Preamp

[gfiandy]

OK he made some mistakes, but I don't really understand the point of in a DIY forum telling someone to go and buy a commercial product. If he wanted to do that he wouldn't have posted on DIY Forums.

Since he has said he is going to bread board this he can learn about the problems with some help. Just squashing someones enthusiasm is not "constructive criticism" and just telling someone to go and read something with no pointers to why isn't either.

If you don't want to help people who post noob questions then just move on but don't ruin their enthusiasm.

Having said that the rest of what sreten has said is true (as usual).

If you want help on an instrument amp design you might find a more enthusiastic reception on the Instruments and Amps section.

Andy

[sreten]

Originally Posted by gfiandy

but I don't really understand the point of in a DIY forum
telling someone to go and buy a commercial product.
Andy

Hi,

I'm all for DIY when it gives you what you actually need, and you won't be
disappointed. If you don't understand the problem it is highly unlikely you
will build something suitable. Chip amps and basic tone controls are fine
for audio, and relatively straightforward.

Music instrument amplifiers are a different kettle of fish if you want a
good one. They are far more complex. The above is a viewpoint to
consider, buy or build, analyse it, what you'll get, make your choice.

rgds, sreten.

[happy hippy]

Ok, look at this one. Copied from

Guitar preamp tone control circuit with IC TL072 – Free Electronic Circuit Schematics

Incidently, the first one was copied from

Pre-Amp Equalizer Using TL074

Originals are attached.

Thanx
The Happy Hippy

[pacificblue]

Why don't you google for schematics of commercial bass guitar amps to get a feeling for the gains and input impedances that are typical? It is also recommendable to determine a frequency for the treble control, where your electric bass guitar still produces sound.

[gfiandy]

Hi the pre-amplifier stages you have found are not really suitable for guitars. This site has a solid state preamp and power amplifier for a guitar and a good description of the reasons for the design choices.

You could use a chip amp to replace the amplifier design although my experience of chip amplifiers is they have poor saturation characteristics so if you are expecting to use overdrive in the power amplifier for a rock effect it is likely to sound nasty. By looking at it it appears that the pre-amplifier has an overdrive type circuit in it (the diodes in the second stage) but I haven't read it in full or evaluated the circuit.

http://sound.westhost.com/project27.htm

Regards,
Andrew

[discrete]

Originally Posted by gfiandy

Hi the pre-amplifier stages you have found are not really suitable for guitars. This site has a solid state preamp and power amplifier for a guitar and a good description of the reasons for the design choices.

You could use a chip amp to replace the amplifier design although my experience of chip amplifiers is they have poor saturation characteristics so if you are expecting to use overdrive in the power amplifier for a rock effect it is likely to sound nasty. By looking at it it appears that the pre-amplifier has an overdrive type circuit in it (the diodes in the second stage) but I haven't read it in full or evaluated the circuit.

100W Guitar Amplifier (Mk II)

Regards,
Andrew

....also see post 7!

In general Rod (ESP) has very solid designs.