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How do you use impulses in Recabinet 4?

Poweramp section enabled + IR
4
80%
Poweramp section disabled + IR
1
20%
R4's "Neutral poweramp" + IR
0
No votes
 
Total votes : 5
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Topeznor
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210 posts since 18 Jun, 2015

Postby Topeznor; Sat Oct 31, 2015 7:10 pm Poweramp simulation and 3rd party IRs

I've been experimenting with some different impulses and if I'm not mistaken, every IR has nuances of the poweramp that was used to capture it. For example: Redwirez uses a neutral poweramp, Rosen Digital a tube poweramp, and Ownhammer has both options.

So, theoretically I should disable Recabinet's power amp simulation when using 3rd party plugins, but when I do that the volume drops excessively. To the point of needing trim plugins to get it back to level in some cases (Recabinet's amps behave in a strange way when not using their poweramps and have massive differences in volume).

So how do you guys combine IRs with Recabinet and what way do you think it sounds best? (I think I can make a poll with this :) )

- Stacking built in power amp simulation + IRs
- Disable poweramp section completely + IRs
- Using Thermionik's neutral poweramp + IRs

My own findings show that Thermionik isn't really optimized to be used with 3rd party IRs. Poweramps make a huge impact on tone and disabling them have undesired effects (Psycho B gets very thin sounding, as the poweramp has a very pronounced bass response, etc). I'm aware this may be due to stay faithful to the real thing, but there are other problems: Using poweramps and preamps out of their normal operation (unlinked) there are massive differences in volume between them. The "Neutral" poweramp doesn't seem to help much.

Other plugins like LePou's or Mercuriall's (that only work with IRs) sound astounding with Rosen Impulses, but they're missing the feel of R4. In case of Mercuriall's new Engl sim you can disable the poweramp if you're using impulses and it retains the core of the tone with no massive volume drops or frequency changes. It's a shame, because if you prefer 3rd party IRs to Recabinet's bundled cabs you're out of luck.


So... Discuss! :D I look forward to read your opinions! :phones:
jorismak
KVRist
 
135 posts since 10 Mar, 2014

Postby jorismak; Sun Nov 01, 2015 1:37 am Re: Poweramp simulation and 3rd party IRs

volume drops are 'implementation details' and not something to worry about. Trim it back to what you, don't worry about it.

Recab4 in it's neutral-poweramp option (no preamp active of course) with everything set to noon is supposed to be almost transparent. It does not 'add tube amp' flavour or impedance curves or anything like that.. it just tries to recover some dynamics lost due to the static nature of IRs (the Recab3 dynamics knob).

The most important thing when using a _solid state_ poweramp and a _tube_ poweramp to record IRs (both neutral in frequency response) is that you miss the poweramp-speaker interaction, dominantly the impedance response (which isn't linear on speakers hence the impedance curve).

So RedWirez stuff is captured through a solidstate poweramp, and thus misses the impedance curve (which is basically a bass hump and then slow rise up). They supply a bunch of IRs files to be used _together_ with the speaker IRs to get that curve back (and then you can say how much you want of it by mixing the impedance-IR in a certain way).

Rosen's have this impedance curve built in, and because of that seem to work better out of the box with regular (simple) amp sims and sound more 'body', 'crisp' and resonant.

Both are not the wrong or right way to do it, it's just something to think about. When you compare RedWirez or (modern) OwnHammer stuff to Rosen, just remember that Rosen has an EQ curve on it that the first two don't so it isn't a 'fair' comparison. If you like one or the other more, is just up to you.

OwnHammer captures them flat, because they are more meant for the AxeFX and the Axe has impedance control in it. Together that sounds fantasic. But if used without an amp sim that does impedance stuff, it can sound flat. That's OK, just add an EQ curve to emulate _an_ impedance curve. What I do, is add 'ignite amps free TPA-1' poweramp simulator (Which sounds extremely transparent.. really, phase cancel-tests show almost no sound difference :P)) but on the 'back' of TPA-1 is a 'resonance' control which you can crank up to get the 'flat' IRs to sound more like IRs which the impedance curve on it. When I load in Rosen IR's, I turn the control back down again.

