Tubelife-257 MKII

Description of Tubelife-257 MKII

All voltages are electronically stabilized and filtered in order to optimize the residual noise level. The good qualities of the predecessor model Tubelife-2 were improved further.

We use a shielded ring transformer with static shield between primary and secondary and a magnetic shield of transformers sheet metal and optimized the schematic to find the best solution for good mains filtering, low noise and stable output voltages. The adjustment of 5,8V heating voltage betweenn PSU and employed microphone is not requisite. It is necessary with the original supplies N61 or UN61, each mic needs it's own power supply.

This PSU is suitable also for microphone models, that are very sensitively for noise and humming of the PSU.

In the regulation of heating voltage a soft start circuit avoids the cold electric push and thus extends the life of the tubes of microphones. The full voltage will be reached after approximately one second.

At the rear side of PSU the Inputs as 6-pin XLR female sockets are built-in. The Outputs are standard 3-pin XLR male sockets. The symmetrical audio voltages of the microphones are directly connected to the XLR Outs of the PSU.    

At the potentiometers on the front side can be selected the polarization between omni, cardioid and figure-eight without steps. The selection is made through the polarization voltages at the pins 6 of Input connectors. If the used mics are not switchable, the pots don't have any influence of their characteristics, because the pins 6 inside the microphones are not connected.

As option we offer a modified Tubelife-257 specifically for UM57, which works with +160V anode voltages and polarization voltages of 0 to +160V. In this case the UM57 are sounds even better and headroom and dynamic higher. So it can work with its optimal capsule voltage up to 80V. But these modified PSU are usable exclusively for UM57. The connection of CMV563 or M582 would damage the capsules because they would be loaded until 107V.

Rear side of Tubelife-257 MKII