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AB-Di-MK IV - Automatic bias control module for DYNACO MKIV MKIII with isolation transformer
Automatic optimize bias control module for four triode output stages or four pentode push-pull (PP) amplifiers with isolation transformer.
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| Manufacturer: | TES |
| Price: | 75,35 $ |
| Availability: | In stock |
The model AB-Di-MKIV MKIII auto bias module is designed to fit the Dynaco MKIV MKIII amp chassis.
It optimizes the bias for two triode or pentode output tubes in Push-Push (PP) amplifiers that have their own negative bias supply circuit.
Suitable for class A, AB, or B tube amplifiers.
The AB-Di-MKIV MKIII dynamically controls the bias in two tubes.
The module automatically optimizes the bias settings and maintains a strict symmetry of currents through both tube branches in the output stage. It will also stop any DC current flowing through the output transformers, all with the minimum of current loading on the anode of a tube.
DC current saturates an output transformer which results in increased low frequency distortions.
The bias level is kept at the preset value irrespective of the input signal.
This module may be powered by the filament supply of an amp, with a range from 6.3V to 12.6V AC.
It is important to note that the AB-Di-MKIV (MKIII) NOT MUST use an isolation transformer, as the Dynaco MKIII' (MKIV) s filament supply is referenced to ground.
Table of resistance values of the resistor when replacing the trimmer on the AB module with a fixed resistor:
