Helix preamp-only models, out to amp’s effects return sounds terrible

[boynigel]

I find that I get a better sound using a model of the whole amp, sans speaker modeling, when I go out to any amp’s effects loop.  When I select a preamp model by itself, it sounds dull and lifeless.

 

This doesn’t make sense as I’m putting a (modeled) power amp into a physical power amp.  On paper it should sound worse.  Is there some step I need to be taking when attempting to use a preamp only, out to my amp’s effects return?

 

At the end of the day, I’m more than happy w/what I’m hearing using whole amp models, but I am curious as to how/why the preamp alone sounds crappy in comparison.

[rd2rk]

AFAIK, Helix models the effect of the Speaker Impedance Curve (SIC - google it) in the Power Amp section of the model, as that is where it occurs ITRW.

There's also an interaction between the Pre and Power amp section modeled that obviously wouldn't occur between your digital pre and a separate analog power section. At least that's my take on it.

 

[datacommando]

On 2/12/2026 at 3:35 PM, boynigel said:

but I am curious as to how/why the preamp alone sounds crappy in comparison.

Hi,

 

You might want to treat yourself to the “The Big Book of Helix Tips & Tricks v1.5 2” by @craiganderton, where he discusses using preamps to save on processor power, but adds a section on the downsides of preamping. See page 309.

 

I will not infringe the copyright of the author.

[stapani]

Never owned a tube amp but kinda remember reading somewhere reading preamp used with those.

And whole amp with solid state.

[Schmalle]

What amp do you have and what preamp model do you want to use with it?

Maybe we can figure out how to make it sound awesome ;)