Hardware

Systems

Medusa PreAmps

Medusa PreAmps feature TDT’s unique preamplifier design in a smaller, lower-count package. Signals are digitized at up to ~25 kHz on the preamplifier and sent over a fiber optic link to a DSP device such as the Pentusa or Medusa base station, where they are filtered and processed in real-time. A standard DB25 input connects the preamp directly to any of TDT’s headstage designs. Multiple preamplifiers can be connected in parallel for higher channel count acquisition.

Preamplifiers are available with either PCM or Sigma-Delta A/Ds. Typical applications use PCM A/Ds to acquire bioelectric signals with minimal delay. Choose Sigma-Delta A/Ds to record near high frequency electric or magnetic noise sources (e.g. eye-coils, wireless motion detectors, or touch screens).

Part numbers:
RA4PA 4-channel preamp
RA16PA 16-channel preamp
RA16SD 16-channel Sigma-Delta preamp

Technical specifications:

S/N (typical):	rms 3 µV bandwidth 300- 3000 Hz; 6 µV bandwidth 30- 5000 Hz
A/D sampling rate:	~ 6, 12, or 25 kHz
Input Impedance:	AC(1 kHz): 100 kOhms
Frequency response:	3 dB 2 Hz- 7.5 kHz
Highpass filter:	2.2 Hz
Power requirements:	500 mA while charging, 50 mA once charged
Battery:	Li-ion Battery 1500 mAh, 20-30 hours battery life between charges
Charger:	6-9 V DC 500 mA, center negative
Fiber optic cable:	5 meters, maximum cable length 20 meters

RA4PA and RA16PA:

A/D:	4 or 16 channels, 16-bit PCM
Maximum voltage in:	+/- 4 mV
Lowpass filter:	7.5 kHz (3 dB corner, 1st order, 6 dB per octave)

RA16SD:

A/D:	16 channels, 16-bit Sigma-Delta
Maximum voltage in:	+/- 5 mV
Lowpass filter:	7.5 kHz (3 dB corner, 2nd order, 12 dB per octave)
Group delay:	20 samples