[Circuitbender]

I've had this CMOY project going since, oh, probably a full year ago. I sort of abandoned it after being too lazy to do the offboard wiring. Well I finally did the offboard wiring tonight in like an hour and the year-old CMOY is finally done! Here, have some pics

 

 
Whole setup. Fuze/Computer -> CMOY -> HD555
 

 
Front. Yes, the LED light is super-ghetto. Yes, the jumper cable I made is even ghetto-er. Whatever.
 

 
Rockbox'd Sansa into CMOY into...
 

 
Sexy Foam-mod HD555

 

[classakg]

Nice! how many days you spent on finishing it? 

 

[Circuitbender]

From board fully done to everything fully done was just an hour today.
From nothing to board was probably 2-3 hours over 1 or 2 days, I think.
 
Quote:

Nice! how many days you spent on finishing it? 

 

[Wawrzyniecki]

Good, good.
How's the sound? I've finished my about a month ago and I have to say it was a love from a first note!

 

[Circuitbender]

TBH I don't really notice any difference. I don't have a line-out on either my laptop or my Sansa Fuze, and both of them drive the 555s equally well (they aren't hard to drive). My friend also just got a pair of HD555s, so I told him if he's having trouble driving them with an iPod he can buy my headphone amp for like 20 bucks.
 
Quote:

Good, good.
How's the sound? I've finished my about a month ago and I have to say it was a love from a first note!

 

[Wawrzyniecki]

I see, maybe HD555 are just good - I never had them to judge. I noticed that my CMoy gives a tad bit more space to my Sansa music, definitely not worth the price I paid for the components. But on the other hand it does not make anything worse and I had so much fun building it! Plus bass is punchy but not muddy so I don't use EQ anymore at all.
 
Maybe next week I start to build k272 tube kit I got some time ago from Australia. I've always wanted to experienced a famous "tube sound" but never had money to buy some real deal. So maybe a pocket version will tell me if i like it or not. Anyhoo, I will try not to forget to post some results.
Best regs

 

[Circuitbender]

"so much fun building it" That makes it worth it no matter what the cost. I love love LOVE electronics. building circuits is probably one of my favourite pass-times

"pocket (in reference to a tube amp)" It's either impossible, impractical, or sounds like garbage. Tube amps are big, hot, and fragile. Having something like that in a pocket is definitely NOT something I would want to try. Give it a try just for the experience, and you can always use it at home, but I would really really strongly recommend against having something like that in your portable setup.
 
Quote:

I see, maybe HD555 are just good - I never had them to judge. I noticed that my CMoy gives a tad bit more space to my Sansa music, definitely not worth the price I paid for the components. But on the other hand it does not make anything worse and I had so much fun building it! Plus bass is punchy but not muddy so I don't use EQ anymore at all.
 
Maybe next week I start to build k272 tube kit I got some time ago from Australia. I've always wanted to experienced a famous "tube sound" but never had money to buy some real deal. So maybe a pocket version will tell me if i like it or not. Anyhoo, I will try not to forget to post some results.
Best regs

 

[Wawrzyniecki]

Of course.
by "pocket" I meant something small and transformerless. And I believe is possible as long as small tubes create similar distortion (here: coloration) to their big brothers. Anyway I was tempted enough with this DIY article to give it a try
http://diyaudioprojects.com/Tubes/6418-Tube-Preamp-Headphone-Kit/
The circuit itself does not differ much from CMoy anyway. It just have two stages instead on one. Well the output opamp is configured as voltage follower but I don't see any reasons why it should sound bad.
Take care.

 

[Circuitbender]

The circuit seems sound... I can't comment on the tubes though, I've never heard/worked with anything that small. When I work with tubes it's always guitar amplification...
 
Quote:

Of course.
by "pocket" I meant something small and transformerless. And I believe is possible as long as small tubes create similar distortion (here: coloration) to their big brothers. Anyway I was tempted enough with this DIY article to give it a try
http://diyaudioprojects.com/Tubes/6418-Tube-Preamp-Headphone-Kit/
The circuit itself does not differ much from CMoy anyway. It just have two stages instead on one. Well the output opamp is configured as voltage follower but I don't see any reasons why it should sound bad.
Take care.

 

[soviet911]

I build a cmoy recently but didnt have a chance to stress it with any good headphones, they boosted greatly the sound of my crappy sony headphones wich i would bearly be able to drive with my zune, but it stayed flat, i guess a good thing. What caps are you useing? I have right now 220uf for power supply and .01uf for input, and planning on going to down to see how much bigger I go at local electronics store (not radioshack =P ) this thing will hopefully help me power up the HD25-1 II that on the way!

 

[Fred_fred2004]

I hope you didn't use .01uf caps for the input
 
up it to 0.47-1uf and your bass will be much better
 
cheers
FRED

 

[Wawrzyniecki]

@soviet: In my amp I used 0.33u caps at the input as I coudn't fit larger ones to my case. Input caps -> the larger capacitance the lower frequencies can be transmitted to the amp.
Good luck!

 

[soviet911]

I used the .1 or was it .01 >.> well I will see if can find some polypropelny 1uf caps at the elctronics store but from what I saw on their website I only saw tantalum onse wich im tempted to give a try and from what I read they will work fine, I shall see, its only 96 cents each. and then the highest electrolytic cap I found was 4700uF rated at 25V...and from pics they didnt look toooo big...I will see though...Im planning on going down from 18 volt power supply to 9 volt in order to fit the bigger power caps, as I tested it at 9v at the moment and it sounded same. Wish me luck haha!

 

[soviet911]

well installed the 1.0uF MYLAR/POLYESTER FILM NTE caps on the input that rated for 50volts and 4700uF 25volt caps for the power supply. The headphones I use distort now when turned up to fulll sound due to insuffient power for the opamp chip, with 18volts no distortion occurs, they bass quality went up by alot and now limited by the headphones rather then the amp. Cant wait to see how the HD25-1's will sound! I already enjoy the 20$ sony's now only thing I wanted is a bit more bass, cant wait for my new headphones...should be here monday =/ 
 
Some pics 

 

[Circuitbender]

I used big polypropylene input caps (0.1uF) for mine.