DE3938993A1 - Magnetic pick=up for guitar - enables number of iron cores and coil position to be varied to optimise output balance, when used in dual configuration - Google Patents

Abstract

The basic pick-up consists of an iron base (1) with an iron core (2) attached to it by two screws (3), one retaining an earthing eyelet (4). Secured lengthways either side of the iron core (2) with like poles (North upwards) facing, are two magnets (6). Secured above the magnets (6) is a coil (7) whose output lead passes through the base plate (1). To ensure that the top of the coil (7) and the iron core (2) are exactly coincident four spacer washers (5) are secured between the base plate (1) and the magnets (6). A cap (8) covers the pick-up assembly. The option, which introduces a variable number of iron cores (2) and reverses the position of the coil (7) and the magnets (6), results in an increased volume. USE/ADVANTAGE - High output low noise pick-up. Allows lower amplifier output setting. Position under strings not critical.

Description

As an active guitar player I was bothered by bad reproduction Convenience of conventional pickups in electric guitars. No commercially available pickup gave the tones clearly and precisely enough again. The tones also sounded to me without electrical closes block circuit too fast. The volume ratio of the tie Tones to the high notes were also not balanced in terms of hearing Either the low notes sounded too loud and the high tones too quiet; or the low notes sounded too soft and the high ones Sounds too loud.

The output power of these pickups was also too weak, to get a satisfactorily loud reproduction through an amplifier reach so that the guitar player takes the amplifier from the Volume had to be fully controlled. At high volume of the The amplifier not only gives the tones, but also his background noise louder again, which I find very annoying found.

According to my considerations, it must be possible to use a pickup To be designed so that none of the men listed above gel has, without doing a resistance-condenser to use.  

So I took apart several commercially available pickups to see how these are structured. I noticed:

• 1. the pickups have a shaped sheet,
• 2. The magnets are on an iron sheet below the mold sheets attached,
• 3. predominantly only one magnet is used,
• 4. if two magnets are used, they are very small and only weakly magnetic,
• 5. If two magnets are used, they are at the same height the coil,
• 6. Screws are screwed through the cover cap to the spu le and sometimes the magnets together with the shaped sheet to keep.

Instead of the shaped sheet, I passed an iron core ( 2 ) through the coil ( 7 ) ( picture 2). Through measurements and listening tests, I found that the volume increases when:

• 1. the thickness of the iron core increases,
• 2. the magnets are more magnetic,
• 3. the coil on the iron core is shifted in height,
• 4. the wire cross section of the coil becomes smaller and the turns number increases.

I came up with the idea of using a strong magnet, two strong magnets and a coil from a standard pickup instead of a strong magnet. Through measurements and listening tests I found that the volume increases considerably if both magnets ( 6 ) ( Fig . 2 ) are approached to the iron core ( 2 ) at the same time. The magnets are arranged so that they repel each other, the north pole is on top and the magnet ends have the same pole. Magnets with an adhesive force of 125 grams and the dimensions 59.5 x 5.5 x 14.5 mm were used.

The next time I tried, I put the coil ( 7 ) (picture 2) up, then the magnets ( 7 ) ( picture 4). I noticed that the coil or the magnets had to end with the upper end of the iron core ( 2 ). If the coil or magnets protrude beyond the iron core, the sound becomes quieter again. So with my pickup system either:

• 1. Complete the iron core ( 2 ) guided through the coil ( 7 ) with the upper edge of the coil ( 7 ) and the magnets ( 6 ) (north pole above, magnet ends with the same pole) directly under the coil ( 7 ), mutually repelling each other, on the left and to the right of the iron core ( 2 ) (see Fig . 2)
  or
• 2. the magnets ( 7 ) (north pole upwards, magnet ends with the same pole) are mutually repellent to the left and right of the iron core ( 2 ) (the magnets ( 7 ) are flush with the upper edge of the iron core ( 2 )), and the coil ( 6 ) must lie directly under the magnet ( 7 ) (see Fig . 4).

Through oscilloscope measurements I found that the vibration generated by my pickup ( Figure 5) corresponds to an ideal resonant circuit. This means that the tips that are generated during toner generation by hitting the sides are round; Immediately afterwards, the peaks merge into an even, decreasing sine curve.

The tones are in the entire tone that can be represented on the guitar area produced clearly and cleanly.

With the commercially available pickups I tested, the tips shown are not round, but pointed; then frequency overlaps appear before the peaks settle into a sine curve. When the strings fade away, a similar frequency mix is created. This frequency mix is the cause that the low and high notes sound washed out ( Fig. 6).

The magnets must be exactly opposite each other, because if they are offset from one another, a phase potential shift occurs ( Figure 7). With this potential shift, half of the sine curve is shown flatter on the oscilloscope.

If the magnets are not exactly opposite one another, one is dirty There is no better sound reproduction because the vibration is not in the center to the O line on the oscilloscope.

