So back to my question from a year ago: Can the onboard Tubescreamer boost, especially in 4cm method? The answer ist a little complex: In 4cm the Tubescreamer ist right before the loop, which contains the preamp of the tube amp head. That means between the Tubescreamer and the input of the amp head there is another gain stage: the send level of the loop. And that send level is crucial for the 4cm to sound natural. With my Laney GH50R i have to go as low as level 55 so the amp input (expecting a guitar signal) does not get overrun by the line level of the Core's loop send. BUT when i put the send that low, it compensates the level setting of the Tubescreamer in front of it. So in order to boost, you have to run the send of the Core's loop exactly at the right level and when you boost with the screamer, you easily get into the territory of digital harshness, because of the tube amp input clipping. So yeah, it's not really YES or NO. The GT can boost somehow, but not like a real Tubescreamer, and that is because of the impedance mismatch from loop send to real amp input. It's the same with the Digitech GSP1101, and even worse with Line6 HX Effects (because it can't have different levels for send and return, it's one loop one level). One day someone will build a 4cm device that does not cause impedance and level mismatches between line loops and intrument inputs, but right now we are just not there, it seems.
Superb Dan thank you. I am an old guy and just got the core a few days ago. I want to run it 4cable with my Marshall AFD. Initially I thought effects only. But incredible to learn I can have a clean channel too 😮😎 Superb tutorial. What an amazing honest and humble guy, helping others. Thank you Dan 🙏🙏🙏
Such a helpful video Dan! Really opened my eyes to what it can do. The other vid on the overlooked settings really made a difference too!! I had the input setting way too low!
Ah man, so glad it was helpful to you. I really do love the unit once the initial ‘house keeping’ is dialled in for your rig. Insanely flexible.. It’s just avoiding the option paralysis that I struggle with at times 🤣
Great video. I’ve had a GT100 for about 5 years and it’s ridiculous how many different set ups you can achieve. I am using 4 cable method into a Roland Jazz Chorus so love experimenting with Roland JC cleans and then A/B into GT100 preamps for gain tones
this is a great video. I just exchanged my Line 6 HX Effects unit for the gt core and what an amazing upgrade. The sample rate and bit depth is already higher on the boss unit i believe at 24 bit, 96khz, so the digital effects all sound better than the line 6 unit to me. secondly, there was a bad batch of line 6 units that have a noisy hum going through the effects loops that can't be mitigated, this was my main issue. I ran my tube amp 4 cable method just like i did with the line 6, but into the gt core and instantly solved my hum and noise problems. it's way more versatile, the line 6 doesn't even have the ability to have a global eq, and there are zero amp or cab sim's so its just a win win for the boss all the way around. amazin
@@johnycat7373 Sold it because the GT core runs everything A/D/A, fully converting even your dry analog signal to digital, which is a big no no for me. If you're running analog effects and using analog cables, into an analog tube amp, why the fuck would you want to convert your dry signal to digital? At least the HX effects left your dry signal alone and just put digital effects on top.
Excellent video. That is how I use my GT1000 Core. I mainly bought it for Reverb and don't use the onboard amp and speaker modelling. It is useful to have the ability to put a delay in front of your amp sometimes and this is how to do that. You can of course put another delay after your valve preamp in the loop. So versatile and a brilliant device. Stick it in your bag when you are working away and take a guitar with you. Use the amps and speaker modelling that way. Best of both worlds.
Best of both worlds pretty much sums it up for me. I love units like this that can add flexibility but still leave the tone alone when needed. Thanks for watching 👍
GTK today seems to be the best solution to play with tube amp in one rig. As it is: 1. The most compact FX board on a market with AMP CONTROL feature. All other like Line6 HX Effects are much heavier. 2. Has great FX sections and modern 32 bit core - you shoudn't want to use GT8 or GT10 in front of Your valve preamp today 3. Can be effectively used both for recording and live jams 4. Has IR support making it perfect for recording together.
Certainly one of the most comprehensive, thoughtful and detailed application reviews out there... cannot understate the FX comment @ 5:46 Been using a GT-100 in 4CM mode for a long time with multiple Mesa models. Placement of the S/R block in the chain seems to yield varying results. I've experimented with the divider in single mode, then in dual mode before the divider, in parallel (split path) and after the divider. It seems when the divider is in single mode there is noticeable overall signal drop that requires boosting vs running the split path in stereo and the 4CM after, which produces a larger signal to the S/R block. Setting the sum to Pan L/R definitely lowers the signal to the S/R, but still noticeably more signal vs single mode divider. There's a number of adjustments in this signal path you could use to compensate, ie: S/R, master level in the MST block, manual vol knob, etc. So if setting up the divider in single mode, where would you suggest boosting the signal to compensate? Hope that makes sense. Oh great playing too :)
Thank you! Glad the video was helpful. I would experiment with your amp a bit. Personally I would look towards the back end of the chain so return volume and master 👍
Hey Dan, I am currently on the quest for a nice multifx compact processor that can do 4Cm, amp channel switching and also, like you show, using clean preamp sim because my DSL20HR don't have a real clean channel. Your video definitely got me on the GT1000 core ! I am going to buy one § Thanks and i subscribe immediatly !
GT1000 CORE has a really annoying hiss problem when used in 4CM. It is quite perceptible when used with the drive channel of your amp. That's the reason why in the video there is a noise gate after the Send and Return block. The problem is bad digital to analog converters.
Hi Dan, very comprehensive and informative as always. Some lovely little bits of playing and dynamics. Really be interesting to see this new board when its done.
Hey Ben Love what you do Thank you Brother Im coming too the Uk to do a radio tour would love to meet up will be in Yorkshire and London as well as going to Ireland afterwards Cheers My Friend !
Hi Dan, cheers for making this video. It helped me finalise my pedalboard inconjunction with my jcm2000 & existing switcher & separate pedals. Also, the clean preamp suffered a volume drop due to a valve so using your method an AIRD clean preamp now goes directly to the power stage for my clean tone. Thankfully the crunch channel is still fine & will hopefully last until I can get it in for service.
