50 watts vs 1000 watts

I run my gt1000fx stereo (a/b) into a pair of 2x12s. Purple blinking front panel indicators means its moving serious air.

Axe out @ 11:00 and Matrix @ 2:30 on the attenuators.

The FRFRs are self powered.
 
This is a very old topic on the Fractal Audio forum, but I think it's good to revisit it for review.

If you're used to 100W of tube power into a 16-ohm cab, then you should probably consider a SS amp that can deliver 500W-600W (bridged) - or more - into 8 ohms. The reasons for this are two-fold.

First, with SS power, you'll definitely want lots of clean headroom. To match a tube power amp, a rule of thumb is "Five times the tube wattage, for solid-state." This is not because tube amp watts are any 'louder' than solid state watts -- a watt is a watt, no matter where it comes from. It's more because, when overdriven, tube power amps ease into a musical type of harmonic distortion, whereas solid-state amps exhibit nasty-sounding distortion when they are overdriven. Five times the power ensures that the solid state amplifier has plenty of headroom to handle musical peaks, without ever going into overdriven states or producing any nasty distortions. Tons of SS power will give you the air-moving THUMP that you're used to feeling.

Second, most SS amps are power-rated into 8-ohm loads. Now, you can certainly drive a 16-ohm cab with a SS amp that's rated at 8-ohm, because most SS amps have no output transformers that require impedance matching. However, if you double the load impedance (using a 16-ohm cab instead of an 8-ohm cab), this will roughly halve the amp's effective output power.

So - If you're used to the volume levels of 100W of tube power into a 16-ohm cab, then look for a SS power amp that can deliver 500W - 600W (bridged) into 8 ohms. The good news is that powerful SS amps of this size are generally both much lighter (and less expensive!) than comparable tube-powered amplifiers.
 
Budda said:
Still posting there too lol.

I dont mean return on fractal though, I mean return on a power amp.

You wont get stereo from your single evh cab either, you'd need a second cab (which works better for stereo spread, space them out).

With a traditional tube amp, the headroom affects how its going to sound. With a modeller, you're going to be getting that headroom feel from the device so you just want to make sure the power amp delivers the volume for your application. A 5w amp with a 412 rattles windows. 100w plus of clean power and you're probably fine. Speaker effiency matters too.

There's tons of power amp threads in the amp section here.
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Hooo boy. Lots of replies so I'll start with Budda's.

Power amp: I'm sure Matrix have a pretty good returns policy. Will double check.

Cabs: yep that's why I said I wanted to run 2 quads. Rectifier 4x12's are rated 240 watts RMS so if the Matrix pushes 150w into each cab @ 16 Ohms that should be fine, right? Hope I have that right lol.

Headroom: okay good to know. Didn't know that. So I could run a MESA 2/90 or something? So that begs the question: why do guys run GT1000's instead of traditional rack power amps?

Thanks.
 
lauke-lux said:
2 years ago I played over a 20kW PA on a stage in a towncenter....it's absolutely amazing and what a kick to feel all that 'air'moving and reverberating back from the building faces....to have so much power (1kW) just in a band, bar or at home seems a bit overkill IMHO.
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I'm trying to get to the bottom of why the practice seems to be common. Why would crabcore dudes power their Fractal Ultras with GT1000's (we're talking back in 2013) instead of a Marshall or MESA power amp? . I'm referring to a particular video I watched and his hi-gain tone was unreal. Sh*t was so brutal it was like someone had to die every time he hit a chord haha.
 
Budda said:
You could have a 1M wattage power amp - you'd still set it for the volume you want.
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This seems to be a crux of it. It's not that people use these Matrix power amps for how loud they go but how cleanly they power your Fractal. Maybe I'm getting it wrong. Having said that, knowing that you could blow up a cabinet if your niece turned some knobs while you weren't looking is terrifying.
 
∞Fractals said:
I run my gt1000fx stereo (a/b) into a pair of 2x12s. Purple blinking front panel indicators means its moving serious air.

Axe out @ 11:00 and Matrix @ 2:30 on the attenuators.

