AU Lab/POD Farm 2.0/Live Laptop Rig Tutorial Part 2

In the previous post, an AU Lab session (or document) was established and an A/B POD Farm patch was created.  In this post, I’m going to start modifying the patch to make it more useable.

Building the rig:

Okay first I’m going to swap out the amp. I like the Double Verb instead.

You can drag and drop amps into the signal chain, but if I click on the down arrow to the right of the AMP field – I can just scroll down to the Double Verb amp.

Here are the settings I’m using.

If you look in the left hand corner underneath the input knob on POD Farm, you’ll notice the global gate is on.  I tend to use the global gate at a low setting.  This came from a ruined session where I switched to a distorted sound that DIDN’T have a gate on it and squealed between each phrase.  Now I keep the master gate on to not worry about that scenario.


Louder isn’t always better.

Compression has it’s place – but I try to play dynamically, so the compression is the first thing to leave the POD farm signal chain.

If you click on the compressor in the signal chain and then ctrl-click on the compressor you’ll get the following options.

Just select Delete.  If you change your mind you can drag and drop another compressor from the menu into the signal chain.

Another point to bring up, is that when I use an amp and effects – I try to use the same signal chain for all of them.  (This comes from years of playing gigs and having a bunch of effects pedals going through the same amp and reverb).

Looking at this set up, the mic pre (currently between the amp and the reverb) would be something that I would want in the channel signal chain in AU LAB instead of POD Farm – so that it was the same mic pre for any amp I’m using.

The first step is to delete the mic-pre from the POD Farm signal chain (using the same method as the compressor above).

Next (in AU LAB) in the Audio 1 channel – click on the arrow in the next available Effects field below PODfarm .

If you scroll down to Line 6, you’ll see that in addition to PODFarm, that each individual component of a PODfarm rig has been broken down into components (aka POD Elements).  This is so you can use individual effects or amps as an AU plug in which much less of a CPU hit than loading in another instance of POD Farm.

In this case choose: POD Farm Element – Preamp.  I’ve chosen Vintage UK.


The reverb would also be something that I would want in the channel signal chain – so that it was the same reverb for any amp I’m using.  (The other advantage is that by placing the reverb outside of POD Farm, when I change amp settings the reverb doesn’t cut off with the amp change.)

Delete the Reverb from the signal chain in POD Farm (using the same method as the compressor and the mic-pre above).

Next, (in AU LAB) in the Audio 1 channel – click on the arrow in the next available Effects field below POD Farm Element – Preamp.

If you scroll down to Line 6, choose: POD Farm Elements – Reverbs.  I’ve chosen Standard Spring.  Here are the settings I’m using.

Impulse Responses:

I use impulse responses rather than the speaker sims in Pod farm.  So the next thing I’m going to do is get rid of the speaker cabinet/microphone on Podfarm.  If I click on the CAB button – I’ll get a list of speaker cabinets and microphones used.  If I scroll to the top of the list – I’ll get “No Cabinet” which deactivates both the cabinet and the microphone.

Next, (in AU LAB) in the Audio 1 channel – click on the arrow in the next available Effects field belowPOD Farm Element – Reverbs.

Scroll down to Lernvall Audio and select LA Convolver.

Now I’m going to select to impulse responses to act as a speaker simulator.  I’ve experimented with putting multiple instances of LAConvolver  on buses and running multiple cabs, but since I want to run SooperLooper in the bus (Where I can loop guitar and any other incoming audio source), I’m going to just stick with a stereo set.

Select a channel and hit “choose” under file. In this case I’m using the free RedWirez cabinet I got as part of their birthday giveaway.

I want to use a high sample rate to get better definition so I’ve chosen 88.2 K. (or 2 times 44.1k)

I’ve chosen an SM57 on the grill and a KM84 about 3 inches behind the back of the amp.  I tend to start with the Wet gain in the center position and adjust as necessary.

A brief note:

I’ve mentioned this in other posts, but since I want to use the same speaker cab for all the amplifiers, I’m going with a 4×12 for familiarity.  Normally,  I wouldn’t match a double verb up with a 4×12, but since I’m going to be running a Marshall on the other channel, I’m going to just have to adjust the clean amp signals accordingly.

Fixing the Sample Rate:

If you notice, the plug in sample rate and the Impulse response sample rates are different.  It will work like this – but I want to use the highest sample rate I can for the most clarity.  There is a delicate balancing act that comes between high sample rates, stability and useable latency, so everything here is a compromise.

I’ll fix this with Audio Midi Set up :

First: click on AU Lab and look under Preferences.

When the preferences window opens, click on the tab marked Devices.

If you click on the expert setting arrow you’ll see something like the following:

Another  brief note:

I’ve set the CPU to 100% to avoid glitches.  I’ve also set the latency really high to attempt to keep the system stable.  Depending on the system and interface that you’re using, you’ll probably have to lower the setting to the point that you get glitching (or max out the memory) and then bring it up a little bit from there.  With the headphone out of the Duet – even with these settings the latency is suprisingly tolerable.

If I click Edit Device – that opens up the Audio-Midi Setup application (or you could find it in the Application – –  > Utilities folder)

Note:  I’ve changed the output format to 88.2.

Going back to the Audio-midi sample rate window – it shows:

An Important note about sample rates:

I’ll mention this again – but if you’re going to be incorporating other audio into the session (including looping in SooperLooper) – you’re probably going to have to set the sample rate back to 44.1 (and set the Impulse responses back to 44.1).  If I’m not looping –  I try to set the rate as high as I can, but know that it’s going to have to get bounced down to 44.1 for recording, etc.

While I’m on the preferences Tab I might as well set up recording to the external drive.  Click on the tab marked “Recording”.

Now if I click on the “Rec” button at the bottom of OUTPUT 1 in AU LAB, it will record whatever I do to the Lacie as the default location, in a 24 Bit AIFF format.

With the changes in this part of the tutorial, the AU Lab Input looks like this with some sample input:

You’ll notice that the output is a little off balance.

If you pan it to the left you’ll balance the signal out a little more. Here’s the setting with all the global FX so far.

You may want to save the AU LAB session now, if you haven’t done so already.

In the next session, I’m going to complete the clean channel effects and automate some parameters with the Midi Learn function to be able to make changes to the sounds with the Line 6 Shortboard.

You can find all of the laptop guitar rig posts on the Blueprints tab on the top of the page.  Once on the blueprints page – just scroll down to the Laptop Guitar Rig section.

Thanks for reading!

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s