Ok, so its been a while since our first installment and a bunch has changed in the HD500 since my initial review. Firmware version 1.3 added a handful of new amp models and version 1.4 fixed some bugs as well as added a input impedance control. I originally wanted to feature some genre specific tones with this article, but I think there's some more ground work to cover first. 

1. The FX Loop, Hiss, and You - In my initial auditions with the HD500 loop, I was discouraged to say the least. My hope was to perhaps run some stomp boxes or even A/B between the internal models and my TM60 in a 4 cable setup. But what I found was even when bypassing the loop, I was treated to all the noise from any pedals in the loop...which in my case was pretty high due to having some high gain pedals in the loop. Boo!!! Well, what I found out is the HD500's Trails feature which allows delay and verb to spill over when changing presets also applies to the FX loop by only bypassing the FX send rather than the whole loop or just the return like most FX loops work. By disabling the Tails feature, the loop works exactly as I would expect! Much thanks to gregr over at thestompbox.net for this tip. 

2. Smooth It Out - I'll proudly admit to having a preference of warmth to brighter tones, and I stumbled onto a little trick in the HD500 which creates a notch around 8K which really smooths out the tone of the HD500, especially when used at louder volumes. Basically create a signal chain as follows: Amp before the split, graphic EQ (or any eq set to neutral) in the top loop, no effects in the bottom loop, set the mixer at the end of the loop with both sides panned to center. Voilà! Instant notch filter. Wait, how did that happen? Well, rather than calculating maximum latency and then always offsetting your signal, the HD500 appears to process dynamically, meaning each effect added adds a little bit of latency. By introducing latency on one side of the split but not on the other, we have created a text book comb filter. Adding additional EQ's will create additional notches which you might find tonally interesting as well.

3. Low/High Pass Filter - I lamented the omission of the inclusion low/high pass filtering in the HD500. If you're not familiar, this type of EQ creates a hard cutoff at a defined frequency which can remedy low end rumble and piercing highs. Guitars are almost always processed in this fashion when recording to reduce aural interference with the bass guitar and bass drum as well as giving room for cymbal shimmer. Well, Line 6 has included such an option, its just not apparent at first glance...and a bit difficult to use. Enter the Mid Focus EQ. I know, you don't want to boost mids, neither do I (in this scenario) but understanding this powerful and oddly named EQ will really open some doors for you. The Mid Focus EQ does not boost the mids, but rather combines low and high pass filtering and then boosting to resultant signal. The default settings do in fact boost the mids, but by setting the gain to 0, HP Freq to 0% and LP Freq to 100% you get a totally bypassed signal. To remove the rumble, place the effect after your amp model, set the HP Q to 0%, and a subtle adjustment of the HP Freq to 2 or maybe 3% works wonders. Conversely, setting the LP Q to 0% and reducing the LP Freq to between 80% and 90% really help warm up your tone. Thanks to HolyMuffDiver over at TGP for this tip!

4. Input Impedence - This is a new feature in firmware 1.4 allowing the ability to load down your input signal similar to the tones one might get from turning the guitar volume down (without and treble bleed installed) or using a product like the Radial Dragster. In an guitar to amp scenario, this will typically darken one's tone though some claim a "squishier" response. However, experimentation with how the input impedence reacts to some effects delivers some very curious results! The Boost Comp is one of the best effects in the POD IMHO, and the way it interacts with the input impedence is darn near magical. I typically use it like a treble boost with the gain set low, volume maxed out, lows cut, and highs boosted. Well, cutting the input impedence down low seems to have an exponential effect on the treble boosting goodness of the boost comp, which makes it a simply magical pairing with the JTM-45 model.

5. Reduce Modeled Crossover Distortion - Actually, I'm not even sure its modeled crossover distortion. I find a splatty, squelchy artifact (for lack of better terms) in the high end of a couple amp models which sounds like perhaps overemphasized crossover distortion. Seems to be masked fairly well when using the HD500 into a more traditional setup but running it direct into a FRFR, it can get a touch grating. Bias excursion to the rescue! Firmware 1.3 introduced new deep editing parameters, one of which is Bias Excursion. I find that turning this parameter down really helps minimize the occurrence of this sound and generally smooth out the sound of a few amp models. You can read up on crossover distortion here.

In the next installment, we'll put together some of these tips to create a few genre specific patches. Check out Part 1 here.