Pre amp

[Gary1963]

Does anyone have any ideas about plugin my bass into a modelling amp then plug that into my main amp so I can get different sounds? I heard I can do this if I use a low wattage modeling amp and keep the volume low and use my main amp for more volume, but don't want to damage anything

[fretmeister]

If the modelling amp has a headphone out use that into the FX loop return of your big amp.

 

Do NOT connect a speaker out into an input on another amp.

[Gary1963]

Thanks that's  great help

[agedhorse]

Do not use a headphone out except for headphones. Some are not intended to be ground referenced and can either cause noise problems or in some instances damage.

You can use a post-modeling line output into the effects return of the amp that is connected to the speaker.

Check the owner’s manual to see if there may be other (safe) ways.

[Gary1963]

Thanks . I really don't know weather to just use A multi FX pedal . 

[Skybone]

If you're using the Multi-FX to achieve different sounds, as in different amp & cab models, you can run the Output of your Multi-FX to the Effects Return in your amp. 

You'll simply be bypassing the amp's own pre-amp section, and going straight into the power amp.

[Gary1963]

Thanks I will try that

[Gary1963]

Or can I plug the headphone from modelling app to the aux in on my main amp 

[Downunderwonder]

On 01/02/2021 at 09:58, agedhorse said:

Do not use a headphone out except for headphones.

This man's advice is never to be ignored.

[Gary1963]

5 hours ago, Downunderwonder said:

This man's advice is never to be ignored.

 

[Gary1963]

I'm still a bit unsure what to do

 I thought you could plug headphone from another source to aux in on my amp. Isn't that what you can do to play along to your favourite tracks

[Frank Blank]

3 minutes ago, Gary1963 said:

I'm still a bit unsure what to do

 I thought you could plug headphone from another source to aux in on my amp. Isn't that what you can do to play along to your favourite tracks

Remember what @agedhorse said...

On 31/01/2021 at 20:58, agedhorse said:

Do not use a headphone out except for headphones.

 

[jrixn1]

9 minutes ago, Gary1963 said:

I'm still a bit unsure what to do

What make/model are your low-wattage modelling amp and main amp?  Or could you post photos of the inputs & outputs on each.  I think it will be easier for people to advise if it's known exactly what equipment and connections are available.

[Gary1963]

I'm coming out of a 20w cube and into my main amp which is a behringer ultrabass bx3000h

[Gary1963]

This is the amp I want the cube to go into. It has the c d in which I was thinking or going into

[jrixn1]

The Roland Cube has a output labelled "Recording Out/Phones".  Using a normal guitar cable, connect that to the "Return" input on the back of the Behringer.  Only the "Master" control on the Behringer will now be in use i.e. you get the sound of the Cube, but just a lot louder.

Or yes, try your other suggestion of a multi FX pedal.  If you don't already have one, I saw this current thread https://www.basschat.co.uk/topic/445593-budget-multi-fx/ and agree that the Zoom B1 Four could be a good place to start.  It all depends really on what type of sound you want to go for; or if you don't know yet, then the Zoom is a good way to experiment.

The Zoom's probably a better bet overall, unless you absolutely adore the sound coming out of the Cube (which is a guitar amp, I think).

[Gary1963]

Thanks for your advice. Much appreciated. 

[agedhorse]

If the Roland amp states that using the headphone out as a recording or aux output, that means that the designers determined that it was safe to do so. 
Different circuits can behave in unpredictable ways when used in ways the designer did not intend. This is why using a headphone output MAY not be safe unless stated so by the manufacturer.