Using more than one input at the same time.

[Michedelic]

There are passive and active ABY pedals, any recommendations? I’m looking at ART Pro Audio.

Do you actually use four basses live? Now, I’m not one of these one bass only purists(I usually have two), but I use my tuner as a line kill switch if I have to swap out. I can’t imagine having that many cables flopping about.
Otherwise, for a quickchange, I have a Radial Big Shot, or in your case I’d look at their JX42, but that gets into rack configuration.
There’s also these that could be worked in…

Or possibly just get a mini-mixer, and run the sum out to the front of your amp?

 

[beans-on-toast]

There are passive and active ABY pedals, any recommendations? I’m looking at ART Pro Audio.

Be careful that it isn’t one out to two different amps. In those cases the buffer is usually on the output.

 

[butterfingers1]

Thanks everyone, got the passive ABY, no wire or battery, works in both directions. Reduces the highs a tiny bit, easily corrected if desired by a whisper on the high mid and treble. My tuner is plugged in too.

 

[Matty V PDX]

It depends on the design of the amp. There are 5 or 6 common ways to implement the 2 input jacks with active/passive circuitry. Some disable one of the jacks, some do not. Some alter the input impedance and some do not. Since this feature is predicated on using only one input at a time, that's what I recommend to avoid adverse performance.

How about a blackface showman? Would it make a difference, or have a positive effect, if I went first into the normal channel, then chained to the vibrato channel?

 

[agedhorse]

How about a blackface showman? Would it make a difference, or have a positive effect, if I went first into the normal channel, then chained to the vibrato channel?

For this amp, I would split the signal and take the output of the splitter into input 2 of each channel. Won't load your pickups that way for sure. On most of these amps, you can go into input 2 of the normal channel, come out of the input 1 jack into input 2 of the vibrato channel with the same effect, but that assumes that the amp hasn't been modified or screwed with.