All measurements were made with an oscilloscope setting of 50 ms / 0.1 volt.

The output voltage of my pickup has a maximum value of 0.8 volts and is in the middle range of 0.3 to 0.5 volts. Commercial pickups showed voltage values from not measurable to peaks of 0.5 volts and a mean value of 0.1 volts. The center value (Figure 5 and 6) results from the sinusoidal transient.

To check if the position of the pickup has an impact to the volume of the respective string, I pushed the tone reciprocating horizontally under the strings. It posed I find that this is not the case.

When using my pickups in electric guitars the amplifier no longer needs to be driven as high. This keeps the noise floor of the amplifier low.

The first pickup TA1 ( Fig. 1 and 2) consists of a base plate ( 1 ) made of iron. An iron core ( 2 ) is screwed upright on the base plate ( 1 ) with two fastening screws ( 3 ). The two fastening screws ( 3 ) are screwed through the base plate ( 1 ). At the same time, the soldering eye ( 4 ) is fastened with one of the two fastening screws ( 3 ).

The solder eyelet ( 4 ) is used to ground the pickup, because depending on the sensitivity of the amplifier, a hum may occur.

On the base plate ( 1 ) four sealing discs ( 5 ) are glued (two right, two left) to ensure that the coil ( 7 ) with the iron core ( 2 ) closes. On the sealing washers ( 5 ) are the magnets ( 6 ), which stick with their long side (north pole above, magnet ends with the same pole, magnets repelling each other) left and right on the iron core ( 2 ). The magnets ( 6 ) are also secured with glue. The coil ( 7 ) is placed on the magnets ( 6 ), the iron core ( 2 ) protruding through the coil ( 7 ). The iron core ( 2 ) must end exactly with the upper edge of the coil ( 7 ).

A 3 mm hole is drilled in the base plate ( 1 ) in order to lead the coil cable ( 9 ) out of the pickup. The coil cable ( 9 ) is secured against tensile stress with special adhesive.

About this structure comes the cap ( 8 ), which is also glued ela stically, so that no foreign objects can penetrate the pickup, and thus the vibrations are caused, which are caused by the pick when playing the strings. For these reasons, the inside of the cap was additionally provided with an anti-boom protection.

The second pickup TA2 ( Fig. 3 and 4) was now constructed by me so that I used round iron cores ( 2 ), which were threaded at one end into the base plate ( 1/1 a) (also made of iron) are screwed. The iron cores ( 2 ) are attached so that they are centered under the string. I hoped that this would produce even better sound reproduction, but this was not the case; it was only louder than the first pickup.

The problem with a guitar with two pickups is that the pickup attached to the tailpiece reproduces the tones more quietly than the pickup attached to the guitar neck. To compensate for this difference in volume, I placed the coil ( 6 ) on the sealing washers ( 5 ) and the magnets ( 7 ) directly above the second pickup (TA2). The magnets ( 7 ) adhere with their long sides (north pole up, magnet ends with the same pole, magnets repelling each other) left and right on the iron cores ( 2 ) and close with the edges of the iron cores ( 2 ) towards the top.

Because the second pickup system (TA2) through this design a louder sound than the first pickup (TA1) has it, built into the guitar neck, screwed deeper and thus a volume balance to the first pickup (TA1) effect. Both pickups then sound equally loud.

Because the pickups also through their arrangement and wiring the amplifier can still deliver a large output power can be controlled lower than just with a pickup. The The noise floor of the amplifier can be even lower be.

The string spacings of the different guitar models are different due to the construction of the tailpiece and the guitar necks. Due to the individual iron cores ( 2 ), the pickup TA2 on the guitar neck would have to be recalculated for each guitar model. In terms of production technology, this manufacturing process would be too expensive, so it is advisable to manufacture the second pickup TA2 in the basic structure of the first pickup TA1, but with a thinner iron core.

The base plate ( 1 ) was made by me to fit peavy guitars and guitars with Dimarzio pick-ups and may also fit in other guitars with humbucker pickups.

Claims (6)

1. Pickup for use in electric guitars, characterized in that it is equipped with a base plate ( 1/1 a) made of iron. 2. Pickup according to claim 1, characterized in that it is provided with an iron core ( 2 ) screwed onto the base plate ( 1/1 a) ( Figure 1). 3. Pickup according to claim 2, characterized in that it is in the construction and the number of iron cores ( 2 ) ( Figure 3) varia bel. 4. Pickup according to claim 3, characterized in that it works with 2 magnets ( 6 ) ( Figure 2) and ( 7 ) ( Figure 4). 5. Pickup according to claim 4, characterized in that it is provided with a soldering lug ( 4 ) on the base plate. 6. Pickup according to claim 5, characterized in that it has no fastening screws on the housing cap ( 8 ).