Puresound L300 - preamplificator pe lampi
The Pure Sound L300 Line Stage Pre- amplifier has 5 inputs and twin outputs (2 pairs single ended and 2 pairs balanced via XLR).
The circuit uses output transformers and a sophisticated full valve rectified, choke smoothed, regulated power supply including a 300B triode as the series element.
A line stage pre-amplifier needs to offer the facility to select between different sources to provide some means of attenuating the chosen source and then deliver it in an uncorrupted form to the power amplifier.
In the L300 source selection is via a high quality switch located near to the input sockets. The chosen source is routed to a high quality film potentiometer and from there on to the audio circuit. This consists of 2 directly coupled triode stages, the second loaded by an output transformer which steps down the amplifies signal allowing it to be coupled to the power amplifier at a manageable level and via a low impedance output.
The output stage of the L300 is impervious to long interconnecting cables or lower impedance power amplifier input stages. The use of output transformers also allows the option of a true balanced output configuration if desired.
The L300 also incorporates an extremely sophisticated regulated power supply to maintain constant operating conditions for the audio circuitry. It includes a valve rectifier, a choke filtered stage and then a series regulator featuring the 300B power triode as the passing tube. A very elaborate error amplifier referenced to a gas voltage reference valve allows the circuit to precisely maintain the high tension supply regardless of fluctuations in the mains supply and the varying current drawn by the audi circuit. Filament supplies are also fully regulated to further reduce the potential for noise.
The L300 preserves the verve and energy in recordings. It does this without sacrificing transparency or introducing euphonic colouration to the sound.
Frequency Response 7Hz - 50kHz
Inputs 5 x RCA (Single Ended)
Outputs 2 x Pre Out (RCA) + 2 x Pre Out (XLR)
Dimensions (H x W x D) 180mm x 480mm x 420mm
Weight 20.00 KG