Mad Professor CS-40 Tube Amplifier Head
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Listed:8 years ago
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Carmel, IN, United States
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This is one of the early units of the CS-40. See the serial number in one of the pics.
Unit has been examined by a professional tech and biased properly with a set of EL-34's as pictured.
The manual will be included which describes other footswitching features. The only thing footswitchable in this unit is the Volume Boost.
-THE TONE!
-Hand made point to point wired 40-75W tube amp that is fine-tuned for the best possible tone.
-Based on the experience Bjorn Juhl has had working with finest tubes amps for 20 years.
-The circuit is as original as a tube amp can be, respecting the heritage of the greatest amps designs. The fine-tuned circuit with built-in bias adjustment accepts 6L6, EL34, KT66, KT88 … even 6V6 if you can find ones that can handle 500V of plate voltage.
-The overbuild custom transformers have enough juice to drive the KT88’s/6550’s to about 75W of power.
-With special POWERSUCK switch you can drive the power-amp to fat compressed tone at bedroom levels.
The touch response is awesome, this is about the most dynamic amp there is. There are tones from sparkling clean to fat and sweet, singing overdrive, from sparkle to rumble… ALL the parts are overrated and should last for ages. The amp is available factory direct by custom order only and it can be played all over the world (100/117/230/240V)
The real beauty is in the amp circuit that is a piece of art. Lot of special tuned circuits where the placement of components and length of wires makes a difference in tone.
NORMAL INPUT used for clean sounds to light overdrive
ABNORMAL INPUT used for overdrive sounds
FET-TUBE SWITCH selects the type of distortion obtained from Abnormal input - where the FET option lets the input tube be driven without the rectifier action of an overloaded control grid resulting in a sound with a little less buzz, slightly cleaner tone than ordinary tube overdrive. TUBE is an all tube structure for a classic tone
VOLUME sets the gain of the preamp
MIDDLE works as normal midrange control except it's affected by FOCUS
BASS works as bass control except it's affected by FOCUS
The 4-position FOCUS control (amp rear) affects the amp’s feel and the sonic textures it produces:
- Position 1, the CS-40 delivers American-style sounds (think classic Fender tones).
- Position 2 yields some really amazing, early British sounds (yep, think Vox AC30 here as a reference).
- Position 3, you’ll easily cop some later British-style tones (thinking classic Marshall isn’t a bad idea).
- Position 4, CS-40 enters the realm of modern British sounds enhanced with top boost. These tones are grittier sounding, but very defined.
TONE BALANCE this controls the balance between bass and treble, work similar to most treble-knobs on other amps.
TREBLE controls... well, treble
BOOST sets how much level-boost is obtained when boost footswitch is pressed
PRESENCE controls the treble response of power amp - works by removing feedback at high frequencies
MASTER controls output level - works by attenuating level at power-amp input.
The CS-40’s Tonal Balance knob is another deviously designed audio manipulator. Turning it counterclockwise from noon offers a really fat midrange sound that gets close to Dumble territory. Turning it clockwise from noon makes the sound brighter and thinner. However, in this scenario, turning up the Master volume or Channel volume fills things out very, very nicely. It’s clear the CS-40 was designed from the ground up to deliver well-defined, heavy distortion.
The amp is LOUD but has also great tone at club-levels thanks to special BJF design “POWERSUCK” option.
The Powersuck (amp rear) is an ATTENUATOR-type feature that allows you to get big-sounding overdrive tones at progressively lower volumes—low enough to talk over in the Bedroom setting. Powersuck doesn’t work exactly as you’d expect, and it wasn’t designed to replicate the amp’s full-tilt sound at reduced volumes. Its effect is literally changing to a lower-powered amp—and going from, say, Arena to Pub gig and get precisely the tones and dynamic feel you want.
Next to the input jack is a 2-position switch labeled Tube and F.E.T. In the FET position, this switch can take weak pickups (such as Danelectro lipsticks) and make them sound much stronger. It’s uncanny! The Tube setting is voiced for hotter pickups, such as humbuckers on a Les Paul. P-90s produce gnarly tones in any of these settings, and this marriage of amp and pickups is one of my favorite—it’s so beautifully rude.