The FRFRs are self powered.
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So you'd recommend that particular unit for someone like me who wants to run two 4x12's?
 
xrist04 said:
If you're used to 100W of tube power into a 16-ohm cab, then you should probably consider a SS amp that can deliver 500W-600W (bridged) - or more - into 8 ohms. The reasons for this are two-fold.
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Agree completely with this, and will add a third good reason to. I was for many years a 100W tube head and 4x12 user much of the time. When I went for SS modelling I understood, as Xrist04 does, that I was often driving amps way past the 100W that they are rated at for cleanly reproducing a sine wave. Tube amps sound good run like that, but for a SS amp to reproduce the same clipped waveform you need some headroom in power handling. Unless you are expecting to run at any higher volume than you do with your cab(s) with a tube amp, you won't hurt your speakers. They only see volts and amps that produce a sound pressure level, and they don't care much whether they came from a tube amp or SS.

The third good reason for going a little high with power capacity is in case you ever want to use with a big FRFR cabinet. I use a 3 speaker 15" Fearless FRFR cab. It is great, but has a relatively inefficient passive crossover, and it can reproduce the sound of a 4x12 driven by a cranked 100W tube head at loud stage volumes, but is probably using 500W of SS power to do so.

I use a Matrix GT1000 for this, and I am really happy with it.

Liam
 
LiamH said:
Agree completely with this, and will add a third good reason to. I was for many years a 100W tube head and 4x12 user much of the time. When I went for SS modelling I understood, as Xrist04 does, that I was often driving amps way past the 100W that they are rated at for cleanly reproducing a sine wave. Tube amps sound good run like that, but for a SS amp to reproduce the same clipped waveform you need some headroom in power handling. Unless you are expecting to run at any higher volume than you do with your cab(s) with a tube amp, you won't hurt your speakers. They only see volts and amps that produce a sound pressure level, and they don't care much whether they came from a tube amp or SS.

The third good reason for going a little high with power capacity is in case you ever want to use with a big FRFR cabinet. I use a 3 speaker 15" Fearless FRFR cab. It is great, but has a relatively inefficient passive crossover, and it can reproduce the sound of a 4x12 driven by a cranked 100W tube head at loud stage volumes, but is probably using 500W of SS power to do so.

I use a Matrix GT1000 for this, and I am really happy with it.

Liam
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Awesome thanks for posting up. The GT1000 is pretty inexpensive so it seems like it wouldn't do any harm me getting that 2U one (since it's the same price as the 1U). I'm in New Zealand so trying this kind of gear out before I buy isn't really feasible, so most of the time I'm just getting feedback from owners of things I'm interested in.
 
Sorenspete said:
I'm trying to get to the bottom of why the practice seems to be common. Why would crabcore dudes power their Fractal Ultras with GT1000's (we're talking back in 2013) instead of a Marshall or MESA power amp? . I'm referring to a particular video I watched and his hi-gain tone was unreal. Sh*t was so brutal it was like someone had to die every time he hit a chord haha.
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Part of the point of going digital is to reduce weight and size. Adding a 2u or 3u 30lb+ power amp to your rack doesnt help reduce weight or space lol.
 
Budda said:
Part of the point of going digital is to reduce weight and size. Adding a 2u or 3u 30lb+ power amp to your rack doesnt help reduce weight or space lol.
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Makes sense. I'm building a home studio rig for my own leisure, so weight isn't a bit deal at the moment. Later on down the line I'll probably invest in some more live-friendly sound solutions. I just want to build something that sounds massive and in stereo.
 
Budda said:
Part of the point of going digital is to reduce weight and size. Adding a 2u or 3u 30lb+ power amp to your rack doesnt help reduce weight or space lol.
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This is why I play over the sound system in rehearsal and with a CLR or floor monitor for stage backup....if not it just make no sense; totally agree with that.
 
Sorenspete said:
I'm trying to get to the bottom of why the practice seems to be common. Why would crabcore dudes power their Fractal Ultras with GT1000's (we're talking back in 2013) instead of a Marshall or MESA power amp?
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Worth remembering that a lot of the tonal advantage of Fractal is in the simulation of the power stage of a tube amp. Putting another tube power stage designed for guitar amplification after this is an unnecessary limitation, as the aim needs to be to amplify the signal from the Axe FX to the speakers as faithfully as possible, and without colouring the signal or introducing artefacts from output transformer interaction with the speaker. You could do it with a big (maybe 500W) high fidelity tube amp, but it would be big, heavy, expensive, consume a lot of power, loads of issues... If you do it with a Marshall tube guitar power amp, every model you try will sound a bit "Marshally"... Same for any other guitar power amp manufacturer.

