KR20100014298A - Electronic bass register musical instrument tube preamplifier - Google Patents

Abstract

An electronic bass register instrumental tubular preamplifier. It is an inline signal preamplifier that enriches the pitch of electronically amplified bass register instruments.

Use standard 1/4 ”input jacks and 1/4” output jacks to connect the unit to the signal path between the instrument and amplifier. Other effect processors may be arranged before and after the preamplifier.

A variable current source driver further includes a volume control and a speed increase switch to further reduce distortion and enrich the bass register tones. The variable current drives a half of the plate of the 12AX7 tube at 48vdc plate voltage in the acceleration drive position and 40vdc plate voltage in the normal position. Use of increased speed position may cause initial failure of 12AX7 tube and should be used with caution.

EBIP is useful for semiconductor and tubular amplifier applications.

Description

Tubular preamplifier of electronic bass register musical instrument {ELECTRONIC BASS REGISTER MUSICAL INSTRUMENT TUBE PREAMPLIFIER}

The preamplifier of the electronic bass instrument (hereinafter referred to as EBIP) is the audio preamp section for electric bass guitars and other amplified bass register instruments. The EBIP invention is based on the use of paper in oil capacitors and on the use of these capacitors in combination with the latest thin film capacitors in the circuit, rather than the circuit configuration it uses. EBIP uses half of the 12AX7 tube and includes a switch that can be further improved by driving the tube at increased speed. The input socket must be isolated from ground due to radio frequency interference (RFI).

Although papers in oil capacitors have not been manufactured for general purposes since the 1950s, today they have been reborn for high-end audio equipment. In the schematic below, C1 consists of Mylar paper in the oil capacitor and C2-C3 consists of two .47uf copper foil paper in the series oil capacitor. C4 is a modern "orange drop" capacitor and C5 is a ceramic disk capacitor. All registers are 1/2 W. Only the B + voltage is 153vdc, which is a common voltage, and the other voltages act the same by some adjustments to the values of R1, R2, and R4. The grounded metal box contains the electronic components of the EBIP.

The circuit includes a volume control at the last stage, and the EBIP is designed to be placed in the signal circuit between the instrument and the amplifier.

Tube heaters require 6.3vdc or 12.6vdc. The heater circuit is not shown in the circuit diagram but is included as usual in such a tube circuit.

The present invention has been described in accordance with its preferred embodiments. Its shape, arrangement and value may be modified without exceeding the scope of the present invention.

In the 1960s, there was a clear change in the pitch of audio amplifiers. During this period, the first transistor radios were mass-produced, and new manufacturing methods for signal capacitors were developed and used. The new capacitors have become smaller and easier to mass produce.

At this time, most of the instrument's amplifiers were still tubular amplifiers, but the latest signal capacitors began to be used. This did not affect the pitch of treble register instruments to the extent that they affect the pitch of bass register instruments (for example, the pitch changes when played on amplifiers manufactured using methods before the new manufacturing method of signal capacitors was developed). In contrast, the pitch was not significantly changed by the tonal control of the bass guitar).

 Most musical instrument amplifiers from the late 1960s to the 1980s began to be manufactured as solid state amplifiers. The pitch of these amplifiers has not improved, but the manufacturing process has improved. Until the 1980s, specific amplifier and effect manufacturers began introducing 12AX7 tubular preamp circuits that were very effective in enriching and less distorting the treble resistor. Bass register instruments were unaffected to the same extent and new methods of playing electric bass (eg, slap peaking) were developed. In addition, the development of a digital effects processor improved the pitch of the bass register instrument to some extent, and Kennedy (US Patent No. 4672671) and Kennedy etc. (US Patent Publication No. 4672671) using both sides of the 12AX7 tube. The preamplifier circuit used in 4644289) produced a rich, low distortion pitch in the same way as the EBIP invention.

The present invention has been described in accordance with its preferred embodiments. Its shape, arrangement and value can be modified without exceeding the scope of the EBIP invention.

An electronic bass register instrumental tubular preamplifier. It is an inline signal preamplifier that enriches the pitch of electronically amplified bass register instruments.

Use standard 1/4 ”input jacks and 1/4” output jacks to connect the unit to the signal path between the instrument and amplifier. Other effect processors may be arranged before and after the preamplifier.

A variable current source driver further includes a volume control and a speed increase switch to further reduce distortion and enrich the bass register tones. The variable current drives a half of the plate of the 12AX7 tube at 48vdc plate voltage in the acceleration drive position and 40vdc plate voltage in the normal position. Use of increased speed position may cause initial failure of 12AX7 tube and should be used with caution.

