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A tube power amp is like a distortion box; put time-based effects *after* it for clarity

As far as effects placement principles, a tube power amp is just another type of distortion box, and thus belongs *before* echo-effects, not after them as per the effects industry convention. The guitar-gear industry has established a convention of placing a multieffects unit, including echo-related effects, before a tube amp. However, this convention inherently cannot sound good, when combining significant echo-effects with significant power-tube and speaker saturation. For clear, professional Tone, echo-derived effects should be mixed in "through the board" -- that is, after the power tubes and guitar speaker. This avoids unmusical muddiness and beats. For the clearest saturation Tone, echo should not be placed before *any* saturation, distortion, or clipping stage, whether clipping occurs in the preamp tubes or power tubes. Power tube saturation is coming to be recognized as the *essence* of guitar saturation, and will thus be used much more extensively in the near future, so users need to observe the same principles of effects placement as for preamp distortion: echo *after* clipping. For effects placement considerations, a tube power amp with mic'd speaker is just another type of distortion pedal and should be placed before echo, reverb, chorus, or flanging. This way, effects contribute to the basic amp Tone rather than muddying and disintegrating the amp Tone.

Ignore this principle at your peril; attention to preserving amp Tone is the mark of first-rate studio recording. Hard-rock, heavy-guitar players have a good reason for their philosophy of plugging straight into a vintage Marshall stack, the kind with no reverb. Reverb, chorus, echo, and flanging can be safely placed in front of the amp only for clean, wimpy, undistorted, non-cranked tones. When you are driving the power tubes hard like Jimmy Page (with his small tube amp), these effects, if placed before the amp, would just confuse the power tubes and produce a garbled tone, garbled profoundly and inherently, unlike the clear and musical type of complexity that results from adding echo after the Basic Tone has been secured all the way through the (saturating) power tube stage.

This setup offers you the *choice* of where to place effects -- before or after the saturated tube amp. Current standard rigs don't allow you to put echo after a saturated tube amp. They always force you to put echo before the tube amp.

Everyone should consider putting another effects unit after the mic'd speaker cabinet, rather than always limiting themselves to putting all effects before the tube amp. The equipment to do this is available, particularly in the studio by using the mixing' board's effects loop, post-amp equalization, flat-response final amplification, and full-range monitor speakers. But when using the post-amp resources of the professional recording studio, the guitarist should keep full control of the effects and not let the sound man take over, *post*-amp, any more than letting the sound man take over the guitarist's use of effects *before* the amp. Always try to keep the effects pre-guitar-amp processor units and the post-guitar-amp processor units together, and treat them all as fair game for full manipulation.

If you want so much control that you put a programmable effects unit before the amp and another after the amp, you'll appreciate the control that a speaker isolation cabinet offers. Everyone should have a speaker isolation cabinet to play with -- they're cool. They seem clumsy, but consider how clumsy a blasting 40 watt amp is. And this approach turns out unmistakbly real power tube saturation and speaker dynamics. No inductive loads or speaker simulators are used. It's all real and just has a different type of speaker cabinet.

By muting the cabinet noise, you can concentrate more on experimenting with effects and basic tone. When you hear the true sound of a saturating tube amp, it greatly inspires you to explore the programmable space of power tube saturation and speaker tone, together with a huge palette of advanced effects.


Put the multiprocessor in the effects loop of the mixing board, not the effects loop of the tube guitar amp

>Subject: ART Xtreme Plus in the effects loop

>I primarily play in a small venue that doesn't require miking (it's really small!) I have a Crate Vintage Club 30 watt amp, which I really love!

I've heard it at low levels; I like the liquidy preamp distortion.

>It's got great tone - it has sort of made me into what you described as an amp freak [an amp-only purist], becuase I love the amp tone itself, and hate what the effects do to its sound.

>I've also got an ART Xtreme Plus, which I bought primarily for its multieffects, but not its overdrive (which is not bad, but I just don't need it with the Crate). When I go into the ART, then into the amp, I lose the amp's natural warmth & "vibe" - it doesn't allow me to play as subtly - I can *just tell* something was lost. But I *need* special effects such as delay, and chorus in my live playing. Morover, the delay, when placed before my amp's preamp, the distortion is GROSS!!

