amsdenj

The problem with the amp Drive control is that there's no way to change the voicing of the amp as the Drive is increased. The more distortion you get from an amp, the more you have to cut bass to eliminate mud and cut treble to eliminate ice pick. The Drive control just increases the gain into the front of the amp, it doesn't do anything to the voicing. That's why my "Drive" footswitch controls both a Studio Tube preamp and the Drive amp control. I use the studio preamp to add drive while using the low and high pass filters to control the mud and ice pick. The preamp also adds some extra gain to Fender amp models that don't have enough Drive. S-Gear amp models, which are guitar amplifiers created in the digital domain, not models of existing analog guitar amp channels, has lots of switches for voicing the bass and treble of the amp, and the boost and channel switches also have different voicings for different distortion levels. The Duke even has three choices on how to voice the distortion - normal, thick and bright. This makes a huge difference in how the amps sound. I'd like to see Line 6 start taking more of this approach to amp models instead of just reproducing what has already been created. Another option is to use distortion pedals with their tone controls to create voicing for overdrive and distortion tones. My goto patch does all three. The Drive footswitch controls the preamp and amp Drive controls. The Overdrive footswitch controls one distortion pedal, and the Distortion switch another. I gain stage these so that I can have many different tones from clean, blues, crunch and metal from the same patch. This works great for me and eliminates the need to do a lot of patch changing to get a wide range of great tones.

If you really love your guitar amp, then you should probably stick with it. You can use Helix two ways with a guitar amp - as a digital pedalboard into the front of the amp, or using 4CM. Using the latter you probably won't use any amp models, neither would use cab or speaker IR models. So you would be under-utilizing Helix, but that might be fine. The biggest motivation for FRFR is flexibility, and the ability to play multiple instruments, especially acoustic guitar - which will never work well into a guitar amp. So to me its more what you want to achieve then it is specifically the tone. I suspect that any of these approaches will produce good and useful tone even though they might be different. Different is probably neither good or bad in this case, just different.

@optimus_7, couldn't agree more. Another solution to spillover is to design your patches so you don't need to change patches in the middle of a song. I have a blog post I'm working on that discusses the various merits of sticking with a patch and changing effects vs. changing patches. Personally, I mostly use one patch and avoid distracting myself and my audience with too much variability.

I use one Helix patch for electric guitar, almost all the time. Unless I change instruments, I almost never change the patch in a live situation. I get the tones out of my hands and the pickups on the guitar along with a fixed set of effects in the patch. I like to concentrate on the playing and not the patches. The subtle differences in patches aren't that noticeable to the audience and as you've seen, can become a distraction. That said, I love the flexibility and options of Helix, I just don't need to use them all all the time.

I think you need another Helix :) .

See this blog post for how to do that: https://jimamsden.wordpress.com/2015/12/24/creating-an-acoustic-guitar-impulse-response-for-line6-helix

If you have another audio device connected to your Mac, try creating an aggregate device with Helix and that device, setting it as the clock source in Audio/MIDI setup. This should temporarily solve the problem with Helix clock drift.

If BIAS has too much latency, there's possibly something wrong with your setup. On Mac, just make sure the buffers are set small in the app that is hosting BIAS (likely Logic or MainStage). On a modern computer, latency in an amp modeler like BIAS FX or S-Gear should be unnoticeable. If you use a Mac then you might consider keeping the Apogee Quartet for a while for two reasons. First Helix doesn't yet play well with Mac OS X 10.11, clock drift renders it useless as an audio device. This should get fixed eventually by Line6 and/or Apple, but right now, you need other options. Second, Mac OS X lets you create aggregate devices synchronized by a single clock. This gives you additional inputs and convenience, as well as a way to solve the Helix clock drift on Mac OS X. Just create an aggregate device with Helix and Apogee Quartet, and set Apogee Quartet as the clock source in the Audio/MIDI Setup app. Use that aggregate device in Logic or MainStage, and Helix works great. Plus you have the Apogee Quartet inputs and outputs too which might be convenient in your setup. Regarding recording in Logic, I still prefer S-Gear over Helix. The tones are somewhat better (although that's a matter of opinion, Helix is great too), but the ease of re-amping with a VST or AU plugin is pretty compelling. Only problem is S-Gear doesn't have any front of the amp effects (yet). Note that Helix makes a nice pedalboard for front of the amp effects into S-Gear, and MIDI control of S-Gear in Logic or MainStage. Lots of options and the best of both worlds. I really like them both, and together the whole is even greater than the sum of the parts.

