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vvega

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About vvega

  • Rank
    Member
  • Birthday 03/25/1977

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  • Location
    New Zealand
  • Gender
    Male

Converted

  • Headphones
    Audeze EL8c (2017) Sennheiser HD600 Akg q701 -K7xx Beats studio 3 (gym headphones ) Stax 404 signature
  • Headphone Amps
    Lehmann cube , Xduoo-05 , Topping dx7s , Stax srm-006t
  • Other Audio Gear
    Pioneer Sc-lx901

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  1. All good , if it wasn’t for the article you wrote I would still be sitting here annoyed at an amp that was sub par at best . I appreciate that you put it out there and it’s work like that that keeps diy alive and out there . Its appreciated I guess all I’m trying to do with the testing is show the reasons behind why you did spec the ceramic insulators in the first place . But for me missing that detail and using silicon , something that would have failed at even 500v , I wouldn’t have damaged my amp and had to repair it. The testing so far has shown that a steel bolt with cera
  2. JimL saying the purpose is contrariness actually a pretty offensive thing to say to an engineer . Its just an adventure in building some electronics , I didn’t decide to build the circuit just to be a dick about it , i started doing it because I wanted better sound , i started testing because I made a mistake , a potentially harmful one and I’d like to not make that mistake again . Im still quite grateful to the fellow because it was his article that set me on this path and Kevin’s support that got me through it . ps I’ve started acquiring parts to build a carbon
  3. I don’t agree , when someone tells me on the internet that the specs are wrong on a part ... then why shouldn’t you test those specs . And if you have something against testing when hv is concerned well , that’s just silly. as an engineer I spend a lot of time testing to failure because that’s how we keep opinions in check over facts . Fact is mica is thinner and at the same thickness has very similar thermal barrier property’s . So a thinner insulator less thermal resistance . Whats wrong with looking for efficiency or better design From the testing I’ve
  4. Do you want to send me that part ? Give me a pm and well sort it ... it’s not avalible here as far as I can tell
  5. I have a ceramic washer and steel screws and the messy paste , can test that combo .
  6. In this case its an arc , a direct short , however the meter does measure leakage ... you will get voltage leakage before you get an arc . You select a voltage and it will give you a resistance value ... you then work out from there using I=VR to determine the current ... Type of Equipment Maximum Leakage Current Class I 0.75mA for hand held devices 3.5mA for other devices Class II 0.25mA Class III No hazardous voltages Both gave an open circuit test @1000v
  7. Did the testing with the ceramic insulators with a steel bolt .. 500v ...pass 1000v ... fail with a nylon bolt .... 500v... pass 1000v .. pass 2500v ... fail so same results as the mica with the nylon ... i don't doubt that there is a point between 1000 and 2500 that the ceramic would pass at a higher voltage but my tester doesn't have a mode between .. ill look at creating something to do that later .. but for now it would seem the issue is the steel bolts and not the insulation thickness or type of material . well between the mica and the ceramic . the sil is thinn
  8. because testing it showed ... I don’t have too . But hey I already have the ceramic bolts and pads coming , so I’ll do a test when they arrive and see how much better they are as well as a thermal test to see how much worse they are at transmitting heat , Because ceramic is not just a electrical insulator ... its a thermal one too as is Mica . whats wrong with good engineering and testing ?
  9. So i got my insulation tester today . i have videos of the failures ill upload later but .... steel bolt , silicon pad and the plastic bolt insulators 500v - Fail 1000v - fail with visible arc 2500v - fail with visible and audible arc The arc when front the fet plate .. through the plastic to the bolt .. from the bolt .. through the plastic to the sink. so ... that combo .. failed at every stage the mica plastic/rubbery collets and nylon bolt combo 500v - pass 1000v - pass 2500v - fail 5000v -fail In this case the arc went from the fet , around the mica at the bo
  10. That is literally exactly what the both and collet i used looked like just a tiny little dot instead of a weld mark (i got those on the chassis wall ) . There was just a dot on the screw and a little bit of melted plastic . I originally though I had got some swarf stuck between the pad and the fet and that caused it .. but all evidence says otherwise. Its a interesting failure because the arc would have had to go to the bolt and then back to the heat sink so thats a lot of point energy to initiate the arc . because the bolt itself is electrically isolated the heat sink as well . So physi
  11. I’ve been looking for where it happened for the last hour and it looks like I had the exact same issue , the screws , one has a mark on it that looks like an arc mark (there is no reason for it to have a white mark on it otherwise it’s brand spanky plating ). The collets I used in the first instance were just thin plastic as well . I guess the reason I’m asking was just simply if the pad is rated for 1kv and the 10n90s for 900v the fet should fail before the insulation does , also mica is a little better at thermal Transfer than silicon and a lot better than ceramic , so my thoughts we
  12. 1) already ordered and I’ll look again , I am going to ask thou , the mica I got is rated to 1kv , the voltage is only 580v the ceramic to 27kv , is it a concern it’s going to break down over time ? , the first ones I used were silicone and I couldn’t find any arc marks however I did tests resistance from tab to heatsink before installation on the first instance . However there was clearly an issue . 2) yes , you asked for 2 ? Watt Kevin had me fit .25 watt , I’ll have to check that , but I’ll correct it , was just a typo. 3) ohhhhhh ok I’ll have a look to see if it’s there when
  13. well then , will change and order , Ive used mica before up to 1kv ( I'm not going to lie Kevin did say go ceramic ) but will order and replace , already have the peek screws ordered because unhappy with nylon at this temp . the heatsink is 43 deg c ATM and hasnt changed for the last 24 hours of continuous use however did you drill the PCB to mount ? or just use an epoxy ? will move it asap because ... good engineering is just the right way to do things . cheers for the corrections update , Ceramic To-220 insulators ordered and also ceramic m3x12 capscrews and nuts , Ill compare
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