diy amp

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hello everyone.. i was planning to build a guitar and a bass amp.. i have a few questions about constructing it.. i have built alot of those smokey amps and i want to challenge myself now by creating a bigger and louder amp.. i have a 4558 ic and a tda2030, can i use these chips to create a 50 watt amplifier?? can a 50watt speaker be used in a 20watt amplifier, if yes then how will the sound of the amp be affected?? about the power supply, can i just build any power supplies or there are standard power supplies for amplifiers.?? and lastly how does a bass amp and a guitar differ?? thanks in advance for anyone who could help enlighten me.
 
Hello,
The 50W speaker, is a maximum rating above which it will break down (slow if just a bit above, pretty quick if it's a lot more), and since a nominal 20W amp will put out a tad more in peaks when used for music, that seems to me as a perfectly safe situation. Problem is though, as soon as you get near the 20W rating, the amp might distort more than when played in smaller volume, but that might not be a problem depending on the sensitivity of the speaker and the intended use of the amp system, since in a living room, especially with neighbours, you don't need too much power for your guitar, but on a stage you might want to blast away well above those 20W.

As for the parts, I'm assuming the 4558 is the dual opamp? so that won't have anything to do with power, but will do for input stage (though there are a lot of better opamps around). The TDA2030 is a 14W max amplifier, and that's when you use a 4 ohm speaker, so that will never be able to put out 50W, if that is your intention. There are a lot of other options for that though, just look around these forums, you'll find a lot of chips and modules suited for it.

The difference between a bass and guitar amp is bandwidth (though one could do with the same bandwidth for both, which then spans both the ranges), probably the tone control cornerfrequencies, and possibly the amount and type of effects that might be added to the sound (chorus, overdrive, etc.), but when you build it yourself, you may build all of it in one package with all the things you want on board (skill level may be an issue there but that is what this forum is for )

Regards,
Leroy
 
thanks for the info, now correct me if i'm wrong the circuit will be input>>pre-amp(that would be any chip like 4558) >> power amp( any chip suggestions) >> speaker... basically that is my plan create one "mega amp" but i will separate the speakers.. what type of speakers are generally used for guitar and for basses??
 
Speakers- Jensen, Peavey, Eminence. See tubesandmore.com in arizona USA for speakers, kits,not just tube amps. I've used them. Many other suppliers are out there. I don't recognize your flag, In Europe Arena Electronics Ltd Amplifier Parts sells some guitar amp parts.
4558's are not a bad idea for guitar amps because the hiss they produce is not reproduced by the tweeter speaker, because guitar amps don't have a tweeter. They are slow enough to not need feedback resistor bypass capacitor nor local socket disk capacitor to not oscillate. Guitars just don't produce much high frequency, unlike keyboard amps and hifi amps.
 
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I don't recommend using the TDA2030, its notorious for oscillating.

I'd rather suggest building something like the 50-100 watt guitar amplifier on sound.westhost.com

The P3A is a simple and good one, just needs a guitar preamp and u'll be all set.
Well you need the guitar preamp no matter what amp you choose.

Its not recommended to go above a gain of 20 on poweramps, any higher and their prone to oscillate.

Though most chipamps tend to oscillate if you use a gain less than 10 due to poor internal compensation.
 
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