n0on3 0 Report post Posted March 16, 2007 Hello ppl, I'm really interested in building a headphone amp, and have done a bit of research and found out abt this simple Cmoy amp. I managed to somehow get the big picture of how it is built, but I have no idea on where to get the parts ( the guides on the net are mainly for US ). May I know where to buy them in singapore n how much it would cost me to get the parts?( Btw, im a mere newb with not much knowledge, but if I can get parts and follow the guide,I can still build the cmoy amp rite? ) In addition to that, would the parts be different from the parts mentioned on net? If it was different, would any kind souls be willing to list all the parts to get ...... ( I'm looking at the guide from http://tangentsoft.net/audio/cmoy-tutorial/ this guide is the most comprehensible to me... ) Anyway, would the amps be any use if my headphones are Koss Sportapro n PX100 ? If not, would it still be worth it to build the amp based on my own curiousity... you know.... this electrical stuff kinda interest me pretty much... unless building one would cost me a fortune..... I have minimum knowledge about all these electronics ( currently still in sec 3 ><) but I'm more than willing to learn . One last thing I wanna ask is the Tools i should get.... I have no idea on what to get for the tools... but I hope in total... i would not need to spend more than 70 dollars on all the things i should get... the lesser the better. lol. my budget's kind of tight... anyway, this is the first thing i would do DIY... I want to build the amp due to my own curiosity and interest more than anything else. I hope the budget doesn't restrict me too much. All advice and suggestions are sincerely appreciated . Thank You !! Share this post Link to post Share on other sites
kross 0 Report post Posted March 16, 2007 If you want to save the trouble then maybe you can get a ready build amp. if not i think you can look through the cmoy 2 guide on this forum. it's not difficult to build if you have done soldering before. Share this post Link to post Share on other sites
1bit 0 Report post Posted March 16, 2007 welcome to sgheadphone!!! still in sec 3? wow that's great! well, i think one of the friendliest place to look for parts is Koba. it is at people's park centre and it sells a very wide range of surplus components most notably capacitors. you can print the parts list from tangensoft and bring it to the shop, there you can ask the young clerk (i think he's the owner's son) to help you. and another good thing about the shop is that it opens during the weekend unlike the shops at sim lim tower. The next best place to shop is of course sim lim tower. there are many shops there with different specialties. you probably wanna check out federal components, you can get different kinds of ic (including opamps) there. Another alternative is to buy online from farnell or rs component. they have most of the stuff that you need including the potentiometer for the amp's volume control. but you'll need debit/credit card to shop there. well the thing about amp is that it improves sound but in unexpected ways most of the time. mm i dunno it's just my opinion i guess. but anyway, it's quite fun building diy electronics, the end result is not too important in this case. The most basic set of tools will be solder, soldering irons (and its holder with sponge to clean it), and solder sucker. try to get soldering iron with a fine tip although it can be more expensive. another optional tool is the multimeter, but this is only if you know how to use it. well that's it for now, good luck on your first electronic project and have fun. hope you don't scald your fingertips while soldering though lol. Share this post Link to post Share on other sites
n0on3 0 Report post Posted March 17, 2007 Thank You very much . May I know where exactly is Koba in ppl's park? n do they sell opamps there? I know how to solder from my sec2 D&T lessons... hahaha. Should b enough skill right? If im not wrong ,the soldering is just to connect wires which are under the board. So I think i can do it. lol. One more thing, where can i get the soldering materials?(iron, solder, stand). What would be the good price range for a decent soldering set? Thank you again Share this post Link to post Share on other sites
kross 0 Report post Posted March 17, 2007 i remember koba selling transistors but I'm not so sure about opamps. anyway, you can always go there. It's on the top floor iirc and it's quite an all-in-one shop... for soldering sets, there are also those 'branded' ones...personally i am using some cheapo types, those without temperature control, no stand..etc. it works fine but maybe for a start you can try to get some decent set with all this. a set should cost around $30-$40 maybe..? Share this post Link to post Share on other sites
zhang_junyang 0 Report post Posted March 17, 2007 Koba is not opened on Sundays and public holidays so dun go there on those days. Mondays to Saturdays are fine. Since you are still quite young, it will be good if you are able to get someone experienced to guide you along the way. Share this post Link to post Share on other sites
1bit 0 Report post Posted March 17, 2007 Koba is not opened on Sundays and public holidays whoops sorry, lol never realize this, so that means i always went there on saturdays last time. Share this post Link to post Share on other sites
