Tube power amp sounds better than solid state power amp for modelers

[EOengineer]

I set up my Helix -> BAM200 -> guitar cab today to do a reality check. I modified my silent rehearsal presets to use send 1 tapped before the cab impulse out to the BAM. I forgot how much fun this is with current gen modeling.

Once the volume starts getting up there, this really does kick ass. I found the most realistic results had me pulling down the master and sag parameters - it makes a huge difference in feel as you start getting loud.

I’m playing around with keeping the amp master down around where I’d set it on the amp if it was in the room with me, and then approximating that real volume with the BAM. I THINK I’m finding that the accuracy is pretty incredible if you set the model master to correspond with where you’d expect to set the amp in the playing environment you are using it in and then using the class D amp to get as near that volume as possible. The cab and speaker play an important part in this equation…they need the right volume too.

 

[Tritium3H]

Two pointless questions in life:

1. Does God exist?
2. Why does modelling exist, when we have tube amps?

The second question may veer towards pointless. Respectfully, the first question is quite the opposite...given that it has infinite import and consequence. Ipsum Esse Subsistens, and all that.

 

[Bob Zaod]

Today I was messing around and set up my MX5 in a wet/dry config with the "FRFR"/PA handling the wet (Cathedral reverb on the mixer) and SpiderValve dry, and it was lovely to say the least once I got the 2 mixed right. I never bothered doing such a thing, so I could just be enamored with the different way it sounds but HO-LI-FOOK it's good.

 

[Achilles]

Seems to emphasize that being smart with Hi and Lo Cuts is important with guitar tones, period.
Whether it is done via amp and speaker, or at FOH, or in the modeler......

Or in your amp's effects loop!

 

[Antipodes]

Unless you have access to the schematics of each design, how can you be sure you are comparing tube vs solid state design or simply 2 different circuits?

My thoughts also. In a tube power amp, coupling caps can be chosen to give you bass extension down to 20 Hz and below or, by choosing a smaller value for the capacitor, you can get 100 Hz as the bass rolloff point. This is just simple RC filters in operation. So the particular rolloff point observed in this test is not something that can be generalised across tube power amps.

 

[timbuck3]

 

[dronerstone]

I'll have to do some blind tests.

When I play my Helix or my (all-analog) Exegol preamp through the power-amp return of my Katana, they sound really good.

But when I plug them into the power amp return of my Fender 1994 Twin Amp or even the (padded) input of my VT-22 (all knobs @ noon and ultra-hi switched off = "flat"), a certain "magic" happens that I can't really understand.

It seems like there's something added to the sound, very probably has to do with the overall response. Not too different from the Katana and might go unnoticed in a live setting, but it's there.

I hate to say it, but the feel is different.

 

[mavrick102000]

The feel is definitely different after you try to pick up an move that VT-22. - I think it's called a hernia.

 

[dronerstone]

The feel is definitely different after you try to pick up an move that VT-22. - I think it's called a hernia.

It's resting on top of a 15" LAB Series cab at the moment. I don't know how I did that, but I'm sure it hurt.

 

[fuyume]

At this point I compared the Blackstar against the Katana and still preferred the tube amp. I tweaked the EQ by ear and that got me to a better place, with a little more low end and a little less highs.

What you are missing here is the fact that the "magic" of a tube amp can't necessarily be properly measured by a mere frequency response curve, because you lack any sort of phase relationship data.

The "magic" of a tube amp is the interaction between the tube(s), the output transformer, and the loudspeaker driver(s). It's not the tubes, it's the whole circuit topology, and the complex interactions of the relative and characteristic impedances that are inherent in the fact of a high output impedance source being transformer coupled to a very low impedance transducer.

This article will help explain why.

“House of Fire”: Firebottles And Groove Tubes Versus Devices That Find Their Origins in Sand (Part 1)

Why do Tube Amps and Solid-State Amps Sound Different?

www.electronicdesign.com

Tubes Versus Solid-State Audio Amps—The Last Word (Or “House Of Fire,” Part 2)

In the debate over tube amps vs. solid-state amps, Part 1 discussed the differences in applications. Part 2 concentrates on the difference between transistors—MOSFETs and bipolar...

www.electronicdesign.com

I was doing some testing with some new overdrive pedals some years ago, and running them into my Ampeg VH-140C combo amp (solid-state). Everything just sounded somehow a little "two-dimensional". Like, it sounded good, but like some indefinable thing was missing. And then I plugged the exact same signal chain into my Mesa/Boogie F-50 (tubes), and everything was suddenly *three-dimensional*. Like, it just somehow *came alive*.

Solid-state amplifiers definitely have their place, and they are very "accurate", but that's all they will ever be. Tube amps aren't accurate, but that's why we love them for making music.

As has been famously said, to paraphrase, if you can't measure it, and you can't hear it, it doesn't exist; if you can't measure it, but you can hear it, you're measuring the wrong thing.