Preparing for building the Pleiades V6 battery tube preamplifier prototype

Serial number is according to date time code 17072112.


It will look similar to the Pleiades Elektra series headphone electron tube battery power amplifiers.


It will consist of 2 parallel anodized aluminum reinforced panels spaced at 4in by 4 aluminum columns.


So the enclosed defined will be 5in x 2.5in x 4in.


The back panel will contain 2 Neutrik XLR in, out for each channel, on each side.


At the middle there will be a high quality AA battery holder with no rivets for 3 batteries.


Below it there will be a fuse holder.


On the front panel there will be:


The screw structures supporting the 2 EF183 triode connected electron tubes.


The screw supporting the 2 Magnetec Nanoperm Nanocrystalinne ring cores making the input and output transformer for each channel.


The flush mounted Velleman on off switch for the heaters only, connected to the fuse holder. This
will insure the smoothest and noiseless turn on and off of the front end microphone preamplifier.

The plate or anode circuits will be supplied directly by the fuse holder.


Somewhere in the front there will be the Pleiades logo with the star. And at the back the serial number which be effectively a military type year, month, day, hour time code, ie date time code.


The anode will be supplied by less than 4V through the primary of the the output transformers. The cathodes will be connected to 0V. A capacitor will couple from the secondary of the input transformer to the grid .


Operation is made possible by a 3.9MΩ resistor from anode to grid for every channel. This will free electrons at such low anode potential. Cathodes will be deliberately under heated. Bass compensation will be done by fewer wire turns on the input and output transformer. This construction adjustment will aid flat frequency responce from vocal chords of singer to lostener's brain.


The above will insure the quietest possibly operation. More details on other euroelectron posts on the Pleiades preamplifiers including the V6 schematic.


One of the reinforced aluminum panels was original made with 4 holes so that XLR female to male adaptors can pass through containing inside them input or output? transformers. The chassis Neutrik male or female connectors would be supported by screw structures near the other panel inside of the enclosure.


A mono prototype may be built as an alternative construction in an die cast aluminum box.


It would be nice if all components which are few anyway could be mounted in the direction of the signal path, topologically as on the schematic.


Everything could be inside the die cast box including the tube, the tube base supported by longer screws, nuts on each side and the box upside down so that everything could be seen from above.