zappazapper

I was thinking about doing something where I record a guitar track in Reaper direct, reamping it through my Helix in 4CM with my amp, recording the direct out, recording one pass with a preamp model and another with the same full amp model, flipping the polarity on one and comparing the difference. Like, try to find which settings null out as much as possible, and maybe that's as close of a representation of what the power amp in my own amp is doing, in the same terms as the Helix parameters. But there's a lot of variables there. I would have to select an amp model that had a power amp that is similar to my amp, and I don't really know enough about power amps to know which one that would be. The .50 Cal is essentially a poor man's Mark III but what's essentially different between it and a Mark series amp is the straight Class A/B power amp instead of the Simul-Class thing. So I don't know how useful that kind of approach would be.

https://www.aikenamps.com/index.php/what-is-sag I'm not suggesting that Aiken Amps is a particularly credible source of information, but it was the first thing that popped up when I googled "tube sag". It mentions rectifiers, transformers, and filter caps. I know the transformer is part of the power amp, but what about rectifiers and filter caps?

That is essentially what an impulse response is, isn't it?

Is it possible that both preamp tubes and power amp tubes experience sag, and that the preamp models are modeling only preamp sag and full models are modeling both?

Well, I think it's part of the same conversation. I mean, I get that it's entirely possible to get useful tones by doing things that are completely wrong from a technical point of view, but let's not forget that Helix is a modeling processor, with the supposed goal of accurate representation of the amps being modeled. IIRC, you were part of the discussion I started about impedance of the loops and why my amp sounded "screamy" in 4CM. If I hadn't had that discussion, I would have never figured out that the issue was actually that by placing a buffered device between my guitar and my amp, I wasn't loading my pickups in the same way. In that case, "how does it sound" was being affected by a technical issue that I didn't properly understand, and now that I do, it sounds exactly like it does when I plug straight into the amp. Y'know, I saw a YouTube video the other day where someone was measuring the effect of the Bias and Bias X controls on an oscilloscope and I think it may have been him. And I didn't put two and two together, but that's the guy that's always on about the 5150 III, IIRC. Thanks for the tip. I'll check out his stuff and maybe contact him with some questions.

It's my understanding that Sag is a phenomenon that occurs more in the preamp than the power amp. I only say that because the parameter is available in the Preamp models while Ripple, Bias and Bias X are not.

Thanks. Ya, you had the .50 Caliber, I have the .50 Caliber Plus. Two 6L6s, sockets on the chassis. When I started having problems I deep dove the Caliber series. Although the EL84 versions might have more "personality", it seems like mine has a more dependable design. The amp tech said that nothing that was wrong with it was unusual for a 30 year old amp.

I run my LT in 4CM with my Mesa Boogie .50 Caliber Plus. Because I've only had the Helix for a year, and because the pandemic has offered me little opportunity to play (I took it as an opportunity to take a break from music after gigging almost every weekend for a decade), I've almost exclusively used the .50 Cal preamp on all my patches instead of amp models. Now that things are picking up and I'm playing more, I'm starting to become more interested in experimenting with the amp models. Just to get it out of the way, I want to state for the record that I know that using 4CM makes cabinet models basically unusable, at least if accuracy is any factor at all. No cabinet model is going to sound accurate coming from any of my speaker options, and at any rate, what's being modeled is a MIKED cabinet, and that's a whole other thing entirely from an amp in the room. So at least in terms of using my Helix as a live-performance device, I have no plans at all to use cabinet modeling. What I'm wondering, however, is whether or not I should stick with Preamp models for the same reason (power amp modeling is unlikely to sound accurate through a tube power amp... maybe?), or whether I can use the full Amp models with their power amp modeling. Just before I got my Helix I had my .50 Cal serviced - I was getting serious sparking inside the amp, and I believe the amp tech said it was the bias cap, and while it was in there I had all the filter caps replaced, and I replaced the power tubes. https://www.thetubestore.com/tung-sol-7581a I ended up getting these. At the end of the day, I'm really not a roots/country/blues player, and the .50 Cal is not the ideal amp for those styles anyway (it's sister amp, the Studio .22, with its lower wattage power amp using EL84s is much better suited). It's a rock amp, dare I say a heavy metal amp; the kind of amp where you get your dirt from the preamp. And so tubes described as having more clean headroom and a balanced frequency response seemed to be appropriate for the amp's intended purpose, and also how I would be using it: with an amp modeling multi-fx. And so, since I have tubes that are, in theory, giving me all this clean headroom and a relatively flat frequency response, I'm thinking that maybe I can use the power amp modeling in the Helix to some degree. But instead of just asking for anecdotal opinions on the matter, what I'm hoping is that someone can point me in the direction of being able to actually run some tests on my power amp to see how it performs. If my power amp is already providing the characteristics that are modeled with the Hum, Ripple, Bias and Bias X controls, then I might have to live with just using the Preamp models. On the other hand, if my power amp is still pretty linear(?) at full stage volume, then maybe I can get some use out of these controls. I have an pretty good audio interface for testing (MOTU 896HD) and Room EQ Wizard (REW) for software. I'm assuming that I should be able to send test signals into the FX Loop Return and measure what comes out of the Direct Out, as it is an attenuated line-level signal that is tapped off the power amp. Or maybe I need a load box for this? So, a few questions I would like answered... Is REW the right software for this? What am I looking for in REW, assuming it is? How would the power amp controls modeled in the Helix manifest themselves in testing software? How do I measure how much "Hum", "Ripple", "Bias", and "Bias X" my .50 Cal power amp has? Any advise is most appreciated. I've received some very good, detailed technical advice on this forum and I look forward to another interesting and informative conversation. On the other hand, if all you have to offer is that I shouldn't bother thinking about this kind of stuff, thank you but I'm not interested in a discussion about why I'm interested in the things I'm interested in.

