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SwitchBlade signal-route switcher

>I came across your web site by accident. Just wanted to thank you for mentioning the Switchblade 16 in your site. In case you are into updating your information on us, the SB-16 is now out of production but has been replaced by the Switchblade GL and Studio Switchblade and soon the Switchblade-8 which is an unbalanced version of the Switchblade GL in an 8x8 configuration. We will also have some additional products ready in a few weeks along the lines of the Octapus and A/B boxes. The GL and Studio are both listed at $2300 with factory direct prices of $1725. Please check our web site for more information.

Again, thanks for the informative and useful web site.

kenc at soundsculpture.com

Quality Pro Audio Products

Sound Sculpture - Studio Switchblade $2499. Uses studio signal levels.
Switchblade GL - $2299. 16x16 guitar routing system. Servo-balanced I/O for series or parllel mixing/fading via MIDI. VU metering.

Switchblade is reviewed in the Feb 1995 issue of Guitar Shop, page 61, which I have.

Background for Switchblade: Painting with Sound

This section covers:

>Date: Wed, 26 Feb 1997 08:28:44 -0800
>From: Steve
>To: Michael at amptone.com
>Subject: Tone Theory

>Michael, your core tone-philosophy has deeply influenced and clarified my thinking regarding guitar tone. However, after much experimentation, research, and rumination, I have concluded that your approach is too narrow in several key ways.

>The emphasis on the superiority of power tube distortion, while certainly much-needed, nevertheless limits thought on the possible contributions of tube preamp, and solid state generated distortion, as well as the possibilities being generated by COSM and similar modeling technology.

>All preamp distortion is *not* the same. A preamp tube can be overdriven softly if you bias it properly so it does not get into forward grid voltages but instead runs into cutoff. It can also be overdriven softly if you limit the overdrive to no more than about 12db of overdrive. If you drive it in a way to avoid the abrupt clipping in forward grid voltage, it's quite soft in distortion character. Not many amps have their triodes biased or driven this way. If you want more than 12db of overdrive, you use multiple sections, and limit the amount of overdrive to each section. This gets easier as the preceeding sections limit the signal, as the signal voltage maxes are more predictable.

>Preamp distortion *can* be dynamic and touch sensitive.

> You should not summarily dismiss any non-power tube sources of distortion.

> You encourage people to use the chain: programmable EQ-->preamp distortion-->EQ-->Power Amp-->EQ. But more discussion is needed on the degradation of tone due to digitalization and because of overly complex circuitry and signal path.

> You should not summarily disparage the potential of load/boxes attenuators. The limitations of the Marshall Power Brake do not mean the entire idea is a failure. Devices such as the Power Brake are certainly an advance over Power Soaks (such as Tom Scholtz's), but compared to even better attenuators, are today very backwards technology. There exist attenuators/reactive loads of vastly superior quality. To even mention putting a merely second-generation device such as a Power Brake (or GT SEII) into a guitar rig is ludicrous, given the obsolescence and inferiority of those units.

>You ignore the vast tone-possibities generated by intergrating mixing technology into the guitar rig. Your emphasis seems to be on creating the perfect classic power tube saturation tone at low volume. [I also emphasize hard-driven speakers as essential for dynamics. -- Michael]

>You should consider the possibilities of linking various tone sources in series and parallel configurations.

>Such Tone Sources could include:

>Various tube preamps Various power-tube tone generators (amp/load) Various solid-state distortion generators

>To these are added special-effects processors other than distortion and eq.

>These factors can be thought of as Harmonic Colors. The guitarist would them have them as part of his tone palette, and like a painter, could mix colors in unlimited combinations.

>These ideas represent a fusion in my mind of many of your concepts, and the ideas of other tone explorers such as Ken C. at soundsculpture.

>Ken's Switchblade represents to me a stellar example of one of the crucial elements in the "21st century guitar rig": the mixer/ switcher.

> To carry the Metaphor forward.

>The tone generators (Guitar, pickups,Distortion generators, efx etc) are the colors

>The MIXER/ SWITCHER is the BRUSH (which can choose individual colors or mix them)

>The CANVASS is the AURAL SPACE (live or recorded) where the instrumentalist PAINTS his/her MUSIC.

>From Soundsculpture Web Site

[To do: make a link and summarize.]


>The ways in which the Switchblade can integrate signal processors, audio sources, and audio destinations is vast. Some simple techniques such as series and parallel effects are shown here as are some not so obvious techniques such as multi tap points and isolated group functions and such bizarre setups as cross fading between effects that are wired in series. All examples given here can be achieved using the Switchblade. Keep in mind that all of these applications can be achieved without touching a single patch cord if all of your equipment is plugged into the Switchblade.

