1bit

hmm i can't say for sure about battery life. never really test it proper. i'd say it's between 5 to 10 hours or probably longer. well the gain setting is up to you, when i first made it i used the standard part list (gain 2x) to drive my cheapo koss 100 ohm headphones and i felt unsatisfied. that's why i increase the gain. that time i haven't got my alesandro yet and therefore never had the chance to try the 2x gain on a lower impedance phones. cmoy2 can fit inside an altoids tin, but it's a pain to make the holes for the pot and jacks.

hi joe, welcome to sgheadphones! and happy new year too, btw i've built my cmoy2 about a year ago and i'm quite happy with it. currently i'm using it at home with either alessandro ms1 (32 ohm) or sennheiser hd590 (120 ohm). i've set the gain to 6x by changing the feedback resistors to 50k ohm. in this way, i can use both headphones. for the alessandro i raise up the volume knob to around 40% and for the senn around 80%. looking through your part list, it seems alright. it's just that you seem to forget to put the led and the enclosure/casing in the list. and also don't forget the switch, you'll need this. btw, i opened the newark website and it looks like the (well i'm not too sure about this) the resistors are ordered not per pieces but in tape/reel. i'm not sure how many piece of resisters per reel of tape, but you could end up with more resistors than you need. not that it's a bad thing anyway lol. you can try matching up the resistors that way. and keeping spares is always a good idea anyway. but anyway, i'm not sure about this, please check with newark. you could probably get a pair of higher capacitance caps for the coupling capacitors (C1& C2). i managed to fit in two 3.3 uF polyester caps replacing the 1uF ones. you need to be sure about the size first though, so need to open up the datasheet sigh ... and if you have more money to spend or a bigger enclosure you can try finding exotic caps both for the coupling and the electrolytic caps. a low esr electrolytic cap should be better i think. i'm not sure about the availability of the pcb. you need to check it with jasonhanjk. you can use two or more 9v batteries in parallel. this won't be a problem. to use two batteries in series, you'd need to change the electrolytic caps to ones with higher voltage rating (currently they are 6.3V). i think the max you can use is 2 batteries in series as it is limited by the absolute max supply voltage that the opamps can take. please check the data sheets. electrically, i think it's gonna be ok if you wanna use a wall wart (adapter) to power the amp. just use something with around 9V output and be careful with the polarity when you do that. it's just that some say the sound quality will be affected in some way. another option is to build your own power supply. it roughly consist of a fuse, a step down transformer, diodes in bridge configuration (rectifier) and a regulator. hope this helps

Wolfmother with a nice Frank Frazetta painted cover

alright! speedknight, care to give us a review of what you think about rp-htx7 headphones? especially compared to the akg k26p.

here's another alternative for alps pot: accidentally found this while browsing farnell website vishay sfernice dual log pot 50k it'll fit the cmoy2 board however it is quite expensive at S$16 a piece.

if what you mean by battery holders are compartments for the battery with connectors, you can easily found them in one of the shops at sim lim tower.

rs component sells the br variants but it's curently out of stock. the page also says it has "short lead time", not too sure what it really means but it says that the item will be available in 7-10 working days. link nonetheless, the br parts are much more expensive then the ar and rs-component marked up the price even higher. btw from the datasheet, it seems that the br parts have better characteristics (e.g. input offset voltage) albeit very small improvement. the differences are similar to between opa627ap and opa627bp i guess.

there's a shop at around one of the corner in sim lim square level 1 that sells rather nice toslink cables with interchangeable connectors so you can plug it in 3 variations i.e. mini-mini, square-square, and mini-square. iirc it costs around $20+ and the cables come in pearly white colour. btw, afaik the optical out from most pcdps can only be used if it is powered from external power source (the wall adapter) and not with batteries.

hi nanbe1st welcome to sgheadphones

some of the inspirational songs would be: queen: spread your wings creed: don't stop dancing mm i just realized that quite a lot of queen's songs are inspirational e.g. bohemian rhapsody, it's a hard life, and the show must go on. if you want to wallow in your sorrows, pearl jam songs are great, especially about relationship problems e.g. nothing man.

you should get one of the the hi-md models, i think it has much more capacity and fully supports unlimited number of uploading of line-in recording to your pc you can have a comparisons of the different models at the minidisc.org website however, i'm not sure where you can get these hi-md players in singapore.

