is it safe to: use an external preamp signal directly into a combo amp's effects loop return jack ?

Ro_S

I have a few drive/pre-amp type pedals and devices.  Some are valve; some solid state; and some amp-in-a-box type pedals with JFETs.

I'd like to experiment with using these in conjunction with a combo amplifier but with the latter being used just as a power amp and speaker.

Specifically, if I was to plug my external preamp signal directly into the combo amp's effects loop's return jack , thereby bypassing the combo amp's own pre-amp.

I wish to know whether it would be safe to do this or do I risk damaging an amp?

Advice please?

thanks!

John_A

That's exactly what I do and many others on here, it's just fine

fretmeister

Yup.

I use my bass amp as just a power amp for many things that way.

Works very well.

Sassafras

I sometimes use an AMT preamp straight into FX returns on many amps.

ecc83

Yes, perfectly in order.

FYI if you try this with most of the Blackstar range you must put a dummy plug in the input jack to defeat the auto standby feature. A 1/4" headphone adapter works a treat.

Dave.

mark_jwedge

So can you do this with 'normal' drive pedals as well as pre amp type pedals? For example I have a skreddy screw driver mini deluxe, Thorpy peacekeeper and a klone. Would I be able to put these into the return of the FX loop of my cornford roadhouse?

professorben

mark_jwedge said:

So can you do this with 'normal' drive pedals as well as pre amp type pedals? For example I have a skreddy screw driver mini deluxe, Thorpy peacekeeper and a klone. Would I be able to put these into the return of the FX loop of my cornford roadhouse?

I have found this to sound awful in the past, the pre amp section is there for a reason, I expect the drive pedals straight into the fx return to sound horribly fizzy and nasty. However, as a 'sound' it could be something you want for an effect, but it won't damage your amp.

ICBM

Yes, it's always fine to do this with any external drive pedal/preamp.

What is sometimes not fine is to connect the send as well, so the pedal/preamp is actually *in* the amp's FX loop. That can cause instability, self-oscillation and in the most severe cases damage the amp. Not common, but it can happen occasionally.

Ro_S

Thankyou all for the replies and advice.

SRich

Sorry to necro-bump but I tried this last night using my Adrenalinn III into my Delta Blues. I thought it a neat trick and it worked perfectly.

You learn such a lot hereabouts.

Cheers.

drwiddly

Used my back up rig on Sunday as it was a small stage - Axe FX Ultra into the fx return of a Wharfedale TCT35 valve combo. It sounded great and takes up very little space.

Dopesick

My Amptweaker pedal sounds like a demon going into the FX return of my Matamp. (However I think it sounds even better going through the input all on clean.)

I'm tempted to get a Matrix GT1000FX power amp at some point to go with my Amptweaker.

jesone

Kemper into DSL40c sounds great too. Mind you I'm all about the Marshall tones anyway