jtfoo

sorry not my its Xin's super-mini not my i'm looking at his design to improve my own i think it works with the AD823 cause of its low voltage requirement, my cha47 with 2 AD823 op-amps has already lasted longer then the cmoy with 1 OPA2132 on 1 9v batt according to Xin this super-mini will last 75 hrs on the 3 AA , thats very impressive, i'll see how long my CHA47 last anyone knows if the cha47 will work with AD823 as amp with LM6172 as buffer? will be getting my LM6172 after the holiday Still I have my doubts with it's low voltage supply. It's not how long it'll last, but whether can it provide the voltage swing. But if you running it with mini earphone or low impedance and high sensitivity headphone, then probably you can get away with a decent sound. But if that's the case might as well run direct from your source which already provides similar voltage swing. This way as least you get direct path from source to earphone without the coloration of a mini headamp.

Yoour latest creation is really compact... But with just 3 AA, you have only 3.6V. Might not be optimum, and also might not provide enough voltage swing especially for high impedance headphone.

The 0.1uF is actually C2+ and C2- on your attached picture from Tangent's site. It will NOT replace the power supply cap. This 0.1uF should be placed as close as possible to the opamps, if you read Tangent's article properly. In fact best is directly solder on the leg of the opamps. Here's a pic of on the underneath of my CDplayer with the bypass caps. Right under the legs of the opamps.

the LM6172 is suppose to be a high speed op-amp, but not as stable, so can use it to test how good the board is rite? Read up Tangent's article on dealing with cranky opamps. I've swapped my CD player opamp to the LM6172 and I used 0.1uf polypropylene caps to bypass the power to the opamps. Very stable. YMMV.

Can, but BUF634 not cheap.. If gonna use higher price buffer, I'll rather for the meta..

Try the Grados on the cmoy first, and crank up the volume. You'll notice lots of distortion. Now try the Grado on the CHA47 and crank up the volume, no more distortion. That's the main diff between the cmoy and your CHA47.

You workmanship is getting better. Very neat, can see that you properly bent the resistors lead...

No I have not tried both crossfeed you'd mentioned. Will try if I happen to have a chance.

If I could change my vote, you will not be the only one. I beginning to dislike crossfeed, coz it takes away the dynamics & life out of my music. Lost all those in yer face feeling with my AC/DC music..

Hudson mint box it just nice for the cmoy + Battery and all sockets. I had my cmoy in a Hudson mintbox too.

Yup, diagram is for one channel only. So for stereo, you'll need 2 pieces of dual opamps. Different opamp should work and that's the fun for opamp rolling. But take note the opamp that is gonna be used for the buffer has be unity gain stable. Check the datasheet of the opamp if it's stable at unity gain. The OPA2134 should be stable at unity. Power can be the same circuit as cmoy, maybe you want to increase the elco cap to 470uF.

A47 can be easily expanded from the cmoy, Just using two opamps where one of them acts as a buffer for the current boost for low impedance headphone. http://headwize2.powerpill.org/projects/sh...pheared_prj.htm Why not put the micro cmoy in a mint box. I'm sure you can squeeze in the 9V battery with it.

Yup, so the Apheared47 or CHA47 should be the next logical project for Tropicalrips.

The cmoy with the OPA2132 or 2134 should have no problem with high impedance headphone like the HD580 of 300ohms. It's the low impedance headphone like the grados, 32 ohm, that might poses some problem as the OPA cannot supply high current.

Mackie, you're right, normal music won't reach the extreme end of the audio spectrum.. Btw, anyone who needs a sweeping sine wave can make yourself one. All you need is a tone generator and a CDR burner. I've made a few sweeping sine waves of various band to my speakers measurements and calibrating my subwoofer. The tone generator I'm using is NCT, which is rather flexible as it allows you to set a lot of parameters for your sine waves.

Most sound or music are actually made up of many sine waves of various frequencies. IMHO, by playing your music everyday, I don't see why there's a need to play sweeping sine wave..

At the rate you're churning out miniature cmoy, pretty soon you'll be the 'sijosae' of SGheadphones.

I think HY is referring to the brand OMEG that is lousy, not the blue alps. Blue alps is imo decent for most audio diy, but agree with HY, for the price it's an overkill for a cmoy.. save the blue alps for bigger project like the meta42.

Your R5 is 43K or just 43R ? 43K seems too big.

Here's some Battery FAQ link, http://homepages.paradise.net.nz/ianjenki/faq.htm This one is for Nicd, but many point are still relevant for NiMH. http://www.repairfaq.org/ELE/F_NiCd_Battery.html http://www.repairfaq.org/ELE/F_NiCd_Memory.html

I also think there's no need to discharge first and no damage will be done. You should be more concern of overcharging, which is more damaging. Read thru this site about memory effect.. http://www.dansdata.com/gz011.htm

Just adding one more tips, Paste a higher price tag on the CD cover. This technique works on all audio equipments. EFFECTIVENESS: Read the rave comments & followups here, http://db.audioasylum.com/cgi/m.pl?forum=c...tag&r=&session=

Nice job.. The knob looks a little big. But still better then my knobless cmoy..

I hope private sectore won't be following.

Usually bare wire to ground, red to right, white to left.. But better check with multimeter to confirm.