[Earwax]

I'm sure you're all tired of these threads by now, but I'm so amazed that it works, I just gotta share.

Built pretty much according to Tangent's guide, except with 470uf & .22uf caps. No pot yet.

Here it is hooked up to MD player in the forground and KSC55 in the background. The cyclops eye sticking up is the LED.

Closeups:

 

[Earwax]

Mounting in the tin is harder than I thought it would be. How do some of you ever get 2 x 9v into a mint tin?

Below, one jack and switch mounted in a tin. Yes, there ARE too many holes in the tin, once I get a layout that actually works I'll transfer it into a fresh tin.

 

[superjohnny]

Quote:

Originally Posted by Earwax Mounting in the tin is harder than I thought it would be. How do some of you ever get 2 x 9v into a mint tin?

Looks great, nice work! Getting two 9v batteries in a mint tin is really tough... especially if you include a pot. That's what differentiates "us" from "them" (amp builders like Tangent). I originally started my CMOY with 1 9v, but the 2134 opamp starts to distort with less than about 6v. To me that means I only use 1/3rd of a 9v battery. With 2 9v batteries it means I use 2/3rds. I had to put it in a bigger case to make it work though.

Nice job

 

[Earwax]

Thanks SuperJohnny.

I still haven't wired the pot and already I'm thinking of building a second amp. I really want to get a 2 battery version running. There's a photo at the bottom of tangent's assembly page http://www.tangentsoft.net/audio/cmo...rial/assy.html that looks like two batteries in a standard mint tin. I know others have done the two battery version by tightening the board layout significantly.

I think I can shorten the board by two rows without really changing the layout. Or I could use the 276-170 board version and gain a couple of rows that way.

 

[ProFingerSk8er]

awsome work earwax.
internal looks very clean and those long caps sure looks funky

DIY is like a drug, you can never quit

 

[meat01]

Nice Job! Yes, mounting the stuff into the tin can be tricky.

 

[Earwax]

Well, you are at least partly to blame for getting me hooked, Pro!

You and the ipodstudio project share the blame. I started out just wanting to do a little practice soldering to see if I could do their project, and then once I saw and listened to the amp I bought from you, my practice soldering turned into a whole amp!

Now, I want to end up with several amps in different configurations, portable, transportable and home, and hopefully with each one optimised for different headphones. [the one you built works well with the E3s, it helps fill out their somewhat anemic bass and recessed treble].

Oh dear, is this getting out of control or what??

 

[Zemo]

I usually use 2x 9vs whenever possible in my Cmoys, and this achieved by a little more efficent use of the protoboard. It looks like you're using about 12 rows of that board, along with the wide chunk of dead material on the end. My cmoys generally use 9 or 10 rows, and I trim off the end chunk....like this:

Viola! Cmoy and 2x 9v in a tin!

-Z

 

[Earwax]

Take a look at this, 2 x 9v and room to spare:
http://www.geocities.com/dip16amp/dip16amppics.htm
http://www.geocities.com/dip16amp/

I wish there was a clearer photo of the bottom...

 

[ProFingerSk8er]

if you feel like taking your time bending the resistors, you can always build a clone of my mirco-cmoy

http://www5.head-fi.org/forums/showthread.php?t=57362

 

[Zemo]

Dude, where are your powersupply caps!?

-Z

 

[Lil_JV]

Very nice for your first amp earwax. That looks a lot better than a lot of other cmoys I have seen here. Good news earwax, you're hooked.

JV.

 

[ProFingerSk8er]

Quote:

Originally Posted by Zemo Dude, where are your powersupply caps!? -Z

wired to extra space in the tin, right next to the battery

 

[Jaypetermen]

I just build my first Cmoy headphone amp and I am very impressed with its performance when used off of a PCs sound card.

I currently do not have a DAP yet, so I tried running the amp off a cell phone/PDA which can play MP3s. This did not work. My first, and currently only, thought is that the cell phone/PDA output impedance is to high to drive the amp.

Can I adjust something in the signal circuit to resolve this issue? Like add a resistor to the line-in signal to ground prior to C1 or be changing the value of R2?

 

[Earwax]

Quote:

Originally Posted by Jaypetermen I just build my first Cmoy headphone amp and I am very impressed with its performance when used off of a PCs sound card. I currently do not have a DAP yet, so I tried running the amp off a cell phone/PDA which can play MP3s. This did not work. My first, and currently only, thought is that the cell phone/PDA output impedance is to high to drive the amp. Can I adjust something in the amp to resolve this issue? Like add another a resistor or changing the value of R2?

Hehe, here I just finished my first amp and I'm going to answer like I know what I'm talking about.

First, did you build it according to standard specs for gain and cap values? Do you hear anything at all from the PDA, noise or dead silence? What headphones? The standard CMOY seems to match well for portables, I'd start off looking for other problems, such as intermittent connections, before trying to tweak the amp.