ablaze 0 Report post Posted July 15, 2003 ok. I've replaced another opamp. (just now was the filter opamp) this time, its the left buffer opamp (5532-->8620 as well) so the right buffer opamp is not replaced (ie. still the 5532) ..which brings me to an interesting comparison! since I can now downmix my music from stereo to mono (ie. the same music in both channels) and additionally, mute one channel at a time, I'm able to directly A/B the left (8620opamp) vs the right (5532 ie. the original opamp)! initial impressions are positive in favour of the new opamp (of course. if it wasn't better, after all that work, I would've shot myself ) the 8620 sounds much cleaner and crisper. the old 5532 sounds overly warm and boomy in comparison. of course this is assuming, my left ear and right ear hear the same, and the left and right drivers of my headphones play the same. do opamps need burn-in too? Share this post Link to post Share on other sites
evil-zen 0 Report post Posted July 15, 2003 (edited) hahaha left ear and right ear doesn't hear quite the same. so are you planning to go for the third opamp change as well? how about the DAC? it sure looks interesting. Edited July 15, 2003 by evil-zen Share this post Link to post Share on other sites
ablaze 0 Report post Posted July 15, 2003 maybe I should try turning the headphones around to test? haha.. yeah. the only reason I left that last 5532 there is cos my second batch of 8620 'samples' haven't arrived yet DAC? have you seen how many tiny lil legs are on that thing? Share this post Link to post Share on other sites
adhoc 0 Report post Posted July 16, 2003 just think of it this way ablaze: another day.. another challenge! btw i've managed to desolder my dt880's wires already. what made this step very very very dangerous was the fact that actually the metal piece where the input wire is soldered is the same metal piece to which the thin copper wire (thinner than a hair) that led into the driver was soldered onto. this meant that all i had to do was apply a bit too much heat and BOTH the input wire and the copper driver coil wire would have desoldered. try to picture yourself trying to solder something that's thinner than a hair! whatever it is, i managed to pull it off successfully ( whew) and i'm resting now and trying to stop my hands from shaking. i think ill have to continue another day my hands are shaking too much liao. btw ppl i DO NOT RECOMMEND YOU DO THIS. one thing i realised was that the dt880's diaphragm is made of paper. one touch with the soldering iron and ... ablaze! Share this post Link to post Share on other sites
adhoc 0 Report post Posted July 16, 2003 oh btw ablaze i got the same soldering iron as you.. Share this post Link to post Share on other sites
ablaze 0 Report post Posted July 16, 2003 thats nice adhoc. don't you just love the micro-tip? oh btw, if you keep all your updates on my thread, then there won't be any updates in your own thread? http://www.sgheadphones.com/index.php?act=...ST&f=2&t=636&s= Share this post Link to post Share on other sites
ablaze 0 Report post Posted July 16, 2003 got my samples from AD today. I ordered 6 parts. they only sent two pieces. THANKS GAWD those two they sent were the AD8620s anyway, replaced my last opamp just. overall, I think one word sums up the mod for me. DETAILS Share this post Link to post Share on other sites
ablaze 0 Report post Posted July 16, 2003 final pic Share this post Link to post Share on other sites
Sipher 0 Report post Posted July 16, 2003 how u got your samples?! Share this post Link to post Share on other sites
ablaze 0 Report post Posted July 16, 2003 http://www.analog.com/productSelection/ord...ples/index.html quite cool. I got 4 8620s, and they're US$12 each Share this post Link to post Share on other sites
Sipher 0 Report post Posted July 16, 2003 ooh still need to pay ah?? hehe Share this post Link to post Share on other sites
ablaze 0 Report post Posted July 16, 2003 I meant if I had BOUGHT them it'd be US$12 each. samples are free Share this post Link to post Share on other sites
adhoc 0 Report post Posted July 16, 2003 haha maybe they sent you defective ones.. Share this post Link to post Share on other sites
ablaze 0 Report post Posted July 16, 2003 well they only have A grade ones for sample. no free B(etter) grade opamps Share this post Link to post Share on other sites
