The HEAVY TONE from HEPTODE, inspired by the famous Soldano SLO-100* Overdrive channel, has this typical High Gain sound that was found in the 80’s tube preamps.
The Heptode VST plugins are configured with a single mono input and a single mono output. If you plug directly your guitar into your audio card input, check that its impedance is compatible with your intrument (typically guitar with passive microphones will require at least a 500kOhm impedance).
You can use your computer speakers to listen to the Heptode VST Plugins. In this case, you should turn on the CabSim switch to simulate a guitar cabinet. You can also plug the audio card output in a guitar amp, either in the normal guitar input, or n the effect return input, as you would do with the real pedals.
HEPTODE plugins do not generate any noise, but they naturally amplify the guitar and the audio card noise. Audio card inputs with 100db Signal to Noise ratio or more will give excellent results.
It is still difficult to simulate the whole behavior of analog components (analog pedals are still alive!). The virtual pedals are therefore not perfect, and do not intend to replace the real pedals. Quality also depends on external components such as the audio card or the computer itself.