My year with Stellavox
"When I first have seen this tape recorder, I was surprised how different it's construction is from the studio tape recorders of other manufacturers machines, which we service and restore."
Peter Čvirik on the first TD-9: The whole device is extremely precisely designed and manually assembled. No machine assembly of components, only manual work.
The chassis allows quick and easy conversion to different tape formats and types, and speeds, without the need for readjustment.  Spooling motors are very robustly designed with a significant power reserve. We are assembling original motors, that were developed and manufactured by Stellavox.
The brakes are unique, they can be reversed in the opposite direction if a tape with a magnetic layer is used from the outside.
Furthermore, it is the regulation of tape tension, which is controlled optoelectronically. The system includes two easily interchangeable units (tensiometers), which, in addition to information about tape tension, also sense the speed and direction of tape movement (Biphase signal).
 
Another interesting fact is that the head block directly contains the electronics of the playback and recording circuits plus the oscillator. When replacing the head block, the settings and calibration also change directly.
All audio circuitry is designed with a minimum number of operational amplifiers, what has a beneficial effect on sound quality.
Biggest obstacle to finish the assemblage was to find out the procedure of basic RAM initialization, which is necessary after replacing the backup battery. It is used for the correct operation of the tape counter, but it also has the function of counting the total time of the device (capstan motor hours) and the number of running hours on the heads and spooling motors (play / rec hours).
We are very happy that we have managed to launch this demanding project. However, it is also a challenge for the future to implement possible improvements and upgrades. The first upgrades hints are comming soon and we will keep you informed.
More pictures please find here. |
This machine works with ½ “ tape, stereo, 15 + 30 ips (38 + 76 cm / s) speeds.