I only use FRFR amps, so electric, acoustic and mandolin can go through the same multi output. I currently send the XLR outs into a stereo PA input for FOH. In some cases where the venue is small, I don't have any stage amp at all. In that case, my guitar and vocal come through my monitor, a JBL EON610 fed from an Aux output from the PA. That way everyone else can mix whatever part of my guitar they need in their own monitors. For larger venues, I like to have an amp behind me. I currently have a Hafler Transnova p3000 power amp into a pair of 10" coaxial Eminence speakers in a Tremolux cabinet. I this case I don't include any of my guitar in the EON610 monitor as I find it distracting to have both, and I have nice stereo from that Hafler and cabinet. However, I really like the sound of Helix through an EON610. And they are light, powerful, small and look reasonably good. I'm thinking about getting another to run behind me. I this case I would still run the Helix XLR outs to the PA for FOA, but use the Helix 1/4" outputs to the second channel on the EON610 monitor (along with my vocal from the PA aux out), and other the EON610 behind me. Since these are the same amp and speaker, the phase distortion will only be based on the distance between the speakers, and that shouldn't be too bad. I would adjust my monitor mix so that there's no guitar coming from the PA into my monitor, just vocal. Using a digital mixer makes it easy to save these different configurations in scenes. Ok, having thought that through, I'm even more tempted to get another EON610. Anyway, its great that Helix has all these routing options. But now I find my mic input isn't work, so it looks like its going to have to go back to Line6 again.

Now I see my mic input isn't working either, with a dynamic or condenser mic. This is starting to look like a common problem. I'm not sure it ever worked since I don't use that input. But it should. The Mac OS X USB issue, scribble strips and mic input seem to be the most common and persistent issues.

What I do is go look at the rigs used by guitarist I really like - Matt Schofield, Mike Bloomfield, Jimmi Hendirx, Robben Ford, etc. you get the idea. See what they use for pedals and amps and learn, these are the professionals. Then I try to reproduce those setups with some of my own modifications and preferences in Helix. That's the starting point. Then I play the thing live and see how the interaction between the tone, the guitar and the audience works and effects how I play and enjoy the music. Then I adjust from there. As a result, I mostly use one amp, one IR and a fixed set of effects in one patch. I get the tone changes mostly from my hands and the volume control on the guitar. This has been a very satisfying experience with Helix. I'm no longer hunting all the time for that missing tone. I just play.

In a traditional guitar amp, everything clips, preamps and power amps. Which one contributes to most of the clipping has a big impact on the tone. Sag is mostly a result of power amp cliping, but it can effect the preamps too as their plate voltages drop and recover. Some guitar amps use diodes, possibly offset with a bias voltage to do preamp clipping. Preamp tubes run class A thend to have very asymetric clipping due to the difference between cutoff and saturation, one being much more abrupt than the other. Tone voicing after the diodes can help warm up the distortion tone to make it more tube like.

A magnetic pickup just can't generate the frequencies that would be required for an acoustic tone. The highest frequency from most magnetic pickups is around 6kHz, an acoustic guitar might go as much as twice that. An acoustic guitar body image can't create frequencies that aren't there, it can only dynamically shape which is there.

The SM57 has a high-mid boost that can create some fizz when played through a PA speaker with a horn in your face. I tend to like a warmer speaker tone and use the ribbon mics for most cab and IR models.

