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Details

Specs

Ordering

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$1795 Shipped

Includes Amp, Power Cord

and Owners’s Manual.

Please indicate your choice of:

- 15 Watt or 25 Watt Tube Configuration (info)

- Clean, Classic or Extreme Ammo Can Style (info)

Description

15/25w Lead

$1495

Shipped. Now through July 31st.

Only

DESIGN AND CONSTRUCTION DETAILS

For the technically inclined, here are some details about the design and construction of Amplifier No. 7.

SIMPLICITY = TONALITY

The circuit design of Amplifier No. 7 is intentionally simple, because I believe that the more electronics your guitar’s signal passes through, the more it becomes degraded.  The simpler the circuit, the purer the tone.

LOOK MA, NO BOARDS

What's more, the true point-to-point wiring implemented in Amplifier No. 7 provides a physically direct signal path not obtainable any other way.  Parts are connected directly between chassis-mounted components, without the need for wires running back and forth to a board - whether that board be an eyelet board, turret board or printed circuit board.

OCTAL PREAMP

Rather than the familiar 12AX7 tubes found in nearly all guitar amps today, Amplifier No. 7 uses two 6SL7 octal tubes in the preamp section.  These large, hi-mu twin triodes do not exhibit the over-brightness or harshness that 12AX7s can, which many amp makers attempt to filter out with additional circuitry.  

There’s something about these big octal tubes - perhaps the larger plates and heavier construction compared with 12AX7s - that gives them a bigger, more power-tube-like tone, particularly when overdriven.  A DC heater supply eliminates heater-induced hum.

POWER TUBE CHOICES

In the power section you may choose a pair of 6V6s or 5881s.  6V6s are loved for their unique midrange bark.  And to my ears, they just kill EL84s, which are found in many amps of comparable wattage.  Popping in a set of 5881s ups the ante considerably, increasing dynamics and harmonics, and giving you enough power to keep up with even the loudest of rhythm sections.  

The power tubes are run in a Class A cathode-biased configuration, adding to the amp's dynamic feel.  Natural tube compression gives the amp a singing quality.  The tubes may be changed without the need to adjust bias.

TUBE RECTIFICATION

And let's not forget the power supply.  It would have been easier and cheaper to use silicon diodes here.  But a tube rectifier is one more critical component that adds to Amplifier No. 7's feel by lending just the right amount of "sag" to the B+ rail.  

The 5Y3 brings out the 6V6's honk, as it has done famously since the Fender tweed era.  The GZ34, used in Marshall's very first amp, the JTM45, feeds Amplifier No. 7's 5881s a tight - but still dynamic - B+ voltage.  

High voltage rail filtering - the right amount in the right places - is provided by the twist-lock multi-section capacitor can.

THE RESULT

All of these technical details were not just thrown together like the Frankenstein monster.  They were carefully and deliberately worked out in the lab and on the stage.  The result is a superb sounding and performing amp that will withstand the rigors of the road and give you inspiring tone for years to come.

Want to know more?  Check out the FAQ or contact me.

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