The Doepfer A-148 Dual Sample & Hold/Track & Hold module provides you with two identical S&H sub-modules. Each of these is designed to generate 'staircase' voltages. Patching in a signal to the sample input of a sub-module allows the A-148 to sample the signal at a rate set by the signal that is patched into the trigger input, and is held at that voltage at the S&H output. The 'staircase' shape of the voltage is determined by the type of waveform patched into the sample input. Patching in noise or random signals will result in random patters, whilst an LFO would produce a rising or falling staircase pattern. Each sub-module is equipped with an LED to provide visual indication of the voltage polarity of the sampled signal.

Usage Examples

Random Arpeggios

The A-148 can be used in conjunction with a module such as the Doepfer A-118 to create random voltages from the A-118's random output. An LFO triggers the S&H module, so that with every oscillation of the LFO, a new random voltage is output to your VCO's CV input. If you patch an A-130 VCA in before the VCO, you can adjust the Gain and Out amounts to restrict the frequency range of the random voltages to whatever you desire. You can also use a similar setup, but patch the S&H voltage output to the CV input of a filter set to high resonance to produce a variety of interesting rhythmic timbral changes.

Glisando

If the CV output from a keyboard is patched into the Doepfer A-170 Slew Limiter, the A-148 can be triggered by the rising edge of an LFO, which samples the output from the slew limiter, and produces a staircase voltage which controls the pitch of a VCO. With this configuration, playing two notes, particularly ones that are spaced widely apart, produces an interesting glissando effect.

Controls & Indicators

Indication LED: Each sample and hold sub-module features an LED to give you visual feedback regarding the polarity of the sampled and held signal
Inputs/Outputs
Each S&H sub-module/section features the same I/O configuration.

Trig. In: This is the sub-module's trigger input. The trigger input signal determines the rate at which the sampling takes place. Triggering takes place at the leading edge of the waveform, so the pulse width is not important
Smp. In: This is the sub-module's sample input. Simply patch in the signal you wish to sample. The voltage must be in the range of -12V to +12V to prevent damage to the module
S&H Out: This is the sub-module's output for the sampled and held signal

Specifications

Width: 4HP/20mm
Depth: 30mm (Measured from the rear side of the front panel)
Current:
+12V: +20mA
-12V: -20mA