placing a rubber pad between them just to be safe.
May 9, 201214 yr Nothing wrong with running the wires underneath PCB's but stay clear of AC lines and use wire with ample insulation. I also hope you aren't running the amp with the transformer sitting on the metal chassis? I would recommend placing a rubber pad between them just to be safe. I am using a rubber pad. And I like the idea of running the input wires. Ujamerstand, you forgot to cross the 50k. resistors, unless your board is a different version from mine. Edited May 9, 201214 yr by eggil
May 9, 201214 yr I crossed the diodes instead, because I had installed the feedback resistors before we knew they need to be crossed.
May 9, 201214 yr I believe Kevin also said that the O+ and O- ought to be flipped as well to ensure that the phasing is correct. But this will be for the later stage when signal wires are being dealt with.
May 10, 201214 yr I think it depends on where you flip the connection. In my case, I think I need to do that. But in eggil's case, he won't need to. I could be wrong though... Hmm. We should probably make a spreadsheet of the most important comments in this thread. We can split the thread up to speed up the process. Anybody want to help out? Edited May 10, 201214 yr by ujamerstand
May 10, 201214 yr I think it depends on where you flip the connection. In my case, I think I need to do that. But in eggil's case, he won't need to. I could be wrong though... Hmm. We should probably make a spreadsheet of the most important comments in this thread. We can split the thread up to speed up the process. Anybody want to help out? Whatever way you chose to cross i.e. diodes or resistors the outputs also need to be also need to flipped on this particular board version.
May 10, 201214 yr I think it applies to both the diodes and the 50k resistors: #479606 Posted by kevin gilmore on 09 November 2011 - 09:37 AM Sure enough, the feedback is flipped. Easiest way to fix it is to cross the 2 x 50k resistors. Or cross the 2 x 1n914 diodes. This is for the off board heatsink boards #479668 Posted by kevin gilmore on 09 November 2011 - 01:50 PM Remember that O+ and O- are now flipped, so wire accordingly to maintain absolute phase. . Edited May 10, 201214 yr by eggil
May 10, 201214 yr Hmm.. interesting. Got it. Edit: Right. Drew it out, and it should be swapped in both cases. Don't know why I thought otherwise. Edited May 10, 201214 yr by ujamerstand
May 10, 201214 yr #479668 Posted by kevin gilmore on 09 November 2011 - 01:50 PM Remember that O+ and O- are now flipped, so wire accordingly to maintain absolute phase. . Is this on the onboard version as well?
May 10, 201214 yr Eggil, you might want to twist/braid your ac, dc and input wires together or more tightly with each other to reduce noise. This is a electrostatic amp with very high gain and more susceptible to noise pickup. Output wires I believe are less prone.
May 10, 201214 yr Congratulations John. Very nice build. The encapsulated transformer looks really neat. What attenuator are you using?
May 10, 201214 yr Wow! Beautiful! Would you mind posting more pictures of the internals? Thanks Victor, I will Edited May 10, 201214 yr by eggil
May 10, 201214 yr Thanks guys, Victor the attenuator is a Khozmo smd version. Yun, I’ve just had my first O2 MK1 ear massage, basically to test amp, and the briefest listen, I will post some impressions as soon as I get some more head time. eggil, the wiring needs some cleaning up, ground wiring and the bias wire needs to be routed properly and the LED needs to be wired into the front panel. BTW my build is a 450V A1968 version... Here’s where it’s at now... Edited May 10, 201214 yr by johnwmclean
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