What I didn't hear you mention in this video is that the beautiful overdrive sound of an amp isn't from the preamp, it's from the power tubes and transformer being overworked. An effects send won't cut it. What you need is a chain like this: Guitar-->GT1000-->Preamp-->Poweramp-->Marshal Power Brake (no sound output, so what's the point?!) plus, either Poweramp-->Aux Output from the transformer-->GT1000 (post POWER AMP loop)-->PA amp-->guitar cabinet speakers-->mic-->record or Poweramp-->Aux Send from the transformer-->GT1000 (post POWER AMP, include speaker cabinet sim and mic sim)-->record I don't know how common amps are with this kind of Aux Output are. You MUST have one that is taken off the output transformer. You do NOT just want the preamp out, you HAVE TO HAVE THE POWER TUBE/TRANSFORMER OUT. My Mesa Road King has one, as does my Ampeg PF-50T. (The Ampeg also doesn't need a power brake--it has the equivalent built in.) So that does what you suggest, using the GT1000 both as a before-the-amp FX, AND as an after-the-amp FX, but, it is an after-the-POWER-amp FX. Truth be told, I've had my Mesa 20 years and only played it about four hours total with any effects between guitar and amp. But, I've had this whole effects chain with a Kurzweil multi-effects unit. The PA amp is stereo, and power the Mesa's 2x12 speakers in stereo. The nice thing is I can play super-clean as loud as the speakers go (it's a 300W amp) or play with all gains on 10 at a speaking volume, and either way I have stereo reverb and echo coming out of the combo speakers. And there's no tone suck!
Hello friends! I just ordered a GT Core. I have a Boss Katana 100mkii. Should I use 4 cables, or set the output to the line in for the Katana..and just plug straight into the back? Thanks!
Outstanding demo! I was looking for this to be sure I could use this in 4cm with my 5150III amps! Fantastic tones and great playing as well. Looking forward to getting this now! Thanks!
Awesome video, thank you! I was thinking of 4 cable method if I buy the Boss core unit with my EVH 5150 III combo, and now I'm totally sold! I used to do it with a Kemper and it was great, I think this will have even more creative options running them together.
Nice one dude. This seems to be an amazing bit of kit. That picking dynamic feature and the ability to add a clean channel (or any amp sim) bypassing the tube amps preamp is awesome. For the size of it I think even just adding it as a “utility” pedal on a board would be a good shout, albeit about the most expensive way to do that 😆
In the 2010s, I was in a couple of bands whose main venue was performing on battery power in the New York City underground (what we Americans call the subway). During my last year doing that (2019), I had a Boss ME-80 and a Roland Cube Street EX amp and developed a practice of plugging my microphone into the guitar channel and my Boss modeler into the mic channel (like plugging into a PA input). I’ve tried sticking with that type of practice whenever possible, preferring only hearing the tone of my modeler without needing to balance out the preamp of the modeler against the amp it’s plugged into. (I also like plugging into a bass or keyboard amp with subwoofers.) Is the same outcome within arm’s reach on the GT-1000 Core?
that's not a bad piece of kit ive only just scratch the surface and you can have a lotta fun with that I like the manual patches where you can take a sound you like straight out the box and ad more or less tones and effects manually great fun. its both an effects unit and a pedal box 👍🎸. ive not done the 2 or 4 cable method yet, ive just plugged straight from r/mono out and mono input and its sounds good
Hi! Awesome video! I got an issue, I have an EVH 5150 50W and i can't switch the channel with the GT1000Core. I put the correct setting on the Assign Menu and using the CTL 4.5 input on the side. Not working. Sometimes it will work but it will glitch back and forth between channels... Anyone have an idea?
8:46 "The GT output knob will act as a master volume in 4CM" i've been scratching my head trying to defeat this issue with a Marshall DSL40C, but haven't got to experiment with my JCM2000 DSL 100 head yet. I want to use the channel volumes from the amp, so when i switch to my lead channel on the amp, i'll get my volume boost. This other way described above basically puts the GT1K into the return of the amp and bypasses the Marshall volume controls, leaving the Output Level knob on the GT1K as your amps master volume. I don't want this. Is there a way to put the GT1K into my amp's fx loop WITHOUT it doing this? Any help is much appreciated.
It won’t bypass the Marshall controls unless you are using the preamps from the GTK. You have to have the amps preamp (Input & Send) in the GT fx loop. All the Marshall controls will behave the same but the GTK volume will just be a master. Unless I’m missing something in your setup?
@@DanLeggatt then theoretically using it this way we dont even need a 2-channel amp, because the gt1k takes over the power section, then to boost lead solos you need to alter your gt1k patches to reflect different volumes? this makes no sense to me, as i've always switched to the other amp channel (at a higher volume) for leads. why even have anything other than a power amp at this point? i do like a few of the preamp tones from the gt1k, but using them in 4cm neuters my amp into a straight power amp with no volume control besides the gt1k output knob. way-to-go Boss/Roland! i wanna put the whole thing in my fx loop and still control my amps 2 channels. why even bother with the gt1k channel switching capabilities unless you're gonna frontload it into the input jack? i'm still at a loss (in my mind) that this was even designed this way. i still feel like im missing something here, like a setting on the gt1k that allows you to turn off the internal preamps taking over control of your master volume? seems like a bad design to me, unless you are wanting to edit each patch volume for rhythm and leads.
Yo Yo!! What’s up Dan? Just picked one of these up on the cheap used and have been spamming videos to learn the eco system. Thanks so much for taking the time to create these videos. Looking forward to you making some presets for this one as well. I have your Kemper profiles and they are Top Notch! Cheers, Jason
My Boss GT-5 and my Line 6 floor boards are both rotting and barely work anymore, lol. I really like the looks of that. Boss do tight gear. Those aforementioned processors I got during the 90s. So if anything, that GT-5 has impressed me for being exposed to hillbillies who think they're Sid Vicious, being stored for periods during our summers, when Texas and planet Venus trade climates etc, and lasted 20 years! Since I'm fixated quite a bit on Amplitube and other software, I haven't considered getting another. But I love wasting bill and rent money on gear, so hey. Great demo. It was all comprehensive and stuff. Plus it was explained thoroughly. Hee hee.
The Best video about 4CM ever!!!! Thank you so so so much for this content. Do you think that extracting the sound of the 5150 via the "sub out" adding some IR into the audio interface or a PA, would sound Nice? I mean, your 5150 running through gtk with 4CM and getting out via main out to the real amp cabinet and simultaneously out via the gtk sub out, IR added, to PA( or audio interface)
Thank you! I did actually try and figure this out but I couldn’t get it to function quite right. It seemed to apply cab to the return even though it wasn’t in the same path. I’m sure it was my error or there is a workaround but I didn’t spend enough time to figure it out.
