[mmcaleer]

I am new to the forum and this is my official first post.  Comments welcome.
 
After lurking the forums for a while, wanting a desktop tube amp, I decided to take everyone's advice I was reading and build a CMoy.  I used the plans I found on the forum and ordered my parts from Digi-Key.  I followed the BOM but upgraded the resistors to the Vishay/Dale as suggested.  For the OpAmp I went with the recommended OPA2132PA for my first build.  I also added some of the optional items such as the DIP-8 IC Socket, aluminum volume knob, volume control, power switch, and 9v battery clip.  I stopped by Radio Shack on my way home from work and purchased the PCB.  My total cost for the project is $33 which includes shipping.
 
While I am waiting on my order to ship I started with halving the PCB and adding the jumpers.  Ok, don't laugh at my soldering, it has been a while.  That's all for now.  I will update with more as soon as my parts get here.
 
Oh, and this will be used for my Denon AH-D1001 headphones. 
 
Mike
 

 

 

 

 

[Fred_fred2004]

The way you are doing it is, perfect and will make trouble shooting easy
 
cheers
FRED

 

[vixr]

This was my first amp too...I have never had the same sense of accomplishment on any amp since...welcome to the cool group and sorry about your wallet.

 

[Willakan]

Looking good: I would advise trying to make sure your solder joints cover the whole width of the pad, as when they do it's generally indicative of a good joint IMHO. 

 

[mmcaleer]

Quote:

Looking good: I would advise trying to make sure your solder joints cover the whole width of the pad, as when they do it's generally indicative of a good joint IMHO. 

Thanks Willakan,  I see what you mean.  I corrected the joints.  It is amazing how much better the joints become when you actually apply flux. 
 
Thanks to everyone else for the input.
 
 
Mike

 

[mmcaleer]

I received my components from DigiKey today and did some more work on the amp.  As you can see R4 is missing.  When I was adding my components to the BoM I selected 10 Ohm instead of 10k Ohm.  I had to reorder anyway since I was buying more stuff.
 
Does anyone know the pinouts on the POT?  The one I received is just six pins in a single row.
 
Thanks,
 
Mike
 

 

[tomb]

That looks like a Panasonic EVJ.  If so, Tangent has the pinouts defined on his site in the CMoy tutorial.  Under "Assembling the Amp", look for the link of "How to Wire Panel Components:"

 
I'd also get something that's insulating on the bottom of that mint tin - some craft sheet foam or simply strips of electrical tape will do a good job.  Any lead, solder connection, etc., that touches the bottom of that case will short out the amp.

 

[mmcaleer]

Quote:

That looks like a Panasonic EVJ.  If so, Tangent has the pinouts defined on his site in the CMoy tutorial.  Under "Assembling the Amp", look for the link of "How to Wire Panel Components:"

 
I'd also get something that's insulating on the bottom of that mint tin - some craft sheet foam or simply strips of electrical tape will do a good job.  Any lead, solder connection, etc., that touches the bottom of that case will short out the amp.

 
Thanks Tom,
 
The insulating of the board was my next question.  Thanks for the information. 
 
Mike

 

[GeneralSmirnoff]

I built the same exact design CMOY a few weeks ago. All I can say is boy is that thing sensitive! The audio input and output have to be held at a certain angle to work and I don't know if this is my pot or not but I always hear a massive amount of static whevever adjustinv volume. Also, sometimes the left channel gets no sound and the right channel stays at like %70 amplification, adjusting the pot fixes the problem. I'll probably save up for an iBasso D-Zero or get a new pot and audio input/output jacks.

 

[tangent]

There's something wrong with your amp, General.
 
....pause....Sir.
 
Post high res pics, top and bottom.

 

[mmcaleer]

Done!  It sounds great!  My wife wants one now.  The only problem I had was with the switch, I had it wired incorrectly.  Once that was fixed everything is working great.  I ended up using an old Altoids tin I had laying around.  I think I will purchase some different OpAmps to play with and see which I like, although this one (OPA2132PA) sounds great.
 
Thanks for all the help from the forum.  On to the DAC now.  Then I need to decide on a desktop hybrid tube amp to build.  Any suggestions?
 
Mike
 

 

[mmcaleer]

Tangent,
 
Thanks for the great website.  Your site is what I used for my information, BoM and instructions.  After reading your DIY article, How to build the CMoy pocket amplifier, it inspired me to give this project a try.  Great work.  I appreciate it.
 
Mike

 

[GeneralSmirnoff]

Tangent wrote that? Oh my god TANGENT I LOVE YOU!
 
Oh the reason why I keep on having to hold the headphone plug at a certain angle is because I used the ones radioshack had. The switchcraft one has the springs which have more strength when it comes to holding in the headphone jack. I think I just have a bad pot and I was thinking of replacing it anyways since its too big. I'll post pics of my pref board that I made. Also, is there an enclosure somebody might recommend that make the headphone amplifier look more professionally built and that allows you to attach an iPod to it with a rubber band? Sort of like the mini3

 

[tangent]

Quote:

Thanks for the great website.  Your site is what I used for my information, BoM and instructions.  After reading your DIY article, How to build the CMoy pocket amplifier, it inspired me to give this project a try.  Great work.  I appreciate it.

You're welcome!
 
Quote:

Tangent wrote that? Oh my god TANGENT I LOVE YOU!

Um....I...love you too, General.  Sir.  
 
Quote:

Also, is there an enclosure somebody might recommend that make the headphone amplifier look more professionally built and that allows you to attach an iPod to it with a rubber band? Sort of like the mini3

 
Why not build a Mini³ then, or at least use the same case? The Mini³ gets the compactness advantage of a PCB and PCB-mounted hardware and panel components, but it's also a more complicated circuit than the CMoy, so it probably nets out to near zero difference in space terms.
 
Quote:

My wife wants one now....Any suggestions?

 
I suggest you let her have the CMoy and go build a PIMETA v2 for yourself. You might be surprised how much difference buffers, a stiff virtual ground, tight layout, etc. make.

 

[mmcaleer]

Quote:

 
 
I suggest you let her have the CMoy and go build a PIMETA v2 for yourself. You might be surprised how much difference buffers, a stiff virtual ground, tight layout, etc. make.

Actually I was just on you site researching that amp as a possible next amp.  Do you have a Mouser Project BoM link?  I didn't see any kits available on your site.  I used Mouser on my last order and didn't realize they are just outside of Dallas, I live in North Dallas.  I received my order overnight with regular USPS shipping.