Click in any of below diagrams to simulate circuit. The online calculators all deliver DC quiescent state, but none include AC small-signal estimations.
Circuits available only in PC app
From version 1.9, most calculators deliver small-signal estimations of gain and impedances.
C9 – Dual stage amplifier with level shifting
![](https://tubes.astefo.com/wp-content/uploads/2021/11/C9.png)
![](https://tubes.astefo.com/wp-content/uploads/2021/11/C9.png)
C10 – Phase inverter: constant-current bias
C13 – Gain stage, constant current bias ![](https://tubes.astefo.com/wp-content/uploads/2021/11/C13.png)
![](https://tubes.astefo.com/wp-content/uploads/2021/11/C13.png)
C14 – Gain stages with DC level shifting ![](https://tubes.astefo.com/wp-content/uploads/2021/11/C14.png)
![](https://tubes.astefo.com/wp-content/uploads/2021/11/C14.png)
C15 – Differential phase inverter, long-tail pair, cathode bias ![](https://tubes.astefo.com/wp-content/uploads/2021/11/C15.png)
![](https://tubes.astefo.com/wp-content/uploads/2021/11/C15.png)
C16 – Serial voltage regulator ![](https://tubes.astefo.com/wp-content/uploads/2022/03/C16.png)
![](https://tubes.astefo.com/wp-content/uploads/2022/03/C16.png)
C17 – Basic serial voltage regulator ![](https://tubes.astefo.com/wp-content/uploads/2022/03/C17.png)
![](https://tubes.astefo.com/wp-content/uploads/2022/03/C17.png)
C18 – Shunt voltage regulator ![](https://tubes.astefo.com/wp-content/uploads/2022/03/C18.png)
![](https://tubes.astefo.com/wp-content/uploads/2022/03/C18.png)
C19 – 3-stage coupled by HV line ![](https://tubes.astefo.com/wp-content/uploads/2022/11/C19.png)
![](https://tubes.astefo.com/wp-content/uploads/2022/11/C19.png)
C20 – 2-stage coupled by HV line ![](https://tubes.astefo.com/wp-content/uploads/2022/11/C20.png)
![](https://tubes.astefo.com/wp-content/uploads/2022/11/C20.png)
C21 – “Aikido” cascode (Tubecad)![](https://tubes.astefo.com/wp-content/uploads/2022/11/C21.png)
![](https://tubes.astefo.com/wp-content/uploads/2022/11/C21.png)
C22 – Cascode for preamp (Tubecad)![](https://tubes.astefo.com/wp-content/uploads/2022/11/C22.png)
![](https://tubes.astefo.com/wp-content/uploads/2022/11/C22.png)
C23 – PP amplifier DC feedback (Tubecad) ![](https://tubes.astefo.com/wp-content/uploads/2022/11/C23.png)
![](https://tubes.astefo.com/wp-content/uploads/2022/11/C23.png)
C24 – SRPP headphone amplifier (Tubecad) ![](https://tubes.astefo.com/wp-content/uploads/2022/12/C24.png)
![](https://tubes.astefo.com/wp-content/uploads/2022/12/C24.png)
C25 – Basic current source ![](https://tubes.astefo.com/wp-content/uploads/2022/12/C25.png)
![](https://tubes.astefo.com/wp-content/uploads/2022/12/C25.png)
C26 – CCDA Constant Current Draw Amplifier line amplifier (Tubecad) ![](https://tubes.astefo.com/wp-content/uploads/2022/12/C26.png)
![](https://tubes.astefo.com/wp-content/uploads/2022/12/C26.png)
C27 – Janus cascode Shunt regulator (Tubecad) ![](https://tubes.astefo.com/wp-content/uploads/2022/12/C27.png)
![](https://tubes.astefo.com/wp-content/uploads/2022/12/C27.png)
C28 – Totem pole split load phase splitter (Tubecad) ![](https://tubes.astefo.com/wp-content/uploads/2022/12/C28.png)
![](https://tubes.astefo.com/wp-content/uploads/2022/12/C28.png)
C29 – Triode with anode to grid feedback ![](https://tubes.astefo.com/wp-content/uploads/2023/01/C29.png)
![](https://tubes.astefo.com/wp-content/uploads/2023/01/C29.png)
C30 – Mu-follower ![](https://tubes.astefo.com/wp-content/uploads/2023/01/C30.png)
![](https://tubes.astefo.com/wp-content/uploads/2023/01/C30.png)
C31 – Cascode SRPP+ ![](https://tubes.astefo.com/wp-content/uploads/2023/01/C31.png)
![](https://tubes.astefo.com/wp-content/uploads/2023/01/C31.png)
C32 – Common-grid gain stage![](https://tubes.astefo.com/wp-content/uploads/2023/01/C32.png)
![](https://tubes.astefo.com/wp-content/uploads/2023/01/C32.png)
C33 – White cathode follower ![](https://tubes.astefo.com/wp-content/uploads/2023/01/C33.png)
![](https://tubes.astefo.com/wp-content/uploads/2023/01/C33.png)
C34 – Half-mu stage ![](https://tubes.astefo.com/wp-content/uploads/2023/01/C34.png)
![](https://tubes.astefo.com/wp-content/uploads/2023/01/C34.png)
C35 – Cathode follower with current sink ![](https://tubes.astefo.com/wp-content/uploads/2023/01/C35.png)
![](https://tubes.astefo.com/wp-content/uploads/2023/01/C35.png)
C36 – Pentode amplifier ![](https://tubes.astefo.com/wp-content/uploads/2023/09/C36.png)
![](https://tubes.astefo.com/wp-content/uploads/2023/09/C36.png)
C37 – SE triode power ![](https://tubes.astefo.com/wp-content/uploads/2023/09/C37.png)
![](https://tubes.astefo.com/wp-content/uploads/2023/09/C37.png)
C38 – SE pentode power ![](https://tubes.astefo.com/wp-content/uploads/2023/09/C38.png)
![](https://tubes.astefo.com/wp-content/uploads/2023/09/C38.png)