Going with the GT1000FX means that you can get the sound of a Marshall or Mesa power stage, and flick between them, swap the tubes in them (in virtual world), adjust the bias, play with transformer matching, all kinds of tricks. If you ever do go FRFR you can go a bit further, and simulate cabs as well. I still find it mind blowing that I can have 4x12 Marshall tone, then flick to an open back like a Twin Reverb, and if I really feel like it then change to a Champ or a Princeton, and they can be louder and cleaner than any of the big amps if I want.

I've got the GT1000FX 2U version. It's light! I have only really used it for rehearsals and gigs, but I seem to recall someone saying the fan was noisy for studio use compared to the 1U version. Just finishing a home studio build, and can happily say if that turns out to be true, I'll happily buy another. I think they are great.

Liam
 
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LiamH said:
Worth remembering that a lot of the tonal advantage of Fractal is in the simulation of the power stage of a tube amp. Putting another tube power stage designed for guitar amplification after this is an unnecessary limitation, as the aim needs to be to amplify the signal from the Axe FX to the speakers as faithfully as possible, and without colouring the signal or introducing artefacts from output transformer interaction with the speaker. You could do it with a big (maybe 500W) high fidelity tube amp, but it would be big, heavy, expensive, consume a lot of power, loads of issues... If you do it with a Marshall tube guitar power amp, every model you try will sound a bit "Marshally"... Same for any other guitar power amp.

Going with the GT1000FX means that you can get the sound of a Marshall or Mesa power stage, and flick between them, swap the tubes in them (in virtual world), adjust the bias, play with transformer matching, all kinds of tricks. If you ever do go FRFR you can go a bit further, and simulate cabs as well. I still find it mind blowing that I can have 4x12 Marshall tone, then flick to an open back like a Twin Reverb, and if I really feel like it then change to a Champ or a Princeton, and they can be louder and cleaner than any of the big amps if I want.

I've got the GT1000FX 2U version. It's light! I have only really used it for rehearsals and gigs, but I seem to recall someone saying the fan was noisy for studio use compared to the 1U version. Just finishing a home studio build, and can happily say if that turns out to be true, I'll happily buy another. I think they are great.

Liam
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Thanks bro you've sold me on it!
 
LiamH said:
I've got the GT1000FX 2U version. It's light! I have only really used it for rehearsals and gigs, but I seem to recall someone saying the fan was noisy for studio use compared to the 1U version. Just finishing a home studio build, and can happily say if that turns out to be true, I'll happily buy another. I think they are great.
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I believe it's the other way around - the 2U is sold as the 'quiet' version.
 
∞Fractals said:
I’d up the power ... call Matrix. Perhaps the GT1600fx
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I don't think you could need more. For a mono rig, run 2 16 ohm cabs in parallel in bridge mode, and you've got 1000 watts into 8 ohms. If you want to run stereo, rewire the cabs to 4 ohm (all speakers in parallel, make sure you keep the phase the same) and you have 500 watts a side. In both cases you will not feel the need to max out the Matrix, but should avoid it anyway as it's more than the speakers will handle.

Liam
 
LiamH said:
I don't think you could need more. For a mono rig, run 2 16 ohm cabs in parallel in bridge mode, and you've got 1000 watts into 8 ohms. If you want to run stereo, rewire the cabs to 4 ohm (all speakers in parallel, make sure you keep the phase the same) and you have 500 watts a side. In both cases you will not feel the need to max out the Matrix, but should avoid it anyway as it's more than the speakers will handle.

Liam
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I’m always stereo thru my cabs. I don’t use the bridge. But you make good points. (I would still likely recommend the GT1600FX)
 
Had a guy years ago at Circuit City (remember that place?) trying to sell me on some ghetto blaster 5000 watt power amp to go with a little pair of 10" subs I was having installed in my car (I was lazy at the time and didn't want to do the wiring myself). He was trying to convince me that it's bad to "underpower" speakers with a small amp. I just laughed and kindly pointed out that is exactly what happens every time you turn the volume down on your stereo. Poor guy seemed confused like I had just uprooted his entire understanding of how amplifiers work. No fat commission for you today bud...
 
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