This is an interesting competition - I'm sure there will be some great designs put forward!   I would love to put something together but unfortunately there's not much to go on in the way of technical specifications expected from the amplifier board or any details on the layout of the board...

Quote:   That looks brilliant :)  

Hello Head-Fi     I saw this and thought of you http://www.qrpbuilder.com/downloads/pcb_chassis_a.pdf     I have not tried it but it looks fantastic... a great idea for when that Hammond enclosure just doesn't fit :)     Has anyone tried this method?

Quote: Hello,   I'm almost certain that the 5 V will not be wired directly from the battery as most laptop batteries are in the magnitude of 12-16 V. I'm guessing that it would be a DC-DC class D power supply due to the efficiency afforded and relatively low cost of implementation...

If you read the link I posted you should find the answers to your questions about alcohol.   Good luck.

Hello,   I remember one of my electronics lecturers saying (quite rightly) that your first build of any circuit is guaranteed not to work. Don't worry, by the time you are done with this your greatest worry will be how to keep up with a crippling addiction to op. amp's, input capacitors and...

Wow - brilliant. As if by magic I had just finished a conversation with a friend about making a portable amp and how he'd go about charging the batteries without removing them... HeadFi, you've done it again!

  Quote: +1 !! I can not stress this enough :)

I hope that's your problem solved!! :)

Hello, a very similar thing happened to me a few years ago on a CMoy housed in a metal case - one of the feedback resistors was just touching the case resulting in sporadic noise. Even if it's not a resistor it may be worth looking over the circuit, checking the sockets for the amps/reseating...

d Hello, I'm not sure if there are any projects that are designed to be super small - I don't think there are many designs with less components than the CMoy. As other people have gone here you can go down the minituraisation of the CMoy - fredfred I love that SMD design!! And the Zippo...

Hello, your link doesn't go to a product! :) There may well be a replacement part that is more readily available in the UK - let us know what it is!    

Fantastic, loking forward to more photos!

Great news!!

Quote: Yeah, must be a UK thing

Cold solder joints are often hard to predict from your method alone, unless there is something severly wrong with it!   If I were you, I'd re heat your solder joints you made, making sure that the two pieces do NOT move wile getting soldered/cooling down. You should not need to heat the...

Fantastic!!   Regarding the blue tape, I wrap it around all my cables and it dramatically reduces RF induction. I also like to cut small rectangles out of it and place it over most of my opamp IC's. Some people say that 2 layers of the tape is better but I can't hear the difference after one...

Cheers guys - interesting and informative!!

Nice one regal!!   Fred_fred, that is CHEAP!! How do you find it compares with the ferric chloride with regard to etch times and setup complexity?

Quote:   If you were getting ferric chloride (it's a good method despite the mess - I can only talk about this etch method is it's the only one I have used), you can buy it in granulated form which seems to be pretty standard in potency. The benefit of this is that you can make it...

Quote: Ferric Chloride owes me a few pairs of jeans and a good few tshirts! It's incredibly messy and WILL stain

Like these guys are saying, there is no universally accepted 'best' opamp.  Put a socket in and try loads!!        

Fantastic results - I'd be dead happy!!

Easy solutions are always the best!!

Huh huh huh... Insert.