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Block Diagrams 

The block diagrams of the Pritchard amplifiers show how the minute electricity coming from your guitar, instrument, or microphone becomes bigger, fatter, resilient, full-bodied, and alive. As you will quickly see, these amplifiers do more than simply amplify your signal, they amplify your artistry with patented and proprietary designs.

  Pritchard amplifiers are based on the Black Dagger. Sword of Satori and Gold Estoc adds a second, nominally clean or crunch channel from a common input and channel switching. Sultry Margaux adds her second channel from a separate input and then mixes the two channels together. The amplifiers are also assembled somewhat differently to emphasize key issues. Thus, Blood Dagger and Jade Dagger are different than the Black Dagger.

Click below to view the block diagram for:

Sultry Marguax

Black & Blood Dagger

 All Daggers' artistry starts with a Compatibility Preamplifier and its special input circuitry that controls the energy flow back and forth between the guitar and the amplifier. This minimizes the harsh highs while extending the desirable treble - all to make your guitar sound better. This stage continues with the patented XGPA Technology that exaggerates the wondrous grid-plate action found in great amplifiers. The Guitar Compatibility Preamplifier has variable gain to accommodate weaker single coil pickups as well as hot double coil pickups.

  From the Compatibility Preamplifiers, the signal is further amplified by the Volume stages. The volume stage has a regular volume control and variable gain XGPA so to minimize the low gain amplifier noise.

  Next, you can give your guitar one of six voices with the Voice Knob™, a super tone control with great flexibility and versatility. These voices have their roots in American and British tones and the needs of guitar players. The guitar voices for Black Dagger are listed below. The Blood Dagger Voice Knob ™ replaces the A voice with an H voice for a high bass notch with a lot of treble emphasis.


A- Airy Art A really cool clean tone inspired by acoustic guitar tone.
S- Smooth Solo A bass and treble accent for smooth clean tone.
F- Famous Flat Inspired by a American guitar amplifier tone.
M- Moderately bright Inspired by a British guitar amplifier tone.
V- Very bright Inspired by a chimey British guitar amplifier tone.
L- Liquid Lead A proprietary combination of American and British amplifier tones.

Other Voice Knob™ or tone switches substitute other voices for one or more of the above for still more versatility. These voices are:

B- Ballad or Bass Boost A soft voice for jazz standards or mellow ballads.
H- Heavy Dirt The treble emphasis of the M voice doubled.
N- Notch A mid-range scoop with treble emphasis
P- Precision Punch A very interesting guitar tone inspired by a Precision bass.

  The output levels of the Voice Knob™ selections follow their intent with the quieter tones having more attenuation than the leading tones. Consequently, a player can readily switch voices without significant further adjustments.

  The voiced guitar signal then goes into the third XGPA gain stage that has a two switch selected gains, and in the Dagger and Sword, one of the gains is variable and controlled by the Boost (B) Switch. This stage drives a three-band tone control and the next XGPA stage. This fourth stage also has a switch selectable gain boost to make a clean tone louder or crunchy and is controlled by the Channel or Crunch (C) foot or panel switch.

The Output System

  The output systems for the six Pritchard amplifiers share the same structure and continue the XGPA character. The first of the common stages is the Treble and Mid-Range Noise limiter that in high-gain Boost modes dynamically reduces the noise as the guitar signals goes away. This unique version of a noise gate does not slam shut, but allows the guitar sustain to continue with the treble rolled off. This limiter as well as the similar reverb limiter is controlled by the Noise Limiter Control Amplifier that is driven from the first stage. The limiter is enabled when the Boost is on for the "dirty" channel, or when both boost are on.

  The Effects Send and Return jacks are next and they support both serial and parallel effects loops. The serial loop is enhanced with an internal connection through a resistor to improve the reliability of the amplifier. Both returns go to the Signal Mixer where they are combined with the Series Effects driven Spring Reverb and its Mid and Treble Noise Limiter.

  The Pritchard Amp's Spring Reverberation system is an enhanced version of the classic spring reverbs. Pritchard Amps magnetically shield electro-magnetics of the spring reverbs so that the reverb channel does not hum and can include bass frequencies for a fuller, fatter reverb tone.

  The Signal Mixer drives the final stages in the Output System. These final stages are the subject of most of Pritchard's investigation, research and patents because the real artistry of vintage amplifiers is not in the preamplifier stages but in the output stages. Buyers are being duped into believing that using one or two 12AX7's provides the same character as the complexity of the interactions of the phase splitter, output stage, speaker/driver, and power supply. The vintage output stages provide the bulk of the artistry of amplifiers: life, resilience, body, fat, and touch-sensitivity.

  The proprietary Speaker Enhancer drives the following Current Controlled Amplifier, which is key to producing life, resilience, body, fat, and touch-sensitivity. This unique amplifier stage gives Pritchard amps exaggerations of the compression, harmonics, and effects of artistic amplifiers for true above and beyond tonal experience. This amplifier accepts feedback from the Watts Knob™ and is controlled by the Watts, Fat, and Life circuitry. The CCA drives the Power Amp, which is a super smart monolithic circuit. This circuit not only provides the raw power to the speaker, it features protections against short circuits (made quite possible by phone jack connections), excessive voltages, and over temperature conditions. The Power amplifier also accepts voltage feedback from the Watts Knob™ and current feedback from the speaker.

  The Watts Knob™ circuitry lets you turn down a Pritchard amplifier without substantially changing your tone. It does what the master volume control wishes it could do. The Watts Knob™ adjusts the nature of the output stage and keeps the various inter-relationships in the output stage constant as the Watts Knob™ is changed:

  • The amount of input necessary to produce clipping in the output stage is held constant so that the same picking creates the same distortion.
  • The output impedance of the amplifier is held constant by simultaneously changing the feedback and the gain of the Current Controlled Amplifier so that the amplifier's relationship to the speaker or driver.
  • The proportion of the various output stage effects, sag, compression, fat, etc. is held constant.

