There is a lot of confusion about this. The volume control in a passive is no different than the volume control in any active preamp. It is in a different box so you neeed cables to hook it up, that's the only difference. The volume control inside a preamp is also a passive device. You can build either one with a transformer, pot, stepped attenuator, whatever.
You can successfully use a passive if:
1. the rest of system has enough gain to drive the speakers to the desired level
2. the input impedance of the passive is high enough to properly load the source
3. the output impedance of the passive is low enough to be a good match to the amp
4. you don't try to use cables that are too long or have high reactance
Those that had poor results failed to meet one or more of these requirements and finding a passive that meets all of the above for a given set of components may be impossible. Trying to use one in a system that requires the extra gain from an active preamp is doomed to fail. Many don't understand what these requirements mean, choose an ill suited passive for the job, and end up with lousy sound. That's not the fault of the passive but of the person putting together the system.
The big problem with volume controls of any type is that they always take something away. The advantage designers of preamps have is they can optimize their design for the type of volume control they choose. Unless the user of a passive takes the same care in choosing they will likely end up with poor results.
You can successfully use a passive if:
1. the rest of system has enough gain to drive the speakers to the desired level
2. the input impedance of the passive is high enough to properly load the source
3. the output impedance of the passive is low enough to be a good match to the amp
4. you don't try to use cables that are too long or have high reactance
Those that had poor results failed to meet one or more of these requirements and finding a passive that meets all of the above for a given set of components may be impossible. Trying to use one in a system that requires the extra gain from an active preamp is doomed to fail. Many don't understand what these requirements mean, choose an ill suited passive for the job, and end up with lousy sound. That's not the fault of the passive but of the person putting together the system.
The big problem with volume controls of any type is that they always take something away. The advantage designers of preamps have is they can optimize their design for the type of volume control they choose. Unless the user of a passive takes the same care in choosing they will likely end up with poor results.