Speaker load changes tone of DI?

[metropolis_4]

I ran into something I didn’t expect. When I run these signal paths:

Amp -> Mic No Mo -> speaker cab

Amp -> Mic No Mo -> Suhr RL

The tone coming out of the Mic No Mo is very different!

I’ve never done this before, I didn’t realize the SIC would have an impact on the tone coming out of a DI run before it. I just expected a change in feel and I thought it might change the tone if the DI was after… Am I right that it’s the SIC causing this?

This is why guitarists believe in Voodoo and Mojo when it comes to gear, there’s definitely some suspicious witchcraft going on here

 

[laxu]

The DI box taps a small portion of the signal going to the speaker, so the speaker influences the behavior of the amp. Yes it's speaker impedance curve.

 

[OrganicZed]

The load on the amp will affect the response of the amplifier. What you observed is exactly what I would have expected.

 

[HotRats]

yes! There's definitely an electrical interaction between the speaker+cab (or any other load) and the amp itself.
Therefore different load systems will give different results.

I am no technician and I can't tell how it works exactly but the difference between playing through a tube power amp and a solid state one is pretty clear in my experience. The difference is tonal and physical and is due (at least partially) to that "real time" interaction.

 

[EOengineer]

This is part of why when I do direct NAM or Tonex captures, I connect a real cab and not a reactive load. I want the authentic response of the amp there.

 

[Boudoir Guitar]

I ran into something I didn’t expect. When I run these signal paths:

Amp -> Mic No Mo -> speaker cab

Amp -> Mic No Mo -> Suhr RL

The tone coming out of the Mic No Mo is very different!

I’ve never done this before, I didn’t realize the SIC would have an impact on the tone coming out of a DI run before it. I just expected a change in feel and I thought it might change the tone if the DI was after… Am I right that it’s the SIC causing this?

This is why guitarists believe in Voodoo and Mojo when it comes to gear, there’s definitely some suspicious witchcraft going on here

Yes, the load impacts the tonal balance. It is not witchcraft and it is very well understood. This is why the speaker impedance curve is in the amp block of the fractal -- because its not something that impacts the sound of the speaker, it is something that impacts the sound (and modeling) of the amp.

 

[Humbug]

This is why guitarists believe in Voodoo and Mojo when it comes to gear, there’s definitely some suspicious witchcraft going on here

No, not witchcraft, just the effect of the load's impedance curve on a valve power amp :-)

 

[Chocol8]

This is due to the low/lower damping factor of most tube amps, and the amount the load matters depends on the amp design, especially the amount of negative feedback in the power section.

The short of it is that the power output of the power tubes varies with the impedance of the load they are going into. The impedance of the load varies by frequency, so the frequency response of the power amp changes with the load attached to the amp. Different load curves will have different frequency response, and that means the signal the amp is sending out and the DI is picking up will be different.

For amps with little or no NFB it can be a pretty big and noticeable difference. For highly damped, high NFB amps, less so.

 

[gearJunkie]

No, not witchcraft,

 

[metropolis_4]

Yes, the load impacts the tonal balance. It is not witchcraft and it is very well understood. This is why the speaker impedance curve is in the amp block of the fractal -- because its not something that impacts the sound of the speaker, it is something that impacts the sound (and modeling) of the amp.

No, not witchcraft, just the effect of the load's impedance curve on a valve power amp :-)

View attachment 45789
View attachment 45790

 

[gearJunkie]

 

[James Freeman]

I didn’t realize the SIC would have an impact on the tone

VOX amps have no poweramp negative feedback, the speaker impedance will change the tone a lot.
@Chocol8 said it all pretty much.

 

[Chocol8]

VOX amps have no poweramp negative feedback, the speaker impedance will change the tone a lot.
@Chocol8 said it all pretty much.

I didn't make the connection that he was using a Vox, but this ^^^^^

 

[metropolis_4]

View attachment 45793

View attachment 45794

Sorry, your post wasn’t deserving of my snark

 

[metropolis_4]

I didn't make the connection that he was using a Vox, but this ^^^^^

Yeah, pretty sure my JRT 9/15 also has no negative feedback. Sounds like that plays a part in why I’m hearing so much difference with both amps

 

[gearJunkie]

Sorry, your post wasn’t deserving of my snark

Of course it was. Snark accepted and appreciated in the true spirit of our TGF community.

 

[PatF]

Doesn't the MicNoMo have analog speaker simulation built in? The various reactive loads do sound a little different mostly in the treble and the Suhr is considered to be one of the better sounding ones.

 

[metropolis_4]

Doesn't the MicNoMo have analog speaker simulation built in? The various reactive loads do sound a little different mostly in the treble and the Suhr is considered to be one of the better sounding ones.

Yeah, it does. I had very low expectations for an analog cab sim after past experiences, but I’ve been impressed with how it sounds in a live mix. Not quite as great as my favorite IRs but significantly more convenient.

I’m finding the Suhr just a little on the scooped side and bass heavy for my taste, but overall I really like it!