DIY project - headphone amp

docentore

Hi folks,

I'm new to this forum but not for the boards

Recently I've lost my favourite pair of KPPro's, modded and customised by be.
I had to get new pair and because we are officialy still in recession decided to opt for Koss KSC-75, cheaper brother of KPPro. They sound great, bit less bassy than KPPro's, better middles and highs.
Also recently I had to use my phone (HP Pre3) as player as my iPod decided to give up on me.

So anyway, both sound very good with each other, but I software eq in Pre3 isn't great also amp doesn't have much power (as most phone amps) and KSC-75's are small but love amplification (tested on home main HiFi). I've decided to get myself an amp, buy one or build one. Still in R, my target would be something like FiiO E6 or cMoy.

Few days ago I was bored and was looking at some scrap electronics I have around the house and found on one of mainboards (Philips LCD) interesting op-amp (TS482). It's not the greatest one but it doesn't need over 9v to work, 5v is more than enough (3xAA or 3xAAA batteries).
After one evening this is what I ended with:



There is a lot of space for improvement, I'm still working on it, but this is more POC than finished product. I've ordered cMoy PCB of JDSLabs. But it works, and have to say there is a difference, in plus!

Today I found this on car boot sale, this was a sign that I need to carry on with the project



Any comments are welcomed, also if anyone has spare cMoy parts which aren't needed let me know please.

docentore

Small update on the project.

Last amp was just a POC, it was never to be desired one. After spending some time on Head-fi and other forums decided to go with real cMoy. And because best opinions has JDSlabs one I got bare pcb of them. Unfortunately price of some parts in EU was blocking me from building this amp, not in the planned budget.
After few days I reordered the parts that I had most trouble finding in EU (Alps potentiometer + jacks) and ordered full DIY set as well. 3 weeks ago I was amp-less now I have 3 of them.

Anyway, I decided to build those 2 cMoyBB's with some customisations, different passive parts and op-amps. First of all I was blown away from the quality of the sound compared to bare player, even with my cheapo Koss KCS75's.
To get it to the next level I modified my iPod mini so there is no coupling caps in the mini on line out, I've installed some small electrolytic in the plug.

Some pictures of both finished products. I will be keeping one for defo - so good product for such small price.




green one is standard cMoyBB 2.03, red one is rechargable


decided to go with M&S tin at the end

PPC

Very nice, the led on the side is a nice touch.

docentore

PPC wrote: »

Very nice, the led on the side is a nice touch.

the LED is part of jds design, its a one of the best cmoy designs.

thanks

doggiedee

Hi folks,
Just wanted to pop in and mention that I ended up buying the rechargeable cmoy from docentore, and was well worth the money! I've never used a headphone amp before, so wasn't too sure what to expect, but it has certainly blown me away. I'm using it with an Ipod video running Rockbox, all flac files, and listening on Sennheiser HD518's and Monoprice 8323's. On the Monoprice, I didn't notice as much of a difference, but on the Senn's the difference is quite noticeable. I'm not great at explaining things, but things just sounded clearer and a bit fuller.
I would defo recommend the JDS Labs cmoy to anyone wanting a little bit more from their phone/mp3 player. Or just get the kit and get docentore to build it for you!
Anyways, sorry for waffling on,
Cheers,
Dave.