If you had a tube amp and a solid state amp with the same RMS power rating for the same load, going into the same speaker, with both amps running clean, you would have exactly the same power and loudness. If you completely distort both amplifiers at 100% distortion, the amps would also have exactly the same loudness and it would be twice the power and 3dB louder than what the amps were putting out at maximum clean output. Power is area under the curve, and a sine wave has exactly 1/2 the area under the curve as a square wave at the same amplitude, which is what you get then the clip an amp at 100%. RMS is clean power, and an amp clipping at 100% is putting out twice as much power and 3dB more loudness. The perception of loudness difference occurs between these two extremes since the amps behave differently when they distort. When an amp distorts, the top and/or bottom of the sine wave is clipped off since the amp has no more headroom in which to amplify the larger input signal. The corners of that clipped wave form add harmonics to the sound that are whole number multiples of the frequency and any overtones generated by the guitar string. That's what we hear as distortion. Tube amps tend to distort musically, that is, the overtones they generate when they clip are generally pleasant to our ears. Solid state amps generally don't distort musically. So a tube amp can sound "clean" and nice, ever though it might be distorting quit a bit, and therefore have more area under the curve and deliver more power and loudness. Plus the overtones generated by distortion give a different, more exciting tone - that's why we love it. It sounds more powerful (because it is) and gives more sustain since the distorted amp is actually a big non-linear compressor. The overtones from solid state amps that are just beginning to clip don't sound as nice, possibly because of more odd order harmonics created by sharper clipping. So we don't tend to turn those amps up as much. To apply this to modeling - if you are using Helix with amp and cab/IR models into a FRFR, Helix should be doing all the distorting, not the FRFR. Solid state is fine here, but you want to make sure you have enough power that the FRFR never even gets close to clipping. This is especially true of Class D amplifiers which don't clip musically either. I use a Hafler Transnova P3000 300W RMS (150/channel) power amp into my home-made FRFR cabinet (Tremolux style) that has two 10†Eminence Beta-10CX 10†coaxial speakers, with ASD:1001 compression drivers for the high end. If I were using to 10" guitar speakers in the same cabinet, 60 W RMS would probably be more then enough. If you're using Helix as a pedal board into the front of a guitar amp, then you probably don't have any amp or cabinet models in Helix, but will be using distortion blocks to create controllable distortion into the guitar amp which should be run mostly clean. Again, a solid state amp will need to be much higher power than a tube amp in this situation since the tube amp can distort musically while the solid state amp should probably never clip. If you're using 4CM, then you might be getting some distortion from the preamp in your guitar amp, but the power amp (effects loop input) will likely be running clean. ​Another approach that can work well is to use an amp model in Helix, but no cab or IR, and just run that into the effects loop input of your guitar amplifier. You can use its power amp and speakers to get the advantages of a real guitar amp, but have the choice and flexibility of Helix for everything before the power amp. Again, the amp should be running pretty clean for this setup, get the distortion from Helix.

Well, that's probably a good indiction of clock drift in the Helix. I hope this isn't a hardware design issue.

This blog post might be helpful: https://jimamsden.wordpress.com/2014/12/07/using-a-looper-for-solo-gigs/

The mic sim has to be an integral part of the speaker model since that's the only way the IR can be captured.

I read somewhere that the Helix headphone output uses a separate A/D converter. Is that the case and if so: 1. Why 2. Is there loss in output quality from the headphone jack compared to the 1/4" or XLR outputs? 3. Is it reasonable to use the headphone output into a power amp for a separate monitor?

I like the Helix compressors. The LA Comp is great at the end of the signal chain to just glue everything together. It adds a little to the overall tone that's hard to describe. I use Deluxe Comp for the beginning of the signal chain, its the first block the guitar sees. It takes some experimenting to get the effect you want. Use Attack to control pick noise. Use release to control how responsive the compressor is to your playing. Regarding the looper fizz after a few layers, that could still be distortion. You may have no distortion on the first layer, but each layer takes up more headroom. Its the same problem with multiple tracks into a mix buss. Even though none of the tracks may be clipping, as they all add up into the mix buss, it may clip. Try bringing the input level down a bit more.

