Preamp, poweramp vs. amp head

[irg7620]

ok, i got tired of not being on the board since my surgery last week and i had this great question. i read about a lot of people using stand alone preamps and poweramps for their cabinets. why not just use a head that has both? greater tone flexibility? more watts going in? someone please let me know what the greatest advantages/disadvantages of using the stand alone items are vs. the head.


thanks!!

 

[Christopher]

In most cases it's simply a matter of not having a head do what you need. Often, preamps separately have more versatility. Sometimes, in more complex rigs, more than one preamp can be used.

 

[7 Dying Trees]

It's all about the blinky xmas lights...

In most cases it's just having the flexibility of being able to save loads of sounds, and midi switch between them.

 

[Crucified]

Its all about what you want/need out of a rig. I blend 2-3 preamps at a time in my rig and it can do anything i need from sparkly cleans to sick distortion and everything in between. I blend a recto pre, 5150 pre out and a rocktron prophesy II and have nearly any tone i need.

 

[InTheRavensName]

2112 FTW,

although I have a rack pre/processor and a head, I normally just use the rack through the poweramp of the head

 

[Bartok]

Splits the cost: Can get the power amp first, manage with pedals for a little while, then get the rest of the scratch together for the pre.
If you're looking at a head with the same quality of pre and power stage, you have to do all the saving and wait for it
Easier to change parts of the setup when they're separate boxes too

 

[starsnuffer]

Racks came into popularity in the late 80s when people wanted a wide variety of tones that were all midi switchable.

These days, most amp heads have full midi capability and very good FX loops, which makes them just as good at being as versitile as most preamp setups.

It comes down to a tone choice. The only exception being for fully programmable preamps like the H&K access, triaxes, ada mp1, and jmp-1, and soldano/caswell X99. . . of course, you can also do all that with an H&K switchblade head.

I used to be a rack junkie, I've owned a lot of preamps and poweramps. I just found the rack world to be limited in options. There are simply a LOT more makers of amp heads then there are preamp manufacturers, especially for modern tones. That isn't to say preamps aren't god, if you find one that has your tone, go with it.

-W

 

[Spinedriver]

For myself, I say that both money & multi-function come into play.

1. I don't now & probably won't for some time to come, have the coin to spend on a Mesa Boogie/Engl/Bogner/etc.. type head. They're just way out of my league price wise. Add to the fact that if I buy a tube head like that & want to change the tubes in it, it could easily run close to another $150-$200. Instead, you spend $400 or so on a Pod XTL (less for a bean) and you have access to a variety of tones for a fraction of the cost. Power amps are easy to come by and you'll have more wattage than most amp heads can push.

2.When I'm home and want to practice/record some stuff, all I have to do is whip out the Pod, plug it into the pc, and it's ready to go. There aren't many tube heads that work well plugging directly into any sort of recording device. You pretty much have to mic a cabinet and living in an appartment, cranking a tube head (to get the gain) is NOT an option. Not to mention it's a lot easier carrying a 10 lb (or less) Pod XTL vs. a 50 lb + amp head to and from the jam space.

So, I don't think it's a case of one is better than the other. It's more along the lines of what you're looking for. If you're interested in having 1 really awesome tone and have no need for a lot of effects, then you'd probably like a single amp head more than all the muss & fuss of programming a pre-amp. If you're more into experimenting and you play a lot of different styles and then you should look into the separate pre/power amp thing because you'll get a LOT more versatility than you will with say, a 2 channel Dual Rectifier or Soldano SLO-100.

 

[metalfiend666]

It's all personal choice, but rack gear gives you a chance to try things you can't necessarily get in a head. For an example: Say for instance you liked the sound of a Marshall preamp, but not EL34's in the power section. You could mate a JMP-1 with a Mesa poweramp with 6L6's.

A lot of preamps have the option of storing presets and recalling them via midi (Mesa Triaxis and Engl SE Pre for instance), so you can have a lot of settings stored and recall them all at the touch of a button. Very useful for covers bands for instance.

 

[Ancestor]

I think that they could work well. One cool thing might be to get a Mesa preamp and a Marshall power amp. I've heard people sound really ripping on a rack. For me, I prefer an old school head/cab setup.

 

[irg7620]

now, here is another question. i swear i feel like a beginner again. how do you listen to just a preamp and just a poweramp? don't they both have to be on to get sound out of a cabinet? or is the clean channel on a head the pre and the distortion the poweramp? this has confused me for a very long time.

can each one be used by itself? and, can just a poweramp be used to power a cabinet? sorry about all these beginner like questions, but i have never had these answered by anyone.

 

[Bartok]

Pre-amp is line level so you can plug it straight into a desk/soundcard etc. but it won't drive a cab by itself. You can plug a guitar straight into the power amp but it isn't ideal. The power amp is what powers the cab, but it won't do anything very exciting without some sort of pre, be it an actual pre-amp, pedal, amp modeler or something before it.
Distortion comes from the pre and the power stages.

 

[Benzesp]

In most cases it's simply a matter of not having a head do what you need. Often, preamps separately have more versatility. Sometimes, in more complex rigs, more than one preamp can be used.

Flexability is one major reason another is rack setups are more unique and you can introduce all sorts of stuff in your signal path in series or parallel to get your own sound. Plus it all fits into one nice rack case.

 

[InTheRavensName]

normally it goes guitar->pre->fx->poweramp

preamp shapes tone, poweramp makes it loud

 

[The Dark Wolf]

Another issue between stand-alone poweramps and traditional amp heads - most poweramps can be operated in STEREO, whereas most amp heads cannot.

For those of us who prefer a stereo setup, a poweramp makes more sense.

 

[InTheRavensName]

but you need a stereo cab

 

[The Dark Wolf]

but you need a stereo cab

Or 2 cabs.

That goes without saying, but the issue is 'amp head vs. poweramp', and that's something no one covered. It's my motivation.

 

[irg7620]

the preamp is for tone shaping and the poweramp is just for powering the cabinet, but the poweramp can shape the tone a little. ok, now i'm getting it. now, when you twists knobs on a head, does that make changes just to the preamp or to the poweramp also?

 

[budda]

just the preamp, as far as i know. with a tube head, you can get preamp drive and poweramp drive (a la volume knob per channel, with or without gain knob on dirty channel, and master volume), it depends on which you like. where im headed with that is that the EQ of the amp changes depending on which one you turn up.

my only *example* of this is my JSX - if i keep the crunch volume low, and turn up the master volume, then i get louder without much tonal change. i can have the chan. vol on 2 and the master on 8, and it's not overpowering anything. but if i put my master on 2, and my channel on 6... the tone comes to life, i get more gain, and it just gets beastly. i like blending some power amp drive with a fair bit of preamp drive as well, with more pre in there. my EQ settings for low volumes may not work as well for higher volumes, and i find that the EQ is more sensitive when you crank it up.

 

[Bartok]

The 'tube sound' you get when you turn up is saturation. The whole point of a tube amp is the saturation you get in the power stage- the soft clipping of a tube is what gives that big fat tone, it's all about adding 2nd order harmonics. That's why there's not point in buying a honking great 100W amp to use in your bedroom.
The reason the EQ changes at different volume levels is because you have completely shifted the level of harmonics, chances are you'll have far more midrange harmonics going on than at low volume.