freestompboxes.org

First post so be gentle

Hello Folks,

I have recently bought a second hand Fernandes Zo-3 travel guitar





The electrics work fine but it only overdrives at quite loud volumes, I'm wondering if there is anything I can do to improve the overdriven sound at low volume? perhaps even add a bit of reverb, delay or chorus?
I know there are newer models and I should probably just sell it and buy one of them but where is the fun it that?




Inside the back cover it looks like this,



and a little closer,



Close up of the circuit board,



and the back,



My soldering skills are decent and I do enjoy a tinker about with electrics so any suggestions would be superb

There is a variable resistor on the board by the way but moving just seems to take it from low volume with no overdrive to very loud with quite a bit of overdrive

Thanks for looking and I hope the pics are at least of passing interest to some of you

Hyster wrote: The electrics work fine but it only overdrives at quite loud volumes, I'm wondering if there is anything I can do to improve the overdriven sound at low volume? perhaps even add a bit of reverb, delay or chorus?
I know there are newer models and I should probably just sell it and buy one of them but where is the fun it that?

Thanks for looking and I hope the pics are at least of passing interest to some of you

Welcome Hyster

My guess is that it is not designed to be overdriven so you are probably clipping the output stage or the speaker is "farting out" because it has reached xmax (maximum cone movement).

You could put an overdrive circuit (insert overdrive of your choice) between the pickup and the output amplifier. That would give you an overdrive of your choice up to the point where it now overdrives, where it would once again revert to what you have now.

Very interesting pictures and thanks for posting them.

Hi there.

I'm a bit desperate here. I found someone to check my Zo-3 and he found that the black "chip" (C10?) is burned out.
but he did not tell me exactly what it is or where to find a new one.

Can you help?

I'm sorry, i know very little about circuits and stuff....

That's actually IC1 - the amplifier IC. Are you getting anything out of the speaker? If you are, that IC is unlikely to be faulty!

If you really want a little amplifier to go inside there, take a look at http://runoffgroove.com/ruby.html - it will distort quite nicely and will make a lot of noise for its size!

Thanks for the answer.
When I plus the guitar in an amp, all is good.
When I switch it to use the internal speaker, I get a very very very weak sound, as if it was asking for much more power.
I tried plugging earphones in place of the speaker: sound is good!
so the problem would be something else?
what can I try?

jfmaheux wrote:Hi there.

I'm a bit desperate here. I found someone to check my ZO-3 and he found that the black "chip" (C10?) is burned out, but he did not tell me exactly what it is ....

Now in your picture is an orange arrow. On the opposite side of the arrow there is something written on the chip. Try to determine what is written there and post the result here. Then it could be possible that you get the information needed.

there is something written on the chip

I was hopping for that, but not...

I think mictester is right: must be the amplifier chip...

So what can I do? Is there a way to change this with a "generic" one? Is there a way to make sure that is actually the problem?

jfmaheux wrote:

there is something written on the chip

I was hopping for that, but not...
.....

Take it to a better light and use a magnifying glass - I bet you will find "KIA7313AP" or "TA7313AP" written on it. That is the "generic" chip name with which you can buy a replacement.

Dammit, you are right!! Thank you!!

I managed to take a decent picture of the other side of the chip. It reads out:

TOSHIBA 9301U
TA7313AP B M'SIA

I did some googling and found this for example:
http://www.aliexpress.com/store/product ... 08052.html

Should it simply work?

Thanks!