lm3886 guitar amp?

[etec_noob]

http://www.generalguitargadgets.com/...lm3886_amp.pdf

hey everyone im pritty big noob, i buy guitar pedal kits and build them..but i came across this for an amp idea...does it look any good?

[CJ900RR]

This where the first LM3886-amp i ever build. Simple and good sounding. I would recomend it for a "first-timer".

[Minion]

that is just the standard datasheet implementation for the LM3886....

i built an awesome guitar amp useing a LM3886 that was pretty much the same as what you posted accept i put a preamp with tone controlls before the LM3886 stage and put a couple of overdrive pedal curcuits with bypass switches before the preamp....

so a LM3886 with a good overdrive curcuit in front of it and a good speaker will make a very good sounding amp, mine sounds awsome and is really loud......

Cheers

[KSTR]

An amplifier for guitar speakers can greatly be improved by making it a high impedance output, like a tube amp is. Guitar speakers don't like HiFi-amp damping factors, they sound very "choked" with that.

Just one more resistor is needed, details see:
http://sound.westhost.com/project56.htm

- Klaus

[etec_noob]

Thanks guys...yea i was planning on using it as a power amp then running a few preamps infront of it to make it a 4 channel amp

[getafix]

what will you use for the power supply?

[gideon]

Hey Guys, i am quite happy to find this post and also while its still active.
As i am a few days in Singapore and decided to build something similar for my bass guitar.

Any ideas on a simple pre-amp? i have seen someone mention the jFet fetzer valve from ROG in this link: http://runoffgroove.com/fetzervalve.html
but i am not sure if they meant it as a pre-amp.
- i am a big fan of ROG!!!! and its damn simple looking like the amp is which is great for me because of time and noob constraints.

I know bass amps should rightfully be louder, but i am not going to try to compete with any drummer, maybe only with my neighbors' peace of mind. (and if i do find some friends to jam with i will make sure the drummer plays the congos until i get something better .

what i want to know basically is
a: would the above be sufficient as my pre-amp
b: would i need to make any mods for bass
c: anyone know a good place to buy the lm3886 in Singapore
d: what is an 18v bipolar power supply?

Much thanks, Gideon

[-_nando-_]

BAD implementation and bad board

[gideon]

Hi nandos,

can you please help me understand why its not a good implementation? are you reffering to the ggg board?

maybe you have a better one which is easy to implement aswell?

[-_nando-_]

First, it doesn't have input decoupling capacitor, and there's nothing to protect the amp against nasty oscilations coming trought the cables.

Althought it have the inductor + resistor protection, it don't have much protection as it is missing the RC output filter. It use to be 4R7 + 100nF.

input Impedance is determined by the POT, and this is not good, as if the pot start to make noise, the amp can blow.

That's why its a bad implementation.

I've drawn quickly a little schematic, it's missing the power supply bypass caps, and mute function, but you can see what I'm talking about.

An oscilating amp gets hot, sounds fool, and is likely to blow. This is MUCH more safe.

Check out:
My GIFT for you: TDA7293 board + extras

It also works for you, and the board is far better, also the amp is more powerful, as it can handle +/- 40V rails on 8 Ohms.