@@DanLeggatt Can definitely be done, need to make sure the applicable GT-1000 SND is configured as a sub-out which is done via Main Menu - Hardware Settings - and change Send 2 to sub out. Then on Output Settings make sure Sub-Out is on 100. Then in the sub-out blocks you can set a different output mode (IR) independent of the main out and also have another global eq just for the sub-out and it should be game on.
Hi Dan great info I have just acquired the victory kraken preamp pedal for home recording will the 4 cm work with inputting into my interface instead of a speaker cab and using my fave ir in the GT1000 And do you plug the output of the preamp pedal into the interface . Thanks for your great info
I tried the 4 cable however when the loop is not turned on in the GT-1000 I am still getting clean signal coming through. I suspect that clean bleed is always there. How can you fix this?
I LOVE your videos about the GT-1000! You seem very knowledgeable, and your playing is very expressive!!! I have the GT-1000 and two 2x12 cabs! I am using the Behringer A800 class D stereo amp to power these two cabs. The sound seems "wrong to me" Any normal amp sounds better. Do you think that Using two tube amp heads (7cable method) with the GT-1000 will get me a genuine tone? one problem wit the GT-1000 is that you cannot disable the "power amp" you can only disable the speaker cabs! Thanks once again
It’s very hard to advise on a solution to why it doesn’t sound right to you. I use the GT1000 all the time with a traditional amp just for fx in a 4 cable method or just in the loop. If you bypass the amp and cab models there is no power amp tone in the GT.
It would be great to hear how the GT100) sounds with low gain amp models and various amp models when connected straght into the front end of a tube amp. I have a new 68 fender twin amp I use as a pedal platform and so far I havent been able to get the gt1000 to sound good in previous amps that I have owned
While you can get decent sounds, it will always be a compromise running any modeller like that. When you think about it, you are running a preamp into another preamp. It can be a struggle to get the 2 to work together. It’s much easier to run into an FX loop return or power amp if you want to use the amp models. I think you would get much better results using the drive pedal models rather than preamps.
Wow. So the CORE version can actually switch amp channels? I assumed it couldn't because it doesn't have the Amp Control on the back like the full GT-1000. You show this at 11:58, but I'm not sure I follow. How do you get it to change amp channels? EDIT: Never mind. Found it. But thanks for making me realize this!
Great advice about getting the signal strengths straight for input and output. I think people tend to overlook this on almost anything (amps, guitars, pedals, etc) and as a consequence declare that the device "it colors the tone". Is there a reason you have set the output where you do? I've tried different levels but found that noon is the easiest to keep consistent since there is an index point there (easily knocked by a clumsy foot), but I'm curious if I've missed something by doing that.
I bought the headrush 8” FRFR speaker for ease compared to an amp. Looking at it, it feels too much for me when I prob should be learning on something simpler.
Can the virtual Tubescreamer boost the front end of the amp, like a real one would when you crank the level control? What are the output settings when the CORE-preamp is switched off, are there any, or do the options (recording, tube stack, tube combo etc.) disappear when disabling AIRD?
The internal TS model can definitely do that. I don’t have a TS to compare it too but it sounds like I remember TS pedals sounding. I set it to either recording and bypass amp / cab or to tube amp FX return.
A quick question! What do you have your speaker setting at for 4CM if you’re doing a hybrid rig? If you’re using a pre amp in the gt1000 for clean out of your valve amp.
Great video, thank you! I just bought a GT1000 core. I think it sounds great with my amp. However it’s got a lot of backround noise. Even with all the blocks and aird turned off it’s noisier than my analog pedalboard. I’m going straight into the input of my amp. I have done all the gainstaging, still a lot of noise. You wouldn’t notice at a gig with the amp turned up. Still, I think it’s too much noise coming from a digital unit. Anyone else noticed this? Thanks/Calle
Great demo, thank you! This is exactly how I'd like to use it, but if you have 1 switch dedicated to the amp channel switching, you are only left with 2 other switches? How do you manage individual effects? I typically like to have independent on/off control of reverb, delay, phaser, and maybe a rotary.
Hi Dan. Could you make a video about setting the levels with the Gt-1000 the 4cm with tube amp? Is it normal to use the Gt-1000 to have a lower volume on the amp? Does it cause any dammage on the amp? Cheers from Portugal 🤘🍺🇵🇹
I see that you switched channels on the EVH but did you have to connect to the foot switch input on the EVH to a port on the Boss? Would it be a TS or TRS cable? Did you have to set extra parameters on the Boss? I am trying to figure out channel switching with my GX100 (I just got it and only spent minutes with it). I can't figure out channel switching on my Super Kraken and I haven't yet tried my Iconic. Thanks
@@DanLeggatt I got the 4cm method working. Is there a best way to run the AIRD amps in the chain. Say put the pre and post of the GTK in the amp effects loop. Thanks
Yes absolutely. Don't really want to send people away from Dan's amazing page and content but check out Simon Mcbrides recent pedalboard build video. He uses ES-8, GT-1000CORE and a load of other cool toys with his amp.
Great video Dan. Just curious, have you tried this setup but with the CORE outputs going direct in for recording? So basically we're talking valve preamp through the CORE's cab sim or an IR straight to an interface or FoH console or something. I understand that you need to run an AIRD preamp in the chain somewhere in order to activate the CORE's cab sim, but you can isolate the AIRD model in a divider and zero its volume to take it out of the mix. What I'm not sure about is if the Speaker Sim block is doing any compensation for a power amp tone, or if it even matters. Just curious if you've tried it, and how it sounded if so! Seems like it could be a great easy solution for recording or gigging with a real amp but without needing to mic its cab. Thanks!
Either! Works great both ways. In fx loops it gives you the ability to move them around in the signal path and turn them on and off if you change presets. If that’s not important to you, I’d just keep it simple and put them in front. Hope this helps.
@@DanLeggatt very cool! Thank you for your reply I appreciate it. Do you hook your amps effects loop then into the return and send of the boss? Or to the main in and out? Thanks that’s my last question I promise :)
Very helpful Video. Which output settings you use with the valve poweramp? I tried to use my gt1000 with my engl poweramp and marshall 1960 cabinet with the internal preamp but sounded not very good
The 'named' Output Selects (412RTN etc) all do some sort of signal optimisation type tone colouring designed to match the assumed cabinet commonly used with that amp type. In your situation I'd use 'Recording' and then go to the L/R Output (Speakers) block and use the drop-down to turn the speaker type off, this way you know there is no cab sim coming through. With that done then go to P001 Premium Drive and use this patch to tune to your cab through the global EQ to remove any obvious tone issues (suggest 8K high cut and then cut/boost highs and lows as necessary to remove any woofiness or shrill). Get P001 sounding good through your amp first before you start trying to build tones with GT-1000 Amp models.