n0on3 0 Report post Posted March 17, 2007 Lol. Icic. mayb i should b able to visit koba sometime next week. Just gotta buy the soldering set and the parts. Thank god i found a multimeter in my house , so less things to buy. hahha. So i suppose i have to order the opamps from Federal in SimLim Tower is it? Which op-amps would b recommended for a newb, just in case the op-amps would not b the same stated from the guide... i dun wan to spend so much money on too good op-amps, most probably i would get it spoiled somehow in my first try anyway(i read from other posts that it get spoiled quite easily from solder's heat) so i might want to buy a couple of cheap, but still decent, op-amps... op-amps cost around $5 rite? Share this post Link to post Share on other sites
n0on3 0 Report post Posted March 17, 2007 O, after reading more forums.. i think it's possible to get the op-amps in singapore. I think I would go with the OPA2132PA. Just have to order from federal in SLT i suppose? (i have no credit card whatsoever...) I just realized the board have to be of a certain pattern... would kobe sell this specific board or something similar? or is ther any other place i could get such board? Share this post Link to post Share on other sites
Kippei 0 Report post Posted March 21, 2007 (edited) When are you going down to koba. It been a lot time since i done DIY. My first project is cmoy2, which i instantly upgrade to PPAv2 den tried my hand on a SOHA den i quit due to wheeing problems. Can spare you some opamp provided i can find it. 2132 2134 Edited March 21, 2007 by Kippei Share this post Link to post Share on other sites
heady 0 Report post Posted March 22, 2007 O, after reading more forums.. i think it's possible to get the op-amps in singapore. I think I would go with the OPA2132PA. Just have to order from federal in SLT i suppose? (i have no credit card whatsoever...) I just realized the board have to be of a certain pattern... would kobe sell this specific board or something similar? or is ther any other place i could get such board? You can find strip boards in Koba or Sim Lim and then improvise. The pattern shown in the CMOY tutorial can be found but with some difficulty. Share this post Link to post Share on other sites
n0on3 0 Report post Posted March 22, 2007 Just went there on tues. And I just have to say it.... the people there is very very nice. esp. the guy who helped me out to get the stuff that I needed and told me d things abt resistors ( how to read them ). That store looks like it's got everything. lol. Kippei : I don't think i would need to get the 2132/2134 lol. Thx anyway I finally got everything i needed by substituting things i couldn't find. Koba don't sell the OPAs but they have JRC 5532D. It's 1.50 each, so i got a couple. they'r also dual opamps anyway...... mayb im using it first b4 I go to federal n order OPAs or mayb i don't need to Anyway, I substituted the board with a pad-per-hole. The strip boards they have there doesn't look to be foolproof... the pad-per-hole looks much better.... i'll try to figure out the schematics and design my own set-up. I managed to make sense of the schematics. Except for one thing. What is the "grounding" and "virtual ground".... Anybody out there can explain to me what is "virtual ground"? mayb any web dat explains how to make the "virtual ground" for grounding... Currently still designing out the plan on the pad-per-hole. but i seriously have no clue where does this ground connection has to go to.... From what i have read ,there should b a "virtual ground". but how do i make a " virtual ground" on a pad-per-hole anyway? The one at tangentsoft shows dat virtual ground is the long vertical strip of white line on the board.. which definitely is not present on pad-per-hole... Btw, thx to all : 1bit,kross, zhang_junyang, heady, Kippei, for all the advices and offers really appreciate them. I am going to start the project as soon as i get to finish the design, and figure out the grounding. hahha Share this post Link to post Share on other sites
n0on3 0 Report post Posted March 22, 2007 http://tangentsoft.net/audio/cmoy-tutorial...tangent-sch.pdf Lol... i just realized there's this POT thing with the 10K sign beside it... which item does it refer to? resistors? film caps? or does it just mean that i have to split the left n right and ground? After looking at my stereo plug, looks like it's just about splitting left,right,ground( there's three metal thing sticking out, which i think is for splitting the connections.) However, the 10K bothers me... is it a resistor? i dun quite get it... i did not see any POT in the parts list... i hope the 10K doesn't mean a thing though..... Can anybody tell me what it is? Share this post Link to post Share on other sites
zhang_junyang 0 Report post Posted March 22, 2007 The 10K pot refers to a 10k ohm potentiometer (variable resistor). It is used to change the volume of your amplifier. It normally has 6 pins; 2 rows of 3 pins each. So, for the left/right channel, u normally connect 1 end to ur input jack input, the other end to the ground of ur jack and the middle pin to the 0.1uF in the schematic. The virtual ground is the ground split by the 2 4.7K resistors. Just connect this point to ur input jack and output jack grounds and all other ground points depicted in the schematic. Share this post Link to post Share on other sites
heady 0 Report post Posted March 22, 2007 n0on3, the 10K stereo potentiometer (pot) is hard to get in SG. First, not all pots are usable. Only those with logarithmic or audio taper can be used. Many of the pots available in SG are linear. I do know that a 20K audio taper stereo pot can be bought in a shop in Sim Lim Square, it's on the 4th level and is called Bytetronic. This should be usable. Or, if you are connecting a MP3 or CD player, you can use the volume control on the player and you can omit the pot completely. Share this post Link to post Share on other sites
