Rameish 0 Report post Posted February 26, 2003 (edited) Please get an experienced builder to build one for you. Headphone Warrenty does not cover shorts that fry the drivers. The service dept of any headphone distributor can easily tell if the voice coil is burnt. And they are the most expensive part of the headphone and you may even need to change both for matching purposes. Also either lower the volume knob to zero (or switch off the amp) before plugging and unplugging the headphones. Some amps need to be switched off while others need the volume to be set at zero. Even though the Corda doesn't need either, I still lower the volume knob to zero before unplugging or plugging in the headphones - good practice and it can save you $$$. The Grado RA-1 need to have the amp switched off and the Creek needs the volume to be set at zero. FYI only. Also please understand the op-amp you're using - if the socket fits does NOT apply here. Good Luck on the DIY jobs - Ablaze please add somthing to this. Coming from me it does not have as much credibility as I sell Corda amps. Cheers Edited February 26, 2003 by Rameish Share this post Link to post Share on other sites
N@Z 0 Report post Posted February 26, 2003 Be it DIY or manufactured amp it makes sense to use good practices as mentioned by Rameish. I do it regardless eversince I started on the road to audio hell / nirvana which ever you may see it! As is common with good DIY builders, they normally test the amp at nearly all stages of construction. I am aware that KurtW on Head-Fi uses a special equipment to test his finished products upon completion to measure distortion. For newbies buying DIY amps my suggestion obviously would be to commission a well known experienced builder who would honour any defects within an acceptable period of time. Also a good start would be to buy a used amp from a fellow member/friend who is upgrading so you know they are not offloading the amp due to a problem. Share this post Link to post Share on other sites
jtfoo 0 Report post Posted February 26, 2003 (edited) One thing I think most dangerous with diy headphone amp is doing a tube headamp. The tube uses very high voltage as high as 400V. This can be life threatening if that high voltage line accidentally touches the leads of the headphone while your head is in between them. Really electricfying. You built yourself a module for the electric chair instead. Edited February 26, 2003 by jtfoo Share this post Link to post Share on other sites
ablaze 0 Report post Posted February 27, 2003 yeah..DIY amps can have problems. but once properly built, they should work just fine. My first meta42 from one of the headfi-ers reached me and although tested to be working great just before it was shipped, when it came..sh*te man. the pot was screwy, all I got was one channel sound, then as I turned it up, the other channel slowly trickles in..but never quite reaches the level of the louder channel. then there was this goddam BUZZZ..all the time.. best part, when it reached the builder again back in the US, he tested it and found it to be perfectly FINE! then there was a KGCA that I got to look at. the builder put in a wrong transformer. instead of a 230v transformer, it was a 120v transformer. I plugged it in, the blue LED came on, and within a few seconds, it went off again. later found the fuse had blown, and that I had needed to use a AC converter (to bring our voltage down to 120v to be useable)..then of course, after that, it still didn't work very well. light buzz again.. not to mention the finish of the enclosure wasn't exactly.."scratch-free" either.. then Firefox's meta42 (first version) he built for me..worked perfectly, sounded absolutely fantastic for that price. but after a few weeks, one of the wires on the neutrik jack had come loose. ok lah..my fault cos I hadn't handled the plugging and out of the headphones into the jack properly (it was one of those locking neutrik jacks) or maybe it was one of you guys at the first meet we had! when I brought it back to him to fix, I got greedy and wanted to max it out..and now its taking too long and he's gone to the army.. and THATS why..I eventually decided to just go with nice X-can V2 for myself. I've had it for a few days now. doesn't sound too bad at all! I think what I like about it is..if I wanna "upgrade" the amp from here, I don't actually have to buy new amps..I can change tubes, change the parts inside etc etc..well, in time I guess in summary, I'd say its not such a good idea to get a DIY amp from overseas. voltage different, and if there're problems, shipping back and forth is hell. get someone local (or do it yourself if you got the patience..and the l33t skillz ) to do it..at least got problem, no worries, the builder's just a phone call and a bus/car/mrt away oh, I should say here that firefox/dreamslacker's amps are quite nicely constructed. when he eventually comes out of the army (is it this weekend?) and when he's done with the meta42, I'll post some pics then you all can see for yourself hehe Share this post Link to post Share on other sites
jtfoo 0 Report post Posted February 27, 2003 then there was a KGCA that I got to look at. the builder put in a wrong transformer. instead of a 230v transformer, it was a 120v transformer. I plugged it in, the blue LED came on, and within a few seconds, it went off again. later found the fuse had blown, and that I had needed to use a AC converter (to bring our voltage down to 120v to be useable)..then of course, after that, it still didn't work very well. light buzz again.. not to mention the finish of the enclosure wasn't exactly.."scratch-free" either.. Is your KGCA still around? Maybe can wire it to 230V if your is the dual primary type transformer. Share this post Link to post Share on other sites
ablaze 0 Report post Posted February 27, 2003 its not my KGCA though. it was a fellow head-fi-ers..I think he's not back in SG yet.. Share this post Link to post Share on other sites
N@Z 0 Report post Posted February 27, 2003 That's a shame ablaze. So far all the amps I had from the US all worked great. However, in my case I asked for battery powered & with an option for operation using a transformer rather than direct from wallwart. Share this post Link to post Share on other sites
ablaze 0 Report post Posted February 28, 2003 yeah. i suspect a lot of my issues lies with this questionable linear but unregulated wallwart I got Share this post Link to post Share on other sites
jtfoo 0 Report post Posted February 28, 2003 yeah. i suspect a lot of my issues lies with this questionable linear but unregulated wallwart I got Talking about wallwart (I assume it's those AC->DC converter), what brand are you guys using? Share this post Link to post Share on other sites
ablaze 0 Report post Posted February 28, 2003 hah..mine's some Newstar piece-of-crap Share this post Link to post Share on other sites
Northern Oak 0 Report post Posted February 28, 2003 hah..mine's some Newstar piece-of-crap ablaze, That's REALLY an UNSTABLE piece-of-crap, should only used them for non-important applications. Go for a better one and you will find nirvana Share this post Link to post Share on other sites
N@Z 0 Report post Posted February 28, 2003 For what it's worth, mine is a Powa-Labs 1000mA with 'noise filter'. What would you recommend Northern Oak? Share this post Link to post Share on other sites
ablaze 0 Report post Posted February 28, 2003 problem is I couldnt' find any other 24v DC power supplies in SLT. you know any? anyway..I'm using it as an upgraded psu for the X-can now. it goes up to 5000mA, and its switchable to AC current (for the X-can)..I measured it with a multimeter outputting about 11.2-11.5v for the X-can. ok lah, no hum, no distortion. In fact, it worked fine for the meta42 that dreamslacker built for me too. btw, the KGCA wasn't using this. it was using another AC-AC converter (240v-->120v) when it exhibited the hum problem.. Share this post Link to post Share on other sites
jtfoo 0 Report post Posted February 28, 2003 (edited) I'm using Epson Notebook 24V,800ma supply from my apheared47. I replaced the head with a generic one, as the one with Epson is not a standard piece. It even comes with ferrite clamp... It still has a slight hum problem when the PCD is off. But once the PCD is on, there's no hum... SLT has one HP notebook 19V, more than 1 Amp. Solid construction, but the cost at $49 is way to ex.. My epson only $28. Edited February 28, 2003 by jtfoo Share this post Link to post Share on other sites
ablaze 0 Report post Posted February 28, 2003 one question: WHERE? Share this post Link to post Share on other sites