I mostly use Recab4's neutral-poweramp + cab section as an IR loader these days, but like I said, I put TPA-1 in between with the resonance control cranked for IRs that are captured without a tube-amp. I do enable each module one at a time to make sure what my levels are doing between each of the plugins / modules.

Older OwnHammer stuff had different captures to be 'through solidstate' or 'through tubeamp'. These days he doesn't batter and only captures solidstate (or something similar to it, without impedance curve at least). In the manual he then states to be more like a tube amp to apply a simple EQ curve which he describes. Like I said, I use TPA-1 resonance control for that, leaving anything else in TPA-1 neutral (the amount of drive I do in TPA-1 seems to have pretty much zero impact on the final sound...)

If I play through my real 20 watt amp but into an IR to play/record silent I still apply TPA-1 resonance control because if the IR sounds flat it is flat :P. And my real poweramp adds very little to the sound / curve (it's very HiFi like, Soldano always does that :P).

I _never_ use Recab4's 'normal' poweramps in combination with a complete amp sim. Poweramp-in-poweramp stacking. (like use a Lepou plugin into Recab4 poweramp into IR). It is NOT wrong if you like it, I just never felt a need for it.

LePou into TPA-1 into Recab4's 'neutral' poweramp into solidstate-captured IRs I do. Disabling TPA-1 for tube-amp captured IRs (Rosen, most 'free' stuff out there).
X50v2 into TPA-1 into Recab4's neutral poweramp into solidstate-captured IRs I do.

But always remember the only important thing: What matters is how it sounds to you. Not if it's technically correct.
frthib
KVRist
 
49 posts since 29 Nov, 2017, from Québec, Québec, Canada

Postby frthib; Mon Dec 18, 2017 12:04 pm Re: Poweramp simulation and 3rd party IRs

This should be stickied.. Important stuff here.
Last edited by frthib on Wed Dec 20, 2017 5:06 am, edited 1 time in total.
frthib
KVRist
 
49 posts since 29 Nov, 2017, from Québec, Québec, Canada

Postby frthib; Tue Dec 19, 2017 12:19 pm Re: Poweramp simulation and 3rd party IRs

I eq matched TPA-1 Resonance effect on pink noise to guess what was the EQ curve used. Results are

Image

who is really close to the documented impedance curves published on the web...

Image

If anybody was to apply this curve to a IR captured with a SS amp it should, in theory, somewhat reproduce the eq curve effect of a tube amp. It gave an very interesting result with celestion impulse response.

Interesting fact : if I A/B celestion G12M with the "curve" it matches realitely closely 3Sigma 3A who was captured with a peavey 5150 power amp. Difference are in the highs, but both providers used different mics
lajosuti
KVRer
 
6 posts since 25 Jan, 2014

Postby lajosuti; Wed Dec 20, 2017 1:58 am Re: Poweramp simulation and 3rd party IRs

Hi,

thanks a lot for this tip about TPA-1. I'll try it :) Indeed I have purchased IRs from 3sigma, ownhammer, valhallir, drbonkers, and some of them were just plain flat, especially the ownhammer ones.

I wonder if you know the answer for the notch filter issues as well :) I found that during a rehearsal I don't have to put notch filters after my tube amp + 2x12 v30 cab, but with this soft sim + IR technology I have to use these filters. Is it a problem because of the IR technology?
frthib
KVRist
 
49 posts since 29 Nov, 2017, from Québec, Québec, Canada

Postby frthib; Wed Dec 20, 2017 4:47 am Re: Poweramp simulation and 3rd party IRs

I can confirm that Celestion "removed" the Impendance information from their IR. They are made to be used with a real power amp or the AxeFX who has a impendance system implanted who will provide the impendance curve.

If you use them with an ampsim, they will sound flat, too middy, no sparkle and real bass shy. That EQ "correction" help bring back what's missing.

