spritzer Posted April 19 Report Share Posted April 19 (edited) Well this just arrived and as is our fashion, it has not been plugged in at all before I rip it apart. I'm having some camera issues (bloody Lightroom) so not as many as I'd like. Now first off why this belongs on a trashpile... here is the output: It's a pain to get a camera to focus between the transformers so I ended up grabbing the phone. Those are the ballast resistors, two 1M units in series and one 3M3 unit, all in 1206 package so likely 150V rated. Yeah no... just no, this is not good enough!! It gets worse though... It's a shit angle but here is how the transformers connect to the output socket: Now do you notice any parts on this PCB except connectors? Nope, neither do I... there is no protection on the output at all. No 5K1 output resistors nor the clamp circuit found on all later Stax adapter boxes. This thing will kill your headphones when pushed hard enough and there is nothing to protect the user if something goes wrong. Yup, pure class here... zero fucks given. Some other random pics, main amp runs off a +/-15V supply and the PSU brick is 15V/2A. Preamp presumably and the whole thing looks to be AC coupled through those electrolytic caps so that will not sound good at all. I see no other reason for those caps to be there so yeah, who does something like this. At least the volume pot is 4 gangs so the thing is fully balanced. Conclusion, without even plugging it in, this is a pile of crap and should not be used by anybody. The small changes to make this secure and sound good cost next to nothing but nobody cares. Best avoided unless you want to have a special talk to the manufacturer of your headphones as to why there are holes in the diaphragms... Now if I have time, I'm going to fully strip this thing down and design a PCB for the Stax socket which adds full protection and a clamp circuit. Fix the input caps and other issues that I find and this might a semi good 400$ amp. Personally I'd take a Stax SRM-313 over this pile of crap. Edited April 19 by spritzer Fucking typo's.... 2 4 3 Quote Link to comment Share on other sites More sharing options...
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.