  The Power Amp drives the speaker in two ways, through the Gig Speaker Jack or through the Practice Jack™. The patent-issuing Practice Jack™ features a hearing compensated attenuation so that practice has much of the fullness of tone that playing has. It also give you the ability to play screaming leads to acoustic accompaniment.

  The speaker, whether connected to the Gig Jack or the Practice Jack™, is housed in a patented cabinet. This cabinet is a unique balance between open and closed back cabinets and has deeper bass than an open back without the roughness of the bass boom of the closed back cabinet. It truly gives a small cabinet the tone of a much larger, harder-to-carry big cabinet. The Pritchard cabinet designs also have a unique, retro appearance. It looks old but it is so new that it is also protected by a U.S. Design Patent.

  The Equalized Direct produces a hot microphone level out on a balanced XLR output for direct connection to a board. This output signal has the character of a typical speaker. The Amp Jack attenuates the Gig Jack output (balanced TRS or unbalanced TS) for connection to an external amplifier for driving external instrument speakers with greater power.

  The Foot Switch and the amplifier front panel both have B and C push button switches for quick changes in the amplifier setup. In Black Dagger, the B and C switches control the boost levels, one for the screaming Boost and one for Crunch. In Sword of Satori, the B and C switches control the Boost and the Channel selection. In Sultry Margaux, the B and C switches control boost in the B and C channels. In each amplifier the Foot Switch gives the player four different instant tonal selections to pick from.

  The Foot Switch does more than merely changing channels and boost. What is not shown in the simplified diagrams are the Foot Switch controls of the Output System. The Foot Switch changes the character of the Output System to change the character of the tone as well as its level. The implementation of these controls is different in the different amplifiers.

 

Blood Dagger

  The Blood Dagger is very similar to the Black Dagger, but leans towards the more modern tonality and uses a different Voice Knob™ with the H voice instead of the A voice.

H- Heavy Dirt An upper bass notch with substantial treble emphasis for high gain distortion

 

Jade Dagger

Click here to view the Jade Dagger block diagram

  The Jade Dagger features a Deep Tone Control instead of a gain boost. and a different Voice Knob™ which is oriented to clean tones and replaces the V and L voices with two other voices, B and P:

B- Bass Boost A bass boost for mellow ballads and jazz standards
P- Precision / Tele An upper bass plus treble accent.

Sword of Satori

   The Sword of Satori features a second channel with its own Volume control, Voice Knob™ and Tone Controls. This second channel is driven by the Guitar Compatibility Preamplifier and is selected by the Channel Switch. This channel is the nominal clean channel although it can distort quite nicely. Whether distorted or not, it does not have the super gain capability of the main channel. Its boost is fixed and nominally designed for a crunch tone, which is much more closely related to a clean tone.

  The Sword's upper channel Voice Knob™ is oriented to dirty tones and replaces the A voice with another voice, H:

H- Heavy Dirt An upper bass notch with substantial treble emphasis for high gain distortion
   The Sword's extra lower channel Voice Knob™ is oriented to clean tones and replaces the V and L voices with two other voices, B and P:
B- Ballad or Bass Boost Treble de-emphasis for jazz standards and mellow ballads.
P- Precision / Tele An upper bass plus treble accent inspired by a Precision Bass

Gold Estoc

  The Gold Estoc is similar to the Sword of Satori, except for the following: The main channel uses the Voice Knob™ that emphasizes clean tones with the versatility of the A, S, F, M, B, and P selections. The second channel has still another Voice Knob™ with the added flexibility of the H, N, F, M, V, and L selections. The second channel also includes an added distortion stage plus a post distortion volume control.

  The Sword's upper channel Voice Knob™ is oriented to vintage clean tones:

A- Airy Art A really cool clean tone inspired by acoustic guitar tone.
S- Smooth Solo A bass and treble accent for smooth clean tone.
F- Famous Flat Inspired by a American guitar amplifier tone.
M- Moderately bright Inspired by a British guitar amplifier tone.
B- Bass Boost An upper bass boost for mellow ballads and jazz standards
P- Precision / Tele An upper bass boost plus treble accent.
  
The Sword's extra lower channel Voice Knob™ is oriented to clean tones and replaces the V and L voices with two other voices, B and P:
H- Heavy Dirt An upper bass notch with substantial treble emphasis for high gain distortion
N- Nasty Notch An lower mid notch with substantial treble emphasis
F- Famous Flat Inspired by a American guitar amplifier tone.
M- Moderately bright Inspired by a British guitar amplifier tone.
V- Very bright Inspired by a chimey British guitar amplifier tone.
L- Liquid Lead A proprietary combination of American and British amplifier tones.

  The Sultry Margaux is the nominaly clean amp although it does have enough gain to get dirty as well. It is a mellow monster. Sultry Margaux also features a second channel, but this second channel has its own input and is mixed with the main channel instead of switched. The second input may be from a microphone or from an instrument. Its TRS jack can accept two-channel signals from two channel instruments and feeds the ring terminal signal to the main channel. This second channel features a Volume Control and 3-band Tone Controls. Sultry Margaux also features a parametric notch/band boost filter that can operate on either channel.

  The Voice Knob™ in the main channel is the same as the second channel Voice Knob™ of Sword with A, S, F, M, B, and P selections.

  Additionally, the Equalized Direct for Margaux uses different components to represent speaker systems with higher frequency rolloffs.

 
     
 
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