UPDATE: I changed a lot on this patch, after listening to it I think it sucked majorly. Lack of higher frequencies and not enough “middle crunch”.

Here it is to you again with a few changes. The equalization curve is VERY important, even for YOUR setup!

Please listen to the clip.

Yes I know, all of us are striving to achieve AC/DC tone or for that matter, classic rock tone.

Therefore, please give it a listen before you continue reading (soundpatch version 2.0):

Angus Tone on Back in Black from SoloDallas – Attempt

Since this is an extremely long subject that I intend to treat as in depth as humanly possible (many, many considerations are needed here) I will just narrow the matter here and just talk about my current settings on the Eleven Rack (a piece of hardware built into a rack shape by Digidesign – Avid Digital – that “models” guitar recording) to achieve decent AC/DC (Angus’, but it could apply to Malcolm’s as well) tone.

What is extremely important as a premise for us to understand – me included, I just learned this recently – is what is called a signal path.

Id est (i.e.) what path the guitar signal makes before it gets to to tape or to disk (nowadays) when being recorded.

Having said this, I will concentrate for a second on a simulation of “Back in Black” tone, promising as I mentioned above to get back to this in depth to the best of my ability.

According to Tony Platt, recording Engineer for studio album “Back in Black”, Angus’ rhythm guitar being recoded (that is, when he played rhythm tracks with the band, laying out the backing track onto which subsequently Brian would sing and Angus would apply solos) had the following signal path:

<Begin Angus’ Rhythm Guitar Signal Path During Recording of album Back in Black>

Guitar straight into Marshall amplifier (to be identified with further precision) passing through a Schaffer-Vega Diversity System (discontinued, it was a wireless unit), then two condenser microphones used to record, then equalization was added (YES, during recording, as to say that what went on tape, even prior to mixing and mastering, was an equalized guitar!).

<END Angus’ Rhythm Guitar Signal Path During Recording of album Back in Black>

We will be talking about the solo guitar below (with regard to the Eleven Rack).

So, according to one interview of Tony Platt’s, it was two condenser Neumann U67 on a single 4×12 Marshall cabinet.

According to another interview of his, it was one condenser Neumann U87 and one condenser Neumann U67 on a single 4×12 Marshall Cabinet.

Does mentioning the type of microphone used really matter? Heck yes it does. Both the “condenser” aspect and the brand and type of microphone!

At the time – 1980 – tapes were still used to record in studios. There was no such thing as hard disk recording yet.

Also, the microphones had pre-amplification (tube) and they were plugged into the studio board (mix board) which added itself tone characteristics. The tape – typically 24 inch tape, pretty big – added some compression to the recorded signal, whatever that was. An effect to be taken into consideration as well.

As an added surprise, feature, Angus was known to use on the whole album, for all the guitar parts (solo and rhythm) his remote “Schaffer-Vega Diversity” wireless system to plug into the amplifier. This unit had a boost knob on both the transmitter and the receiver end. Angus has been known to use that boost to make the amplifier hotter, thus getting more gain!

So as you can see by now, a big number of variables came into play.

Unless you have at disposition all of these elements – I don’t! – we have to simulate most of them.

With the Elven Rack – and most modelers – I am specifically simulating:

• The Amplifier: using a “Marshall Plexi” model

• the cabinet(s): using a 4×12 with 25 greenbacks model

• the microphone, its placement on the cab, a simulation of the environment, the microphone built in power supply (on vintage Neumann U67s it was a box with tubes inside) and the mix board preamplification: here I am using a condenser U67 placed off axis model

• the equalization: using a post , graphic equalizer (i.e., a graphic equalizer placed after the amplifier, see image) with a given equalization curve (see image for the equalization pattern, appearing as FX2)

• In order to simulate a signal booster, I chose to not use any modeled stomp boxes in my signal path, but I chose the most transparent booster I could find in the Eleven Rack, this being another graphic equalizer with all the settings to “idle” with the exception of the output of the equalizer itself, resulting in a considerable boost (i.e., added gain). This appears as FX1.

In order to being accurate, I placed this additional boost in front on the amplifier in the signal path (see image).

A lot of stuff, huh?

The “results” are what you heard on my last videos. For each and every one of them, I always “tweaked” a bit here and there, and so you will have to, too.

There are several modeling software and hardware products out there right now.

I am still using Guitar Rig 4 at times, but I have been using The Eleven Rack solely for the recording of these last videos. The reason is not the supposed superiority of the Eleven Rack (though some say so), it’s just for this one was new and I wanted to study it in detail.

A simulation of the above mentioned signal path will follow on the Guitar Rig 4 as well, soon.

I hope you found this interesting, as it does apply to any amplifier and modeler you may have at the moment.


Eleven Rack Signal Path (only yellow illuminated components are active):


The equalization pattern on the graphic equalizer used “in post” (that is, equalization being performed on the signal coming in from the microphones, before going to tape).


Note: for the ones who do own the rack, you should be able to download the sound patch here:

Eleven Rack AC/DC Sound Patch – by SoloDallas

Post to be continued, edited for improvement.