tropicalrips

i managed to desolder the resistors and changed the values following those given by jason the heat problem is not as bad now, opa2132 now works on the board but it sounds different from before the rework...i actually prefer the sound of the amp with the wrong values will need jason the analyse what "went wrong" with the values i first use on the board... my gain now is 6 R1,R5 = 42r R2,R6 = 100k R3,R7 = 20k R4,R8 = 20k R9,R10 = 4.7k

i think i got the resistor values crossed up 1+(R2/R3) = gain, this is only for 1 side rite? the other side is 1+(R6/R7) correct jason? can explain what is R1,R5 for? output resistor? and also R4,R8? i tried to trace the board, but its a little confusing with each opamp buffering itself i think i should be able to desolder the resistor the resistor values that i hav now on the board : R4,R8 : 100k R3,R7 : 1.5k R2,R6 : 42r R1,R5 : 42r jason, what is the result of my resistor values? is this whats causing the problems? the amp still works but not with opa2132 with these values myR9,R10 is 4.7k , is this whats causing the ground opamp to heat up?

as promised, here's a pic of the new board, the sound has improved, my only concern now is heat from the op-amps, there also seems to be noise being picked up by the board or cables...

just finish soldering the new version 2.0 of this amp first off, my opa2132 does not work on the board...strange...will need jason to explain why, there's just lots of distortion with the 2132, i think the chip is osilating badly on the board. i use 4.7k for the rail spilter resistor, not sure if thats the cause. also tried LM6172, used them on left/right + ground, this chip works but heats up...after about 5 mins of play, i remove them...fearing i might send them to opamp heaven next up, opa2228, agian this was the surprise opamp for this board, though it also gets warm, it was not as bad as the LM6172. my final configuration for tonight, opa2228 for left/right + JRC4556 on ground, the 4556 also gets quite warm, but i hav place a piece of ram-sink on it to help it stay cool first impressions of the new board : the sound is an improvement over the first board, the 2228 sounded fast, has good punch, this is without any modification, i also did not use my Alcaps on the input. but the board don't seem to ba as stable as the first one...i did not hav the 2134 to try out, but shouldn't the 2132 be almost same as 2134? anyway i like how the amp sounds with the 2228, its better on this baord then on the first one. will still need to confirm with jason on the resistor value that i used, maybe i got it wrong starting with R4 & R8, i used 100k,100k - 1.5k,1.5k - 43r,43r my gain should be more then 6 i think...need to sleep npw will post pics tomorrow...

sold thanks for your interest

who is Ahfart where do i find him how about using those silver wires if braid those at 4m...3 wires for the braid thats 12m of silver wire the cable might cost more then the headphones

yes jason sorry didn't see your sms today no work today, playing online game whole afternoon i don't quite understand the new board...if the iG & oG is already connected together, what is the third op-amp for? can the new board work with just 2 op-amps? left & right channel op-amps only, the first version can't work this way

my budget around $400, i prefer to get a new set...does not hav to be HDCD or SACD, thats just bonus for me anything thats better then my current sony pcdp and mini-compo is good enough, i'm also not particular on brand, was thinking of some Teac players at first. any player around $300-$400 should be pretty good rite? what about those "half size" players? they look better when paired with my desktop amp cause they hav the same size, is the quality of these smaller players not as good?

cmoy on steroids

i hav been looking for a good CD player for some time now, still not decided on which one to get...NAD, Rotel...now Sony... the only models i can find from the Sony singapore site are the 2 SACD player 3000 & 9000 series. but managed to find a few more on the web, XE570 & a lower model XE370, there is also 2 or 3 more models of SACD player that are cheaper then the 3000 & 9000, can these player be found in singapore? any one tried or own these players? i think bpribadi has post a tread with a short audition of the XA3000

do post some pic of the clone board

that was my original plan i thought any cable of audio quality should be better or at least same as the original, but like i said, i got bored so thought i make it more fun, making the cables removeable i think the cable cables improved the details a little, can't really tell, need to do a side by side compare to confirm, but i'm quite sure it did not make the sound worse

update : brought the Canare cable and 1/4" plug home today to complete the mod the RCA jacks are $4 generic type bought in SLS, the Canere cable is lighter and also softer then the Daiyo cables from the first post, now the headphones don't fell so heavy a shot of the plug, its thinner the the Neutrik 1/4" but i think they should be the same quality, but i still prefer the strain relief design of the Neutrik plugs i made the cables about 3m long, one question...why is too much metal no good? for the weight issue, it feels ok...with the Daiyo cable i did feel it was too heavy, but with the new cable, it feels about the same weight as my W1000, maybe just a little more the weight don't really come from the RCA jacks, cause i don't feel its any heavier then before the mod when i remove the cable, u'll feel the weight if u stand up with the cables running from the headphones to the ground, thats when u feel the full weight of the cables, i place part of the cable on my lap when i use the headphones, and the weight feels no different from before the mod

i was getting bored with my DT331...so i decided to try something i hav always found the cable of the 331 to be too tiny that let me to thinking about changing it. at first i thought of using the colorful Klotz cable for the mod...then decided since i'm doing a mod, why not make it removeable i didn't like the idea of using a 3.5mm mono jack cause i thought they would fall out easily, then i look at the RCA jack that i hav...there seem to be just enough space to fit them in taking apart the DT331 was easier then i thought, there was no glue or "catch" they just snap together, after desoldering the original cable, i enlarge the hole with a drill, there's not enough space in the headphone's housing for the nut of the RCA jack, so i drill the hole small enough so the jack will not be loose, i had to use a plier to screw in the jack, using the treads on the RCA jack to tap new treads into the housing. its a very tight fit, there's no chance the RCA jack is gonna come loose on its own solder the cables in place and close back the housing, the cables were some left over Klotz cables that i hav from making the interconnects. the completed headphones, i bought some Canere cables and 1/4" Neutrik jacks from Hung bros today but forgot to bring them home they were going to be used in this mod. another shot of the modded headphone, will post more pics with the Canere cables tomorrow

very interesting

for first time DSLR users thats ok, since u don't hav any lens anyway, and the lens for DSLR is not cheap, don't think will be buying that many lens unless u r pro

i'm holding back on plans for the DSLR for now maybe next year, looks like the price for DSLR is coming down, the Olympus E1 has drop almost $1000, now waiting for the rest to drop

bump

i think Digi is saying something about not using the shield of the cable, or is it the other way round can't see some of the chinese charactors. the middle part says not using part of the cable, i'm guessing its the shield, says this will giv more dynamics

Bram, did u attend some kind of knitting class before doing the cable how u braid 4 wires? they look like steel chains very nice, i must try it

can look at some of the Maxim op-amps, i hav used MAX4167 before, rated 2.5 to 6v, good for single 9v amps. they hav a few op-amps that are design for portable players that can drive headphones but not possible for DIY work direct headphone driver

don't know where to post this so thought i try this forum first i'm looking for a Dremel, new not used, anyone knows where i find it in Singapore? also...any idea how much it cost?

new layout looks better more neat

i open shop aaround 10:30am now making an "adaptor" for the jason amp

not sure which is it...i think the 627 does not output a lot of current, so may be the mod itself it will also work with BUF634 rite thinking of using BUF634 on the ground channel