Recently I have been gigging using the Boss GT-100 direct into a PA, due to playing in a few quite small rooms and I wondered how it would perform in these situations (and if I could actually get used to it!) First off, I should say that I am very happy with the unit for recording, and will be putting up a full review at some point, and on the whole it is a very versatile unit and there are a couple of features which I totally love!! Here is a little sound clip of the GT-100 recording of a improvised solo over Steve Vai's Tender SurrenderI was quite happy with that, especially when mixed in the rest of the track.What I will be discussing here is how it performs direct into the desk and not how it performs as a pedal board into an amp (I am yet to try this live, but I will!). On the whole, I am quite impressed with the unit, it performed really well. The set up was as follows, guitar into the GT-100, this fed directly into the PA and I then got a feed directly into my monitor. It was a strange at first to have no amp sound, but with the GT-100 set to Line/Pa output, it actually sounded very full and as expected from setting up patches at home, there was a lot of bass which I had to dial out. Dialling this out was quite easy thank to the controller knobs on the front panel which are linked to main parameters of the amp. I thought that this was really useful addition and made it feel like using an amp (even if I did have to bend down a lot further!). Having said that, I did find the controller knobs problematic in another regard as they turn very, very easily and there were a number of times during the gig when either my massive foot or my lead got caught on one and managed to turn it. This ended up with my pedal assigns changing a couple of times and that was pretty annoying. I guess I could technically tape them down to prevent this. (*) Using the GT-100 means that setting up (and loading in) is SIMPLE!! One little flight case and guitars, and the one cable and plug the guitar in.SoundsThis is the most important thing and I found on the whole it sounded pretty good and very consistent. It wasn't a valve amp, it doesn't respond like a valve amp, but does anyone in the audience really notice? Probably not, so in that regard it is only me whom is really bothered. Sound plays a crucial role in one's performance and if the player isn't happy it can impact on their performance, and I am actually quite affected by this, but having said that, I found that on the whole the GT-100 performed very very well, and that some of the issues I had will be fixed with time and tweaking (and reading the manual perhaps!)Firstly, I should describe how I approached using the unit, which might have some impact in my experience and might be different from someone else's. I am not someone who tries to replicate in great detail the exact sounds found on recordings, I like to get a ball park sound, and try and get the effects reasonably right. As such, I tend to have a kind of simple is set up. I mirrored my previous set up running pedals directly into a clean amp in the modeller and this worked well, although I got the benefit of a second amp should I want to use it (and I did). Basically, I choose a clean amp model (the Advanced COSM Natural Clean model), which I think sounds fantastic as my base amp, and the Stack Crunch as my 'slightly' dirty channel. I think that modellers do clean very well, and this model is quite responsive too, and if you add a boost you can actually get some nice crunchy, full tones, but they aren't too responsive to volume control interaction, but I still think they pretty fantastic.So I had my set up running some pedals into the amps models, and then a couple of time based effects after the amp (something I can't achieve with my Blues Junior but can with my Egnater due to the effect loop). Before the amp I had the (Wah on the expression pedal), Compressor, OD (set to Mid Boost), FX 1 (Phaser), FX 2 (T-Wah) and then I had Channel 1 (Natural Clean) and Channel 2 (Stack Crunch), after the amps I had the Chorus (I don't use it and wish you could assign it to something else), delay and finally reverb. I set up one patch for the whole gig and set the unit to patch mode (a great feature, just like the Nova System)In preparation I did tweak the amps more detailed settings such as speaker cab and mic positioning. On the whole the speaker modelling was shockingly bad in my opinion, the only thing that seem to work was the 'original setting'. I know I have been spoilt by having some fantastic speaker modelling software (Live G in Digital Performer) but this was pretty ropey in my experience. Having said that I was reasonably happy with the 'Original' setting and with a bit of movement of the microphone and microphone choice, I was happy enough!I was also particularly impressed with the Stack Crunch model, and it does sound very powerful and throaty through the monitoring system I used, paired with a OD drive pedal (I am using the mid boost model at the moment in this set up, but did try the OD-1 model previously), I found I had a great rhythm tone and and a great saturated lead tone! It is still early days, but I think this really has potential for exploration, and on top of that I even got a compliment of my distorted tone. Another factor which is important for live use and something I found particularly heartening with the GT-100 was how it seems to sit well in the mix. This is probably because I wasn't drowning the stage with amp noise, but also how the actually amp sounds. With the GT-100 you also have the added bonus of being able to turn everything down using the expression pedal (depending on where you place it in the chain) without loosing the tone of the patch (if you put it last), this is very useful as you can just adjust the overall volume slightly if it is over powering in some songs. I did have a slight issue with the volume pedal being too sensitive to my big feet, but I have just looked in the manual (first time) and found that you can adjust this. So using the Accel/CTL pedal I was easily able to switch between a lovely clean sound and a nice crunchy rhythm sound. Kicking in the OD (mid boost) pedal, gave a nice blues tone with the clean amp and a nice saturated lead tone with the stack amp, this worked perfectly for me. I would like the option to add in another distortion pedal, but I can just use another mirrored patch for this (which I will). I did have a few problems with inconsistent levels but this is just a matter of tweaking and getting things right, but there was a bit of a jump between the two channels.Using the GT-100 in pedal mode, basically I have one pedal board to work with (until I switch patches), to engage pedal mode was very simple and just needs you to press the two Bank Up/Down buttons together. I didn't have a problem with this, but I did have a problem with the controller knobs mounted on the front panel. When pressing FX2 (or Bank Down) switch I kept catching the small controller knob with my foot, it is very sensitive and in pedal mode if you change the value with these switches it actually changes your pedal assigns. So you go to press what you think if assigned to FX1 and you discover that it has completely changed it's assignment. One thing I really, really, really (Really!) love about the GT-100 is the multi-assignment of parameters to one of the controller pedals, this is fantastic because you can set up the pedal to change multiple parameters with one pedal click. For example, you can increase the level and gain of an overdrive and also increase the delay time and level for a solo, all with one pedal press!! Now that is so cool, and the potential is quite limitless. I am looking forward to exploring this more, especially for setting up certain triggers within songs.One this I will say though the Touch-wah sounded great at home but like a demented duck live, it sounded horrible, will have to tweak. I should add I have tried a number of envelope filters and I think I am very partial to my EHX Q-Tron, so I am probably bias! Also, I switched off the Loop pedal and used this as another assign (more useful perhaps!). Oh and yes I hate the power supply, ROLAND why can't you make it an IEC connection? Would it really take up that much space? I hate these flimsy laptop PSUs!!!!! I hate them, and I have ZERO confidence in them live, they trail all over the place, and are very very flimsy and won't take being accidentally stomped, pulled out or worse if they break, you can't just swap them out for another cable! This plus the fact there is no balanced XLR output, means this unit isn't a professional as I think it actually is. This is very disappointing.I thought it would be easier to sum up some of the key points in a bullet list.Pros

