• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

First amp for a new in valves

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well, i have my first valve amp working but was one I bought as scrap.
This is time to start a valve project, iwas thinking in this:http://www.bonavolta.ch/hobby/en/audio/el84_1.htm
two questions here:
1- I do not have the ECC82 but I have ECC83, i guess this will work, please advice here.

2- In this site: http://www.tubebuilder.com/schematic2.html it is said :TESTED ECC82 input EL84 output integrated amp - Gain was a little high - Great sound...
can the gain be decressed? how..

Please give your opinion as I have all the valves for the project, only need to buy the output transformer, any suggestion here is also apresiated

saludos

Jorge:smash:
 
ECC83 is NOT at all the same thing as ECC82. it will work in the sense that it will light up and some sound will come out, but is not correct to use in that position.

In general, there are several ways to decrease gain, but the easiest is to see if your volume control works.

If the amp is still so sensitive that your volume control is still working at the lower end of its range, you could increase the feedback a bit by lowering the 100 ohm feedback resistor. This will take some testing to ensure that you haven't destabilized the amp. A scope and a square wave source will be essential for working that out. It may or may not be easy...

It really would be easier to see if the gain is too high for your system, and if it is, to decrease the preamp gain.
 
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