ha ha that's ok, the link is kinda confusing

hmm wait, are we refering to the same thing here, huangyong? when you click the link provided http://stores.ebay.com.au/BursonAudio-Melbourne in the page there are many links to the projects and the one that i thought was being refered by topic starter (about opamp mod) was the one about opamp tweaks i've only read a little of it and i think it is talking about an opamp built using discrete component. were you refering to this link about power regulator?

wow this is not just a mod, it's more like building your own opamp from discrete transistors oh boy, it's gonna be tough trying to match the transistors i.e. for the differential input and the current mirrors. i've never tried this myself but dang somehow it also sounds fun. so any idea which opamp to emulate first? hmm need to get the schematics

personally i'm using a pair of sony mdr-w08 for jogging. here's the picture: i still remember i paid $16 for that. bought it at the music junction shop in jurong point. i feel it's very light and comfortable, lighter than beyer's sx-10 (won it from jaben's lucky draw a few months back). it's so light that it almost feel like i'm not wearing it. the sound quality is decent i suppose, similar to sx-10.

for led zeppelin, i'm gonna need to recommend you this album. it is by far their best live and compilation album in terms of techniques/musicianship and sound quality. imho most of their studio album suffers from bad sound quality due to the recording, but not this album. i just can't find any word to describe their performance. it's just magnificent to say the least. jimmy page is amazing here. listen to him play his guitar like a violin in dazed and confused. wow this live album is recorded in 1972 while they are touring in california, and as the title suggest it is really 'how the west was won' over by led zeppelin.

hi cocobean: here's a link to gaiman's journal talking about absolute sandman you can pre-order it a t your friendly neighbourhood comic shop, or buy it online at amazon for example btw, do you have any experience buying things from amazon and shipping it using vpost? it could turn out cheaper, but i'm not sure about the additional tax/duty though.

just click on the file, it'll open a new page and if you have a quicktime plugin it'll play the mp3. can't seem to download the mp3 file though. but anyway, nice 3d/binaural recording. if you listen it with a headphone it'll feel so real it's kinda annoying haha

great, i like comics too i read mainly vertigo and dc comics if you like sandman you should pre-order the absolute edition of sandman vol 1 coming this nov iirc. they are reprinting sandman issue 1-20 in an overlarge format, deluxe slipcased hardcover. and they are recoloring the comics.

analog crossfeed without caps in the signal path? wow that sounds interesting, can i know what's the circuit called? or even better if you know the url to the project

hi referring to the two images above, one is the symbol and another is an example of a sliding dpdt switch as you can see from the symbol, there will be a common terminal and two other terminals that you can switch the signals from. on the physical switch, usually there will be two rows of three terminals just like in the picture, each row is for different parts of the circuit. the common terminal is usually the center one, but to make sure of this you can check it by using a multimeter's continuity tester. this will also confirms which two terminals are connected to each other at a particular switch position. let's take switches S1a and S1b for example, the first row of terminals on the switch is for the left (green component) circuit, the otgher one is for the right circuit. connect the common terminal to R2, the other two terminals to R1a and R1b well, koba at people's park centre level 3, they stock almost everything electronics. the other options will be sim lim tower level 2, 3 and basement level. this is as far as i know: 1) the wattage rating is not related to audio grade. usually what they claim as audio grade resistors have smaller tolerance and temperature drift (more stable against temperature changes). for most audio project 1/4 W is usually enough. make sure you choose metal film resistors with 1% tolerance and not the carbon type. 2) ceramic caps are usually brown in color and disc shaped. polyethylene/polypropylene caps are usually rectangular shaped. 3) not sure about this, i usually choose the switch based on its size to fit the casing. of course the bigger ones can be expected to be able to handle larger currents

OT here: mm actually i am afraid of the line driver ic inside the player itself, especially for portable players, if you do that. most of the line output is rated for 10k ohm load, i'm afraid 16 ohm of the earphones is just too big a load for the chip and i don't think it will do any harm to your ear, the volume will be quite low (especially for 16 ohm earphones)

yeah thank you wilson and yotiao

haha hi guys pleasure to meet some of you at jaben this afternoon i won the first sx-10 haha

wow an ajikan fan here where did you get this album btw? they only sell it online is it? how much did you get it for? interested to get one anyway been listening to this: UFO - Strangers in The Night found the cd at gramophone city hall