That's a fair concern, if you want the latest and greatest. IIRC the main project manager has said that nothing like that is coming down the pipe anytime soon, although there are many reasons he could be saying that, and it might be that not all of them are "because it's true". At any rate, IMHO I can't really think of much that has to be improved from the hardware side. More processing power is always a good thing, especially since the CPU-hogging polyphonic effects came with 3.0, but other than that, all my gripes are about configuration and control, and I'd rather they spend their energy making THIS Helix better in that respect than building a new one. But that doesn't mean they're not, so I certainly can't reassure you that they aren't. Tough call.

I have four Alto TX10s. They're great for my little jam room but I took one along as a guitar amp once with my X3L and it didn't really work out. I'm sure I had some gain staging issues but it didn't seem to have the "burst" power of a tube amp. Like it could be loud but it couldn't be dynamic, like when you have a clean lead country tone, like a cranked Deluxe, and you dig in with the pick on the low strings and it just goes POW!! I couldn't get it to do that at stage volume. I think if I used it more I could figure out how it works but there really isn't a good argument to bring it instead of the Boogie combo I have that does it at really any setting, other than the same curiosity I had the night I tried it.

K, but, I mean, if it's a multi-fx designed for guitar, then the input would be designed to have a level that is appropriate for guitar. Audio interfaces have trim pots because there are a range of sources that could be plugged into them, all with different output levels. Yes, different guitar pickups have different levels, but more or less are in the same ballpark. And the gain knob on a guitar amp is almost never used to set a level that is appropriate for the circuitry, rather it's used as a tone shaping tool, usually by setting it to a completely inappropriate level for the circuitry. And so the different output levels of different guitar pickups IS as much of the uniqueness of one guitar vs another, as much as frequency content is. So I was just pointing out that it seems like a funny exercise to negate one of the fundamental differences between two different guitars. AFAIC the lower level of a single coil guitar is a big reason why I would use a single coil guitar. Having said that, I'm certainly not saying it shouldn't be done. To each their own, and in all honesty, I've done plenty of investigating myself on how to make one type of guitar sound like another, just for the opposite reason - I only owned the one guitar, and wanted it to sound like another for some songs. That makes more sense to me than making two guitars sound the same.

Yes, you would create a Split-Y block by pressing the ACTION button and moving the AMP&CAB block down to Path 1B (you might have to move the Split block to the right place by using the ACTION button), then move the Merge block also down to Path 1B (again by pressing the ACTION button) to create an output on that Path. Then at the Output blocks you set your desired outputs, probably 1/4" for your amp and XLR for the PA.

If I was doing two guitar tracks on a song using a VST plugin for the amp sim, one on the Les Paul and one on the Strat, I would adjust the input gain so that the Les Paul wasn't clipping, then I would use the same input level on the Strat and adjust the gain on the amp sim if needed. I'll accept that the Helix is technically closer to an audio interface than a guitar amp, but I think you treat it like it's a guitar amp. Just seems a simpler solution to have a volume block on a Snapshot Bypassed footswitch than to get into janky hotwiring schemes using the mic input, and only because you couldn't assign a footswitch to the gain control of the amp and have it ignore Snapshots, because... https://line6.ideascale.com/a/dtd/Controller-Assign-independent-of-Snapshots/1000019-23508 Edit: see what I did there?

I can't say for sure, or at the very least I don't want you to spend money based on my assurance that it will. But I will say that from what I gathered from searching this forum for answers to my own switching issues, it seems that Mesa Boogie amps are generally the ones that come up the most for having switching issues. I don't recall Marshalls coming up that much as far as the switching issue. The issue with Marshalls seems to have more to do with 4CM and the parallel FX Loop that some of them have and the adjustable loop level. I have a JCM900 that works fine (it has a serial loop and the loop level is easy enough to figure out), although it's one of those ones that doesn't have separate clean and dirty channels, only a switchable dual volume controls, like a solo switch, which I wouldn't use with the Helix because it's just easier and more versatile to do a solo boost internally on the Helix, so I've never tested it. There's really only one way to know for sure - get your hands on one and see if it works.

Isn't that the whole reason for using a different guitar?

You said... I was just pointing out, as you did, that the Ext Amp function doesn't work perfectly for every amp, but that there are MIDI-based options that might be able to help. This is what I ended up finding: https://amtelectronics.com/new/amt-fs-2midi/ It's the only MIDI-compatible amp switcher that has two footswitches and both sends and receives MIDI CC messages. I wouldn't assume this works with every amp either, but if your amp isn't compatible with the Ext Amp function on the Helix, this might be the first thing to try.

Again, it's my suggestion that once you have the chance to try the LT, and find out that the models it has sound as good or better than your pedals, and that with presets, snapshots, and the ability to assign multiple bypass-states and parameter controllers to individual footswitches, that it's much easier to control than using individual pedals, you're going to have plenty of room on your pedalboard for an LT, because your pedals won't be there anymore.

AFAIK, the XL doesn't come with any more processing power than the normal Stomp, just more switches, so it's not going to help you get the AMT off the board any better than the Stomp.

That's the way some people interfaced their amps with their multi-fx units before multi-fx units came with FX loops of their own. With an FX Loop on a multi-fx you can do what's called the 4-cable method (4CM). Guitar > multi-fx input Multi-fx FX send > Amp input Amp FX send > multi-fx return Multi-fx Output > Amp FX Return Essentially it puts the preamp of your amp into the FX Loop of your multi-fx, which on a unit like the Helix is programmable, which means you can choose to use it or not just like any block (so if you choose to use an amp model, your signal is not going through the amp model AND the preamp of your amp, which would change the sound of the model) and you can place it anywhere in the signal chain, so you can put some effects before it and some after, just like if you were using some pedals in front of the amp and some in the FX Loop of the amp. It's a much more flexible way to use a multi-fx with an amp, but there are some downsides. Mainly that every device has its own input impedance which will load the pickups of a guitar and change the sound. As a multi-fx is inherently a buffered device, it blocks the input impedance of an amp from loading a guitar's pickups the same way, so when 4CM first became a thing, it was a little disappointing because it rarely sounded the same as plugging directly to the amp. The solution on the Helix is the variable input impedance feature - you can set the Helix to have its own input impedance so that it loads the pickups of your guitar in a way that's more similar to your amp, so it will sound closer to what your amp sounds like connected directly. Now, the way you've been connected to your amp would already block the impedance of your amp from loading the guitar, even if you weren't using pedals, and since you've been using it happily it doesn't seem to be an issue for you. But pedals also have their own input impedance, and when you describe that your treble booster "needs direct information" from the guitar and amp, what is more likely to be happening is that it has an input impedance that loads the pickups on your guitar in a particular way that makes it work the way it does. If you put that pedal into the other FX Loop of the Helix, you might be able to find an input impedance setting that would make it sound similar to connecting directly to it. Moreover, there is an "Auto" setting on the input impedance feature which changes the input impedance depending on the first active block in your chain, so the Rangemaster model would come with its own impedance setting to make it work best, and since input impedance as it relates to your amp doesn't seem to be an issue, just leaving it at the auto setting might be the best strategy for you. What i would advise is to find somewhere where you can rent an LT and see if you can make it work without your pedals (your guitar switcher is probably fine to use if it's true-bypass). Every pedal you're using has a counterpart on the Helix, and many people have gone in thinking that they need to keep some of their pedals and found that the Helix does everything just as well or better.

