June 12, 201511 yr ...tighter, tightest. Very nice indeed! Is there room for a trafo as well? Ooh, is there maybe a trafo hidden under PSU? Edited June 12, 201511 yr by JoaMat
June 12, 201511 yr impressive work as always John. Congrats! Have you measured the temperature inside the enclosure yet?
June 12, 201511 yr If you aren't scratching your head wondering how this will all fit then DIY is just too easy. On that note, a mini Carbon is in the works...
June 13, 201511 yr Have you measured the temperature inside the enclosure yet? No need so far, it’s only just warmish after a couple of hours. Ooh, is there maybe a trafo hidden under PSU? Indeed there is, I’ve just added pics in the builds thread.
June 13, 201511 yr Author oops going to fix that in other news, these Vikings seem to want SMALL, so this is for soren to fit into a 2U http://gilmore.chem.northwestern.edu/kgsshvpssicfetsingle.jpg in other other news, Kerry did a HV version of the goldenreference, will evaluate now. Edited June 13, 201511 yr by kevin gilmore
June 13, 201511 yr Very nice Kevin. With split secondary AC input, can 2 small boards be stacked for +/-400VDC? Also FWIW. the zener stack for the 10m90s shows 500V.
June 13, 201511 yr Author details, details, you get the idea. zener stack 500v for 450v output, 450v for 400v output and yes the idea is that you stack 2 of them. sure looks like the carbon really would fit in a single 2U heatsink box this way. still have to do a bias supply, and a simple +/-15 board
June 14, 201511 yr Doesn't birgir have a standalone pcb for generating bias? He also has that board for mounting triad fs36 seems like all the bases are already covered
June 14, 201511 yr I have watched the problem I described below and it still persists. Does anyone have an idea what I could check or replace? Since the volume of the sizzling I hear only through the headphones is dependent on the volume set on the elma stepper I am confused where it could originate? Does it make sence to assume it is not coming from the amp board, but from the elma stepper or so? I recently noticed a strange behaviour of my good old KGSSHV which has probably been there from the beginning, but has gone unnoticed with the 009. Now I have the 007 and I had to turn up the volume a few clicks (elma stepper). I now also notice it with the 009, because I now what to listen for. During the warmup phase, one channel presents a sizzling noise which is clearly noticeable but not loud. After the amp has been running for some time, it dissappears. Does anyone have an idea? I have removed the amp board and visually checked it. Also used the opportunity to add 100ohm input resistors. The problem still persists. The sizzling changes in volume when I turn the volume pot. If the sizzling originated from some arcing, changing the volume should not have and impact? yes? There is no audible physical noise coming from the amp. The first thing I did was checking balance and offset. Both were good. I will try my best to describe what I hear. Its a noise similar to what you hear, when you push the headphone cups against the head but less loud/less pronounced. It is not continous, more like there one second, gone the other. The volume of the sound becomes louder when I turn the stepper to increase the volume.
June 14, 201511 yr Bypass the Elma and see what happens. Those switches are notorious for corrosion and connection issues after a few years.
June 14, 201511 yr Author I have had nothing but grief with the elma (dact) things. after a while the contacts go high impedance. same as the khozmo.
June 14, 201511 yr Ok I did the following test. When I removed the input wires from both boards, without grounding the inputs, the sizzling channel started sizzling well noticeable, whereas the other channel remained almost silent. Interestingly, when I grounded the inputs from the sizzling channel it was almost quiet, with the sizzling being barely noticeable to unnoticeable. This seems to rule out the elma as a source of the problem. Does this sound more like a problem of the first amplifier stage or another stage? What parts would you start working at? lsk389 and mpsw06? below it? I don't have a scope... Edited June 14, 201511 yr by insanity
June 14, 201511 yr Author so Kerry did the analysis on this, and his name is on the board, for the next version and I appreciate his help. This is a big deal because it has essentially 1 less stage, so it runs on as little as 50 volts unreg to reg, so it generates less heat. with 75 volts difference you can run 550V caps with 25V of margin at 450V output http://gilmore.chem.northwestern.edu/kgsshvpssicnew.jpg 6.0 x 6.5 inches if I can just find a way to get rid of the one red, you could make this as single sided like some of the rest of the new ones. Edited June 14, 201511 yr by kevin gilmore
Please sign in to comment
You will be able to leave a comment after signing in
Sign In Now