Another awesome video on the 'Core! I never thought of the possibility of switching between the Core's and Amp's Preamp. May I ask you a question: I want to use the Core's preamp and my amp's poweramp. What would be the most neutral output setting for the signal to get into the amp's FX return? Output select "Record" and Speaker Type "Off" sounds pretty good to me, but is it ok for the amp?
Chrizzler, I'm 1 year into my setup with 4cm into my amp's FX RTN. After much trialling I have found 'Recording' to be the best output. What you say above (Recording + Speakers off) is the most neutral. If the speakers are on you are using an IR which definitely colours the tone.
Hi Dan, You've helped me out before - so thanks! How would I turn off amp modelling on the GT 1000 core? I wish to use the device as just another effects pedal. I like the sound of my amp and do not wish to alter it - thanks, Binit
Hey Dan... how are you getting your sounds to your interface? Also how were you getting that clean sound from the boss if yours still running it through your amp preamp that you said doesn't have a clean channel?? Thanks!
Amp is running to a Two Notes captor and then interface. I'm actually bypassing the preamp entirely and sending the GT1000CORE to the return which hits the power amp.
If the amps fx loop is loosing volume you want to adjust the GT output level. Send level will decide how much signal hits the front of the amp. Return level decides how much level comes back to the GTK.
I am torn between getting the GT-1000 CORE or building my pedalboard. My current rig is Boss Katana 100 MKII , EHX Soul Food, Fender Booster and Fender MTG. Considering either buying a delay, reverb and modulation pedals to complete the pedalboard or getting the GT-1000 CORE, What do you suggest ?
The GTK can do so much so you would have room to experiment or expand your tonal pallet. However it depends what you’re after. Single pedals are a bit more simple obviously but after a bit of a learning curve, there isn’t much that this box can’t do.
I believe most of the midi stuff happens on the amp itself. You can put it into program mode and set which channel is recalled per preset. The GTK should automatically send out the PC changes 👍
Hi Dan, I could really benefit from a 30min video chat to talk about my gt1000 core and my valve amp...and some of my favorite pedals. Are you available on a consultative basis?
Another awesome video! Gt-1000's rule! Do you know if Helix and Pod Go have something like the dymamic control? By the way, i have subscrived! Cheers from Portugal 🍺🤘🇵🇹
if i run 4 cable method into my valve amp and i want to change between my existing amp channels do i need a 5th cable to be connected from the boss gt-1000 to footswitch input of the amp?
I didn’t notice any ‘tone loss’ when playing. If there is any change in tone listening back under the microscope, it’s extremely minor. Certainly no more of a change than plugging in a normal pedalboard with a handful of pedals. Obviously depending on your amp, cables, setup etc results could perhaps vary. Especially if your FX loop is passive or particularly finicky.
I have owned the big GT-1000 for a little over 2 years, and I have gigged with it and used it in the studio a lot. No knob or reliability issues at all. It is really well built.
GT1000 Overlooked Features Video - ruclips.net/video/GeGkpyfnUSk/видео.html
So back to my question from a year ago: Can the onboard Tubescreamer boost, especially in 4cm method?
The answer ist a little complex:
In 4cm the Tubescreamer ist right before the loop, which contains the preamp of the tube amp head. That means between the Tubescreamer and the input of the amp head there is another gain stage: the send level of the loop. And that send level is crucial for the 4cm to sound natural. With my Laney GH50R i have to go as low as level 55 so the amp input (expecting a guitar signal) does not get overrun by the line level of the Core's loop send. BUT when i put the send that low, it compensates the level setting of the Tubescreamer in front of it. So in order to boost, you have to run the send of the Core's loop exactly at the right level and when you boost with the screamer, you easily get into the territory of digital harshness, because of the tube amp input clipping.
So yeah, it's not really YES or NO. The GT can boost somehow, but not like a real Tubescreamer, and that is because of the impedance mismatch from loop send to real amp input. It's the same with the Digitech GSP1101, and even worse with Line6 HX Effects (because it can't have different levels for send and return, it's one loop one level). One day someone will build a 4cm device that does not cause impedance and level mismatches between line loops and intrument inputs, but right now we are just not there, it seems.
Fantastic tutorial! I have learned more about my GT1000 core from you than anyone else on RUclips. Great stuff!
Outstanding video! I was using mine with my tube amp, but missed some of these features. Thank you!
Superb Dan thank you. I am an old guy and just got the core a few days ago. I want to run it 4cable with my Marshall AFD. Initially I thought effects only. But incredible to learn I can have a clean channel too 😮😎 Superb tutorial. What an amazing honest and humble guy, helping others. Thank you Dan 🙏🙏🙏
Really great video. I had a GT100, but want to upgrade to this unit.
Such a helpful video Dan! Really opened my eyes to what it can do. The other vid on the overlooked settings really made a difference too!! I had the input setting way too low!
Ah man, so glad it was helpful to you. I really do love the unit once the initial ‘house keeping’ is dialled in for your rig. Insanely flexible.. It’s just avoiding the option paralysis that I struggle with at times 🤣
Great video. I’ve had a GT100 for about 5 years and it’s ridiculous how many different set ups you can achieve. I am using 4 cable method into a Roland Jazz Chorus so love experimenting with Roland JC cleans and then A/B into GT100 preamps for gain tones
Jazz Chorus in near ideal amp to play together with BOSS's floorboard processors, yeah.
this is a great video. I just exchanged my Line 6 HX Effects unit for the gt core and what an amazing upgrade. The sample rate and bit depth is already higher on the boss unit i believe at 24 bit, 96khz, so the digital effects all sound better than the line 6 unit to me. secondly, there was a bad batch of line 6 units that have a noisy hum going through the effects loops that can't be mitigated, this was my main issue. I ran my tube amp 4 cable method just like i did with the line 6, but into the gt core and instantly solved my hum and noise problems. it's way more versatile, the line 6 doesn't even have the ability to have a global eq, and there are zero amp or cab sim's so its just a win win for the boss all the way around. amazin
It’s actually 32 bit….the only 32 bit processor as of now. That is why it’s so crystal clear…
@@johnycat7373 Sold it because the GT core runs everything A/D/A, fully converting even your dry analog signal to digital, which is a big no no for me. If you're running analog effects and using analog cables, into an analog tube amp, why the fuck would you want to convert your dry signal to digital? At least the HX effects left your dry signal alone and just put digital effects on top.
