Torpedo Cab M questions

Hey guys, is it safe to run the designated preamp out of my 5150III into the CabM without needing to run the speaker out (thru jack) of the CabM?

Hi OliOls9,

if the preamp out can be operated on the amp with the power off (or output volume all the way down) that shouldn't be a problem.

The speaker output on CAB is designed for something else: in case you plus the AMP (not preamp) into the CAB M, connect the speaker output of CAB M into your real speaker.

guillaume_pille":3572kfng said:

Hi all,

because the SPEAKER out cannot be buffered, the ground of whatever you connect there will be connected to the ground of CAB M and your previous device (a preamp).

It may work and you will not break anything, but it's possible that you experience ground loops doing that. In that case, a DI (with isolation transformer) may be necessary.

When you connect a cabinet on that output, because the cabinet is a floating ground, you have no issue.

Click to expand...

Hi !

Thanks for the clarification !

Just to be sure i understand this right, did you mean that to make sure i have no ground loops in my case, i would need to put a DI in between the "preamp out" and the "CAB M input" ?

Also, let's suppose i skip the "inserting a DI" (to prevent ground loops issues) part, I have a hard time seeing the difference (in terms of ground loops issues) between :
- inserting a regular fx pedal (say a delay pedal) in the fx loop of my amp (which is something lots of people do, and do not seem to have a specific ground loop issue this way)
- inserting a CAB M in the fx loop of my amp

Just to be sure i understand this right, did you mean that to make sure i have no ground loops in my case, i would need to put a DI in between the "preamp out" and the "CAB M input" ?

Click to expand...

You won't necessarily have an issue, but in that case a DI can help. It's worth trying it anyway.

Also, let's suppose i skip the "inserting a DI" (to prevent ground loops issues) part, I have a hard time seeing the difference (in terms of ground loops issues) between :
- inserting a regular fx pedal (say a delay pedal) in the fx loop of my amp (which is something lots of people do, and do not seem to have a specific ground loop issue this way)
- inserting a CAB M in the fx loop of my amp

Click to expand...

If the CAB M is just connected in and out to your amp, no difference. But if you plug it to your amp on one side, and then into a mixer, a soundcard, another distant device with a different grounding, things can get funny.

guillaume_pille":3o7qikpr said:

Just to be sure i understand this right, did you mean that to make sure i have no ground loops in my case, i would need to put a DI in between the "preamp out" and the "CAB M input" ?

Click to expand...

You won't necessarily have an issue, but in that case a DI can help. It's worth trying it anyway.

Click to expand...

OK thanks !

guillaume_pille":3o7qikpr said:

Also, let's suppose i skip the "inserting a DI" (to prevent ground loops issues) part, I have a hard time seeing the difference (in terms of ground loops issues) between :
- inserting a regular fx pedal (say a delay pedal) in the fx loop of my amp (which is something lots of people do, and do not seem to have a specific ground loop issue this way)
- inserting a CAB M in the fx loop of my amp

Click to expand...

If the CAB M is just connected in and out to your amp, no difference. But if you plug it to your amp on one side, and then into a mixer, a soundcard, another distant device with a different grounding, things can get funny.

Click to expand...

OK, but if i (insert my CAB M in the FX loop of my amp) and use the "DI out" of my CAB M to reach my mixer, i guess the DI out of the CAB M is supposed to get rid of any grounding issues (using the ground lift button if needed), right ?

I already have a (original) Torpedo CAB, and the appeal of the CAB M to me is :
- the small form factor
- the "DI out" in XLR format
- the "speaker out" (that i would use as a "thru")

All combined, it would allow me to integrate the CAB M in my current chain (in between my preamp and my poweramp), without needing to add a separate DI Box and/or splitters (that have an isolation/ground lift capability).

This is why i wanna make sure that, among others, the "DI out" of the CAB M provides the same isolation (as far as ground loops) as a regular DI box.

I just need to be sure of that before i purchase a CAB M

The problem is not with the DI out, it's about connecting the ground of multiple products via the CAB M, which is what you do by using the THRU not for its original purpose.

The ground lift can help, but sometimes it's not enough, it depends on how the noise travels and where it takes its source. That's the case for EVERY product. And if the noise happens because you use the THRU, well, the ground lift on the DI out is useless...

If you don't want to take the risk, do not buy it.

@guillaume pille :
Thanks !

I will try to borrow one and do some tests !

EDIT : by the way, i added all your answers regarding this "Torpedo CAB M : using the "speaker out" as a FX loop "thru" " in the dedicated thread i created :

viewtopic.php?f=75&t=206665