EBIP is useful for semiconductor and tubular amplifier applications. Particularly effective for electric bass guitars with certain types of strings. Manual pickup is better and improves the instrument's pitch by other effects such as Fuzz Tone and Wah Wah Pedal.

Justice:

Paper in Oil Capacitors: The paper in oil capacitors described herein was manufactured by state-of-the-art electronics companies such as AudioNoteUK.

The following is a general definition of a capacitor:

Generally a capacitor is an energy storage device (component of an electronic device) consisting of two parallel conducting plates separated by a dielectric insulating material. When a voltage is applied to the plate, it displaces the charge by the electric field of the dielectric and then stores the energy involved. Ideally, it is assumed that there is no free charge in the dielectric, and even when the charge is displaced, it is not free or can not move around as in a conductor or semiconductor. Dielectrics fall into two categories, polar and nonpolar. Molecules with the same center of gravity of negative and positive charge are considered nonpolar. If the molecule does not meet these criteria it is considered to be polar. For example, H2O, the molecular form of water, is polar, while H2 is nonpolar. There are polar and nonpolar capacitors based on this generalization. This plate may be an actual metal foil or metal film disposed (laminated) on an insulating material. After the invention of the first capacitor, Leyden jar, almost all conceivable dielectric materials and shapes were attempted. Waxes, electrochemical films, plastics, ceramics, glass, oils, papers, minerals, air and others may be used alone or in combination with paper / wax, paper / epoxy, plastic / plastic, paper / oil, plastic / oil, etc. Combination was used. The quality and quantity of these reservoirs is called capacitance.

Orange Drop Capacitor: Polyester Film Capacitor .1uf 400vdc

Tubular 12AX7 / ECC83

The 12AX7 / ECC83 is a compact high-mu twin triod with each section having its own cathode connection. The 12AX7 / ECC83 is configured to minimize noise and microphony. Noise is reduced by using a coiled tungsten heater. The center tap heater operates the tube with either a 6.3 V or 12.6 V heater source.

The 12AX7 / ECC83 is particularly well suited for use in resistive coupled voltage amplifiers such as those used in preamps at the input stages of Hi-Fi amplifiers, phase inversion circuits, multivibrators, and many industrial control circuits where high voltage gain is desired.

General characteristics

Electrical characteristics

Cathode-applied, equipotential

                    Serial-Parallel

Heater voltage, AC or DC-12.6 V-6.3 V

Heater Current-0.15A -0.3 A

Direct Electrode Capacitance-With Shield-Without Shield

Plate in grid (each part)-1.7 uuf -1.7 uuf

Input (each part) -1.8 uuf -1.6 uuf

Output (first part) -1.9 uuf -0.46 uuf

Output (second part) -1.9 uuf -0.34 uuf

Mechanical properties

Maximum total size

Length-2 3/16 inch

Seat height-1 15/16 inch

Diameter-7/8 inch inches

Mounting position-arbitrary position

The present invention is a very unique device in that the tonality of an electric bass guitar is enriched, especially at the lower one and half octaves of the instrument. It is also very effective in creating a rich tone for other bass register instruments. It is particularly unique to use a combination of paper in an oil condenser and the latest mass-produced thin film condenser as described above.

By S1 in the position of the acceleration drive, the pitch of the electric bass guitar can be less distorted even at a high volume.

1 is a diagram of a 12AX7 tubular 9-pin view from the bottom. The pins 1 and 3 are connected to the plate, and the pins 2 are connected to the grid on one side of the 12AX7 tube. The pins 6, 8 are connected to the plate and the pins 7 are connected to the grid on the other side of the 12AX7 tube. Fins 4, 5 and 9 are connected to the heater filament.

2 is a schematic circuit diagram of an EBIP.

Claims (6)

An in-line signal preamplifier with a 1/4 ”input connection and a 1/4” output connection, one volume control, and one tubular slave drive switch. The electronic device according to claim 1, wherein the 12AX7 preamplifier circuit described herein is used with paper in an oil signal capacitor together with a latest thin film "orange drop" type capacitor to enrich the tonality of the bass register musical instrument electronic signal. Tubular preamplifier for bass register instruments. 2. The tubular preamplifier of an electronic bass register instrument according to claim 1, wherein a tubular speed drive switch for driving a 40vdc or 48vdc plate is used to reduce distortion and enrich the tones. 2. The tubular preamplifier of claim 1, further comprising a DC voltage source (generally 153vdc) for driving the plate of the 12AX7 tube. 2. The tubular preamplifier of claim 1, further comprising a DC voltage source (6.3vdc or 12.6 vdc) for driving the heater in one half of the 12AX7 tube. The tubular preamplifier of claim 1, further comprising a grounded metal box containing components included in the schematic diagram herein to remove RFI.

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