Guitar switcher - you might not be able to keep this, as the input on the Helix has a variable impedance feature that needs to be connected directly to the guitar to work. I think if it's a "true bypass" pedal, as opposed to a buffered pedal, you might be OK. What's the make and model? I'm sure someone on here that knows more about that stuff can chime in and give more knowledgeable advice. Wah - the Helix doesn't have pressure sensors in the expression pedal but it does have a feature that allows a block to be turned on and off depending on the position of the expression pedal. I don't use this feature, so again, maybe someone can chime in about that but it seems to me that you can get the Helix to work in a similar way to your wah. Not to mention that again, you probably don't want to put that between the input of the Helix and your guitar because of the variable impedance feature, as it seems to me that it would be very unlikely that a wah with such a switching mechanism would be true-bypass. Treble booster - again, what's the make and model, and does it have to be THAT treble booster? Because the Helix comes with a model of a Dallas Rangemaster and a host of other overdrive and distortion models that I'm sure can work well enough to get your treble booster off your board. Noise gate - the Helix has a basic noise gate integrated into the input block, plus three different noise gate models in the dynamics block. The only thing it doesn't have at this moment is a gate with a loop (basically it keys off your input signal but cuts the signal AFTER the distortion and amp), and your gate is not one of those so I think you can use the Helix gates. AMT V-1 - Yes, the Helix is going to be a much better option for amp modeling than this pedal. It seems to me that you can get everything off your board and just use the LT. Much lighter XD

You might consider using a DI box from your Send jack. Unbalanced cables will pick up interference and wireless mice are essentially radio transmitters. Use the shortest 1/4" cable you have, connect it from the Send to the DI. The XLR connected between the DI and your interface is a balanced cable and should cancel out that interference.

The Helix with a good tube amp in 4-cable method is a pretty deadly combination. It's probably a better way to go then an FRFR speaker, because what you're hearing is the sound that you would get from a microphone in front of an amp, as opposed to a speaker in the open air. The downside of 4CM is that you probably want to stay away from power amp and miked speaker cabinet models/impulse responses, as your power amp and speakers will color the sound on their own and you'll never get an accurate representation of the models. Even still, every amp in the Helix has a preamp-only version that offers a lot of flexibility for 4CM users. I have yet to have the opportunity to try a Powercab, which is an interesting idea in that it models JUST speakers, not miked speaker cabinets, which in theory should sound more like a real amp in the open air. But I'm in no rush for that because as much as I'm all in on digital modeling, I do love the sound of my Boogie.

Forgive me, but taking the LT out of contention because you want to "save your back" seems a little silly to me. It's not that heavy. Your back will be fine. And it covers everything you'll ever need from a multi-fx (some, like me, have reported issues with channel switching on some amps, but as @spaceatlmentioned, there are MIDI-controlled external switchers that are quite affordable). I bought the LT so I wouldn't be constantly trying to squeeze things out of a unit with limited processing power, and now I'm trying to squeeze things out of the LT. You'll be surprised how quickly you hit that wall when you discover how versatile the Helix line is in terms of control, because with the ability to assign multiple blocks to footswitches, and also the Snapshot function, you can do so much with fewer presets. The only downside is that you need the processing power to have all those blocks in your presets waiting to be engaged, which is why I would encourage you to reconsider the LT.

I wouldn't be so quick to assume that the Spider can't be a viable option for bass, or anything really. It's got a full-range speaker system. I'd start with trying to dial something in with that before spending money unnecessarily.

Ha. I didn't think it was pretentious at all. I wish I could make that claim myself. I was just making a joke. No changes required. I think musicians of all levels would like to hear from full-time players that the stuff they just bought has survived the rigors of pro-level gigging.