Get the “DCTriode” free PC app, far better than the Web site
I maintain a Windows PC application “DCTriode”, freely available for download and usage (freeware license): more comfortable, more circuits, more tube models, more features than the Web version. Pure freeware, fully functional, without any advertisements, telemetry, spy or intentional virus-like functions.
You may download its user manual to figure out what are its features
Online library | PC application | |
Circuits | 10 | 35 |
Include triode models | ECC81 ECC82 ECC83 ECC88 | ECC81 ECC82 ECC83 ECC85 ECC86 ECC88 ECC99 ECF80 ECF82 ECF83 ECF86 ECL80 ECL81 ECL82 ECL83 ECL84 ECL85 ECL 86 12AY7 300B 2A3 |
Include pentode models | none | EF86 (release 2.0 spring 2023) |
Customise, create tube models | no | yes |
Display anode curves | basic | more detailed |
Display µ gm ri | no | yes |
DC data | yes | yes |
Graph stacked voltages | yes | yes |
Graph DC loadline | no | yes |
AC gain and impedance | no | yes (not for all solvers) |
Frequency response | no | with Miller effect and stray capacitances (release 2.0 spring 2023) |
Single-ended and push-pull stages with power triodes and pentodes | no | release 2.1 fall 2023 |
Store and retrieve circuit configurations | no | release 2.0 spring 2023 |
Store results for spreadsheet | no | yes |
Library interface | fixed | flat / tree |
PDF User Manual | no | yes |
Freeware license
DCTriode is a freeware: you may download and use it freely for an unlimited period of time; meanwhile, you are not authorized to sell it. Its code remains proprietary.
Download it freely now
Download from https://tubes.astefo.com/install/dnld.php . Note that your browser may prevent you to download this MSI file, to “protect” you…
Last release #1.9 (February 6th 2023).
Available circuit solvers:
- Basic common cathode stage
- Phase inverter, self bias cathodyne
- Cathode follower, fixed bias
- Gain stage and DC-coupled cathode follower
- Phase inverter, fixed bias cathodyne
- Cascode
- Differential phase inverter, cathode bias
- Cascode SRPP
- Gain stages with direct coupling
- Differential phase inverter, constant current bias
- Dual triode mixer, balanced
- Dual triode mixer, asymmetrical
- Gain stage, constant current bias
- Gain stages with DC level shifting
- Differential phase inverter, long-tailed pair, cathode bias
- 2-triode serial voltage regulator
- 1-triode basic serial voltage regulator
- 1-triode shunt voltage regulator
- Three gain stages coupled by HV RC filters
- Two gain stages coupled by HV RC filters
- Double-cascode after “Aikido” circuit (tubecad.com)
- Cascode SRPP after phono preamp (tubecad.com)
- Push-pull amplifier with DC feedback (tubecad.com)
- SRPP headphone amplifier (after Tubecad.com)
- Basic current source
- Constant-Current-Draw-Amplifier (after Tubecad.com)
- Janus cascode shunt regulator (after Tubecad.com)
- Totem pole split load phase splitter (after Tubecad.com)
- Amplifier with AC local feedback anode to grid
- Mu-follower
- Cascode SRPP+
- Common-grid amplifier
- White cathode amplifier
- Half-mu stage
- Cathode-follower with current sink





Displaying anode curves

Drawing transconductance, internal resistance and amplification factor of the ECB88 / 6DJ8 at 3 different anode voltages:
