DPA-4

Description

The Differential Pre-Amplifier, Model DPA-4 is a miniature 4-channel, high impedance, differential input preamplifier that is designed for low noise recordings from excitable tissue. It is intended for extracellular recording in conjunction with Thomas Tetrodes and Thomas single microelectrodes. It can be used in a number of research or teaching applications requiring extracellular neurophysiological recording from excitable tissue.

Figure 1: Differential input preamplifier DPA-4

The DPA-4 is connected to metal microelectrodes or tetrodes for providing an initial tenfold amplification stage. Ideally Thomas RECORDING quartz glass insulated platinum/tungsten microelectrodes or tetrodes are used to yield optimal recording results with high signal amplitudes and low noise levels.

Figure 2: DPA-4 size comparison to a standard AA-size battery

Figure 3: Connection of a Thomas Tetrode to the DPA-4 input socket

The DPA-4 has a small size and weight and therefore it is easy to integrate this amplifier in many recording setups. Special adapted holders for manual microdrives are available from Thomas RECORDING (see figure 4). Custom-made adaptations are possible

Figure 4: DPA-4 mounted to a manual xyz-manipulator together with a Thomas Tetrode

The DPA-4 is delivered as a DC-coupled preamplifier to yield optimal common mode rejection ratio (CMRR). An AC-coupled version is available on request. The DPA-4 is equipped with an additional common ground and reference electrode input. 
The aluminum case of the DPA-4 provides electrical shielding. Electrode damage is prevented by the very low bias current. The high input impedance ensures stable long-term recordings.

Beside the possibility to use Thomas microelectrodes and tetrodes, adapters for other microelectrodes for acute and chronic recordings are available.

To avoid additional noise pickup from the power supply there is a special designed accumulator power supply and a battery charger available for power supply of the DPA-4 (see figure 5 and 6).

Figure 5: Accumulator power supply for the DPA-4

Figure 6: Accumulator charger

Table 1: Technical Data of the Thomas RECORDING DPA-4

For custom-made electrode adapters, please contact Thomas RECORDING for more information.