Fractal Audio Systems AM4 - Amp Modeler

[Eagle]

Does the cheap hardware cause the sound to be in any way different to the Axe 3? Basically any compromise in the components in the audio chain resulting in audible differences of the same model running on Axe?

 

[jellodog]

Does the cheap hardware cause the sound to be in any way different to the Axe 3? Basically any compromise in the components in the audio chain resulting in audible differences of the same model running on Axe?

LOL "cheap". AM4 really isn't some sort of "lesser" hardware. There's just less of it!

It sounds great.

I sold my AF3 and actually prefer the AM4; so there's your answer

 

[SillyOctpuss]

Does the cheap hardware cause the sound to be in any way different to the Axe 3? Basically any compromise in the components in the audio chain resulting in audible differences of the same model running on Axe?

I think I read somewhere that Cliff said the audio path was the same.

 

[Eagle]

I think I read somewhere that Cliff said the audio path was the same.

That’s what I wanted to know thanks . There are a lot of examples of same design but different hardware makes the same on paper audio path sound different. This is what makes some old rack units sound so good even though the spec is that of a POS.

 

[SillyOctpuss]

That’s what I wanted to know thanks . There are a lot of examples of same design but different hardware makes the same on paper audio path sound different. This is what makes some old rack units sound so good even though the spec is that of a POS.

Don't quote me but I'm pretty sure he said the audio path was the same.

 

[FuzzyAce]

Don't quote me

 

[SillyOctpuss]

 

[GTR37]

Does the cheap hardware cause the sound to be in any way different to the Axe 3? Basically any compromise in the components in the audio chain resulting in audible differences of the same model running on Axe?

Everyone’s ears are different but I like it better than the FM9 maybe because it doing much less
Placebo who knows but it sounds better to me with a lower noise floor

 

[dbfretz]

Everyone’s ears are different but I like it better than the FM9 maybe because it doing much less
Placebo who knows but it sounds better to me with a lower noise floor

Very unlikely I would say.

 

[GTR37]

Very unlikely I would say.

I have had both , AM4 stayed

 

[AlbertA]

Does the cheap hardware cause the sound to be in any way different to the Axe 3? Basically any compromise in the components in the audio chain resulting in audible differences of the same model running on Axe?

I have some gut shots and components here:

Post in thread 'Fractal Audio Systems AM4 - Amp Modeler'

Dec 8, 2025

TL; DR

• TI SoC - 66AK2G12ABY100 KeyStone II Multicore
  
  • 1 Arm Cortex-A15 @1GHz
  • 1 C66x DSP @1GHz
• 512 MB DDR3 RAM
• 64 MB + 48MB NOR Flash
• Cirrus Logic CS4272-CZZ Codec - A/D + DAC

Gut shots




TI SoC - 66AK2G12ABY100 KeyStone II Multicore

• 1 Arm Cortex-A15 @1GHz
• 1 C66x DSP @1GHz

512 MB DDR RAM - 2 Micron MT41K128M16JT-125:K


64 MB NOR Flash - 2...

• AlbertA

• 
• 
• 

I forget what the III uses but you should be able to compare

 

[Karl Houseknecht]

Everyone’s ears are different but I like it better than the FM9 maybe because it doing much less

I have had both , AM4 stayed

When you say because it's doing less, is it because you need less?

I can imagine if all you need are maybe a drive (maybe), amp/cab, delay, reverb then the AM4 makes sense. If you also have an existing pedalboard setup and want to add amp modeling and potentially get rid of a couple other pedals, that also makes sense. In those cases it comes down to preferred form factor.

But I don't see how the AM4 would sound better than an FM unit. I'd expect it to sound the same or possibly be slightly lower audio quality but that all depends on what the signal path and components like converters are. If they're the same as in the FM units, then it should sound at least as good.

 

[synthpenguin]

I know the reverb doesn't have a dedicated core like with the FM9 I'm used to, but I noticed in a lot of videos for the AM4 people are still running the reverb quality at Ultra High even with delays etc. At the same time, I've seen people in forums talking about having to take the reverb quality down to economy.

Is running reverb at High or Ultra High really realistic with a chain like, say, chorus + Amp (+Dynacabs) + Dual Delay + reverb?

 

[GTR37]

I know the reverb doesn't have a dedicated core like with the FM9 I'm used to, but I noticed in a lot of videos for the AM4 people are still running the reverb quality at Ultra High even with delays etc. At the same time, I've seen people in forums talking about having to take the reverb quality down to economy.

Is running reverb at High or Ultra High really realistic with a chain like, say, chorus + Amp (+Dynacabs) + Dual Delay + reverb?

Maybe it really depends what the other 4 blocks are
If you run a jumped plexi w dual cabs and the cab preamp on high quality , plus an echo/ hall ultra quality full density you may run into trouble

 

[synthpenguin]

Maybe it really depends what the other 4 blocks are
If you run a jumped plexi w dual cabs and the cab preamp on high quality , plus an echo/ hall ultra quality full density you may run into trouble

Thanks!

Sounds like it would be fine for me within reason.

My reverb needs are simple, I usually just want a nice quality room, plate, or spring, or occasionally an 80s digital hall, and I guess on the AM4 I'd use the echo reverbs more often.

I imagine that most of my patches would be Amp (with Dynacabs) and Reverb, and then some combo of Delay, Tremolo, Chorus, Phaser and/or Compressor blocks. That's more or less what I do on the FM9, albeit often with stacked delays and with some extra bonuses thrown in.

I lean towards the Fender, Dumble, and Vox style amps. And I almost never touch the cab preamp section tbh.

I'm beginning to think that an AM4 + some sort of MIDI-controllable dual / multitap delay might be the best setup for me. As much as the QC Mini is still very enticing (and the Stadium again with Proxy out).

 

[laxu]

Maybe it really depends what the other 4 blocks are
If you run a jumped plexi w dual cabs and the cab preamp on high quality , plus an echo/ hall ultra quality full density you may run into trouble

I tried to see if I could hit that scenario. You need to go over 90% CPU usage.

It required dual drive blocks, Plexi 100 Jumped amp model, delay, and one of the SFX reverb types set to Ultra-High quality. Basically picking the most demanding blocks for everything. Just dropping the reverb quality to High prevented it from muting the preset.

 

[James Freeman]

I want to buy the AM4 since I'm mostly using just an amp block in the AxeFx.
One thing though, I really need a PEQ at the output without wasting one slot out of four in all the presets.
I've posted a request on the forum, hopefully there will be a solution.

 

[maddnotez]

Starting to love this thing. Finally dove into expert edit and holy shit. The power section especially wow. Im sure this is old news to everyone else but I now see the genius that Cliff is.

I cannot believe all the options to surgically tune your sound.

The only con ive found so far is that some of the parameters, once moved cannot return to their original state which is pretty lame. It isn't bad enough to where it makes a difference but to my OCD this is an issue.

For example the screen frequency in the IIC++ defaults at 14. After adjusting up and down to play it will not go back to 14. It's either 14.1 or 13.95.

Again, not even an audible difference but there is a difference.

Anyway, this thing is pretty dope. Now here is to hoping my headphones translate to the real world.

 

[FuzzyAce]

For example the screen frequency in the IIC++ defaults at 14. After adjusting up and down to play it will not go back to 14. It's either 14.1 or 13.95.

I don't have the app in front of me, but can you not click on it and manually type in a number like 14?

 

[EOengineer]

For example the screen frequency in the IIC++ defaults at 14. After adjusting up and down to play it will not go back to 14. It's either 14.1 or 13.9.

That picks at my own OCD as well.

The IIC+ and pretty much all the Mark series models are so good in that thing.