martthie_08
Well-known member
The time has come to complete my second GSSL compressor, this time it is a more "traditional" approach in a one height unit package, but with relay bypass and internal only sidechain filter. It is not finished yet, the main PCB works, but I must still finish and test the "addons".
The sidechain filter is based on Steffen's design, only that there are no buffer opamps and external connection, only switched capacitors. I have no idea if this will work, I don't see why not. I did some calculations and came up with different series / parallel cap combinations for pretty close approximations to cutoff frequencies of 60, 90, 120, 180 and 240 Hz. The caps are on the little piece of veroboard behind the front panel rotary switch.
The relay board is based on Mark's circuit (see http://www.groupdiy.com/index.php?topic=6510) and is also soldered on veroboard, sitting right next to the main pcb.
I am sure the layout could have been improved and it is not tested yet, but I have to figure out first from where to pull the 12 for the relays. My plan is to make a small dedicated board with regulator getting the rectified voltage from the B350C1000 regulator. Can anyone point me in the right direction on how exactly to do this? Maybe it would be easiest to copy the regulator circuit from Jakob, but could anyone draw up a little sketch on what parts would be involved in this? That would be really great!! When the relay bypass works I will post the board layout, this could come in handy for others.
cheers, Marten
The sidechain filter is based on Steffen's design, only that there are no buffer opamps and external connection, only switched capacitors. I have no idea if this will work, I don't see why not. I did some calculations and came up with different series / parallel cap combinations for pretty close approximations to cutoff frequencies of 60, 90, 120, 180 and 240 Hz. The caps are on the little piece of veroboard behind the front panel rotary switch.
The relay board is based on Mark's circuit (see http://www.groupdiy.com/index.php?topic=6510) and is also soldered on veroboard, sitting right next to the main pcb.
I am sure the layout could have been improved and it is not tested yet, but I have to figure out first from where to pull the 12 for the relays. My plan is to make a small dedicated board with regulator getting the rectified voltage from the B350C1000 regulator. Can anyone point me in the right direction on how exactly to do this? Maybe it would be easiest to copy the regulator circuit from Jakob, but could anyone draw up a little sketch on what parts would be involved in this? That would be really great!! When the relay bypass works I will post the board layout, this could come in handy for others.
cheers, Marten