Consistency in sound reproduction. i.e. sounds sound the same from gig to gig!
Multi-assignment of parameters (this is awesome!)
Switching between Patch and Pedal mode, a little bit easier than my beloved Nova System (only a little bit though!)
Connivence! Oh yes this is so convenient, light and takes seconds to set up!
I really love the Wah pedal, easier to engage than the cry baby's I have and no 'clunk' on switching.
The clean sounds sound fantastic and work well in a live setting, they also work well when driven with FX pedals.
Some much room for exploration.
You can jump right in without reading the manual (but it helps!)

Cons

Controller knobs turning by accident! (*)
Getting the balance between levels (okay probably my fault this one!)
NO balance XLR OUT WTF to that!!! I am pretty shocked at that omission, which meet you need to use a DI box or an XLR to Jack lead (not ideal!)
Power supply is pathetic and why can't it be an IEC connection? cost??
Okay, yes, it just doesn't feel quite right, especially when adjusting volume on the guitar in the crunch range
I had issues adjusting the volume pedal, I think there must be a volume curve somewhere to set this to my big feet, but I found that the volume jump at the end of the range a bit too much.
Wish I could assign the Chorus effect to something else (I hate chorus!)
Oh the speaker modelling is SHOCKING, sorry but it is pretty hideous, it seems the best result you get is by just leaving it on original! (then again maybe I have been spoilt!)

I would say that some of the things I have put down as cons are about 50/50 my fault and the unit! Also, it goes to show how easy the unit is, as I have done all of this without once using the Manual, and of course I will put my hands up and say that some of the issues are down to me!I am very very very very excited that Roland have continued the development of this unit and are about to release a Version 2.0 free software upgrade for the unit, particularly for me that this includes audio to midi implementation, this is pretty phenomenal! Well done Roland!!Things that I am looking forward to trying

Using the GT-100 directly into my actual amps (I hope that I can switch channels on my Egnater with it too!)
Trying two of the same amp models but with different settings (I.e. The Natural Clean model with the gain cracked in channel two)
How much fun and ease in performance the multi-assign makes this, I have a lot of things I want to try!
The acoustic simulator!

SummarySo in a nutshell, for me it perfectly possible to gig with just the GT-100, I do miss the 'moving' air, control of dynamics and tone of my other amps. But being brutally honest, this produces a close approximation and is a lot less hassle when it comes to loading out. I mean my existing set up is already pretty minimal, but this is even more minimal, and if they had included an XLR input it would have been even quicker!! The other thing that I am being brutally honest is that apart from the people reading this, 98.7% (I made that up, it is probably more like 99%) of people at a gig won't notice or even care what the guitar sounds like or what is generating it, as long as it works with the band and as a player you can deal with it. I have to say the GT-100 ticks those boxes. Does it sound exactly like I would like, well no but then again I am fussy, and again having said that, once the band fires up and temporary threshold shift kicks in, even as a player you start to loose definition in your hearing. I wear earplugs and so I am always getting a reduced (in the mid-frequency range at least) sensation of what the amp is actually doing. So, the GT-100 is a good solution. It is an extremely versatile unit and the ability to multi-assign parameters to a footswitch is fantastic, on the whole the effects are very good (sorry but I do prefer TC Electronic Effects and my Nova System, but until they make the changes I would like to the Nova System then this is the one) and the amp modelling in the advanced selection is pretty fantastic too. I think it is a good solution and it helps keep stage levels down too (always something to please the sound engineer!). I will certainly be using this a lot more in future!!EnjoyPeaceNeil (*) I just randomly opened the manual and found that you can actually lock the knobs! Job done!! I am more impressed now.