Yes, it would be muddied by beats and the non-harmonious overtones that are generated.

>I'm sure you know what I'm talking about - that wierd, unusable sound that is not worth it. So, I tried running the ART through the effects loop of the Crate. Doing this doesn't give me that ugly distortion [that I would get from placing the multifx's echo before the guitar amp's built-in distortion circuit and actually using that distortion circuit rather than the multifx's distortion circuit],

Great (take note).

>but nevertheless, I still lose that amp's warm vibe [that is, hear muddiness due to placing echo-before-*power*-tube saturation], losing its subtlety and nuance that I love about it when I just go direct, without using any effects at all.

>It seems as though you advocate an "after the amp" approach to time-based effects. This sounds great, and I'm sure it works great in the studio. I will try this next time I record. I'm sure the studio has better delay effects than my funky little ART. But the dilemma is, what do I do live? They haven't invented your invention yet - the isolation cab with the mike, etc. Again, I don't mike my rig, so I can't solve my problem this way.

All solutions would have to involve somehow tapping the signal after the power tubes (if not after the guitar speakers), sending that as a line-level signal to the time-fx, and then somehow amplifying that post-processed signal and listening via headphones or full-range speaker.

The professional approach to top-notch effects during a live gig is to run the time-based effects in the effects loop *of the mixing board*, and let the sound-man control these time-based effects. It's the same approach as in the recording studio; both situations rely on the effects loop of the mixing board, rather than using the effects loop of the guitar amp for time-based effects.

>Have you ever tried putting your effects AFTER the amp but BEFORE the speaker? The Crate doesn't even have a speaker jack - it just has soldered wires. But this wouldn't be too hard to modify. Anyhow, this SEEMS like it would sort of be the best of both worlds, giving an after-the-amp approach to the time-based delay, but the sound would come right through your own amp's speaker. [Sending the power tube and output transformer signal directly to the effects unit would put way too much power or voltage into the effects input, and would harm the output tubes.] How about a power attenuator at this point?

This could work, but then, the speakers wouldn't be driven fully, and wouldn't have direct interaction with the power tubes directly through the output transformer -- which I have found is the most magic, complex, dynamic part of the guitar rig.

Suppose we are talking about a conventional amp, such as a Marshall head and separate speaker cabinet, loaded with guitar speakers. Putting time-based effects AFTER the amp but BEFORE the speaker is not really feasible, except in this chain:

o the amp's power tubes
o line-level attenuator (such as THD Hot Plate's line-level output?)
o time-based effects
o solid-state or tube amplifier circuit
o the guitar speaker

This could indeed get decent power-tube saturation tone, and uses an actual guitar speaker. But this is a less flexible approach than putting time-based effects after the speaker. Also, this approach prevents the speaker from feeding back to the power tubes, through the output transformer.


Someone wrote:

>Do they make amps with built-in time-related effects (chorus, delays) that are wired after the power amp stage?

No, though some units (Roland?) might try to fully develop the dry, complete emulated tube amp sound, before the time-based effects stage.

>Would that work in keeping with what you say about these effects? Is there a way I could hook up a preamp/effects device (through the amp's effects loop?) so that it would bypass the amp's preamp, or come in after the pre or power amp stage? What if I hooked up a preamp/effects unit after a power amp unit,and then went into 1 12" speaker cabinet?Would this work?

Yes, to these questions, but see the limitations listed in my response above.

>I haven't tried out any preamp/effects units but I am really infatuated with the idea of simulated miked cabinets, and amps...



>Where do you think an Aural Exciter would fit best in the signal chain: before the amp [that is, before the preamp], after the preamp, or after the power amp (mic'd Speaker)?? I own a G-force with 24 bit A/D and D/A converters, so do you think that an Aural exciter is necessary??

