Firmware 19.x - Is there a "quick fix" to make FAS amps sound like 18.x?

Marcel

Inspired
I'm going to admit I'm being a little lazy here but I'm hoping someone has a "quick fix" on how to make the 19.x FAS Modern III amps sound like their 18.x versions. This might also be related to the cabinet block but I think the major change in 19.x was the power amp section of the amps. I've got a gig coming up and don't have the time to play with the settings that much. My backup plan is to revert to 18.x but I'd like to give 19.x a shot.

The biggest change I noticed was the EQ - there's a very noticeable tone shift in the low end of 19.x (bass and low mids). I don't want to re-EQ my mixing board so I want to address this on the Axe FX3. I happen to have over 100 presets and luckily have most of the amps on global so I can make a global change quickly.

Once again, I know I'm going about this the wrong way but I just need a quick fix until I can actually spend a couple of days tweaking the settings. I'm aware I can adjust EQ knobs in the amp but I'm hoping someone has a simpler solution that involves a tweak to the tubes or power amp section.

Any help much appreciated...
 
I'd revert back to 18.x until you have time to mess with it. Updating right before a gig is asking for trouble. After the gig you can record some samples and DI tracks from 18.x and then upgrade again and reamp the same DI's using 19.x and compare that way.
Thanks for the suggestion. I’m aware of the risks and will revert back the day of the gig if needed. I have gigs every other week and it’ll probably take me a little while between gigs to figure this out. That’s why I’m asking if someone else has solved it for a short term fix. Similar to the short-term fix for the AX8 firmware update from 7 to 8 several years ago.
 
After updating to 19 and 19.x while in the middle of recording, I too went back to 18. I couldn't find that quick magic parameter either to get the tones back to what 18 sounded like. Not that 19 is bad, it's just a little different that does require some amp and eq changes. When I'm finished with this project I'll update again and go from there, but it does seem it will be a little time consuming. My advice, switch back to 18 until you have the time to re-adjust your patches.
 
I spent a couple of hours tweaking and found a workable solution. Time will tell if it's a permanent solution and I'll only be able to really test it until live rehearsal and then listening to the recordings afterwards. For those interested, here's what I did:

In the Power Amp tab of the FAS Modern III amp I ultimately settled on adding a Master Vol Cap of 65 pF (rounds off to 64.2 pF) after using a wide range of values. That returned the balance of the original tone when I A/B the FW18 and FW19. However, it also added a little more "fizz" than I like so I rolled back the Presence in the Ideal tab a little bit to counter that (from around 7 to about 5). This got me the best of both worlds in a sense. The mids cut through the mix again, chords are ringing out again beautifully in the background but more importantly I seemed to have kept some of the new low "thump" without sounding bassy or interfering with the low mids.

For the record, I've never messed with the Master Vol Cap setting but now I'm going research it. Maybe there's some threads here about using it properly. Regardless, I hope this post help someone in a similar situation. Not sure if it translates to other amp models but I'm very happy with the results.
 
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Personally, I'm not that anal about it. I play what I have.

I know the sounds matter to YOU, but do you really think the audience gives a hoot? Is somebody going to come up to you mid-gig and say "Nice tone, but shit, that bottom end isn't quite the same in v19 as it was in v18..."

And don't forget that your sound on a gig is going to be completely different from what you hear in your home studio when you're setting it up.
Apart from volume levels affecting the sound, the BIG factor is the room acoustics of where the gig is. All your carefully tailored reverb and delay settings go out of the window. Your carefully crafted EQ-ing of the lows and mids changes drastically as the room nodes get triggered, etc.

The point being that most of the subtle and not-so-subtle changes in the firmware versions are great in the studio, but for live gigs, they're ALL really great. Just play the thing! And feel free to tweak the heck out of the tone and volume settings during the gig - just like you would be doing with a real amp!

Awaiting incoming.... ;)
 
I assumed the biggest change from 18.x to 19.x was the new Chase Nonlinear Feedback (CNFB) method. What I hear from 19.x sounds more authentic to me. I doubt that's something that could be easily "tweaked" back.
 
I assumed the biggest change from 18.x to 19.x was the new Chase Nonlinear Feedback (CNFB) method. What I hear from 19.x sounds more authentic to me. I doubt that's something that could be easily "tweaked" back.
I posted a solution above that works for me. Yes, FW19 sounds great but when your studio workflow and live mix are already dialed-in from years of usage any distinct EQ changes are a challenge. This is especially true if you play with zero stage volume and everything goes through the PA.
 
