The Damp-Factor...

TotalRockstar666

TotalRockstar666

Member
Hi Guys...I've stumbled across something and I'm not sure what it means!

I run Axe Fx Standard -> Art SLA2 -> Mesa Traditional Recto 4x12

I have been having great difficulty getting my setup to sound acceptable. NOBODY's patches seem to sound any good through my rig. Always too light, lacking balls, and 'blanketed' to the max. I've had the Axe for many years now, and have not got access to another amp to compare. I do however know what an amp should and shouldn't do, and have (before the Axe) much experience with all things Mesa.

I was flicking through the high gain amp models, the only one that sounded acceptable off the bat was the Recto Red, which got me wondering why this amp was so special.... It's the only high gain amp with a Damp setting of zero as default.

Naturally I then reduced the Damp value to zero on the Mark IV (USA LEAD 1) patch I am trying to create (that's all I want!! And awesome Mark sound!!) and Ta Dah! Something closer to being balanced sonically like the amp. I then did this to all amps sims and they sounded substantially closer to how I remember them!

Now, Damp is supposed to be something to do with negative feedback right? Which made me think, have I switched something I shouldn't have globally to make the Axe sound like poop, like a phase thing? Or have I simply wired up the SLA2 backwards?! Or worse?

I know the Art isn't the best power amp for the job, but my rig currently doesn't even sound remotely like what it should. As a side note, things seem okay-ish when running into ProTools with a Cab added.

Please someone in the know help!

Kind Regards,
Jim.
 
It isn't particular to any patch, it's across the board. Imagine a reverse smiley eq curve, every patch regardless of setting.

I currently use a Mesa Graphic-esque EQ with the PEQ block on all patches to get them sounding 'natural'/like the real life amp. The lows and high boosted by 8.88db and the mids dropped by 12db! Sounds extreme, but it really does need that to get close.

I'm confident it's not my dialling of patches as there's not a eq combo I haven't tried, and in all honesty, I don't think it should be a case of one 'magic' setting for each amp etc. My complaint is the amps dont remotely come close because of some peculiar blanketed muffle effect inherent in every patch.
 
I've just read my post, and I'd just like to clarify that I'm not Axe Fx-bashing. It really is the best thing since sliced bread! I just need to get it working for me. I sold an extensive Mesa and Eventide refrigerator rack for this baby and I know what I want to hear, i know it can do it, as everyone else seems to be getting it! I just have yet to work out how to get there.
 
Ok, I don't know how my patch will sound with your guitars and cab but here we go :

DAS METALL - drive 0 ; boost on ; bass 8db ; mid 1.5db ; treb 12db ; bright on ; presence 10 ; master 10 (you may love it or hate it) ; depth 10 ; damp 10 ; thump 10 ; bias 1.000 ; spkr Res Freq 106 ; Low Freq res 7 ; Hi Freq res 10 ; B+cap 10 ; tone freq 500 ; tone location end ; tonestack active ; pres freq 5000 ; pres/depth type active pres ; level -22

FILTER - notch ; freq 9862 ; Q 7.09

I'm using passive PUs and V30s + matrix amp.
 
A Damp setting of "0" sets the power amp sim to Class A (Vox, Matchless, Dr. Z, Recto Red), as opposed to Class AB. To properly setup Class A you should also up the Sag to between 4 - 6, and the Power Tube Bias to around 0.752 (Recto Red 0.299), though only you can decide what sounds better etc (if it sounds right to you, it IS right!).

Class A is typically eliminates crossover distortion, and reduces odd-harmonic and high-order harmonic distortion, though it's inefficient and unable to make big power (hence the popularity of Class AB for the majority of tube guitar amps over 15-20W).

TotalRockstar666 said:
Hi Guys...I've stumbled across something and I'm not sure what it means!

I was flicking through the high gain amp models, the only one that sounded acceptable off the bat was the Recto Red, which got me wondering why this amp was so special.... It's the only high gain amp with a Damp setting of zero as default.

Naturally I then reduced the Damp value to zero on the Mark IV (USA LEAD 1) patch I am trying to create (that's all I want!! And awesome Mark sound!!) and Ta Dah! Something closer to being balanced sonically like the amp. I then did this to all amps sims and they sounded substantially closer to how I remember them!

Now, Damp is supposed to be something to do with negative feedback right? Which made me think, have I switched something I shouldn't have globally to make the Axe sound like poop, like a phase thing? Or have I simply wired up the SLA2 backwards?! Or worse?

I know the Art isn't the best power amp for the job, but my rig currently doesn't even sound remotely like what it should. As a side note, things seem okay-ish when running into ProTools with a Cab added.

Please someone in the know help!

Kind Regards,
Jim.
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Speedloader: many thanks, I shall try that tonight, it *looks* like its going to sound awful lol :) But I'll trust you right to the minute you melt my ears off! Hehe

RedBud: every feature I'm aware of is set correctly for my setup, but thanks for not assuming.

DJD100: Geezus man! Thankyou for that, exactly the explanation I needed to understand that quirk, the character changes entirely when the damp flicks to zero- almost like an 'on' / 'off' , now I know it's 'A/B' / 'A'. Awesome.

