Peavey ReValver 4 - ACT Combo and ACT Rack released!

[spacekid]

I'm really not trying to be a jerk

Hey, me neither

Well, because some people may not get it..yes things are said that are out of line, but that's what friends do when they argue...so

[kohitsu]

I've been wondering how the ACT inputs work, so I've done a bit of investigation

First of all, it asks you to play as many notes as possible on your guitar to "build a profile". I'm assuming that what happens here is there's a FFT running constantly, and it's collecting all of the frequencies you hit. There's probably an array representing frequencies from 0 Hz to 40 KHz and whenever your guitar makes one of those frequencies (from the note you're playing and its harmonics) it gets ticked off in the array. When it's finished (probably after ticking x amount of boxes) it has a rough idea of the frequencies your guitar pickup or mic can reproduce.

I imagine the target ACT profile (of a Telecaster, say) is compared to the input profile (your Strat, say) and they figure out what they need to do to make your input profile either A) more accurately match the target profile or B) flatten your profile out so there's essentially a flat frequency response to work with when they apply the impulse response.

There's definitely an impulse response at work - first of all they have ACT profiles called Takemine Mic A and similar, so it stands to reason IRs would be involved. Second of all - I recorded an input profile using the Reaper JS white noise generator rather than a guitar, so the frequency response of that input profile should be reasonably flat. Second of all I got a 0.1s clip of white noise and fed it into revalver running 3 different ACT profiles, and there's definitely a little bit of a tail created when it's run through revalver:



Out of interest, using the white noise input profile, I played white noise into a few different ACT profiles to get a sense of the curves:



Tele style neck pickup is pretty much what you'd expect, frequencies dropping off pretty hard >2k. Takemine Mic'ed is pretty flat - louder in the bass region. Resonator is almost flat but has little peaks which I'm assuming are from the resonator's resonances

[spacekid]

I've been wondering how the ACT inputs work, so I've done a bit of investigation

First of all, it asks you to play as many notes as possible on your guitar to "build a profile". I'm assuming that what happens here is there's a FFT running constantly, and it's collecting all of the frequencies you hit. There's probably an array representing frequencies from 0 Hz to 40 KHz and whenever your guitar makes one of those frequencies (from the note you're playing and its harmonics) it gets ticked off in the array. When it's finished (probably after ticking x amount of boxes) it has a rough idea of the frequencies your guitar pickup or mic can reproduce.

I imagine the target ACT profile (of a Telecaster, say) is compared to the input profile (your Strat, say) and they figure out what they need to do to make your input profile either A) more accurately match the target profile or B) flatten your profile out so there's essentially a flat frequency response to work with when they apply the impulse response.

There's definitely an impulse response at work - first of all they have ACT profiles called Takemine Mic A and similar, so it stands to reason IRs would be involved. Second of all - I recorded an input profile using the Reaper JS white noise generator rather than a guitar, so the frequency response of that input profile should be reasonably flat. Second of all I got a 0.1s clip of white noise and fed it into revalver running 3 different ACT profiles, and there's definitely a little bit of a tail created when it's run through revalver:



Out of interest, using the white noise input profile, I played white noise into a few different ACT profiles to get a sense of the curves:



Tele style neck pickup is pretty much what you'd expect, frequencies dropping off pretty hard >2k. Takemine Mic'ed is pretty flat - louder in the bass region. Resonator is almost flat but has little peaks which I'm assuming are from the resonator's resonances

Good work. Yes, it seems very picky, so after trial and error, I found that staying with the same source amp + mic position + cabinet used is important when adding ACT Rack profiles(use the same original source profile that you made, and apply a target that is derived from that same source profile).If not, the results get muddied/phased.

[Agreed]

I apologize if this were already discussed, am I understanding correctly that sound demos were not intended to be that representative of what you're hearing because you're using your monitors clipped as part of your tone in your recording setup?

Also, I always really liked that ReValver had a bunch of analysis tools built in - interesting to see the results of hosting some plugs and checking out their impulse responses, although I personally tended to fall off the deep end with it and start naval gazing after a while and not really trying to make music... I think I might have a little too obsessive of a mindset to be satisfied with so many exposed parameters, to be honest. Always an urge to tweak things more. However that's my own focus problem, not at all knocking the software for being easily tuned.

