Hello everyone,
I'm curious if there's a well-known circuit design available for efficiently controlling the volume of multiple balanced line level signals via a single master control.
Considering the considerable investment often required for a comprehensive 5.1 monitor controller system, I'm exploring the possibility of implementing a more streamlined solution. Has anyone encountered or developed a circuit leveraging things like op-amps, capacitors, and resistors to achieve this task effectively?
I'm unable to design it myself, but I do have the skills necessary to construct it if there's a schematic and BOM. I need to put this device between the audio interface and a group of active monitors.
Looking forward to hearing your insights and experiences.
I'm curious if there's a well-known circuit design available for efficiently controlling the volume of multiple balanced line level signals via a single master control.
Considering the considerable investment often required for a comprehensive 5.1 monitor controller system, I'm exploring the possibility of implementing a more streamlined solution. Has anyone encountered or developed a circuit leveraging things like op-amps, capacitors, and resistors to achieve this task effectively?
I'm unable to design it myself, but I do have the skills necessary to construct it if there's a schematic and BOM. I need to put this device between the audio interface and a group of active monitors.
Looking forward to hearing your insights and experiences.
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Granted, the SMC 2489 is not cheap, but for a niche product that demands a certain level of complexity and quality I don't think it's that unreasonable. A decent set of monitors with sub is generally going to cost rather more (e.g. basic Kalis) or even substantially more (Neumann, Genelec etc.) anyway.
The crux of the matter is that multichannel volume control is not trivial.
6-gang volume pots do exist but are little more common than the proverbial hen's teeth. Mouser currently doesn't stock any that would fit the bill.
Plan B, throw some electronic volume control ICs at the problem. Even if you go with the least expensive option (NJW1159V), 3 of those will cost you as much as the pot would, and by the time you get to PGA2320s, it's almost 10 times as much. That's 7% of the SPL device's retail price just in these parts. (NJU723xx currently seem to be out of stock.)
Then you still need a microcontroller to control your PGAs including programming (ideally without digital interference getting into your audio), jacks, balanced receivers and line drivers, some thoughts on what your input and output levels should be (you neither want your input to clip nor your output to be unduly noisy) so this can be taken into account in the rx/tx sections, a power supply for the whole shebang and a case.
Now Rod Elliott's PCBs would be able to help you with some of these tasks (line drivers, receivers and power supply in particular) but the rest and the task of integrating all of it would fall upon you. That's a lot of work. Weeks, probably. There are all kinds of reasons why one may still want to pursue a project like this but I'm afraid saving money is not a good one...
The crux of the matter is that multichannel volume control is not trivial.
6-gang volume pots do exist but are little more common than the proverbial hen's teeth. Mouser currently doesn't stock any that would fit the bill.
Plan B, throw some electronic volume control ICs at the problem. Even if you go with the least expensive option (NJW1159V), 3 of those will cost you as much as the pot would, and by the time you get to PGA2320s, it's almost 10 times as much. That's 7% of the SPL device's retail price just in these parts. (NJU723xx currently seem to be out of stock.)
Then you still need a microcontroller to control your PGAs including programming (ideally without digital interference getting into your audio), jacks, balanced receivers and line drivers, some thoughts on what your input and output levels should be (you neither want your input to clip nor your output to be unduly noisy) so this can be taken into account in the rx/tx sections, a power supply for the whole shebang and a case.
Now Rod Elliott's PCBs would be able to help you with some of these tasks (line drivers, receivers and power supply in particular) but the rest and the task of integrating all of it would fall upon you. That's a lot of work. Weeks, probably. There are all kinds of reasons why one may still want to pursue a project like this but I'm afraid saving money is not a good one...
thanks @sgrossklass
So, wouldn't building a VCA circuit be a quick, easy, and affordable option?
Here in my country, the SMC is nearly twice as expensive as the list price, and that's too much money for just controlling the volume. Perhaps opting for an USB volume control would be a better choice.
So, wouldn't building a VCA circuit be a quick, easy, and affordable option?
Here in my country, the SMC is nearly twice as expensive as the list price, and that's too much money for just controlling the volume. Perhaps opting for an USB volume control would be a better choice.