It's great to have the Matchless, and similar normal/bright, etc. channels of the same amp modeled. But The Line 6 approach of using a different amp model for each one seems sub-optimal. What I'd rather see is a single amp model with additional parameters for bright on/off, channel switching, tone voicing switches, etc. Then we could create footsitch mappings to control parameters in a single amp model instead of having to switch patches to get differen settings on essentially the same amp. This makes more efficient use of patches and block memory as there's less duplication of models. The motivation for this is to get more flexibility from a single patch, reducing the need for scenes and multiple patches. It simplifies using Helix live, and let's us focus more on connecting to and understanding our amp rather than jumping from model to model, never really getting to know the details of a single amp.

My experience with the HD500X was that I always felt I was one tweak away from the tone I was looking for, but I could never get there. Endless study, experimenting and tweaking never seemed to reach closure. Then I got S-Gear and had a completely different experience. All the S-Gear amps are different, but they all sounded great on almost any setting. They inspired me to play more because of the incredible tone and feel. This made me realize that the digital domain can actually work. Now Helix came along and provided a form factor that eliminates all the issues with trying to use a computer in live settings. I'm having the same experience with Helix that I had with S-Gear. All the amps sound good, they're different, not better or worse. All the effects are easy to dial in. You spend more time playing music and less with endless tweaking. This isn't just because of the Helix UI, it's also in the models. No, it's still not quite S-Gear level tones and effects, but it sure is close and sure is easy to use. I have not missed the HD500X at all. And I'm no longer motivated to try to make a computer-based solution work live. Helix is really great.

Its really impossible to give recommended values, there's just too many variables. All I can do is recommend how to determine the values for your situation. First, let's list the variables: Your actual acoustic guitar, its woods, body style, strings, everything that makes it sound they way its sounds How you play the guitar - the picks you use, where you strum, how you strum, angle of pick attack, palm muting style, etc. Your pickup. The body images I captured were from my Fishman Aura Spectrum. These body images were taken from guitars with Fishman under the saddle piezo pickups. The approach is to essentially subtract the IR of the pickup from the IR for the body so that when you play the pickup sound through the IR you get the body tone. If your pickup isn't a Fishman or is not an under the saddle piezo, the body images might work, but they might not sound that good. Obviously the other Helix preamp, EQ, and effect blocks you use. The FRFR you go through The room you're playing in, size, reflections, acoustic damping, number of people, noise level, etc. All these things have a significant impact on tone and how your music is communicated to your audience and reflected back to you - which in turn impacts how you play. Its an extremely complex feedback loop, and one of the reasons its so fun to plan. (As an aside, I notice a similar effect when mountain biking at relatively high speeds on trails - the amount of information you have to process to stay upright and maintain speed is incredible, and our bodies seem to just love to process all that information in real time.) With that background, we can take a look at each IR parameter. Note that other blocks, like preamps and EQ can have similar controls. Low Cut: The lowest note on an acoustic guitar is about 88 Hz. But your hand banging on the guitar body can generate a lot of high amplitude low frequency pulses, including a lot you can't hear. Unless there's some special effect you're looking for (i.e., a bass drum), you probably want to cut these out with the Low Cut (often called a high-pass filter). Setting this to 80 Hz is a good starting point and will work well in most situations. But if you're playing with a bass player too (especially acoustic or upright bass), that low E string can start to conflict with the bass and result in a boomy or muddy mix that doesn't cut through well and becomes indistinct. Start cutting a little higher in this case, maybe getting up to 100 to 120 Hz. 160 Hz is the first octave. That would be cutting pretty high and would probably only be useful for unusual situations where you want a pretty thin tone. High Cut: For acoustic guitar through a body IR, probably never use it. If the image is overly bright, you might set the High Cut (often called a low-pass filter) to 12 kHz or so, an acoustic guitar don't produce too much above that. You can use high cut to reduce noise created by moving your hands on the strings. But generally you want to preserve as much of the high end sparkle of the acoustic guitar as possible. You may need to cut this more if you set the mix less than 100% with under the saddle piezo pickups since these can be pretty bright. Mix: Ideally what you would try to do is to EQ the piezo pickup to sound as good as you can get it, then blend the IR in with that to provide more of the body tone using parallel paths. It all depends on how good your pickup sounds and how much you like the chosen body image. Adding a bit of the piezo can provide better pick attack and a more dynamic tone. Compression can contribute a lot here too. Body images can have a number of pretty significant frequency peaks and dips, that's what makes a guitar sound the way it does, and how they are all unique. When amplified, this may be a good thing or bad thing depending on where you are standing and how close you are to the amp. These peaks can cause additional feedback problems, and dialing back the mix might help reduce feedback. If you are having feedback problems, the first thing to do is reverse the phase. That will often solve the problem until you move to a different position. Level: this has no impact on tone and is only used to set levels between patches so that when you switch patch, the level is not too low or too high. Hope that helps.