I shall get back to you all about how Speedloaders patch sounds. It's a shame there isn't someone with the same setup close by (other than my other guitarist of whose rig I setup lol)

Cheers so far guys.
 
I hope it'll blend with your friend's amp, just a few recommendations, use the bass control if there's too much low-end (my cab is pretty tight) and widen the Q parameter if the notch filter doesn't tame the top end enough, around 2.03.
 
As far as the model goes I believe Sag simulates an under-designed power supply?

I took those numbers from looking at Fractal's default power amp setting for the various amp models (Class A vs Class AB etc). Personal experience tells me that Sag does effect the transient off the pick with Damp set to 0 as well as greater than 0, and FAS usually sets Sag to 5.98 on Class A power amps (4.02 on Recto red and 5.98 for Dr. Z, Vox, and Matchless).

NOTE: Talking Ultra v11 here.

Smilzo said:
Class A has no sag (dissipation is costant). Maybe you are referring to resistor cathode bias shift, but that's not class related.
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Speedloader: Interesting patch. I didn't have much time to go into detail with it (try getting a drummer high on energy drinks to sit still and not play) but the same issue was there...what I would 'blanketing' or 'no high end, mid heavy'.

I'm starting to doubt my own ears and what is the norm. Most unhelpful was changing to the Axe Fx from my Mesa at the same time as deadening our rehearsal room with acoustic foam- so I didn't ever get the opportunity to hear a 'real' amp to gauge the effectiveness of the acoustic treatment. It may be the case that it is so drastic that the room is blanketing the amp! I don't know. Need to rest my ears and revisit.

Thankyou so far though!
 
You're welcome, well that's interesting, what if you add an highshelf filter between the amp and the notch filter ? Let's say, around 5db, 5Khz, 0.44 Q
 
DJD100 said:
As far as the model goes I believe Sag simulates an under-designed power supply?
Click to expand...
Indeed... a power supply with high resistance and low capacity: the more power needed, the lower the voltage in the amp.

DJD100 said:
...Fractal's default power amp setting for the various amp models (Class A vs Class AB etc). Personal experience tells me that Sag does effect the transient off the pick with Damp set to 0 as well as greater than 0, and FAS usually sets Sag to 5.98 on Class A power amps (4.02 on Recto red and 5.98 for Dr. Z, Vox, and Matchless).
Click to expand...
Sag could be a workaround for cathode bias, but it's not exatly the same. If you built two amp with same operating voltage, one with stiff power supply (regulated) and cathode bias, the second with loose power supply and fixed bias, the two will sound different. To my ears, the loose power supply is smooter: it needs some cicles to lower the voltage, some cicles to recover. The effect is the same of a compressor with added saturation. The cathode bias only affect the peak or so, it does not affect the sustain or release of a note. The fixed bias is is "snappier".
So yes, cathode bias it's sag-like but with different ADSR. It could be I am totally wrong, because I only experiment with a couple of different caps value... careful cathode caps or power caps could revert this... I don't know.
If someone have opinion on the subject, let me know. :)
 
TotalRockstar666 said:
at the same time as deadening our rehearsal room with acoustic foam
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I hope you guys also used bass traps instead of just killing the high end. I've seen more than one rehearsal space with 1" or 2" foam all over, making them extra-muffled - or even worse, in case of inferior materials (carpets etc.) - giving the room extra notches in the spectrum.
 
*looks nervously around*

It seemed like a good idea at the time Don.... :-S

We are in the 'more than one rehearsal space' club I'm afraid....every wall and ceiling covered... What/where would you suggest removing it?
 
I'll buy that!

The other variable is plate voltage, with lower plate voltage's slowing down the tube's response as well (starvation, aside from a sagging PS).

Smilzo said:
Indeed... a power supply with high resistance and low capacity: the more power needed, the lower the voltage in the amp.


Sag could be a workaround for cathode bias, but it's not exatly the same. If you built two amp with same operating voltage, one with stiff power supply (regulated) and cathode bias, the second with loose power supply and fixed bias, the two will sound different. To my ears, the loose power supply is smooter: it needs some cicles to lower the voltage, some cicles to recover. The effect is the same of a compressor with added saturation. The cathode bias only affect the peak or so, it does not affect the sustain or release of a note. The fixed bias is is "snappier".
So yes, cathode bias it's sag-like but with different ADSR. It could be I am totally wrong, because I only experiment with a couple of different caps value... careful cathode caps or power caps could revert this... I don't know.
If someone have opinion on the subject, let me know. :)
Click to expand...
 
One aspect of room treatment that is often over looked is dispersion. You can build a simple device to disperse frequencies. I'll take a look online for some plans. Another thing you should do is hang stuff off the walls. As in not mounted directly on the walls. Especially for dispersion. Dispersion helps brake up standing waves which are all too abundant in rooms with parallel walls.


I'm a high gain djent djent meedley meedely meedely type player...

Sent from my iPod.
 
DJD100 said:
A Damp setting of "0" sets the power amp sim to Class A...
Click to expand...
A Damp setting of "0" simulates an amp with no negative feedback in the power amp section; it's not about amplifier class (which is more about bias).

Increasing negative feedback makes the power amp sound and feel tighter; decreasing negative feedback makes it looser and spongier. Which way to go? That's up to your ears.
 
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