Robin, I appreciate your help and advice. I'll try and build the power supply you suggested... hopefully it will work out.
Again thanx for the help.

Actually my power supply has a +18V, Ground, and -18V. At least that's the design I followed, u can look at the second PDF that I have on my first post. Do you think the 2200uF cap on the amplifier board could have exploded because of undervoltage?  Or maybe overheated because of the overheating regulator that it was connected to? (they are on separate boards and connected with a wire so i don't know if that's possible)

Robin, thanx for the reply and insight. I am using a 230V primary, 24V secondary (two wires coming out of it) transformer. It is also 1 ampere (I wasn't sure what to get). Do you think that transformer is enough to properly operate the amp? Will that transformer work with the power supply you suggested?

I haven't decided yet on the preamp, probably something simple like a Little Gem or Ruby amp. I didn't try to connect a preamp when I plugged the amp in since it would make troubleshooting even more difficult.

What I really want to know is why the LM 3886 amp didn't work, the 2200uF cap exploded, and the power supply's regulator got so overheated, and if there's a connection between those two.

Thanx again, all help appreciated 

So I decided to build a power amp for my electric guitar, and through online search I ended up on the LM3886 design at www.generalguitargadgets.com Here is the power amp schematics:

http://www.generalguitargadgets.com/pdf/ggg_lm3886_amp.pdf

The data sheet for the LM3886 states a needed voltage of 28-35V but the PDF asks for a power supply of 18V. Being a complete electronics noob I opted on following the PDF's directions of 18V. Then I needed a 18 bipolar power supply so I found and built this:

http://www.generalguitargadgets.com/pdf/ggg_bipolar_ps.pdf

When I built and connected the whole thing, it only produced a crackling noise, the 7918 regulator of the power supply got EXTREMELY hot (i couldn't even touch the heat sink), and suddenly the 2200uF electrolytic capacitor on the V- end of the amp exploded. Now I know that the capacitor's polarity was correct and it was rated for 26V. And the rest of the caps and resistors are the correct values for the best of my knowledge.

What could have gone wrong? Can you guys please take a look at the PDFs and tell me if they're correct? I'm fairly electronically illiterate but I'm pretty good at following schematics so I don't understand where I've made a mistake. I would appreciate ANY recommendations, corrections, making fun of my noobness etc.

Please help me fix this sucker. Thanx 

Thank you teemuk, I appreciate the insight and advice.

Speaking of power supply, what do you think would be the appropriate one for this amp? (voltage etc.)

Ok so I decided to built an amp with a LM3886... do you think that would make a decent guitar amp?

I found this one: http://www.generalguitargadgets.com/pdf/ggg_lm3886_amp.pdf
What do you think about it?

Also it says at some point "10 ohm 2 watt resistor with 10-12 turns of #22 insulated wire". I have a 10 ohm 2W resistor but what is that wire deal? Does anyone have a picture of one or know how it's done?

Thanks for the reply joecool85 

Come on guys... any suggestions?

I was thinking about that "Little Rebel" amp but it's only 2W... there must be something slightly better than that. 

Hi everybody, this is my first post here since I'm kinda new new to amp building so please be patient with my noobish questions. So far I am amazed at the depth of knowledge this forum has and so I took the liberty to post my first attempt at amp construction. It is just a Little Gem LM386 amp which I installed in an old PC speaker box I had laying around.

Here it is:


Not much to look at, I know, but it was my first attempt at any electronics build, first attempt at circuit etching, soldering, schematics interpretation, resistor-capacitor readings and all that, and it's working pretty well. So I'm pretty proud and moreover encouraged to build something even better.

So here comes my request for your advise. What would be a good guitar amp for me to build next? This amp was around 1/2- 1watt, with only gain and volume controls. So I am looking for something a little more complex, maybe a couple more control pots, up to maybe 15-20W (if that's too much wattage for a simple build let me know). Also I would greatly appreciate it if there were PCB layouts for it.

I hope I am not asking for too much, please fire away with suggestions, comments, anecdotes etc.