Passive DI-box between Amp and Cab - ready to use impulses?

[JoeJackson]

Hey guys,

today I tried to use my new ampeg Vl-502 with impulses and failed miserably. The amp has an FX-Loop and thought I could get a pre-amp signal out of the FX-Send. But as soon as I plugged in a cable, the sound disappeared.

Well, "of course" I stole the power-amp it's pre signal, but unfortunately the pre-amp signal was lost, too. Maybe the Loop is damaged, somehow.

My idea:
Can I put a passive DI-box between the Amp and my Iso-cab? It's this one here and the switch on the lower right reads something about "Speaker". So, would it work or do I blow up my amp by plugging it in between?

 

[Torniojaws]

I'm fairly sure you will need a dummy load to do that without blowing anything.

 

[aortizjr]

The loop is a serial loop. So the jack is switching. If you plug anything in to either loop jack the signal should cut.

And keep a speaker or some sort of load on the amp, no matter what.

But you can use a DI on the FX loop. Just connect the Pass-Through from the DI back to the FX loop in on your amp.

Using a DI box between the amp and the speaker can be dangerous. So I would just make sure that that the DI box has something about speaker on it. Then you will need lots of pads to get the signal controllable. You will still need a load or a speaker though.

What I have been using is the Behringer GDI with speaker simulation. I use that for monitoring. Then I use a dummy load and take the DI output from that (THD hotplate). Then I use impulses on that signal later. The Behringer you can turn of speaker simulation too.

It works ok. The THD uses a fan to simulate the response of a speaker. Ones like the Weber MASS use an actual speaker motor. The point of that is to theoretically get the poweramp to perform more normally since there is an interaction between the speaker and power output. Something to do with speaker impedances at different frequencies and such. I just finished building a resistive dummy load too, so we shall see how that works out.

 

[JoeJackson]

I got it to work...
Don't know, what I did wrong the first time, but the second time, it worked like a charm.

So, thanks for your comments anyway

 

[TeamOmega]

I got it to work...
Don't know, what I did wrong the first time, but the second time, it worked like a charm.

So, thanks for your comments anyway

how did you finally get it to work? i have a vl-502 and was having the same problem with not being able to get a direct sound out of the fx send

 

[Noumenon]

Try plugging in a dummy plug into the return jack or something. Also, some amps need to be fully on, so no standby (like my triple xxx)