direct output chages if amp unloaded in amp or in dummy load?

[miche]

Hi everyone,

I noticed something rather strange with the line out of my krank revolution 1 head: its sound changes if the speaker output is plugged into a cab or a dummy load [weber mega dump]. It loses a lot of highs and lows and gets tons of more mids. I uploaded a few MP3s to show you exactly what happens:

1. mic in front of cab [I used this mic position to create the impulse I used below]
http://www.metallian.net/vladimir/krank revolution - cab.mp3
2. line out [amp unloaded in cab – impulse applied on the raw track]
http://www.metallian.net/vladimir/krank revolution - impulse - direct out [cab unload].mp3
3. line out [amp unloaded in dummy load – impulse applied on the raw track]
http://www.metallian.net/vladimir/krank revolution - impulse - direct out [megadump unload].mp3

Here is the gear used:

schecter blackjack [modified with EMG 707, since they don't do lefthand hellraisers]
maxon od-9 overdrive
krank revolution 1 series
mesaboogie 4x12 standard
shure sm57

Has anyone an idea of what happens here? I thought the dummy load should just unload the amp and not influence its direct output sound. Has anyone already experienced it? Is it just the krank that works that way? Do you think it is due to the weber's mega dump? Should it work better with a thd hotplate? And finally, does this mean the mega dump could damage the amp?

Thanks for your help!

 

[miche]

I got an answer from Krank which tells everything:

"Any cab or dummy load you connect to the amp is going to affect the way the line out works."

I tried unloading my head into another cab and that's right, the sound of the line out is affected. This is definitely something I didn't know. And that sucks.

Does someone have a few dummy loads here and who could draw a comparison between them, soundwise? But not as attenuators, as dummy loads that influence the line out?

 

[006]

Strange.

~e.a

 

[Kazrog]

I've personally noticed that the line out of my Peavey 6505+ sounds completely different than the line out of my THD HotPlate attenuator. I vastly prefer the sound of the HotPlate's line out, but I'm a bit mystified as to why it sounds so different than the line out - either way we're dealing with (theoretically) the same preamp signal.

I haven't run a comparison between the line out with a cab vs. the dummy load, but your results don't surprise me. I also feel that dummy loads drain tubes faster than speakers do, although I have no concrete way to prove this. In general, although I've produced some good/usable results with dummy load + impulse responses, I still feel that miking a cab is the best way to go, if you have the means.

 

[KeithRT99]

i like clip 2 the best, not that you were asking them to be rated. I'm not exactly sure because i don't own one, but it sounds kinda recto ish to me.

 

[006]

Shane - it's only obvious (to me) that a power attentuator will drain your tubes faster...I mean how often do you run your amp's master at 8 without an attentuator?

~e.a

 

[Kazrog]

Shane - it's only obvious (to me) that a power attentuator will drain your tubes faster...I mean how often do you run your amp's master at 8 without an attentuator?

~e.a

I don't run my amp's master at 8 regardless. I keep my settings the same with the attenuator as I would through my cabinet. In my case, my master is at 3.5 to 4. I've never encountered a situation in real life where I'd need more than that, so it doesn't make sense to do that into the attenuator.

 

[iekobrid]

I've personally noticed that the line out of my Peavey 6505+ sounds completely different than the line out of my THD HotPlate attenuator. I vastly prefer the sound of the HotPlate's line out, but I'm a bit mystified as to why it sounds so different than the line out - either way we're dealing with (theoretically) the same preamp signal.

Isn't the THD's line out a frequency compensated power amp signal vs the 6505's line out being an uncompensated preamp signal?