>Effects in series in any order:

>One of the more basic things a switching system can do is string several effects is series. The Switchblade however is the only switching system that has the capacity to perform this function in any order. This ability to swap effects positions in an instant gives the musician a very powerful tool to compare how effects sound when their position is changed. For example, with 3 effects (called A, B, & C) in series there are 6 possible ways to connect them, ABC, ACB, BAC, BCA, CAB, and CBA. All will sound different and there is no way to tell ahead of time which method is right for you. Depending on the effects and your other equipment and playing style, some will be highly usable and some will not. With the Switchblade, six presets can be created reflecting all six combinations giving you the freedom to A/B compare all six.

>Changing Preamp Distortion under preset control

>As most guitarists are aware, preamps and distortion systems are sensitive to the level of the signal at their input. Typically, the higher the input signal, such as from hotter pickups, the more distortion. Quite often the "drive" control on distortions is nothing more than a variable gain input preamp changing the amount of drive to the second stage. When using a preamp or distortion with the Switchblade, both the signal level driving the device and the signal level from the device can be set under preset control. With this in mind it becomes apparent that it is possible to boost the amount of distortion while keeping the overall volume level the same simply by having a preset that kicks up the signal level to the distortion and reduces the signal level from the distortion at the same time.

>Tuning Multiple Preamps in Series

>The benefit to placing preamps in series is that each preamp in the chain adds its own distortion to the output of the previous preamp in the chain. The result is an accumulation (or buildup) of distortion that can be very pleasing since each preamp is contributing to the overall sound. However, the interaction of 2 or more preamps can cause the sound to become trashed very quickly if not kept in check by careful attention to levels of signal between preamps and the amount of distortion that each preamp is contributing. Therefore with the above two paragraphs in mind, it now becomes apparent that chaining 2 or more preamps in series and adjusting the levels to the first preamp, between preamps, and returning from the last preamp, can have a tremendous effect of the usability of the preamps and the number of useful combinations. In addition (using methods described below), it is possible to mix dry signals across any or all distortions in the chain to greatly enhance the variations in tone.


Effects in parallel

>Placing processors in parallel (side by side instead of one after the other) opens up vast fields of sonic territory. Take the simple example of a distortion device and a reverb. Traditionally, the two devices are strung in series as this is the only way to connect them without a switching system. If the guitar signal is fed to the distortion device first and then the reverb, the reverb will of course reverberate a distorted signal. Because of the complexity of a distorted signal on the ear, having reverberated distortion can be overbearing due to the interaction of distorted reflections. Reversing the order can be worse as the distortion is now forced to act on a complex clean signal from the reverb reducing the ability to "play" the distortion resulting in loss of feel. The interesting alternative is to split the guitar signal, with one side going directly to the distortion, and the other directly to the reverb, then mix the outputs of the reverb and distortion together for the amplifier. The result is "up front" punchy transients from the preamp surrounded by shiny sounding reverb holding on to a cleaner tone. If you are using 2 or 3 amplifiers then instead of mixing the outputs together, patch the preamp output to one amp and the stereo outputs from the reverb to the other 2 amplifiers. This gives a very refreshing three dimensional sound with plenty of "finger" sensitivity. An additional enhancement is to tap off the output of the preamp and mix it into the front of the reverb along with the direct guitar signal. (See combinational networks below).


Preamps in parallel

>A wonderful way to kick up the "thickness" of a sound and still maintain a very precise and responsive tone is to use two or more guitar type preamps in parallel. Placing preamps in parallel does not increase the amount of distortion as happens when preamps are strung in series, rather the tone of the distortion changes with a greater variety of harmonic content since each preamp is able to send its own signature sound to the amp without being "bottlenecked" by a preamp placed before or after it. In addition, with multiple preamps it is a simple matter to create presets that can "mix and match" preamps for different tone. For example, if you are using 4 preamps then you can have a preset that will mix preamps 1 and 3 in parallel, another to mix preamps 2 and 4 in parallel, and a third that will mix all 4 preamps in parallel.


Combinational Networks-bi-amping

>One of the greatest powers of the Switchblade is to create what is called "combinational networks" or networks of effects where some effects are in parallel and some are in series within the same preset. An example of this might be a "biamped preamp" network. To understand how biamping improves sound, it's important to understand the way overdrive works on a guitar signal. As was mentioned above, distortion in a preamp increases with input signal strength. On closer examination, what is really happening is that a preamp changes the shape of the audio signal more at the extremes of the signal (the positive and negative most excursions of the actual audio waveform) and very little at the "zero crossing point" or the resting area. Therefore, if a guitar is plucked hard, (higher signal level) it will distort more than if plucked gently. If the difference in distortion between softly played notes and notes played hard is minimal, without losing dynamic range, then the amp is said to have "high sensitivity", a very desirable feature. The key word here is dynamic range. It is a simple matter to simply crank the drive up on a preamp so that both soft and loud note distort equally, but the overall loudness of the soft and loud notes will be the same. This is the sound most typically used in "speed metal" and shred styles. A preamp driven to this extent has low sensitivity. High sensitivity, high dynamic range sounds are evident in the setups used by such artists as Stevie Ray Vaughn, Neil Young, and Mark Knofler.

