Passive/active inputs on bass amp
 

Hi I have a Trace Elliot series 6 GP7 and I'd like some advice on which inputs to use.
I have a Jazz bass copy (Passive) and a Rickenbacker stereo bass copy (Passive). I'm about to start gigging and wondered if it would be safe to plug one of the basses into the active input to save unplugging one every time I want to use one of the guitars.
Thanks in advance.

""Active" means is that some component inside requires power, either a battery or an external voltage source. "Passive" means that no components inside need to be powered."

"Typically the active input or switch setting just drops the level of your signal going into the amp, to avoid clipping. This is because there was a time in the '80s and '90s when people generally thought an active bass always had higher output levels than a passive bass. It's not always true though! There are some very high output passive instruments, and some surprisingly low-output active ones, and everything in between. So what you need to do is use the "passive" input/setting for all low and medium-output instruments, regardless of whether they are active or passive; and the "active" input only for instruments that have such high output that they cause unwanted distortion in the amp."

So the gist is: If you do what your thinking of doing - there is a distinct possibility that whatever bass you have plugged into the active input will have a significantly lower output to your speakers.

Maybe you could make or buy a "Y" cable that would allow both basses to be plugged into the passive input.

I'm not claiming to be an expert, just relaying what I know.

They also sell A/B pedals that allow you switch between two
different input devices. You plug the two basses into the A/B
box, and the output of the box to the amp input.
One way to see what the difference between the two inputs is would just be to plug in a passive bass to the active input,
if you want to know what it sounds like.

Yes, my singer has one he made and suggested I try.

Not to hijack the OP's thread, but I'd like to piggy back a related question for the amp know-it-alls.

I play a passive fender p 4 string and an active G&L 5 string in my band and have to switch once a set.
Can I just leave them each plugged in to the passive/active outputs and switch at will? My amp is a Mesa M2000.

Keep in mind the first input stage maybe the same for either input, it just switches voltage gain. So if you use both "inputs" with two different basses the one you turn the volume down on my "load" the one you want to use. Could cause some trouble with the sound coming from either bass.

This^^

The basses are still connected together inside the amp, ones signal is attenuated (or not boosted as much) and the other not.

I have always just used the louder, un-padded input with any bass and just don't set the input gain as high if it's a hot bass. Every amp I have ever owned, without exception, which covers quite a few different brands, have always sounded like something is missing from the tone by using a padded input rather than using the un-padded one and adjusting the gain knob for proper level. I don't know why that is, but it is, and doesn't seem to be specific to any brand. It seems somehow weakened, or a bit "cloudy" sounding or something that's hard to explain but it's more than just a difference in the volume level you're starting with. It does something to the tone I don't like compared to the regular input.

The same is true for Y cables. A bad idea.

I'd be concerned with loading if both instruments are plugged in at once as has been mentioned.

On some active basses when you plug in, the battery is on. If it is not being used, unplugging saves on the battery.

You can get cables with what is called a silent plug. They have a switch in them and allow you to plug and unplug instruments on the fly. Neutrik makes them. I've read reports where people have run into problems with them but I've been using them for years with no issues.

Otherwise, turn down the amp's volume and switch the instruments. You'll probably need to adjust the amp volume for each instrument anyway.

Finally, on a single channel amp with inputs labeled, for example, 0db and -15db like an SVT CL, these are not passive and active inputs. The -15bd input has a voltage divider on the input that cuts the volume coming from the instrument. It doesn't mean that one input is for passive instruments and one is for active. You use the 0db input whenever you can. If the bass overloads this input, plug it in the -15db jack. They offer this feature because some instruments are hotter than others, the pad helps eliminate overdriving the input and causing distortion. Then again, sometimes you want to overdrive the input.

i have a fender super bassman 300. One input is 0 the other -6. According to the manual, "if both inputs are used simultaneously, their input sensitivities become identical (-6)"

Ok, thanks everybody,appreciate the help and advice. Very helpful.