Want more volume, even if you’re already cranked wide open? No problem. Just dial in some boost using the front-panel control, hit the CS-40’s Boost footswitch, and prepare to be thrown against the nearest wall. Most other amps have nowhere left to go when they’re already cranked, but this is where the Mad Professor really shines.
-Preamp distortion and/or Power-amp distortion, with or without compression at any volume level.
-Three (3) gain structure options (Normal, Abnormal/Tube and Abnormal/FET).
-Four (4) different ways to adjust the ever critical treble response.
-Foot-switch for adjustable Boost.
-Dynamics you have never experienced.
-Magical Bjorn Juhl circuit.
Mad Professor has FOUR ways to control the critical treble response:
- FOCUS switch has two options with slight treble boost, then there is
- TONE BALANCE that you can adjust treble with, the
- TREBLE control of course adjust certain Treble frequency and the
- PRESENCE controls another Treble frequency.
You will find the optimal Treble response with any guitar and cabinet using these controls.
You can have distortion from Preamp or from Power-amp, you can have it at lower volume levels with the special POWERSUCK switch.
There are lot of different distorted tones from this amp: “clean”, sweet, crunchy, fat, “On the edge”, singing, dynamic, with powertube saturation or without.. You can tailor the distortion so that treble distorts earlier than the low-end etc….
Inside the amp
There are bias test points behind the back panel and you set the bias for the different tubes by using just a normal Volt meter.
A Bias switch to switch between Hi and Low bias for EL34 or other types of tubes.
Wide range bias trimmer to set the bias for different tubes.
It takes only few minutes to change the power tubes and you can do it yourself.
Design philosophy
All parts are deliberately overrated to ensure reliable and safe operation.
Circuit is to be as far as possible original or at least nonstandard.
Construction should be neat and build to last. It should be the best amp ever built.
It must be an inspiring amp to play!!!
FREE SHIPPING
Unit has been examined by a professional tech and biased properly with a set of EL-34's as pictured.
The manual will be included which describes other footswitching features. The only thing footswitchable in this unit is the Volume Boost.
-THE TONE!
-Hand made point to point wired 40-75W tube amp that is fine-tuned for the best possible tone.
-Based on the experience Bjorn Juhl has had working with finest tubes amps for 20 years.
-The circuit is as original as a tube amp can be, respecting the heritage of the greatest amps designs. The fine-tuned circuit with built-in bias adjustment accepts 6L6, EL34, KT66, KT88 … even 6V6 if you can find ones that can handle 500V of plate voltage.
-The overbuild custom transformers have enough juice to drive the KT88’s/6550’s to about 75W of power.
-With special POWERSUCK switch you can drive the power-amp to fat compressed tone at bedroom levels.
The touch response is awesome, this is about the most dynamic amp there is. There are tones from sparkling clean to fat and sweet, singing overdrive, from sparkle to rumble… ALL the parts are overrated and should last for ages. The amp is available factory direct by custom order only and it can be played all over the world (100/117/230/240V)
The real beauty is in the amp circuit that is a piece of art. Lot of special tuned circuits where the placement of components and length of wires makes a difference in tone.
NORMAL INPUT used for clean sounds to light overdrive
ABNORMAL INPUT used for overdrive sounds
FET-TUBE SWITCH selects the type of distortion obtained from Abnormal input - where the FET option lets the input tube be driven without the rectifier action of an overloaded control grid resulting in a sound with a little less buzz, slightly cleaner tone than ordinary tube overdrive. TUBE is an all tube structure for a classic tone
VOLUME sets the gain of the preamp
MIDDLE works as normal midrange control except it's affected by FOCUS
BASS works as bass control except it's affected by FOCUS
The 4-position FOCUS control (amp rear) affects the amp’s feel and the sonic textures it produces:
- Position 1, the CS-40 delivers American-style sounds (think classic Fender tones).
- Position 2 yields some really amazing, early British sounds (yep, think Vox AC30 here as a reference).
- Position 3, you’ll easily cop some later British-style tones (thinking classic Marshall isn’t a bad idea).