I posted a solution above that works for me. Yes, FW19 sounds great but when your studio workflow and live mix are already dialed-in from years of usage any distinct EQ changes are a challenge. This is especially true if you play with zero stage volume and everything goes through the PA.
But isn't that simply surrendering all control of the sound to the FOH sound engineer? He/She will change it to suit the room acoustics if they're any good anyway. If they think it's a bit light on at the bottom, or too heavy down there, they'll just tweak the heck out of it. They will work with whatever you send them, then do their own thing to it. I seriously doubt the difference between FW18 and FW19 would even be noticed.
 
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Note that those comments re: master bias excursion in the moving backward thread were in regard to getting the 15.01 sound, not 18.x.
 

I was referring to this in 19.01:
https://forum.fractalaudio.com/threads/axe-fx-iii-firmware-19-01-public-beta.180948/

Improved Phase Inverter Bias Excursion accuracy for some amp models (mostly non-MV types). Note: The improved PI Bias Excursion accuracy results in an increase in bias excursion in most cases. Bias excursion primarily manifests as intermodulation distortion, particularly subharmonic distortion. This produces a chunkier tone with more growl and also yields a thicker tone when rolling off the volume or playing lightly. The amount of bias excursion can be adjusted using the PI Bias Excursion control in the Advanced menu.
 
But isn't that simply surrendering all control of the sound to the FOH sound engineer? He/She will change it to suit the room acoustics if they're any good anyway. If they think it's a bit light on at the bottom, or too heavy down there, they'll just tweak the heck out of it. They will work with whatever you send them, then do their own thing to it. I seriously doubt the difference between FW18 and FW19 would even be noticed.
I am the FOH engineer. It’s not like I’m saying “I think it might be noticeable” - it is very noticeable and running an A/B comparison with prerecorded 24 tracks shows that. We go through an X32 console that feeds the PA, monitors, live feed and recording chain. Every channel currently “sits” perfectly in its audio space. This is a byproduct of EQ, stereo spectrum distribution and perception depth (I.e. reverb). FW19 displaces that to a degree that it affects the guitar, bass, kick drum and low toms, so the discussion here is not whether it’s noticeable, it’s looking for a short term solution until I can carve out the right tone to sit in the mix.
 
I was referring to this in 19.01:
https://forum.fractalaudio.com/threads/axe-fx-iii-firmware-19-01-public-beta.180948/

Improved Phase Inverter Bias Excursion accuracy for some amp models (mostly non-MV types). Note: The improved PI Bias Excursion accuracy results in an increase in bias excursion in most cases. Bias excursion primarily manifests as intermodulation distortion, particularly subharmonic distortion. This produces a chunkier tone with more growl and also yields a thicker tone when rolling off the volume or playing lightly. The amount of bias excursion can be adjusted using the PI Bias Excursion control in the Advanced menu.
Thank you for this! It makes a lot of sense regarding what I’m hearing. I’m going to tweak in that area to see if I come up with a different solution. Much appreciated!
 
Makes me wish there was a "tone print" that newer FW's won't change the sound
Unfortunately really possible currently on the Axe as it models the actual amp components and circuitry, not a generic distortion "tone print". Cliff continually tweaks the accuracy of various components or their interactions which is not "backward compatible" or freezable.

However, one can always run the same DI track through two firmwares and do a tone match to the same or similar amp (of EQ only).

Also, IIRC, Cliff had also mentioned a patent that might enable something along the lines of matching an amp.
 
I would say that the biggest change in 19.x vs. 18.x is the clipping behavior of the power amp. The preamp is not changed at all so anything you are hearing is due to the new CNFB power amp stuff.

The power amp clips softer now. This is more accurate, however. If you want a harder power amp clipping, which people that are into aggressive styles may desire, increase the Power Tube Hardness parameter. Or turn the MV down a little.

19.x also introduces an improved feedback algorithm in the power amp. It uses what I call "hybrid feedback" and is a way of replicating analog feedback in a nonlinear discrete-time system. This yields better frequency response accuracy above 10kHz compared to 18.x. 18.x tended to be a little brighter as a result. To get this brighter sound in 19.x increase the Transformer HF value.

For FAS Modern III nothing else has changed from 18.x to 19.x
 
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