Ownhammer IR are "flat" or neutral by design. They need that curve. They even documented that fact in the docs that everyone reads :D

3Sigma are interesting, the "A" variation is with a 5150 power amp. "B" variations are with a SS power amp and are similar to Celestion and Ownhammer. "Neutral"

PS : I'm no scientific, the EQ curve could be perfect by somebody who has more talent than me ;) Or use TPA-1 with everything at default position except the resonance maxed or adjusted to taste. Don't worry about tube, presence and other thingies, it's realively transparent at defaut position
frthib
KVRist
 
49 posts since 29 Nov, 2017, from Québec, Québec, Canada

Postby frthib; Wed Dec 20, 2017 4:57 am Re: Poweramp simulation and 3rd party IRs

lajosuti wrote:Hi,

thanks a lot for this tip about TPA-1. I'll try it :) Indeed I have purchased IRs from 3sigma, ownhammer, valhallir, drbonkers, and some of them were just plain flat, especially the ownhammer ones.

I wonder if you know the answer for the notch filter issues as well :) I found that during a rehearsal I don't have to put notch filters after my tube amp + 2x12 v30 cab, but with this soft sim + IR technology I have to use these filters. Is it a problem because of the IR technology?


It not a problem, what you report is to be expected. Your tube amp provide the "notch" by it's own design. You must have used a "SS" captured R in the digital world who's missing that "notch" when you where using an ampsim (I presume Thermionik). You will have to remember to compensate the impedance when using Ampsim used in conjonction with some IR manufacturer.

Celestion : must compensate
Modern Ownhammer : must compensate
Older Ownhammer : use tube power amp, nothing to do
3Sigma : with ampsim, use "A". nothing to do
Rosen Digital : captured with a true tube power amp, nothing to do.
Kazrog : captured with a true tube power amp, nothing to do.
Redwirez : SS poweramp, but they provide their own Impedance Curve to be used before the cab if you have the paid version.
Others ? Feel free to add more, it's all good information
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cturner
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220 posts since 7 Dec, 2009, from GWB

Postby cturner; Wed Dec 20, 2017 6:22 am Re: Poweramp simulation and 3rd party IRs

Greetings-

Very interesting thread here. I did my own look at TPA-1 which I believe I have correct, although I'm just digging into this subject:

TPA-1-171220.jpg


So you're seeing white noise, which has a flat response as opposed to pink. TPA-1 is at its init state except for reduction of oversampling to 2x, and turning the Resonance control all the way up. Green trace is white noise alone at ~0dB peak, orange trace is TPA-1 with a trim afterward to bring its level down to ~0dB peak.

The image doesn't invalidate the previous postings, but you could say this was a smiley face EQ curve: +1dB rise on each end, and a -6dB dip centered around 1khz. If I hadn't trimmed the TPA-1 output, everything would shift up by ~6dB, so you'd be looking at a flat mid-range and shelving boosts of ~+7dB for both highs and lows.

And of course TPA-1 could be doing other things besides the raw frequency shaping.

The TPA-1 manual has an interesting discussion of this issue if folks haven't read it.
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EvilDragon
KVRAF
 
15444 posts since 6 Jan, 2009, from Croatia

Postby EvilDragon; Wed Dec 20, 2017 6:25 am Re: Poweramp simulation and 3rd party IRs

I'm often mixing A and B IRs from 3sigma when doing a patch. Sometimes I even use B because it sounds better to me, for the occasion (even though it's neutral)...
frthib
KVRist
 
49 posts since 29 Nov, 2017, from Québec, Québec, Canada

Postby frthib; Wed Dec 20, 2017 6:38 am Re: Poweramp simulation and 3rd party IRs

Hey, I learned something, difference from white noise and pink noise!

I can add this from the Ownhammer documentation, I tried the suggestion and found them a little shy but they are a step in the right direction. Somebody said Ownhammer where designed with the fractal ecosystem in mind.

