Multichannel Systems ME-System Manual - Manual (Page 13)

Welcome to (USB-) ME-Systems
13
2.2.5 Miniature Preamplifiers (MPA)
The miniature head stage preamplifiers MPA can be connected directly to the microelectrodes
in the test model to provide the first amplification stage of 10. Adaptors for standard multi-
electrodes such as NeuroNexus probes are available. The signal channels can be collected and sent
to a signal collector, which connects to the amplifier. The miniature preamplifiers small size allows
easy placement. The metal housing prevents the amplifier from picking up external noise.
Miniature preamplifiers are available for 8 and 32 electrodes (MPA8I, MPA32I). Both versions
are type I amplifiers, that is, they include a common ground and one reference electrode input.
Please see “Filter Amplifiers with Fixed Gain” for more information on I type amplifiers.
2.2.6 Filter Amplifiers with Fixed Gain (FA)
Raw data from electrodes or from the preamplifier can be amplified by filter amplifiers with
fixed gain. Amplifiers with 4, 8, 16, 32, 48, and 64 input channels are available with two different
input types (S or I).
Amplifiers can be ordered with any gain and bandwidth configurations by the user's choice.
For example, typical pass bands would be 1 to 300 Hz for recording field potentials and
300 to 3000 Hz for recording action potentials. It is also possible to use a broadband amplifier
and filter the data with the digital filter of the MC_Rack program.
Input type S / Single ended inputs
Amplifiers with input type S have single ended inputs. All signals are measured with respect to
the amplifier’s ground. The signal source's ground and the amplifier's ground should have the
same value for obtaining good results.
Input type I / Subtracts reference from input voltage
An amplifier with input type I includes a common ground and a common indifferent reference
electrode input. The reference electrode is ideally identical to the recording electrodes and placed
into a comparable but inactive area or tissue. Background or noise signals that are picked up by
both the reference electrode and the recording electrodes are removed.
2.2.5 Programmable Gain Amplifiers (PGA)
Raw data from the preamplifier is amplified by the programmable gain amplifier, which
is basically an S type filter amplifier, but in addition, the gain can be flexibly adjusted from
10 to 5000 with the user-friendly program PGA-Control.
Standard versions with 16, 32, and 64 input and output channels are available. Also, special
versions are available that feature two different pass bands. Signals are split and the two
pass bands are sent to two separate output channels. For 16 input and 32 output channels,
or 32 input and 64 output channels, respectively. These amplifiers are perfect for recording
signals with different frequencies.
Programmable gain amplifiers can be ordered with any bandwidth configuration by the user's
choice.