I have recently received an order to assemble pair of loudspeakers sensitive enough to drive SE amplifier with 2A3 output/power tubes.
The order was received at the dawn of my research with a pretty „old-fashioned“ design. I was in the proces of testing a design with wide front face, narrow cabinet, strong holdings inside but soft-resonating front. Building material was light poplar plywood of 18mm thickness. Damping material used was asmaphon. Compact construction with internal bracing gives space for driver units to display complete capacity.
Loudspeaker face shows two drivers very close one to another, the hole is at the bottom. Lower frequencies should be delivered with a remarkable SEAS FA22 RCZ wide band unit – it provides extreme linearity and natural reproduction. Blue cone is made of paper and papirus and that adds additional quality to the sound.
Units on the front page – Lower spectrum and high frequency
The higher spectrum reproduction should be supported with a magnetostat OMNES AUDIO MT2 and SABA Green Cone ALNICO paper-cone. Internal wiring was done with high quality silver and copper wires.
I assembled the box and experimented with wiring and positions of the units.
The concept was quite good and it worked pretty well with a hand-made integrated amplifier with 2A3 output tubes (more about the amplifier next time)
The main idea behind the concept was however usage of very old SABA Green Cone Alnico driver unit – very old design with paper cone. Production of these units ended probably 40 years ago but still could be found on internet – they were used in old tube-based portable home radios manufactured in Western Germany.
SABA drivers were installed on the top of the cabinet – not on the front!
Technical specifications: 8Ohm impedance, frequency range 30 – 30.000 Hz, power 40/150W, sensitivity of 93dB. LR is made by 2mm copper coil and non-inductive resistors. In other words, no crossover!
Coouple more photographs …
- Rupić zvučnik
If there is a warm recommendation for any SE amplifier based on 300B or 2A3 tubes, then it can be given for this loudspeaker. Low power Single End amplifiers can really play naturaly with this setup.
I guess the loudspeaker will bear the „Prestige“ name!