This article might be helpful: The Last Word on Class A. It describes different amplifier classes (A, B and AB) and output stage technologies (single-ended and push-pull). The amplifier class and output technology, and whether the amp has a negative feedback loop have a big impact on sag, ripple, bias effect, and bias excursion. Here's a few key takeaways from the article in terms of tone not technology: Fender/Marshall style amplifiers: Use class AB fixed bias, push-pull output stages with a phase inverter and negative feedback loop This makes the amp sound tighter, especially at lower frequencies It generally better for cleaner tones Power supply ripple and noise are canceled because of the push-pull output stage and won't have as much effect. The transition from clean to distorted will be fairly abrupt, and will have more odd-order harmonics which can sound harsher These amps will generally exhibit more sag because of large changes in plate voltage when the amp is overdriven. Some quick notes on preamp vs power amp distortion Preamp distortion is controlled by the amp Drive control. This tends to be be asymmetric (involving cutoff and saturation) and contains a lot of even-order harmonics that sound good. Power amp distortion is controlled by the Master volume. In a class AB, push-pull amplifier, the even-order harmonics will be cancelled causing a somewhat harsher tone. Sag will have a greater compression impact as the Master volume is higher. So you have three volume controls, that behave very differently: 1) Drive that controls the preamp drive and distortion, 2) Master volume with control the volume, distortion, and sag in the power amp, and 3) Level, which just controls the output level and has no impact on tone. Vox style amplifiers: Use cathode biased output tubes and no negative feedback which will generally accentuate sag and bias excursion effects The transition from clean to distorted is smooth and more gradual, providing more control of distortion with the guitar volume control and how you pick So these power amp controls, Master Volume, Sag, Hum, Ripple, Bias and Bias X may be quite different with different amplifiers, and will have little effect if the Master Volume is turned down. This might be why sometimes they don't seem to do anything. Pick an amp with no negative feedback, and run the Master Volume high and these controls will generally have more impact on tone. Regarding the effect of the bias control - whether you bias hot or cold, this will have an impact on how the amp distorts. Bias is used to set the tube's operational point. Under or Hot Biased (lower negative grid voltage): The tube has higher idle current, runs hot, gets more full sounding, then harsh as bias voltage is reduced further, might get muddy at high volumes, shorter tube life, will be noisier, has less crossover notch, saturation distortion occurs earlier (since the tube is already conducting a lot, and pushing the grid more positive pushes closer to saturation). There’s no impact on cutoff distortion (since there's a lot of room to push the grid negative). Over or Cold Biased (higher negative grid voltage): The amp can become sluggish, more crossover distortion but more saturation clean headroom, weaker sounding, can lack sparkle, tubes last longer but amp doesn't respond as well.

I used the acoustic guitar patch described in this blog post Creating a Helix Acoustic Guitar Patch for the first time at a gig last night. I used it with my very old Gibson J50 with an under the saddle pickup. It sounded great. The patch was designed for my Martin 00C15AE, but its in for repair. I had a bit of feedback issues when using the Drive switch for leads. But not enough to get the sound hole cover out. I was probably a bit too close to the PA speaker. The sound was natural, warm and carried well. I would still like to see Line 6 add an acoustic preamp model with tone controls voiced for acoustic instruments, perhaps optimized for acoustic guitar. It would be great if Line 6 could provide some acoustic body images out of the box too. The would really increase the value of Helix, especially when used with a Variax. I would also like to see Line 6 provide a direct out for Variax piezo pickups so we can make better use of IRs with body images. This makes the Variax more flexible and could breath new life into the older variax acoustic 700.