[spacekid]

I apologize if this were already discussed, am I understanding correctly that sound demos were not intended to be that representative of what you're hearing because you're using your monitors clipped as part of your tone in your recording setup?

It's only coming through as what I'm hearing on my own speakers or anyone who has my model of speakers(Event's). You really have to try out the modules, mix and match them, to your own amp'd up speakers. I'm shopping for an extra nearfield(or other)to use as a makeshift rig. I'm pretty sure I can load another audio driver from a second USB audio interface on one computer and switch between my 2 interfaces..but I haven't tried that yet. I'm still just having fun with what this can do..and it can do a lot now. Warning though: The Randy(412) presets I put up are slightly off, as I nudged them away from the original mic position..found and fixing that now They should be default center(slightly right) instead of Right/slightly bottom position. The other models(Michael and Angel) are fine. *edit: you CAN make it come out right(flat response), but you have to kill the things that it can do that other software can't. If you are just making interesting presets by ear, it will probably lead you into the not-so-friendly realm of you have to rerecord it. Figured out all I need is a second mic boom here, and I'll be setup Worked on a happy medium between push and flatland didn't really care about the playing/stopped to turn the volume up, but it picks up a bit: https://soundcloud.com/spacekid1-1/skullz-2

[spacekid]

Also, I always really liked that ReValver had a bunch of analysis tools built in - interesting to see the results of hosting some plugs and checking out their impulse responses, although I personally tended to fall off the deep end with it and start naval gazing after a while and not really trying to make music... I think I might have a little too obsessive of a mindset to be satisfied with so many exposed parameters, to be honest. Always an urge to tweak things more. However that's my own focus problem, not at all knocking the software for being easily tuned.

It's easy to fall off the deep end, more so now. For my test above, I tried to keep out too much push. That sounds easy, but because it's something that other software can't do, you tend to do it. That's when you need to either back off from it, or decide to somehow capture what is coming out of your system(because it WILL be unpredictable). As for backing off of the push, I tried using el cheapo headphones to make sure it at least came through ok without too many problem areas..let me know how it worked out in the example above. I'm 100% positive it'll come through better than the others. As far as software parameters, yeah it's deep..I found that you can 'install' a horn to any cab..it has 3 parameters to check to engage it internally, on any cab.

[spacekid]

Ok, so using headphones to cross-check is a must. I recreated an old amp of mine, from memory. A Fender Blues Jr. This shows a bit more accurately what can be done in Revalver. All apologies for that stuff earlier, it only sounded right to me. https://soundcloud.com/spacekid1-1/blues-jrish

[ASTN]

I've been wondering how the ACT inputs work, so I've done a bit of investigation
I'm assuming that what happens here is there's a FFT running constantly

That's exactly what happens there.
Revalver uses files with 'actprofile' extension, which consist of small header and 8192 points of FFT in single float format (4 bytes). Frequency step depends on bitrate though. So, for 192k - for instance - step is about 0.5*192k/8192 ≈ 11.7 Hz, max frequency obviously is samplerate/2 (192k/2 = 96k).

User input profiles stored in separate profile files, while prepared ACT profiles stored in files which in order stored in other files (with 'sa' extension). That 'sa' files are just containers, which consist of ACT profiles, images, samples and some other stuff.

Btw you can create your own prepared profile since that 'sa' format is quite easy. There are some data and files which meaning I not clear but you can use a ready profile, copy it, and change it... though it requires a bit of programming, or manual hex-data correction.

[ASTN]

If someone is interested I've written a simple extractor that can extract files from Revalver .SA container files. It creates the directory with the same name as SA file +adds 'DIR' at the end of name, and it puts all files from .SA container in that directory
(By default all interesting stuff is stored in 'All Users\Peavey Electronics\ReValver 4' or 'username\Peavey Electronics\ReValver 4' if you didn't choose 'Install for all users' option when installing Revalver)

As a bonus it can load .actprofile files and draw their frequency response.


Extractor:
https://wdho.ru/4X7m

[acousticglue]

If I wanted my guitar sound like something else id sell it