THE POWER AMP
This library’s captures were driven by a mostly neutral tube power amplifier. While the overall frequency response is largely even like that of a solid state reference amplifier, the common tube amp deviation traits are present that both liven and thicken up the sound ever so slightly. As such they are ideal as-is with accurate modeling platforms and tube amps sent to dummy load + line out devices. For platforms that need the little extra scoop of modestly configured guitar tube amp driven files, this is quickly and easily accomplished by implementing the following simple post processing adjustment:
SOUNDING LIKE GUITAR TUBE AMP DRIVEN IR’S
As aforementioned, the IR’s in this library were driven with tonally neutral tube based power amplification. There is a very quick, simple step that can be applied to replicate the sound of IR’s that were instead driven by a guitar tube power amp with the Presence and Depth set to 0, which results in a mid scoop. To simulate this sound, following the cabinet IR loader add an EQ with a parametric bell curve set to -3 dB at 400 Hz. Adjust the Q/bandwidth to roughly where the edges of the curve start to make the initial cut around 100 Hz on the low side and 2 kHz on the high side. If necessary, adjust the Q/bandwidth to taste from here to best suit your sound source and tonal preference.
Last edited by frthib on Wed Dec 20, 2017 6:44 am, edited 1 time in total.
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cturner
KVRist
 
220 posts since 7 Dec, 2009, from GWB

Postby cturner; Wed Dec 20, 2017 6:42 am Re: Poweramp simulation and 3rd party IRs

Ouch! EDIT: for some reason put 3Sigma Audio all over this post when the curves are from Redwirez.

Here are some response curves for a few of the Redwirez impulses I've got:
3SA_Blue_100.jpg

3SA_G12M25_100.jpg

3SA_V30_100.jpg
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Last edited by cturner on Wed Dec 20, 2017 6:47 am, edited 1 time in total.
frthib
KVRist
 
49 posts since 29 Nov, 2017, from Québec, Québec, Canada

Postby frthib; Wed Dec 20, 2017 6:47 am Re: Poweramp simulation and 3rd party IRs

Wow, it was quick!

They look like they follow the web impedance "curve", boost in the lows (+- 60-70hz) and slow rise in the highs...
frthib
KVRist
 
49 posts since 29 Nov, 2017, from Québec, Québec, Canada

Postby frthib; Wed Dec 20, 2017 6:49 am Re: Poweramp simulation and 3rd party IRs

cturner wrote:Ouch! EDIT: for some reason put 3Sigma Audio all over this post when the curves are from Redwirez.

Here are some response curves for a few of the Redwirez impulses I've got:
3SA_Blue_100.jpg

3SA_G12M25_100.jpg

3SA_V30_100.jpg


In theory, you could EQ match 3Sigma A and B file. The matched "correction" file should illustrate the power amp coloration. I did it by eye ( :) ) with TPA-1.
frthib
KVRist
 
49 posts since 29 Nov, 2017, from Québec, Québec, Canada

Postby frthib; Wed Dec 20, 2017 7:08 am Re: Poweramp simulation and 3rd party IRs

I tried a little experiment, non scientific, I put a track with 3sigma "A" variation and the same exact track (vst, settings, all) with the "B" varation and phase reversed it. Then I added an EQ on the "B" (SS) track to try to phase cancel them the most I could... I almost nailed it all that remain is weirds high I can't quite identify but the EQ used to near cancel the power tube "coloration" is this one

Image

PS : it's done by eye and ears in a completely non controled environnement ;)
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cturner
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220 posts since 7 Dec, 2009, from GWB

Postby cturner; Wed Dec 20, 2017 7:10 am Re: Poweramp simulation and 3rd party IRs

Here's another one. This is the frequency response (white noise input again) of the Redwirez Celestion Blue 100% impedance curve graphed against the TPA-1 Response control full up. The Redwirez curve is the orange, the TPA is the blue:
Redwirez_TPA.jpg
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Last edited by cturner on Wed Dec 20, 2017 7:13 am, edited 1 time in total.
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