adalogue
Member
I searched the forums and didn’t find this question specifically addressed so posting here!
I’ve benched tested several g-bus style 500 series modules, two OEM and one kit, with vastly different distortion specs.
1. SSL G-Bus (THAT VCAs)
2. Stam 4k5mk2 (dbx 202C clone VCAs)
3. Sound Skulptor CP4500 (THAT VCAs)
SSL was by far the lowest at unity gain (0.003% IMD and 0.001% THD @ 500 Hz). Distortion values increased as compression increased (1.6% IMD and 0.22% THD @ 500 Hz with 12 dB of compression).
Stam was by far the highest at unity gain (3% IMD and 1.5% THD) and got a bit higher with compression, but not much. IMD plot also looks pretty crazy (attached).
SS was between the two at unity (0.05% IMD and 0.02% THD) and higher with compression (2.2% IMD and 0.3% THD with 12 dB of compression).
I’ve heard it said that the dbx 202C (cloned in the Stam unit) have higher distortion specs, but the cutsheet appears to disagree.
How does a vintage SSL console compare? I’ve tried to find one to test locally and haven’t been successful yet. The dbx 202C cut sheet does not show high levels of IMD or THD at unity, but rather pretty low values, close to those I measured for the SS CP4500:
https://www.gyraf.dk/schematics/Dbx202.pdf
I’ve benched tested several g-bus style 500 series modules, two OEM and one kit, with vastly different distortion specs.
1. SSL G-Bus (THAT VCAs)
2. Stam 4k5mk2 (dbx 202C clone VCAs)
3. Sound Skulptor CP4500 (THAT VCAs)
SSL was by far the lowest at unity gain (0.003% IMD and 0.001% THD @ 500 Hz). Distortion values increased as compression increased (1.6% IMD and 0.22% THD @ 500 Hz with 12 dB of compression).
Stam was by far the highest at unity gain (3% IMD and 1.5% THD) and got a bit higher with compression, but not much. IMD plot also looks pretty crazy (attached).
SS was between the two at unity (0.05% IMD and 0.02% THD) and higher with compression (2.2% IMD and 0.3% THD with 12 dB of compression).
I’ve heard it said that the dbx 202C (cloned in the Stam unit) have higher distortion specs, but the cutsheet appears to disagree.
How does a vintage SSL console compare? I’ve tried to find one to test locally and haven’t been successful yet. The dbx 202C cut sheet does not show high levels of IMD or THD at unity, but rather pretty low values, close to those I measured for the SS CP4500:
https://www.gyraf.dk/schematics/Dbx202.pdf