Thanks for the links guys. It should come handy whenever I needed "rare" components. :tu:

Since all I lack is the buffered input, may I used op-amp to make a voltage follower at the input of LM386?
It seems to be a bad choice to me since this way just consume more current. However, if i just simply use a capacitor to separate the input and LM386, would that be possible? or will the performance become very poor?

Thanks in advance!

Would it be possible if i use transistor instead? Since I lived in HK, tt is quite hard to find these electronic components as most probably no one will DIY a guitar amp here.

I was planning to build a RUBY for my first trial. However, I could not find MPS102, nor could I find 2N5457 in stores. Does anyone know what other components I may use instead?

Oops! I think i have somehow mislead you guys. I should have stated more clearer.

Yes, I do want to make an amp that is supplied by battery. However I have two more constraints, which I think is the most troublesome part :

1. It is suppose used in an open area. e.g. not inside a house.

2. It should be able to play for at least 4 hours.

Since I have no idea in this area, I would still try to make RUBY or LittleGem first.

I have "read through" the schematic of Little Gem and Ruby, it seems that they all use a 9V battery. I am wondering if I can use other voltages like 6V or 12V since this may affects the performance of the amplifier.

Thank you J M Fahey, I will try to study those! Thanks a lot!

   I am new to here and new in making guitar amps. I wanna make a guitar amp that can be used outside, where you can't possibly find a plug to plug in. As a result, I don't know how to start off.

  Feel free to comment. Thanks.