Issues in using an amp without speakers?

[MacDaddy]

Are there any issues in using an amp, but not using the speaker outs?

So for example, bass into amp and then using headphones.

Or using an amp as a DI, instead of a DI box?

[Newfoundfreedom]

Only if it's a valve amp. They should never be used without speakers. 

As far as I'm aware, there's no problem with solid state. I've used mine DI'd to the PA loads of times and never had any issues. 

Edited November 3, 2020 by Newfoundfreedom

[Dood]

As above, I can't think of a solid state offering off the top of my head that must have a cabinet connected. I use my Berg' B|Amp as a pre and it sounds glorious! 

[Pea Turgh]

My local tech advised against it for my Peterson, but it’s almost as old as me.

Conversely, the little Ampeg PF valve amps are ok with no speakers.

[Woodinblack]

2 hours ago, Pea Turgh said:

My local tech advised against it for my Peterson, but it’s almost as old as me.

Any solid state amp is fine. The voltage goes up and down but doesn't go anywhere, so no power is drawn.

Valve amps are a problem because because you are actually getting the power from a transformer, and not connecting it can cause damage.

2 hours ago, Pea Turgh said:

Conversely, the little Ampeg PF valve amps are ok with no speakers.

The ampeg PF amps have a dummy load that is put in place if you have no speaker connected.