- Position 4, CS-40 enters the realm of modern British sounds enhanced with top boost. These tones are grittier sounding, but very defined.
TONE BALANCE this controls the balance between bass and treble, work similar to most treble-knobs on other amps.
TREBLE controls... well, treble
BOOST sets how much level-boost is obtained when boost footswitch is pressed
PRESENCE controls the treble response of power amp - works by removing feedback at high frequencies
MASTER controls output level - works by attenuating level at power-amp input.
The CS-40’s Tonal Balance knob is another deviously designed audio manipulator. Turning it counterclockwise from noon offers a really fat midrange sound that gets close to Dumble territory. Turning it clockwise from noon makes the sound brighter and thinner. However, in this scenario, turning up the Master volume or Channel volume fills things out very, very nicely. It’s clear the CS-40 was designed from the ground up to deliver well-defined, heavy distortion.
The amp is LOUD but has also great tone at club-levels thanks to special BJF design “POWERSUCK” option.
The Powersuck (amp rear) is an ATTENUATOR-type feature that allows you to get big-sounding overdrive tones at progressively lower volumes—low enough to talk over in the Bedroom setting. Powersuck doesn’t work exactly as you’d expect, and it wasn’t designed to replicate the amp’s full-tilt sound at reduced volumes. Its effect is literally changing to a lower-powered amp—and going from, say, Arena to Pub gig and get precisely the tones and dynamic feel you want.
Next to the input jack is a 2-position switch labeled Tube and F.E.T. In the FET position, this switch can take weak pickups (such as Danelectro lipsticks) and make them sound much stronger. It’s uncanny! The Tube setting is voiced for hotter pickups, such as humbuckers on a Les Paul. P-90s produce gnarly tones in any of these settings, and this marriage of amp and pickups is one of my favorite—it’s so beautifully rude.
Want more volume, even if you’re already cranked wide open? No problem. Just dial in some boost using the front-panel control, hit the CS-40’s Boost footswitch, and prepare to be thrown against the nearest wall. Most other amps have nowhere left to go when they’re already cranked, but this is where the Mad Professor really shines.
-Preamp distortion and/or Power-amp distortion, with or without compression at any volume level.
-Three (3) gain structure options (Normal, Abnormal/Tube and Abnormal/FET).
-Four (4) different ways to adjust the ever critical treble response.
-Foot-switch for adjustable Boost.
-Dynamics you have never experienced.
-Magical Bjorn Juhl circuit.
Mad Professor has FOUR ways to control the critical treble response:
- FOCUS switch has two options with slight treble boost, then there is
- TONE BALANCE that you can adjust treble with, the
- TREBLE control of course adjust certain Treble frequency and the
- PRESENCE controls another Treble frequency.
You will find the optimal Treble response with any guitar and cabinet using these controls.
You can have distortion from Preamp or from Power-amp, you can have it at lower volume levels with the special POWERSUCK switch.
There are lot of different distorted tones from this amp: “clean”, sweet, crunchy, fat, “On the edge”, singing, dynamic, with powertube saturation or without.. You can tailor the distortion so that treble distorts earlier than the low-end etc….
Inside the amp
There are bias test points behind the back panel and you set the bias for the different tubes by using just a normal Volt meter.
A Bias switch to switch between Hi and Low bias for EL34 or other types of tubes.
Wide range bias trimmer to set the bias for different tubes.
It takes only few minutes to change the power tubes and you can do it yourself.
Design philosophy
All parts are deliberately overrated to ensure reliable and safe operation.
Circuit is to be as far as possible original or at least nonstandard.
Construction should be neat and build to last. It should be the best amp ever built.
It must be an inspiring amp to play!!!
FREE SHIPPING
This item is sold As-Described
This item is sold As-Described and cannot be returned unless it arrives in a condition different from how it was described or photographed. Items must be returned in original, as-shipped condition with all original packaging.Learn More.
| Listed | 8 years ago |
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| Condition | Very Good (Used) Very Good items may show a few slight marks or scratches but are fully functional and in overall great shape.Learn more |
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