Excellent video. That is how I use my GT1000 Core. I mainly bought it for Reverb and don't use the onboard amp and speaker modelling. It is useful to have the ability to put a delay in front of your amp sometimes and this is how to do that. You can of course put another delay after your valve preamp in the loop. So versatile and a brilliant device. Stick it in your bag when you are working away and take a guitar with you. Use the amps and speaker modelling that way. Best of both worlds.
Best of both worlds pretty much sums it up for me. I love units like this that can add flexibility but still leave the tone alone when needed. Thanks for watching 👍
Thanks for sharing information on this unit! I really enjoy your GT-1000 videos!
No worries! Glad it’s been helpful 👍
GTK today seems to be the best solution to play with tube amp in one rig. As it is: 1. The most compact FX board on a market with AMP CONTROL feature. All other like Line6 HX Effects are much heavier. 2. Has great FX sections and modern 32 bit core - you shoudn't want to use GT8 or GT10 in front of Your valve preamp today 3. Can be effectively used both for recording and live jams 4. Has IR support making it perfect for recording together.
Certainly one of the most comprehensive, thoughtful and detailed application reviews out there... cannot understate the FX comment @ 5:46
Been using a GT-100 in 4CM mode for a long time with multiple Mesa models. Placement of the S/R block in the chain seems to yield varying results. I've experimented with the divider in single mode, then in dual mode before the divider, in parallel (split path) and after the divider. It seems when the divider is in single mode there is noticeable overall signal drop that requires boosting vs running the split path in stereo and the 4CM after, which produces a larger signal to the S/R block. Setting the sum to Pan L/R definitely lowers the signal to the S/R, but still noticeably more signal vs single mode divider. There's a number of adjustments in this signal path you could use to compensate, ie: S/R, master level in the MST block, manual vol knob, etc.
So if setting up the divider in single mode, where would you suggest boosting the signal to compensate? Hope that makes sense.
Oh great playing too :)
Thank you! Glad the video was helpful. I would experiment with your amp a bit. Personally I would look towards the back end of the chain so return volume and master 👍
@@DanLeggatt Helpful??? oh man that's an understatement LOL Thanks for the input, going to give it a whirl. Cheers
Hey Dan,
I am currently on the quest for a nice multifx compact processor that can do 4Cm, amp channel switching and also, like you show, using clean preamp sim because my DSL20HR don't have a real clean channel.
Your video definitely got me on the GT1000 core ! I am going to buy one §
Thanks and i subscribe immediatly !
GT1000 CORE has a really annoying hiss problem when used in 4CM. It is quite perceptible when used with the drive channel of your amp. That's the reason why in the video there is a noise gate after the Send and Return block. The problem is bad digital to analog converters.
Hi Dan, very comprehensive and informative as always. Some lovely little bits of playing and dynamics. Really be interesting to see this new board when its done.
Cheers mate! Need to get a few more cables and bits to do what I’ve got planned but looking forward to experimenting
Hey Ben Love what you do Thank you Brother Im coming too the Uk to do a radio tour would love to meet up will be in Yorkshire and London as well as going to Ireland afterwards Cheers My Friend !
Hi Dan, cheers for making this video. It helped me finalise my pedalboard inconjunction with my jcm2000 & existing switcher & separate pedals. Also, the clean preamp suffered a volume drop due to a valve so using your method an AIRD clean preamp now goes directly to the power stage for my clean tone. Thankfully the crunch channel is still fine & will hopefully last until I can get it in for service.
What I didn't hear you mention in this video is that the beautiful overdrive sound of an amp isn't from the preamp, it's from the power tubes and transformer being overworked. An effects send won't cut it. What you need is a chain like this:
Guitar-->GT1000-->Preamp-->Poweramp-->Marshal Power Brake (no sound output, so what's the point?!)
plus, either
Poweramp-->Aux Output from the transformer-->GT1000 (post POWER AMP loop)-->PA amp-->guitar cabinet speakers-->mic-->record
or
Poweramp-->Aux Send from the transformer-->GT1000 (post POWER AMP, include speaker cabinet sim and mic sim)-->record
I don't know how common amps are with this kind of Aux Output are. You MUST have one that is taken off the output transformer. You do NOT just want the preamp out, you HAVE TO HAVE THE POWER TUBE/TRANSFORMER OUT. My Mesa Road King has one, as does my Ampeg PF-50T. (The Ampeg also doesn't need a power brake--it has the equivalent built in.)
So that does what you suggest, using the GT1000 both as a before-the-amp FX, AND as an after-the-amp FX, but, it is an after-the-POWER-amp FX. Truth be told, I've had my Mesa 20 years and only played it about four hours total with any effects between guitar and amp. But, I've had this whole effects chain with a Kurzweil multi-effects unit. The PA amp is stereo, and power the Mesa's 2x12 speakers in stereo. The nice thing is I can play super-clean as loud as the speakers go (it's a 300W amp) or play with all gains on 10 at a speaking volume, and either way I have stereo reverb and echo coming out of the combo speakers. And there's no tone suck!
Hello friends! I just ordered a GT Core. I have a Boss Katana 100mkii. Should I use 4 cables, or set the output to the line in for the Katana..and just plug straight into the back? Thanks!
Outstanding demo! I was looking for this to be sure I could use this in 4cm with my 5150III amps! Fantastic tones and great playing as well. Looking forward to getting this now! Thanks!
Thanks! Glad it was helpful to you 👍
Awesome video, thank you! I was thinking of 4 cable method if I buy the Boss core unit with my EVH 5150 III combo, and now I'm totally sold! I used to do it with a Kemper and it was great, I think this will have even more creative options running them together.
No worries! Really glad it helped out. I think that will be a pretty mega rig!