I don't know whether an aural exciter falls into the category of 'eq-based effects' or 'time-based effects'. It might depend on the extremeness of the settings. My guess is that the best -- that is, clearest -- saturated sound would be achieved by placing the exciter *after* the power amp (mic'd speaker), because it is *crucial* to keep the signal as *simple* as possible, through the saturated power-amp stage. By 'simple', I mean, having simply a primary frequency and simple multiples of overtones -- never have, say, 220 hz and 222 hz running through the saturated power amp simultaneously, or audible, garbled-sounding beats will result, just as when you tune a guitar and two strings are not quite set to the same frequency; listen to all the garbagy, random, nonharmonious beats accomplished by bending one string while keeping the other string constant, such as at the end of the Rush song "Working Man". Harmony and beats and tuning, become problematic when time-based fx go before any sort of saturation. U2's sound was characterized by such beats, but I consider this a distinctive special-effect, rather than an ideal, pristine, general-purpose echoed-amp sound, which is gotten by using echo in the fx loop of the board, rather than an echo-box placed before the amp -- the latter is a tone with more limited application, and that tone is the reason why amp purists claim that effects muddy the sound. They are right -- time-based effects *do* muddy the sound, but what I'm making a big point of is that this "mud" is a hundred times worse when time-based effects are placed before saturation, rather than placed after all saturation (including power-tube and speaker saturation).

The 2101 processor enabled controlling many parameters of chorus. With short time-delays, the chorus and flanger become eq-based rather than time-based effects, and thus can be placed before saturation, while retaining full clarity of saturation, without introducing beats ('muddiness').

>I also am a little confused at the following. The G-force is from TC and it is without a doubt the best processor on the market right now. This unit has professional-quality noise gates and compression, but I have to put it after the power amp stage, because of its time based effects [if I want to preserve a pure, harmonious power-tube saturation Tone while using echo-derived effects]. Do you think, considering the quality of these dynamic effects, will be that much better before the preamp??

I did most of my research using an extremely high-fidelity unit, the Digitech 2101. Time-based effects cause beats when placed before any saturation-stage; that's a fundamental principle you can't avoid. Certainly a processor that has less self-noise (more headroom), and wider bandwidth response (flatter, full-spectrum response), when placed before any sort of saturation stage, will sound clearer than a noisy, lo-fi processor. But with any echo-related effect before any sort of saturation, you will get garbagy, unclear sound, due to the beats that are inherent in sending two slightly different frequencies through a saturation stage simultaneously.


>With the new processors coming out from TC and Lexicon that are aimed at guitarists, there will be a lot of new possibilities for post-power-tube effects. The G-force and the RG1 are 100% programmable in every way, from series to parallel, and any order you want your effects.

I am very skeptical when I hear "in any order". That usually turns out to mean this chain:

o Compression
o Preamp distortion
o Eq
o variety of effects *other* than the above, in any order

There are some exceptions, at last, that enable eq before distortion, and enable placing a mic'd tube amp in the fx loop of the multieffects processor (between the eq/dist/compression and the time-based effects). But most commonly, just where we *really* could use flexibility in ordering effects, that is where the promise of "any order" fizzles out, in most processors. The order of processing that is needed, as used in a pro studio, is:

o EQ and EQ-based effects (wah)
o Preamp distortion
o Eq
o Saturated power tubes directly driving an actual guitar speaker, mic'd
o Eq, and time-based effects (echo)

The promise of "placing effects in any order" is unable to produce the above, pro-studio total processing sequence, so it can never produce the goods (can never fulfill the promise). Time-based effects do not belong in front of a tube amp, so no amount of rearranging the effects (before the amp) can produce the desired Tone, which is a combination of echo and tube-amp saturation which preserves the clarity of the tube amp saturation. The only multieffects unit I know of that (inadvertently) permits ideal, post-amp time-fx placement is the 2101, by putting a mic'd tube amp in the FX loop *of the fx unit* (that loop is between the distortion and the time-fx stages).

>This makes using a line level signal from a power attenuator (which is connected to the speaker out of a tube amp) more flexible, don't you think??

In my experience, the Digitech 2101 multifx unit, for example, was *too* flexible, with an inadequate user interface. The goal is actually a sort of simplicity, through proper design. Any old processor will do; the main point is, you need two multieffects processors, not one. Buy 2 used processors. Put one before the (conventional) guitar amp, and use it for eq-based effects. Put the other *after* the mic'd speaker cabinet. Play the amp loud, and don't put any attenuator between the power tubes and guitar speaker.

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