Question about GGG tda2040 power amp

Started by Atodovax, March 21, 2018, 10:37:25 AM

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Atodovax

Hello everyone, im planning to build a 2040tda amplifier and noticed on General guitar gadgets that they have a schematic for that but is only a POwer amplifier. Im a total Noob on amps so my question is: Can i plug my guitar directly into that amp or do i need to build a preamp and conect it before the power amp?, in that case do a guitar pedal work as a preamp? if i want two channels should i build two preamps (Guitar effects), im really confused.... Thanks in advance!

MaxPower

Schematic (or link to schematic) would help. Anyway, I'm guessing it should work without a preamp. A pedal which gives a good boost should do the trick if needed.

If you want two channels you need two channels. If you want stereo from the amp then the amp needs to be stereo (have two channels as well).
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PRR

The gain is about 30. On 9V supply, about 3V max output, you need 0.1V or 100mV input to reach full power. Traditional guitar-amp sensitivity is more like 20mV. So far, you will hear "something" but you will have to strum HARD to get even moderate volume.

Also the 22K input impedance will suck-off a lot of the guitar's highs. Very mellow, muffled.

Try it. But I'm sure you want a preamp (at least a strong booster-pedal) in front.
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Atodovax

So i just want it to be clean... Should i build a CLeAn Booster poster pedal and place it in front of the amp? Or do i need to build a preamp? Is it the same?

Sooner Boomer

You really need a preamp in front of the power amp, or the power amp will be running at full gain all the time - a good way to blow out speakers!  Preamps also give you the ability/opportunity to do tone control.  There are lots of inexpensive kits, or pre-assembled "tone control preamps" available from places like Amazon (search there using those three terms).  I'm doing essentially the same thing you're doing, except I'm probably going to build my preamp.  Probably a TL082/TL072 JFET opamp with either a Baxandall circuit or a tone control IC - haven't decided yet (may build all as modules and try them out).  Good luck with your project.
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