Nice one dude. This seems to be an amazing bit of kit. That picking dynamic feature and the ability to add a clean channel (or any amp sim) bypassing the tube amps preamp is awesome. For the size of it I think even just adding it as a “utility” pedal on a board would be a good shout, albeit about the most expensive way to do that 😆
Cheers dude! It’s mental how much power is under the hood for such a small unit!
nice one 👍
Good job. I'm on the fence between this and the mooer GE 300
In the 2010s, I was in a couple of bands whose main venue was performing on battery power in the New York City underground (what we Americans call the subway). During my last year doing that (2019), I had a Boss ME-80 and a Roland Cube Street EX amp and developed a practice of plugging my microphone into the guitar channel and my Boss modeler into the mic channel (like plugging into a PA input). I’ve tried sticking with that type of practice whenever possible, preferring only hearing the tone of my modeler without needing to balance out the preamp of the modeler against the amp it’s plugged into. (I also like plugging into a bass or keyboard amp with subwoofers.) Is the same outcome within arm’s reach on the GT-1000 Core?
that's not a bad piece of kit
ive only just scratch the surface and you can have a lotta fun with that
I like the manual patches where you can take a sound you like straight out the box and ad more or less tones and effects manually
great fun. its both an effects unit and a pedal box 👍🎸. ive not done the 2 or 4 cable method yet, ive just plugged straight from r/mono out and mono input and its sounds good
Hi!
Awesome video!
I got an issue, I have an EVH 5150 50W and i can't switch the channel with the GT1000Core.
I put the correct setting on the Assign Menu and using the CTL 4.5 input on the side. Not working. Sometimes it will work but it will glitch back and forth between channels...
Anyone have an idea?
8:46 "The GT output knob will act as a master volume in 4CM"
i've been scratching my head trying to defeat this issue with a Marshall DSL40C, but haven't got to experiment with my JCM2000 DSL 100 head yet. I want to use the channel volumes from the amp, so when i switch to my lead channel on the amp, i'll get my volume boost. This other way described above basically puts the GT1K into the return of the amp and bypasses the Marshall volume controls, leaving the Output Level knob on the GT1K as your amps master volume. I don't want this. Is there a way to put the GT1K into my amp's fx loop WITHOUT it doing this?
Any help is much appreciated.
It won’t bypass the Marshall controls unless you are using the preamps from the GTK. You have to have the amps preamp (Input & Send) in the GT fx loop. All the Marshall controls will behave the same but the GTK volume will just be a master. Unless I’m missing something in your setup?
@@DanLeggatt then theoretically using it this way we dont even need a 2-channel amp, because the gt1k takes over the power section, then to boost lead solos you need to alter your gt1k patches to reflect different volumes? this makes no sense to me, as i've always switched to the other amp channel (at a higher volume) for leads. why even have anything other than a power amp at this point? i do like a few of the preamp tones from the gt1k, but using them in 4cm neuters my amp into a straight power amp with no volume control besides the gt1k output knob. way-to-go Boss/Roland! i wanna put the whole thing in my fx loop and still control my amps 2 channels. why even bother with the gt1k channel switching capabilities unless you're gonna frontload it into the input jack? i'm still at a loss (in my mind) that this was even designed this way. i still feel like im missing something here, like a setting on the gt1k that allows you to turn off the internal preamps taking over control of your master volume? seems like a bad design to me, unless you are wanting to edit each patch volume for rhythm and leads.
Great video, really useful and super detailed. Thank you very much.
Yo Yo!! What’s up Dan? Just picked one of these up on the cheap used and have been spamming videos to learn the eco system. Thanks so much for taking the time to create these videos. Looking forward to you making some presets for this one as well. I have your Kemper profiles and they are Top Notch! Cheers, Jason
Cheers Jason! Glad the vids have been helpful. I’ve had a few requests for my presets so I’ll look at making them available soon 👍
Great video and fantastic playing. Thanks!!
Cheers 👍
My Boss GT-5 and my Line 6 floor boards are both rotting and barely work anymore, lol. I really like the looks of that. Boss do tight gear. Those aforementioned processors I got during the 90s. So if anything, that GT-5 has impressed me for being exposed to hillbillies who think they're Sid Vicious, being stored for periods during our summers, when Texas and planet Venus trade climates etc, and lasted 20 years! Since I'm fixated quite a bit on Amplitube and other software, I haven't considered getting another. But I love wasting bill and rent money on gear, so hey. Great demo. It was all comprehensive and stuff. Plus it was explained thoroughly. Hee hee.
Great video was very helpful. Thank you.
wondering why the system dont have a on/off button? keeping it on / juz unplug the socket everytime..\
The Best video about 4CM ever!!!! Thank you so so so much for this content. Do you think that extracting the sound of the 5150 via the "sub out" adding some IR into the audio interface or a PA, would sound Nice? I mean, your 5150 running through gtk with 4CM and getting out via main out to the real amp cabinet and simultaneously out via the gtk sub out, IR added, to PA( or audio interface)
Thank you! I did actually try and figure this out but I couldn’t get it to function quite right. It seemed to apply cab to the return even though it wasn’t in the same path. I’m sure it was my error or there is a workaround but I didn’t spend enough time to figure it out.
@@DanLeggatt Can definitely be done, need to make sure the applicable GT-1000 SND is configured as a sub-out which is done via Main Menu - Hardware Settings - and change Send 2 to sub out. Then on Output Settings make sure Sub-Out is on 100. Then in the sub-out blocks you can set a different output mode (IR) independent of the main out and also have another global eq just for the sub-out and it should be game on.
Hi Dan great info I have just acquired the victory kraken preamp pedal for home recording
will the 4 cm work with inputting into my interface instead of a speaker cab and using my fave ir in the GT1000
And do you plug the output of the preamp pedal into the interface . Thanks for your great info
I tried the 4 cable however when the loop is not turned on in the GT-1000 I am still getting clean signal coming through. I suspect that clean bleed is always there. How can you fix this?
All sounds great but since I couldn’t even get the boss katana to work with the tone studio app. This would probably be too time consuming for me
Awesome video. I appreciate it!
After watching the whole video, I realize I need your number as an on call boss gt 1000 tech
Hi Dan why am getting my amp sound underneath a clean tone . what am I doing wrong Thanks
I LOVE your videos about the GT-1000! You seem very knowledgeable, and your playing is very expressive!!!
I have the GT-1000 and two 2x12 cabs! I am using the Behringer A800 class D stereo amp to power these two cabs. The sound seems "wrong to me" Any normal amp sounds better. Do you think that Using two tube amp heads (7cable method) with the GT-1000 will get me a genuine tone? one problem wit the GT-1000 is that you cannot disable the "power amp" you can only disable the speaker cabs!
