Fractal Audio DRIVE models: Using an AMP block as a DRIVE

[yek]

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More and more manufacturers of guitar amplifiers release pedals to the market which capture the character of their amps. Examples: MXR's 5150, Friedman BE-OD, Bogner's Ecstasy and Uberschall pedals.

We can do the same in our virtual Fractal Audio world! We can change AMP models into drives. This expands our arsenal of Drives. And it requires less CPU usage than using a dedicated Drive block.

This approach is especially handy in the Axe-Fx II, because it provides two AMP blocks. AX8 owners can apply this trick when using the AX8 with a real amp.

It's a simple procedure. Turn off power amp modeling in the AMP block by setting SAG to 0 ("p.a. off"), and keep Presence at "5" for a neutral setting. This works in 4CM setups too.

More information about the amplifiers on which these pedals are based:

• 5153 (EVH 5150-III)
• Euro Blue and Red (Bogner Ecstasy)
• Euro Uber (Bogner Uberschall)
• Friedman BE/HBE (Friedman BE-100)

Link to the list of published threads

 

[chucma]

Gosh darn it those things sound good!!! I know what I'm doing later today now, thank you Yek!!!

 

[The Whale]

+1. Wanna read more about how folks are using the XTCs as pedals.

 

[AdmiralB]

Why would you not turn presence to 0 - or remove NFB completely? No power amp means no phase inverter, which is where 99% of designs inject the NFB. Presence is a selective removal of NFB on high frequencies, so no power amp should mean no presence (or resonance/depth).

 

[yek]

When power amp simulation is turned off, Presence changes into a shelving filter where "5" is neutral.

http://forum.fractalaudio.com/axe-fx-ii-discussion/45574-one-thing-always-check.html#post595595

 

[Geezerjohn]

Sounds great. Trying to get past the glasses in vid #2. Dude looks like he has compound eyes.

 

[dr bonkers]

Don't forget @Swedish Chef illustrated this technique a few FW ago when he simulated the tone of a Boss HM-2 Pedal using an Amp block. https://forum.fractalaudio.com/threads/chefs-boss-hm2.91429/

 

[∞Fractals]

I've done this w Bogner and results are as advertised!

 

[The Whale]

Hey Gang - so I fired up a Euro Blue Modern last night as a pedal. The amp I use for live shows is a custom build with basically a Fender twin clean channel. I'm running the Bright Switch on the amp off. I turned the sag to 0 and set all the knobs at noon, using the master volume on the amp block to balance the out the volume overall. The presence for this amp model defaults at 3.5, so I left it there. Overall, I found that 5 was really bright and that 0 was pretty muted. 3.5 isn't just right, but I think i'll find just right. Anybody else using this block with a real amp? How are you setting your amp block?

 

[HarrySound]

Oh wow , great idea!

 

[jlynnb1]

Hey Gang - so I fired up a Euro Blue Modern last night as a pedal. The amp I use for live shows is a custom build with basically a Fender twin clean channel. I'm running the Bright Switch on the amp off. I turned the sag to 0 and set all the knobs at noon, using the master volume on the amp block to balance the out the volume overall. The presence for this amp model defaults at 3.5, so I left it there. Overall, I found that 5 was really bright and that 0 was pretty muted. 3.5 isn't just right, but I think i'll find just right. Anybody else using this block with a real amp? How are you setting your amp block?

i'd put the presence at 5 and use the the tone controls to tame the brightness but hey, if it works....

 

[prometh]

Are you suggesting to use an amp as a drive pedal, feeding into an amp? A preamp-only amp block really uses less CPU than a drive block?

 

[The Whale]

Prometh - yup. The amp blocks have their own chip that they are stored on, thus they don't draw from the space used by the other effects. It's pretty wild.

 

[Rex]

Are you suggesting to use an amp as a drive pedal, feeding into an amp? A preamp-only amp block really uses less CPU than a drive block?

Yes. One of the Axe's processors is dedicated to amp simulation, whether you're running one Amp block or two. There's almost zero hit to your available CPU when you run that second Amp block.

 

[jonny gardiner]

I just tried this tonight. Power Amp Sag to 0. Presence between 3 & 5. This is an awesome use of the Ax8 with an amplifier. I ran my AX8 into the clean channel on my Laney LC50. Even some of the clean amps like the AC30s, the Wrecker & Hiwatt sound great with a bit of tweaking. Im not that happy with the drive pedals so this is a real discover. Thank you.

 

[Rex]

I just tried this tonight. Power Amp Sag to 0. Presence between 3 & 5.

This raises an interesting question: how does Presence keep working with power amp modeling turned off (Sag = 0)?

 

[yek]

Cliff: "If you turn off power amp modeling always check the Presence control. It changes from a "classic" control to a shelving type where 5.00 is neutral."

 

[Rex]

Ah! The human encyclopedia strikes again.

Thanks, yek.

 

[jmcorey]

OK, but where do I find "Sag?" I see Pres, Depth, Tube type, Neg Feedback, Master Volume, Output level.

I assume that Sag is really negative feedback. Turning this to 0 makes the presence turn into a Hi Cut.

 

[Hubertus]

OK, but where do I find "Sag?"

Front Panel: PWR DYN Page, Axe Edit: Power Sply menu

I assume that Sag is really negative feedback.

No.
http://wiki.fractalaudio.com/axefx2/index.php?title=AMP_block#SUPPLY_SAG_.28MAINS_IMPEDANCE.29
http://wiki.fractalaudio.com/axefx2/index.php?title=AMP_block#NEGATIVE_FEEDBACK_.28DAMPING.29