Motivation
This is the 12V Euro single DC coupled version of my NGF dual version. It uses the now obsolete LM1496 balanced modulator -demodulator. But you can still source them and I have some in my stock. So I decided to make a PCB and module. I started with the original Elektor Formant schematic published in "Formant Erweiterungen" p35ff. I left out the microphone and envelope follower part because I already have such modules. I have added input buffers and raised the signal level to my 10Vpp used throughout my system.
Specs and features
- Ringmodulator single DC Coupled
- 10Vpp input and output
- Runs on +/-12V and +/-15V
- Power consumption around 15mA each rail
Implementation
Schematic
Ringmodulator single schematic: Control board
Ringmodulator single schematic: Main board
Description:
This implementation follows closely the original Elektor Formant implementation. Refer to the original documentation if needed. You can find it on the net. My changes are the input buffers and the adaption to my 10Vpp signal level.
Calibration
- You need to adjust the trimmers TR1 and TR2. They are used for canceling the input signal.
- Adjust a sine signal to about 1000Hz and 10Vpp signal level.
- Connect the signal to input ACA (ACB) and adjust TR1(TR2) such that the input signal can no longer be heard or seen (if you use a oscilloscope) at the output.
Building hints
- None
Special parts
- The LM1496 is obsolete now, but you can still source them. Beware of counterfeits.
Download
Ringmodulator single control board documentation downloadRingmodulator single control board Gerber files download
Ringmodulator single main board documentation download
Ringmodulator single main board Gerber files download
Ringmodulator single *.fpd file
Ringmodulator single: Front view
Ringmodulator single: Populated control PCB
Ringmodulator single: Populated main PCB
Ringmodulator single: Back view
Ringmodulator single: Half front view
