Solid State Guitar Amp Forum | DIY Guitar Amplifiers

Solid State Amplifiers => Amplifier Discussion => Topic started by: Crystallas on April 05, 2006, 03:17:08 PM

Title: An old Acoustic project reborn
Post by: Crystallas on April 05, 2006, 03:17:08 PM
Okay, so I have this 76 yamaha acoustic that is aged wonderfully, but beat up. I almost forgot about it until I found it in my attic. Well about 7 years ago I wanted to turn it into a project because its not really valuable, or an amazing guitar to begin with.

So I thought about adding a double top and double back to it. The double top would include a set of pickups. I like mcintrye accoustic pickups for on the fly(namely the CF-70), but i also like the popular LR Bags M1 too. I would use the CF70 as the neck position and the M1 below it.

What makes this a new fun project would be adding a 5w ss amp internally, to make this a very versitile guitar. Im like a few of you, and have a handful of axes.. so 1 project gone bad doesnt bother me, esspecially for this beat acoustic.

Now Ive done an internal amp before, but those were parkers(2), which are great travel guitars as is, and with a premade kit. To my surprize, they didnt lose any warmth.

So Im curious as to what suggested designs would require the least passive cooling and give me what I want to get from it. I would have a great deal of space to work with, and something like this could easily go pcb-less. The double backs clearance is negotiable, but I need to stick to atleast 3.5" in the chamber between the 2 planes.
Title: Re: An old Acoustic project reborn
Post by: joecool85 on April 05, 2006, 03:26:11 PM
I'm not sure what chip you'd want to use for a 5w application...I definetly wouldn't use a TDA2003, I've already posted about how I didn't like that too much.  What type of power source are you going to power this thing with?  That should help narrow down possible chips.  Maybe even a lm1875, it goes as low as 16v (+8/-8), you could do +/-9v with a couple 9v batteries.  Doing that would give you about 4watts of power, should be fine.  To get 5w it looks like you'd need around +/-10v. 

As far as heatsinking goes, in an application like that, an 8" piece of this should do it:
(http://alltronics.com/images/04Z033.jpg)

Probably less than that would suffice, but its better to have more than less.  You can get that from alltronics.com for about $2