Thanks once again
It’s very hard to advise on a solution to why it doesn’t sound right to you. I use the GT1000 all the time with a traditional amp just for fx in a 4 cable method or just in the loop. If you bypass the amp and cab models there is no power amp tone in the GT.
@@DanLeggatt Thank you
Can I use GTX in front of my preamp to use AIRD booster, WAH and compressor effectively? Will it give me a real signal boost for OD channel?
It would be great to hear how the GT100) sounds with low gain amp models and various amp models when connected straght into the front end of a tube amp. I have a new 68 fender twin amp I use as a pedal platform and so far I havent been able to get the gt1000 to sound good in previous amps that I have owned
While you can get decent sounds, it will always be a compromise running any modeller like that. When you think about it, you are running a preamp into another preamp. It can be a struggle to get the 2 to work together. It’s much easier to run into an FX loop return or power amp if you want to use the amp models. I think you would get much better results using the drive pedal models rather than preamps.
Wow, very informative! Thanks👍
No worries! Thanks for watching 👍
Wow. So the CORE version can actually switch amp channels? I assumed it couldn't because it doesn't have the Amp Control on the back like the full GT-1000. You show this at 11:58, but I'm not sure I follow. How do you get it to change amp channels? EDIT: Never mind. Found it. But thanks for making me realize this!
Great advice about getting the signal strengths straight for input and output. I think people tend to overlook this on almost anything (amps, guitars, pedals, etc) and as a consequence declare that the device "it colors the tone". Is there a reason you have set the output where you do? I've tried different levels but found that noon is the easiest to keep consistent since there is an index point there (easily knocked by a clumsy foot), but I'm curious if I've missed something by doing that.
I try and match it to unity gain without the pedal.
My 4cm fx loop only seems to work when the Return of my Engl ironball SE goes into the phones of my gt1000, why might this be?
I bought the headrush 8” FRFR speaker for ease compared to an amp.
Looking at it, it feels too much for me when I prob should be learning on something simpler.
Can the virtual Tubescreamer boost the front end of the amp, like a real one would when you crank the level control?
What are the output settings when the CORE-preamp is switched off, are there any, or do the options (recording, tube stack, tube combo etc.) disappear when disabling AIRD?
The internal TS model can definitely do that. I don’t have a TS to compare it too but it sounds like I remember TS pedals sounding.
I set it to either recording and bypass amp / cab or to tube amp FX return.
@@DanLeggatt Thank you!
Would this work well with an Orange Micro Dark (it has an effects loop)?? I only have an 8" cab though.
A quick question! What do you have your speaker setting at for 4CM if you’re doing a hybrid rig? If you’re using a pre amp in the gt1000 for clean out of your valve amp.
Thanks a lot Dan
hmm should I move from my THR30 to GT1000 - hearing this and your previous vids … its a no brainer
No worries man! Glad it was helpful 👍
Great video, thank you! I just bought a GT1000 core. I think it sounds great with my amp. However it’s got a lot of backround noise. Even with all the blocks and aird turned off it’s noisier than my analog pedalboard. I’m going straight into the input of my amp. I have done all the gainstaging, still a lot of noise. You wouldn’t notice at a gig with the amp turned up. Still, I think it’s too much noise coming from a digital unit. Anyone else noticed this? Thanks/Calle
I haven’t noticed any additional noise to be honest. I’ve been gigging mine a lot in the fx loop of my amp and it’s been dead quiet.
Great demo, thank you! This is exactly how I'd like to use it, but if you have 1 switch dedicated to the amp channel switching, you are only left with 2 other switches? How do you manage individual effects? I typically like to have independent on/off control of reverb, delay, phaser, and maybe a rotary.
You’d need to use external footswitches or midi. If you like more footswitches perhaps look to the full GT1000?
Superb
Very nice tone! If I use the 4cm with a mini rectifier head, do I need a cab? Or can directly to the computer or PA?
Hi Dan. Could you make a video about setting the levels with the Gt-1000 the 4cm with tube amp? Is it normal to use the Gt-1000 to have a lower volume on the amp? Does it cause any dammage on the amp?
Cheers from Portugal 🤘🍺🇵🇹
I see that you switched channels on the EVH but did you have to connect to the foot switch input on the EVH to a port on the Boss? Would it be a TS or TRS cable? Did you have to set extra parameters on the Boss? I am trying to figure out channel switching with my GX100 (I just got it and only spent minutes with it). I can't figure out channel switching on my Super Kraken and I haven't yet tried my Iconic. Thanks
Just using a TS cable here as the EVH only has one function. TRS if your amp has 2 and uses a TRS with the supplied footswitch.
Is it possible to run the boss gt1000 core using 4cm into a boss es8 and then boss es8 4cm to the amp? Thanks, great videos!!
Spooky. I was going to ask the same question but for the ES5.
Yeah this is totally possible, it’s actually not very complex to figure out if you treat the GTK in 4cm as 2 separate ‘pedals’ in the ES chain.
@@DanLeggatt I got the 4cm method working. Is there a best way to run the AIRD amps in the chain. Say put the pre and post of the GTK in the amp effects loop. Thanks
Hi Dan you’ve done a great job on this. I will be getting one but will it work in conjunction with my Boss ES8
Yes absolutely. Don't really want to send people away from Dan's amazing page and content but check out Simon Mcbrides recent pedalboard build video. He uses ES-8, GT-1000CORE and a load of other cool toys with his amp.
Cheers Matt! You’ll love it mate, especially with the ES8.
Great video Dan. Just curious, have you tried this setup but with the CORE outputs going direct in for recording?
So basically we're talking valve preamp through the CORE's cab sim or an IR straight to an interface or FoH console or something. I understand that you need to run an AIRD preamp in the chain somewhere in order to activate the CORE's cab sim, but you can isolate the AIRD model in a divider and zero its volume to take it out of the mix. What I'm not sure about is if the Speaker Sim block is doing any compensation for a power amp tone, or if it even matters.
Just curious if you've tried it, and how it sounded if so! Seems like it could be a great easy solution for recording or gigging with a real amp but without needing to mic its cab. Thanks!
I haven’t tried it to be honest but that sounds like a solid idea. I suppose the only thing you’d be missing is some sort of power amp sim?
Hi Dan, I was wondering about analog drive pedals. Do you use/recommend them in front of the GT or through one of the Fx Loops?