>To make matters more difficult, low notes on a guitar have higher excursions (peak to peak signal strength) than do high notes on a guitar. When both high and low notes are played on a guitar (a chord), then a low level upper note is mixed in with a high level lower note. At the extremes of the low frequency excursions, the higher notes literally get the life sucked right out of them. As the low frequency note passes through the zero crossing point the higher frequency notes can once again breathe. In worst case scenarios the result of this phenomenon is a tinny, intermodulation type of distortion typical of cheap transistor amps or amps that have low sensitivity. Higher sensitivity amps that "spread out" the distortion of the signal over the full excursion of the waveform, allow the higher notes riding on the back of the lower notes to breathe during the full excursion of the low note resulting in the much more pleasing harmonic distortion or what is commonly referred to as a "tube" type sound.

>Enter bi-amping. In bi-amping, the guitar signal is split with one signal going to a graphic or parametric (preferred) EQ device set to reduce all high frequency notes and only pass the fundamental frequencies of low and middle notes. The output of the EQ is then fed to a guitar preamp set for a fair amount of overdrive. Likewise the second guitar signal also goes to an EQ set to attenuate all low and middle notes and only pass upper frequency notes. Its output is then fed into a second preamp also set for a fair amount of distortion. Finally the signals from the two preamps are mixed together and sent to the main amplifier. The main amp should be a clean, hi powered amp, a solid state (MOS type) amp would not be unusual here or a tube stack set on the clean channel. Keep in mind that all overdrive is done in the preamps and not in the final amp. This setup allows high frequency notes to achieve the full benefit of their own overdrive channel without having to deal with the overbearing lower frequencies which are processed separately. The result is a very smooth tone with lower overall intermodulation distortion and very high sensitivity.

>Using the Switchblade it is a simple matter to create this parallel/series biamped network. In addition if you are using two main amplifiers, then instead of mixing the two signals from the preamps together, try sending the signals to separate amps for an even richer sound. Using continuous control techniques described below, an interesting addition to this dual amp setup would be to bypass both EQs with a dry signal assigned to a continuous controller. As the controller is moved down, the amount of EQ is reduced and at the extreme, both preamps and both main amps are getting the same full bandwidth signal. This would then be a simple multi amp setup, the theory of which is described below.


Mulitple Amplifier Theory

>With the Switchblade's ability to split a guitar signal and route the signal to different outputs, multi amp setups are a simple matter. More importantly, a guitar signal can be split and sent to multiple preamps in parallel, and then the returns from the preamps can be routed to mulitple amplifiers on stage, enhancing the multi amp soundfield. The benefits of using multiple amplifiers is described here.

>A basic idea of splitting a guitar signal (traditionally using a "Y" cord) and going into several amplifiers is a staple arrangement of such players as Hendrix, Trower, and many others. The reason it sounds so good is twofold. The first and most obvious reason is that you can use several lower powered amps (such as 50 watt heads) which are more easily overdriven to create a sound that is larger than using a single high powered amp which is not so easily clipped for a given sound pressure level. The other and not so obvious reason is the interaction of the audio wavefronts between speaker cabinets. In a (non) ideal situation, the sound coming from one speaker cabinet would be identical to the sound coming from all the others. The result would be a strong sound directly in front of the cabinets and a weaker sound as one moves off center due to the interference of out of phase wavefronts. In the real world, each cabinet puts out a sound quite different (different harmonic structure) than its neighbor due to differences in cabinets, speakers, and amplifiers and even its position on the stage. The result is a much more complex interaction between the audio wavefronts and an overall sound of much greater "depth". For those of you who are familiar with a "hologram", the theory is the same. A hologram (when viewed in normal lighting) is nothing but a smoky photo of light and dark circles or "wavefronts". This would be equivalent to one amplifier on stage. When a Laser beam (another wavefront) is passed through a hologram, the two groups of wavefronts interact with each other and the result is a striking three dimensional image appearing out of nowhere and sitting in space. Likewise, when finely tuned sounds (wavefronts created by seasoned players) come out of multiple cabinets, the wavefronts interact and the result is a kind of "surreal" imaging whose shape can be molded into a very pleasing sound simply by "playing" the wavefronts (moving toward and away from the cabinets, string bending until t he right "grove" is felt, tapping and bending the neck to enhance wavefront variations, subtle "wah" pedal movements to vary the harmonic structure of the wavefronts, and so on.)

