I have been working on this project since July 2010. I did not want to make any mention of it on the forum with reason.
It has now reached a stage where its becoming a tangible reality and I think I can dare yapping about it here.
This is a dual channel vacuum tube microphone pre amplifier that has been designed (and busy being built) by request from a few of my sound-engineer friends. I guess you can sum it as a "dare".
The circuit is based around plain old common cathode triode stages with transformer input and output - floating balanced in and out as will as high-impedance instrument input (i.e. electric guitar). Zero feedback and isolated power supplies on all the feeds.
Gain attenuation is done with a shunt-type stepped system in 12 steps.
48 VDC power is supplied on the mic lines for solid-state condenser microphones.
The unit features over 200 VA of toroid transformers (custom wound).
Chassis was manufactured at a renowned facility in Pretoria.
All wiring (will) is done point-to-point - no PCBs.
This is a commercial effort and not a mere DIY exercise. Currently I am not planning to enter the same market as Schalk's doing. I am very grateful to Schalk for "guiding" me - he, along with many other folks (locally and abroad) inspired and motivated me. If not for that then this project would not have materialized. I also want to exstend a big 'thank you' to regulars on this forum, Shaun O, Johan P, Gert B, Jacques v Z, for all your support.
Gloria in excelsis Deo
It has now reached a stage where its becoming a tangible reality and I think I can dare yapping about it here.
This is a dual channel vacuum tube microphone pre amplifier that has been designed (and busy being built) by request from a few of my sound-engineer friends. I guess you can sum it as a "dare".
The circuit is based around plain old common cathode triode stages with transformer input and output - floating balanced in and out as will as high-impedance instrument input (i.e. electric guitar). Zero feedback and isolated power supplies on all the feeds.
Gain attenuation is done with a shunt-type stepped system in 12 steps.
48 VDC power is supplied on the mic lines for solid-state condenser microphones.
The unit features over 200 VA of toroid transformers (custom wound).
Chassis was manufactured at a renowned facility in Pretoria.
All wiring (will) is done point-to-point - no PCBs.
This is a commercial effort and not a mere DIY exercise. Currently I am not planning to enter the same market as Schalk's doing. I am very grateful to Schalk for "guiding" me - he, along with many other folks (locally and abroad) inspired and motivated me. If not for that then this project would not have materialized. I also want to exstend a big 'thank you' to regulars on this forum, Shaun O, Johan P, Gert B, Jacques v Z, for all your support.
Gloria in excelsis Deo