Either! Works great both ways. In fx loops it gives you the ability to move them around in the signal path and turn them on and off if you change presets. If that’s not important to you, I’d just keep it simple and put them in front. Hope this helps.
Hey Dan, I tried the 4CM as you showed with your Amp. When I set it up I got so much hiss and noise. Do you have any advices?
Could you use this pedal in the effects loop only? So basically just to use the delays, or maybe a post pre amp eq?
Yep, that’s how I use it regularly as a ‘post processor’. Verbs, delays, chorus etc
@@DanLeggatt very cool! Thank you for your reply I appreciate it. Do you hook your amps effects loop then into the return and send of the boss? Or to the main in and out? Thanks that’s my last question I promise :)
Very helpful Video. Which output settings you use with the valve poweramp? I tried to use my gt1000 with my engl poweramp and marshall 1960 cabinet with the internal preamp but sounded not very good
I think I had it set to fx return stack in the output menu. It should automate bypass cabs but double check they are fully bypassed.
The 'named' Output Selects (412RTN etc) all do some sort of signal optimisation type tone colouring designed to match the assumed cabinet commonly used with that amp type. In your situation I'd use 'Recording' and then go to the L/R Output (Speakers) block and use the drop-down to turn the speaker type off, this way you know there is no cab sim coming through. With that done then go to P001 Premium Drive and use this patch to tune to your cab through the global EQ to remove any obvious tone issues (suggest 8K high cut and then cut/boost highs and lows as necessary to remove any woofiness or shrill). Get P001 sounding good through your amp first before you start trying to build tones with GT-1000 Amp models.
Another awesome video on the 'Core! I never thought of the possibility of switching between the Core's and Amp's Preamp.
May I ask you a question:
I want to use the Core's preamp and my amp's poweramp. What would be the most neutral output setting for the signal to get into the amp's FX return?
Output select "Record" and Speaker Type "Off" sounds pretty good to me, but is it ok for the amp?
I tend to set it to fx return I think as it automatically bypasses the cabs
Chrizzler, I'm 1 year into my setup with 4cm into my amp's FX RTN. After much trialling I have found 'Recording' to be the best output. What you say above (Recording + Speakers off) is the most neutral. If the speakers are on you are using an IR which definitely colours the tone.
Hi Dan,
You've helped me out before - so thanks!
How would I turn off amp modelling on the GT 1000 core? I wish to use the device as just another effects pedal. I like the sound of my amp and do not wish to alter it - thanks, Binit
Glad it’s been helpful. To turn off the amp modelling all you have to do is bypass the amp and cab block in a preset and you’re good to go 👍
Hey Dan... how are you getting your sounds to your interface? Also how were you getting that clean sound from the boss if yours still running it through your amp preamp that you said doesn't have a clean channel?? Thanks!
Amp is running to a Two Notes captor and then interface. I'm actually bypassing the preamp entirely and sending the GT1000CORE to the return which hits the power amp.
What is wrong with the evh over drive
Send / return has level for both. How do you know which one you need to adjust if you're getting louder or quieter sound with 4CM?
If the amps fx loop is loosing volume you want to adjust the GT output level. Send level will decide how much signal hits the front of the amp. Return level decides how much level comes back to the GTK.
do you like this as good as ss pedals? do the overdrive and distortion sound as good as ss pedals? been looking at this and wondering before i buy it.
I would say they get very close to the analog counterparts. I haven’t done a direct A/B comparison but I like them a lot.
@@DanLeggatt ok thanks
I am torn between getting the GT-1000 CORE or building my pedalboard. My current rig is Boss Katana 100 MKII , EHX Soul Food, Fender Booster and Fender MTG. Considering either buying a delay, reverb and modulation pedals to complete the pedalboard or getting the GT-1000 CORE, What do you suggest ?
The GTK can do so much so you would have room to experiment or expand your tonal pallet. However it depends what you’re after. Single pedals are a bit more simple obviously but after a bit of a learning curve, there isn’t much that this box can’t do.
any advice for amp control (channels for 5150 III) via midi using the GT1000?
I believe most of the midi stuff happens on the amp itself. You can put it into program mode and set which channel is recalled per preset. The GTK should automatically send out the PC changes 👍
Hi Dan, I could really benefit from a 30min video chat to talk about my gt1000 core and my valve amp...and some of my favorite pedals. Are you available on a consultative basis?
I am indeed. Drop me an email to the address in the description or through my website and we can discuss 👍 Cheers
Another awesome video!
Gt-1000's rule! Do you know if Helix and Pod Go have something like the dymamic control?
By the way, i have subscrived!
Cheers from Portugal 🍺🤘🇵🇹
Thank you! I’m pretty sure they don’t have anything similar actually.
AFAIK not, but Fractal has it.
Sounds great and I want to get the GT core, but holy shit I feel like you need to be an electrical engineer to operate it.
if i run 4 cable method into my valve amp and i want to change between my existing amp channels do i need a 5th cable to be connected from the boss gt-1000 to footswitch input of the amp?
Yep 👍
It’s only an impression or there is a little loss of tone in your comparison in the suck test?
I didn’t notice any ‘tone loss’ when playing. If there is any change in tone listening back under the microscope, it’s extremely minor. Certainly no more of a change than plugging in a normal pedalboard with a handful of pedals.
Obviously depending on your amp, cables, setup etc results could perhaps vary. Especially if your FX loop is passive or particularly finicky.
Thanks a lot Dan!
I have a question about GT Core...is it true that knobs are fell of during 2 or maby 3 month...is trere anybody had that problem?
I haven’t gigged mine yet but they feel very solid and haven’t heard any stories about knobs falling off.
@@DanLeggatt How many time was passed since you bought CORE and how often do you play on it?
Probably 3 months now. No gigs but I use it very regularly.
@@DanLeggatt ok. Thank you very much for your answers🙌👍🙂
I have owned the big GT-1000 for a little over 2 years, and I have gigged with it and used it in the studio a lot. No knob or reliability issues at all. It is really well built.
No Tone Suck....good
I LOVE my GTK... but I must admit, the BOSS FX are THE WORST of any modeler I have ever owned:)
With Boss the capabilities are there to create any sound that you can get for other pedals. But you have to do the very tedious work of building it
@@ChrisAdkins1985 Yeah, been working tediously on amps and FX for 60 years this Christmas:)
How do I set the output/output-select when I use the 4cm methode? Do I choose a amp-input or amp-return type ?