I finished my second pupDAC today - I soldered the integrated circuits at the university lab and it was a breeze. Solder paste makes it sooo much easier, just dispense that stuff and wipe the edges of the pins with the soldering iron to get almost machine-quality joints - the hardest thing about...

I had the exact same issue - 0V at U2's 3.3V test point and U2 getting hot as hell. It turned out to be a short behind two pins on the 1794. And I mean aaaall the way back there - no chance of getting at it with a soldering iron. I had to remove the 1794, clean everything up, which I doubt I...

Yeah, I tried that but the short wasn't even visible under the microscope with the chip installed so it was a pretty hopeless endeavour. That's nice, although I don't think I'd buy it like that if I had the chance - I'm a bit stubborn when it comes to soldering my own components. In any...

Yeah, it's my own fault for not being careful enough while soldering it. I've soldered SSOP28 chips before and it was fine, I just screwed up and the narrow pitch makes shorts behind the pins (that don't actually touch them but are only between the pads) almost impossible to fix without removing...

I finished the first of my two pupDAC kits yesterday. Had an easily fixed short at first (2 pins on the PCM2707 had a tiny bridge that shorted out the 4.75V regulator) and then it seemed to work for a while, but started cutting out after a few minutes. I noticed the 3.3V supply shared by the...

No problem - I'll gladly take any opportunity to go on a rant about things I'm not entirely qualified to speak about ;) I know exactly where you're coming from, too. When I built my first headphone amp (a "starving student" which I ended up abandoning because I couldn't get it to work), I had...

There definitely is a "science behind schematics". Obviously, amp designers (and the same goes for any other electronic circuit, really) don't just connect random parts together and hope they end up with a working, good amplifier. For the design process, you need to have a good understanding of...

Yeah, I go through lots of iso rinsing my PCBs but the transistor legs on the MAX are very hard to reach with a toothbrush (on the component side, that is) and seem to require extra attention

Alright, time to revive a dead thread! I've been having some issues with scratching noises on the right channel of my Mosfet-MAX that tube swapping did not solve, but that seemed to be alleviated by jiggling the right tube around in its socked. The tube socket contacts appear to be pristine on...

Hi, I'm thinking about getting a pair of SRH940's but the headband cracking problems are putting me off and I want to be sure that I can replace the headband right away. Did you ever measure the diameter of the holes in the 940 cups that the yoke holds them by? I'm thinking about doing a...

Hi everyone, I've owned my pair of Fischer Audio FA-003s (they're actually FA-002Ws but I mounted the plastic cups a while ago as the wooden ones were a bit too bulky for my taste) for a few years now and they've always worked great whenever I used them with my Millett Mosfet-MAX. I only used...

Well, I replaced the LM317 and all is well again. And while replacing it I noticed that I hadn't even soldered the old one in properly, somehow I had failed to notice that its pins were not in the holes while assembling it. I guess it made contact for a while so I didn't notice and at some point...

Quote: Thanks again, but I've already ordered a bunch of 317Ts from Germany now, it'll be faster that way and they only cost like $10 shipped for 10 pieces anyway.

Thanks for the tip Goobley, I'd completely forgotten about ebay even though I use it quite often. I've even found a vendor selling 317s from Switzerland, so I'll just get some from that guy. 5 bucks for 4 pieces shipped is a pretty nice price. Edit: crap, just noticed that offer wasn't a buy now...

Thank you so much for the quick response. I'm getting around 27.5 volts, which, if I remember correctly, is what I got when I accidentally drove the LM317 out of regulation once, so it's very plausible that the regulator is indeed busted. I hope I can get a replacement locally, shipping that...