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Axe-Fx III Firmware Version 5.02

mglemley

Member
Possible bug: Global Block 5 (which I use for drives, amps, and cabs) got messed up after FW 5.00. Worked fine on FW 5 beta.

Other Global Blocks (ie 4) are unaffected.
 
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lp59

Experienced
Played my first gig tonight In a while, on fw 5.

Used the Seymour Duncan PS-170 and my Port City 2x12.

Couldn’t be happier, the sound was fantastic with the improved amp and drive modeling.

I’ve also returned to the trusted Euro Blue models, which sound awesome, cut better than the Friedmans and have that Bogner “growl”.
Do you use your amp and cab in mono or stereo ?
 
I haven’t yet but I did reload all presets from laptop after 5.02 upgrade.
I did verify that the Output EQ is on but the tone is as I reported it earlier. Interestingly, when I tested Austin Buddy’s More Mark IIC++preset with the IIC++ Lead w/Delay scene not only did it sound the same... overly bright with no bottom... it had no delay. When I checked, the delay block was bypassed. When I enabled the delay block there was still no delay. Very Odd.

Again, this was on a preset I reloaded after the firmware update. Something is off. Whether it is just my unit I don’t know. Perhaps someone might be so kind as to check out their unit if they have AB’s Naked Amps pack on F/W 5.02?
 

ElectricPhase

Power User
Perhaps someone might be so kind as to check out their unit if they have AB’s Naked Amps pack on F/W 5.02?

Sure. Preset 'More Mark IIC++', Scene 4 'II C++ Lead w/delay', reloaded from the source files after the 5.02 firmware update. Sounds correct (and really amazing). Delay is not bypassed and sounds correct. Whatever is going on, it's neither the preset nor the firmware.
 
Sure. Preset 'More Mark IIC++', Scene 4 'II C++ Lead w/delay', reloaded from the source files after the 5.02 firmware update. Sounds correct (and really amazing). Delay is not bypassed and sounds correct. Whatever is going on, it's neither the preset nor the firmware.
Thanks very much for this! ;)

I will attempt to reload the preset from source files again and report my results.
 

FractalAudio

Administrator
Fractal Audio Systems
Moderator
I did verify that the Output EQ is on but the tone is as I reported it earlier. Interestingly, when I tested Austin Buddy’s More Mark IIC++preset with the IIC++ Lead w/Delay scene not only did it sound the same... overly bright with no bottom... it had no delay. When I checked, the delay block was bypassed. When I enabled the delay block there was still no delay. Very Odd.

Again, this was on a preset I reloaded after the firmware update. Something is off. Whether it is just my unit I don’t know. Perhaps someone might be so kind as to check out their unit if they have AB’s Naked Amps pack on F/W 5.02?
That's the classic symptom of phase cancellation due to summing to mono.
 
Sure. Preset 'More Mark IIC++', Scene 4 'II C++ Lead w/delay', reloaded from the source files after the 5.02 firmware update. Sounds correct (and really amazing). Delay is not bypassed and sounds correct. Whatever is going on, it's neither the preset nor the firmware.
Thanks again for verifying this and giving me an additional data point.

I think I may have discovered what the source of the issue is. My unit is set up to use output 1 to a Tascam 24SD multitrack unit. Output 2 is setup to copy Output 1 and goes to my Yamaha monitors. This has worked great in the past. While looking at the layout of this preset I noticed it had links to Output 2 and Output 3 that I freely admit I don’t know what they are intended for. But when I hooked up my headphones to the headphone jack (Output 1) the depth and delay was there in spades. So I suppose that my particular integration conflicts with AB’s preset and results in less than stellar output. I don’t fault AB or the unit, just me not expecting what I stumbled on.

Apparently a learning scenario I will benefit from ultimately. :)
 

yek

Moderator
Moderator
Output 2 is setup to copy Output 1 and goes to my Yamaha monitors. This has worked great in the past. While looking at the layout of this preset I noticed it had links to Output 2 and Output 3 that I freely admit I don’t know what they are intended for.
"Output 2 is setup to copy Output 1"

This doesn't work if the preset also contains an Output 2 block. See page 53 of the manual.

Advice: keep your presets as simple as possible. If you don't know what purpose some blocks serve, inform yourself or delete them and see what happens.
 

Marco Fanton

Power User
The real amp actually is worse than the model. I toned it down a bit because it's too excessive IMO.
I read the answer without looking at the previous tread...
I was discussing in the group "Digital Amp Italia" about the latest Fractal updates ... the simulated model of the real amplifier sounds better ....
More and more people are getting used to adequate listening, with FRFR systems, Nearfield monitors, In ear etc.
obtaining the same quality of digital with a traditional system requires time, knowledge, resources and instrumentation that are not easy to obtain
 

FractalAudio

Administrator
Fractal Audio Systems
Moderator
AC-30's have a poorly designed cathode follower. The bias point is totally wrong and crushes one side of the signal considerably. IMO either the cathode resistor should be 100K or the plate resistor of the preceding stage should be higher, 200K. The clipping is extremely asymmetric. Too much IMO. A little asymmetry is good because it warms things up. Too much causes excessive even-order harmonics which makes things fuzzy and indistinct. The clipping is so asymmetric on an AC-30 that it's almost a half-wave rectifier.

