K4010 300W MOSFET Amp as Bass Guitar Amp

Kits Audio Hi Fi Projects
1

Hi all,

I currently use a K4010 as an amplifier for my bass guitar. I have it coupled up to a separate speaker which works very well. The only thing is, I was wondering if I can insert a preamp or something in to maximise the volume. It is currently quite loud (controllable just by using controls on guitar), but when playing along with drums it is hardly loud enough.

Is there anything I can do?

Thanks

P.S. does anyone know where I can get the build manual for this amp. I can’t find mine.

2

Are you feeding the guitar pickup directly to the amp ? The output of a guitar pickup is far too low to fully drive this amp, it needs 1Vrms for max. output. Furthermore, guitar pickups need proper impedance matching in order to achieve a correct frequency response curve.
Kit K8084 is a nice pre-amp. Careful: default it is setup for ‘x1’ amplification, so you will need to alter some resistors to obtain the desired gain.
http://www.velleman.be/fr/en/product/view/?id=369464

3

Thanks for the quick response VEL417,

I just plug my Bass Guitar straight into the K4010. There is an in built pre-amp in the bass that requires a 9V battery but I’m not sure what Vrms it gives out. I can try and measure it with an oscilloscope.

Do you know how I can work out the impedance output of my guitar so that I can somehow match it? Do I match it by altering resistors on the K8084 along with the amplification?

Thanks again

4

Apparantly the guitar is equipped with a pre-amp circuit, so there is no need for matching.

5

OK thanks.

I will try the K8084 preamp and adjust the amplification factor to maximise my amp.

Thanks for all your help. :smiley: