II. Practice

Thinking in terms of analog gear, take the relatively simple example chain of:

Guitar > Tube Screamer > Amp > Chorus (in effects loop) > Amp

Even here, the Screamer has two gain stages - Drive and Output. The amp likely has 5 - Drive, Channel Volume, Loop Send, Loop Receive, and Master Volume. The chorus pedal likely has 1 - Output. You have 8 gain stages to tune, so that they all work in harmony. The Chorus does not have an attenuator on its input. You must set the effects loop send volume low enough to keep it from clipping. You probably want the Screamer to have low Drive (its "hot" gain stage), so that it only provides a touch of distortion, but you want to dime its Output (which stays clean). You want most of your distortion from your amp's preamp. So you crank Drive there. You don't want much power amp distortion, so you set Master Volume just below where the power section starts to break up. Channel Volume likely stays clean even at high settings, so you crank that up fairly high, but it's main purpose is to balance one channel's volume against another - you may have to keep it lower than 100% for that.

How does this translate for such controls in the Pod? The Pod features almost everything mentioned above digitally. Most of the time its algorithms are emulating exactly how an analog signal would be processed. So you want to follow the same advice as with an all analog chain.

Particularly troublesome are the EQ effects. Some are worse than others. When I'm using an EQ as the first piece of my chain, I will get a nasty digital-sounding distortion when I pick hard. To compensate I add a Volume effect to attenuate the signal before the EQ. If I'm using EQ's behind my amp block, I need to keep the Ch. Vol./VOLUME knob relatively low (45%) to prevent from clipping EQ's. For single amp patches, I put everything in Channel A and use the Mixer Levels to set my final patch volume. For dual amp patches, I usually have a Mid-Focus EQ last, which provides a Gain parameter that I use to set my final patch volume.

Digital devices feature the additional danger of digital clipping, where the signal level exceeds the digital resolution and produces a harsh distortion. Yet, if you follow proper gain staging, the principles are exactly the same. You will only achieve digital clipping by setting a gain stage too high (provided you aren't clipping the unit at its input A>D converter).

Some of the controls in the Pod adjust the signal level digitally, rather than emulate an analog gain stage. For instance, the amp block's Ch. Vol. (VOLUME knob) is not simulating analog circuitry. I believe the mixer levels and volume effect operate the same way. This basically takes the consideration of a noise floor out of the equation, but replaces it with loss of precision. Setting one of these REALLY low will not add noise to the tone but will introduce slight manipulations to the signal's waveform and lose certain details. Similar to distortion concerns, it's best to treat everything like an analog gain stage, setting them high enough to preserve the signal integrity.

I believe the Pod has three actual analog gain stages - FX Loop Send/Receive and the Master Knob (the right-most physical knob on the unit). Same rules as usual apply.

Note: the MASTER knob only affects the tone sent to the analog outputs. For the digital outputs (AES, SPDIF, USB), the signal is never converted back to an analog signal and never hits the analog Master Knob gain stage. The Pod's signal is mostly digital; it goes:

Input Source > A/D convertors > digital signal processing > D/A conversion > Master knob attenuation > analog outputs

Even when setting up a patch that is close to maxing out the Pod's maximum digital signal level, with the MASTER Knob at 100%, I do not hear any distortion occuring. So proper gain staging dictates setting this knob to 100%. Line 6 documentation echoes this opinion, saying this setting results in the highest signal-to-noise ratio from the unit. But be wary of what you're connecting the Pod into. I have clipped the effects loop return of my amp when setting this too high - my amp provides no control to attenuate the loop return signal.

The only time I recommend moving the MASTER Knob lower is when you are not using your main rig. By doing this, you are sacrificing tone for ease-of-use. You should gain stage and level your patches as above for your main rig. For other rigs that distort with the amount of volume you're sending them, the easiest way to attenuate the signal is using the Pod's MASTER Knob. Rather than digging into the mixer settings on all of your patches, you can just change one knob and be done for all patches. This may result in additional noise in the signal, but that's acceptable in this case. This applies equally to using headphones.

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