You can tweak this by adjusting the Preamp Bias point and/or lowering the Cathode Follower Compression. Or you can lower the Harmonics value which reduces the asymmetric distortion. The downside of that is that it then overdrives the phase inverter causing blocking distortion from excessive bias excursion. Another thing to try is to increase the Grid Clipping value which will add a little headroom. Start with the Bias point. AC-30's are very sensitive to the tube type and part tolerances. A tiny change in the bias point can make a big difference. The default bias point is based on Mullard ECC83 tubes.

I prefer the AC-20 because it doesn't have a cathode follower so doesn't suffer from these problems. The cathode follower in an AC-30 doesn't even do all that much. Normally you use a cathode follower to preset a low-impedance source to the tone stack but the tone stack in an AC-30 doesn't present that great of a load anyways.
 

Toopy14

Fractal Fanatic
IMO either the cathode resistor should be 100K or the plate resistor of the preceding stage should be higher, 200K.
Out of curiosity, I'm looking over the specs. of the mods. made to my AC30CC2 to compare. Do you know off-hand what the resistor designations are, of the resistors you're referring to?

These are the two of the resistors that were changed on my amp.;

"R6 and R7 are the plate resistors for V1 (Top Boost and Normal channels). In the Custom Classic they are 100K resistors. Change these to 220K resistors."

Here's a summary of some of the mods. that were done to my CC2, to make it sounds more like a 60's JMI AC30.

https://www.mylespaul.com/threads/vox-ac30-custom-classic-common-issues.127243/
 

Disconnector

Inspired
AC-30's have a poorly designed cathode follower. The bias point is totally wrong and crushes one side of the signal considerably. IMO either the cathode resistor should be 100K or the plate resistor of the preceding stage should be higher, 200K. The clipping is extremely asymmetric. Too much IMO. A little asymmetry is good because it warms things up. Too much causes excessive even-order harmonics which makes things fuzzy and indistinct. The clipping is so asymmetric on an AC-30 that it's almost a half-wave rectifier.

You can tweak this by adjusting the Preamp Bias point and/or lowering the Cathode Follower Compression. Or you can lower the Harmonics value which reduces the asymmetric distortion. The downside of that is that it then overdrives the phase inverter causing blocking distortion from excessive bias excursion. Another thing to try is to increase the Grid Clipping value which will add a little headroom. Start with the Bias point. AC-30's are very sensitive to the tube type and part tolerances. A tiny change in the bias point can make a big difference. The default bias point is based on Mullard ECC83 tubes.

I prefer the AC-20 because it doesn't have a cathode follower so doesn't suffer from these problems. The cathode follower in an AC-30 doesn't even do all that much. Normally you use a cathode follower to preset a low-impedance source to the tone stack but the tone stack in an AC-30 doesn't present that great of a load anyways.
Fantastic info Cliff. Thank you sir!
 
Anybody else noticing strange behavior using S/PDIF output?

Had audio cut out for a second a couple of different times.
The Silver Jubilee patch I've been playing lately seems significantly thinner.
Went into the Axe's I/O setting and switched the AES/SPDIF option to AES and back to S/PDIF.
After doing so, the output level of the S/PDIF output seemed hotter.
I'm not overloading via the Axe-FX meters, but the S/PDIF output is clipping the S/PDIF input of an Antelope Zen Tour.
This wasn't happening until I switched the AES/SPDIF option from AES and back to S/PDIF.

I don't recall any of this with the beta versions.

Loading v4.03 to compare...
 

Jason Scott

Power User
Anybody else noticing strange behavior using S/PDIF output?

Had audio cut out for a second a couple of different times.
The Silver Jubilee patch I've been playing lately seems significantly thinner.
Went into the Axe's I/O setting and switched the AES/SPDIF option to AES and back to S/PDIF.
After doing so, the output level of the S/PDIF output seemed hotter.
I'm not overloading via the Axe-FX meters, but the S/PDIF output is clipping the S/PDIF input of an Antelope Zen Tour.
This wasn't happening until I switched the AES/SPDIF option from AES and back to S/PDIF.

I don't recall any of this with the beta versions.

Loading v4.03 to compare...
The operative word in your post is "seems". Unless you compare samples of different firmware versions, it's easy to fool yourself into thinking you hear a difference. If you want to know whether there's an actual difference, compare a reamped DI sample using the current firmware and 4.03.
 
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