#1
somebody put me straight on this please. The preamp out/line out(are these the same thing?) of the master amp runs into what on the slave amp? Also, does this mean the preamp of the master amp is combined with the power amp of the slave? Also....when connected, what amp do you turn the volume up or down with? Both?? Many thanks for any help!
#2
FX send or preamp out if you will into FX return. Yes, you're combining your master pre amp with the slave power amp. Depends, does the master amp have any kind of volume knob before the FX send? I can't think of one that has this so in most cases you'd control the volume (power amp gain) on the slave since you're not using the power amp of the master amp. Thus the power amp gain on your master amp does nothing.
#3
is line out the same as preamp out? I thought if you sent the signal from the fx send youd have to close the loop by sending something into the return??
#4
"Line Out" is often taken from the speaker output and padded down and filtered. This is different from "Preamp Out" which in turn is different from "FX Send" on most amps. But there are many, many loop designs, some pre-mv some post, so how you hook them up really depends on the particular amps in question.

What is it exactly that you're trying to accomplish?
Bruce Clement
BC Audio Hand Crafted Performance
#5
Line out is generally not the same as preamp out. Line out, IIRC will send an uncolored signal out to another preamp where you can use it's controls to shape the sound, preamp out is meant to be sent to a power amp and will retain the qualities of your first amps preamp and the tone/gain settings you dial on it. However, some manufacturers may use these terms loosely and a line out, might actually be a preamp out.
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#6
Quote by anderson80
somebody put me straight on this please. The preamp out/line out(are these the same thing?) of the master amp runs into what on the slave amp? Also, does this mean the preamp of the master amp is combined with the power amp of the slave? Also....when connected, what amp do you turn the volume up or down with? Both?? Many thanks for any help!


Runs into the IN on the slave amp

Pre-master to Power slave = Yes

Not sure about the volume. I never made it that far. I blew up my amp because I did not use a dummy load. Be careful. Make sure you use a dummy load.
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#7
Quote by ecvMatt
However, some manufacturers may use these terms loosely and a line out, might actually be a preamp out.



This is very important as well. For example Mesa Rec's clearly have a "Slave out"

I would check with the manufacturer of the Master amp to make sure. Slaving is a good way to experiment with getting a desired tone. But if you do it wrong its ultimately not worth the end result.
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#8
well im from uk and growing up in the 90s i liked really early oasis stuff. ive found different sites that say the guitarist played a marshall valvestate 8080 through an old wem dominator 25 amp (before that a voxac30). some may find that weird but alot of people loved that early oasis sound.
#9
Quote by anderson80
well im from uk and growing up in the 90s i liked really early oasis stuff. ive found different sites that say the guitarist played a marshall valvestate 8080 through an old wem dominator 25 amp (before that a voxac30). some may find that weird but alot of people loved that early oasis sound.



If thats what your after, and your certain thats what he used. Then you shouldnt have any problems. Just make sure there is a dummy load for the master amp.
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#11
http://www.parts-express.com/wizards/searchResults.cfm?searchFilter=dummy%20load%20resistor

There is a link for one you can make, or find a pre-assembled one.

The only way I can explain it is that the Dummy load replaces the speaker load (speaker cab). You need something to soak up the power.

Here is a link to a different forum that has a great diagram and same topic.


http://www.fryette-users.com/forums/showthread.php?3468-Is-the-quot-Line-Out-quot-on-the-back-of-my-Sig-X-a-Slave-Out
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#12
A Valvestate would not need a dummy load as the output section is solid state.

The WEM probably didn't have a loop (nor does an AC30), so he probably went from the fx send or line out of the Valvestate and ran it into the input of the WEM. In that setup, the preamp section of the Marshall becomes one big huge dirt pedal.

Keep in mind that with a setup like that, it is probably the "voice" of the WEM (or AC30) you're hearing on the records, moreso than the Marshall.
Bruce Clement
BC Audio Hand Crafted Performance
#13
Quote by anderson80
somebody put me straight on this please. The preamp out/line out(are these the same thing?) of the master amp runs into what on the slave amp? Also, does this mean the preamp of the master amp is combined with the power amp of the slave? Also....when connected, what amp do you turn the volume up or down with? Both?? Many thanks for any help!


I knew this diagram would come in handy again!



Here's basically how this works. The top version is how a single amp normally runs, either with pedals in the loop or with the loop bypassed completely. The second one is how your signal would work if you rigged up a slave system (note that the guitar should go to the external preamp, not the internal one.) That said, both amps will still need to be plugged into speaker cabs or MAYBE a dummy load (if that exists) to prevent explosions from happening.
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#14
Quote by anderson80
whats a dummy load? i have an attenuator, what would i do with it?

The power amp/output stage of a tube amp needs to have a load, whether it's a speaker or a resistance box that mimics the speaker load. Without this load, you'll fry your output transformer. A dummy load is simply a large resistor to soak up the power produced by the cranked slave amp. An attenuator is this large resistor.
Set the attenuator to "load". THD Hot Plates have this feature.
A proper line out will include power stage output as well from the slave amp as BC Audio stated above. This gives the ability to get a massively rich, saturated tone at any volume, even down to whisper volume.
This type of rig is what Eddie Van Halen used on almost all of his early records. I use a 50w Mojave Scorpion (basically a boutique plexi with military-spec hardware) re-amped into a power amp to get extremely close to VH's tone. Your FX other than any OD pedal (OD pedal goes in front of slave amp) will generally run between the amps: slave amp(w/ dummy load in place of speaker) lineout->FX->input of power amp, power amp drives the speakers & regulates overall volume. This way, in my rig, I crank the crap out of the Mojave, & the tone of a cranked plexi at line-level signal goes into a reverb/echo rack unit, & then into a power amp. You can use almost any clean power amp. I don't want another guitar amp mucking up my tone when I use this type of setup. It works AMAZINGLY well, but is a bitch to gig with
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Last edited by riffhog at Mar 30, 2011,