>Using a Switchblade, multi amp operation can be taken to new heights since the guitar signal can be sent through seveal effects before going out to individual amplifiers, or alternately, tapping off different points in a complex effect network, remixing to new levels and with other tap points and finally to separate amplifiers. Combine this with continuous control to allow more interaction between amps and the result can be exteme.

>Multiple Instruments

>With the Switchblade's ability to "route anything to anything", instruments that have multiple outputs, such as guitars with both piezo and magnetic pickups can be plugged into the Switchblade and routed to separate processors and amplifiers, or mixed first and then processed. For example, the piezo signal could be routed to an equalizer and preamp and sent to one amplifier while the magnetic pickup can be routed to a multi-effects unit, a reverb unit and a digital delay and sent to another amplifier. This separation of the signal can enhance the overall sound. Or use the Switchblade to mix the piezo and magnetic pickups together before sending the mixed signal to a chain of signal processors.

>A Word About the Switchblade Continuous Control Feature

>Unlike a simple volume pedal that limits the user to having control over volume at a single specific point in the audio path, (usually the last effect and the amplifier), the Switchblade Continuous Control capability allows the musician the ability (under preset control) to insert volume control not only anywhere in the signal chain but in multiple areas of the entire effect network at the same time. In addition, the sweep of the continuous controller can change the levels of these areas in a "scalable" fashion (where the degree of change is programmable) and with different slopes (one patch increasing while another is decreasing in response to the pedal movement). With this in mind it becomes possible to do things that are not possible with other setups. Two such ideas are crossfading between effects in parallel and the other seemingly impossible task of crossfading between effects that are wired in series. Until the Switchblade, there was no known way to perform this function.

>Crossfading Between Effects in Parallel

>Crossfading effects in parallel opens up huge areas of live sound control and lends itself to many imaginative possibilities. One of the more obvious examples is simply controlling the amount of distortion in your sound in real time. This setup is similar to the "wet/dry" knob on some effects devices but is under control of the continuous controller pedal instead. The guitar signal is split with one signal going to a distortion effect and the other going directly to the amp. The output of the distortion is mixed with the direct signal. The gain of the direct signal is programmed from maximum gain to minimum gain as the pedal is moved down and the gain of the signal from the distortion is programmed with the opposite slope going from minimum gain to maximum gain as the pedal is moved down. The signal level from the guitar to the distortion is fixed at 0dB. With this arrangement when the pedal is in a full up position only the "dry" direct signal appears at the amplifier and the resulting sound is full clean. As the pedal is moved down, the direct signal begins to fade while the signal from the distortion increases until finally there is no direct signal and only the signal from the distortion is present at the amp. This simple example can be expanded where both a delay and a distortion are patched in parallel with the output of the delay and the output of the distortion programmed with opposing continuous gain. When the pedal is full up only a clean echo is heard and when pressed downward the echo fades as a non-echo distortion begins to take its place. As you can see this can be expanded to include even more effects for complex crossfading.

>Crossfading Between Effects in Series


>Sometimes, crossfading between effects in series is preferred to crossfading in parallel, especially when the sounds offered by effects in series is required. Such a case might be placing a distortion and a delay in series. This arrangement (without crossfading) causes the output of the distortion to feed the delay device so that the echos also are distorted (This in contrast to having a distortion and echo in parallel where the initial strike of the string is distorted and all echos are clean). Now suppose you wish to be able to vary the amount of distortion and delay under continuous control and still have the echo follow the amount of distortion that is chosen. The only way to do this is to crossfade in series.

>Unlike crossfading between effects in parallel, where the cross gains are simply assigned to the effect signals going to the amplifier, crossfading between effects in series takes some imaginative patching techniques. This unique arrangement is only possible on the Switchblade because it makes use of the distribution and mixing properties of the matrix. The method to do this is to create the following patches: 1) From guitar to distortion with 0dB gain. 2)From guitar to delay with continuous gain from off to +6dB (rising slope). 3)From distortion to delay with continuous gain from +6dB to off (falling slope). 4)From distortion to amp with continuous gain from +6dB to off (falling slope). 5) And finally from delay to amp with continuous gain from off to +6dB (rising slope). Now when the controller pedal is all the way up, the guitar signal from the distortion will pass directly to the amplifier. The output from the delay to the amp will be off. Hence we have pure distortion with no delay With the pedal all the way down, the signal from the distortion to the amp is off as is the signal from the distortion to the input of the delay. The guitar signal instead directly feeds the delay (clean signal) and the output of the delay to the amp is full on, hence we have clean echo. So far we have the same sound as these 2 effects in parallel. The difference however occurs when the continuous controller is somewhere in the middle. In this case the input to the delay sees both a direct guitar signal and the distorted signal. And the amp sees both the output from the delay and the output from the distortion. The result is distortion with distorted echo with the amount of distortion from both varying with the position of the pedal. A very unique arrangement indeed!

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