I started playing the guitar again in the last month and i'm having some trouble with my gear. So, i have a modelling amp from pevey which also has some effects built in. I also have a line 6 POD HD400 multi effects pedal which also has amp/pre amp modeling. Now i am a bit confused about some of the theory behind all this. My pod hd 400 requires an Amp in order to output sound, so i really need to have an external amp and not just a cab (which i didn't know when i bought it). My idea was to have my Pod HD400 model an amp and have some effects and just connect it to a cab or speaker. But since i need to use an amp, i'm confused about the final output of the sound. Here's my questions:

  • When i connect my HD400 to my modelling amp, what happens when i select an amp model in my pedal ? Will it get "mixed" with the amp model from my amp ? or it will bypass the amp settings ?

  • Is there anyway i can bypass the amp settings entirely? or how should i setup my modeling amp in order to use my pod hd 400 multi effects pedal ?

  • I am thinking about aquiring a Marshall DSL1CR. Again, what happens when i choose an Amp model in my pedal ? will it bypass the amp settings or just get "mixed in" ?

I'm asking this because i don't like the sound that i am getting at all and i have played with the settings quite a bit (I just don't know the theory behind all of it).

  • 1
    Have you read the HD400's manual? Do you understand what the Output Mode switch does? Commented Nov 2, 2019 at 13:31
  • there are many knowledgeable answers to your specific query below, but I would like to make a more general suggestion. SIMPLIFY. All of this which you have described will only distract from playing, learning, and enjoying the instrument. Don't get me wrong, I have several guitars, several amps, and many pedals. But approaching this from a gentler angle is far more effective. Get yourself a guitar you enjoy, find a simple but enjoyable amp (check out the Vox AC4C1 maybe) and then take some time and find a single effect stompbox, maybe a reverb, and get used to that. Commented Apr 21, 2020 at 19:41
  • I have the same question, but I'm using a Marshall code 25 modeling amp maybe you can try to use the AUX input port in your amp, if there is one (the aux port in my amp is for connecting to anything like a phone or an ipod, seems the amp bypass the preamp for this input)
    – gary
    Commented Dec 31, 2021 at 17:44

4 Answers 4


The signal chain from player to listener has many components and stages, and all of them can be either modeled or physical ("real"), believe it or not:

  • player
  • guitar strings, neck, body, etc.
  • guitar pickups (microphones) and other electronics
  • stomp effects (if any)
  • signal input (from guitar or stomp boxes) and preamp
  • effects you'd insert in an amp's effects loop (delay, reverb, ...)
  • power amp
  • speaker cabinet
  • room acoustics
  • microphone
  • (recording preamp, tape, mixing console, etc.)
  • listener (not entirely sure about this, but at least they use robots to identify potential targets to threaten with copyright violation claims)

Particularly for speaker cabinet, room acoustics and microphone, you want to make sure that they are present on the signal chain only once. If you're using several modeling devices, if one of them is modeling/simulating a speaker cabinet being recorded with a microphone in a room, then any processing happening after it has to have its cabinet and room simulation turned off. Otherwise you'll have multiple layers of acoustics, and instead of sounding like a guitar amp being played in a room, it will sound like a 3rd person listening to someone in a room, playing a recording of a guitar amp being played in a room. You know, if you watch TV or video that's showing someone listening to music on a stereo system, you won't experience the sound like the person. The person being shown hears it from a first-person perspective, but you as the audience or observer will hear it from a third-person perspective. You can't go inside someone else's head with regular microphone recording. (maybe with binaural recording you could)

As you've found out, if you want to use an actual physical speaker cabinet, you will need an actual physical power amp to drive the speaker. If you connect your modeling system to a PA system, a hi-fi stereo system or some other type of neutral amplifier+speaker, those systems are supposed to sound "flat" and not add guitar-amp-like coloring to the signal. In many ways, any traditional guitar amp combo acts like an effect, because it add so much coloration to the signal. PA systems and PA cabinets are different. It is possible to do all of the modeling in the virtual world, and then use a neutral flat amplification system to make it sound like the modeled amp being played. Today, there are even powered "modeling speakers" which model only the speaker cabinet part of the signal chain specifically, like the Line6 Powercab series.

  • thank you for your elaborate comment. From what i understand, the best way to have it sound exactly like the sound modeled by my POD HD400 is to connect it to an Amp that isnt a modeler and leave at the clean setting? this way the signal only gets modelled once. Commented Nov 2, 2019 at 11:43
  • 2
    @PedroCosta No. To get the exact modeled sound you don't connect it to a guitar amp at all, you connect it to a neutral PA system or a neutral full-range active speaker. If you want to use a guitar amp, then you disable/bypass some components of the HD400's modeling. Commented Nov 2, 2019 at 12:53

If your guitar signal is running from the guitar, through a pedal, and through an amp before it comes out the speaker, it will necessarily be affected by each of those steps along the way to some extent.

But both the effects pedal and the amp have "clean" settings where the various effects are not enabled or dialed up, and that's the closest you'll get to the sound being unaffected by that component. If you want to test individual effects/settings in isolation, turn everything else to "clean" and just tweak that one setting. (And familiarize yourself with EQ and reverb on that clean sound, those are the fundamental tools before you bring effects into the mix.)

  • Well what i have on my amp is like 15 amps that it can model. I can choose one that has a clean tone but i still have to mess with the treble/mid/bass of the amp. This confuses me because i also have to set those settings on my pedal, including choosing an amp to model. So i would have 2 modeled amps in my sound instead of one, right ? Commented Nov 2, 2019 at 11:39
  • If each of the EQ levels are set to the same value, it's equivalent to a single gain level of that value being applied to all frequencies, which is functionally a non-EQ'd signal.
    – user63785
    Commented Nov 2, 2019 at 17:39

Most amps are split into two discrete components - pre and post. The pre-amp looks after all the tonal etc. part of the signal, while the post is basically a power amp., boosting whatever sound the pre has been set to.

Needing an amp. for your effects board, it should be possible to plug from that straight into the 'return' socket on the amp. That then bypasses the pre, and will simply amplify whatever is set on the pedalboard.

  • yeah i hear about that return port. But my amp only has the guitar in port. Commented Nov 2, 2019 at 11:38
  • however if i get an emp with those ports, will in amplify the pre-amp section of the pedal aswell ? Commented Nov 2, 2019 at 11:48
  • Whatever is plugged into the return will get amplified. It just interrupts the signal chain, cutting out the guitar amp's pre-amp.
    – Tim
    Commented Nov 2, 2019 at 11:50
  1. You don't specify what Pevey model you have so it's impossible for me to say anything about it. As other said, if you want to use your POD to full potential, you want the amp to be as neutral as possible (so omit preamp section, or set it to neutral mode, if available). If you want to use a guitar speaker, you probably shouldn't emulate mic and cab in the modeller.

  2. This small valve Marshall combo is definitely not a right choice for a modelling preamp like POD. You want a neutral amp with full frequency range speaker. This is often referred to as "full range flat response" (FRFS).

  3. In a rehearsal or performance situation, perhaps you can connect your modeller directly to the mixer?

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