# Hide poles circuitikz

I would like to draw an amplifier (not an op amp, just an amp) in circuitikz. What I did manage to do is the following picture/code

    \begin{circuitikz}[american voltages]
\draw
(0,0) node[fd op amp] (opamp) {}
(opamp.+) to [short, -o] ++(-2,0)
(opamp.-) to [short, -o] ++(-2,0)
(opamp.out +) to [short, -o] ++(2,0)
(opamp.out -) to [short, -o] ++ (2,0);
\end{circuitikz}


but I'd like to hide the poles in it. Is that possible? Thank you in advance.

Workaround: set the color of the symbols to white.

\documentclass{article}
\usepackage{circuitikz}

\begin{document}
\ctikzset{tripoles/op amp/font= \fontsize{10}{0}\selectfont\boldmath\color{white}}
\begin{circuitikz}[american voltages]
\draw
(0,0) node[fd op amp] (opamp) {}
(opamp.+) to [short, -o] ++(-2,0)
(opamp.-) to [short, -o] ++(-2,0)
(opamp.out +) to [short, -o] ++(2,0)
(opamp.out -) to [short, -o] ++ (2,0);
\end{circuitikz}
\end{document}


Result:

• I was trying out the command \ctikzset{amplifiers/plus={}} \ctikzset{amplifiers/minus={}} from page 91 of the manual but could not get it to work --how to go about using this command to get null values Mar 11 '20 at 14:58
• @jsbibra - Try \ctikzset{amplifiers/plus=\empty, amplifiers/minus=\empty} \null, \space and \strut also work. Mar 11 '20 at 15:14
• Package pgfkeys Error: I do not know the key '/tikz/circuitikz/amplifiers/pluspelled it. ...iers/plus=\empty, amplifiers/minus=\empty} why is the compiler telling me this? It happens every time I try to edit amplifiers options
• @frad maybe you have an older version of circuitikz? The amplifiers/plus and /minus options are a relatively recent addition. Anyway, the workaround in my answer should work for older versions as well, although it is not so 'clean' as setting the plus and minus sign explicitly. Mar 11 '20 at 16:13