US2008699A - Reediting of phonograph records - Google Patents

Description

y 1935- J. H. HAMMOND, JR 2,008,699

REEDITING OF PHONOGRAPH RECORDS Original Filed May 12, 1930 5 Sheets-Sheet 1 INVENTOR BY .44 d

ATTORN EY July 23, 1935. J. H. HAMMOND, JR 2,008,599

REEDITING OF FHONOGRAPH RECORDS Original Filed May 12, 1930 3 Sheets-Sheet 2 gwvemtoz 3 Wm? y July 23, 1935. .1. H. HAMMOND, JR 2,003,699

REEDITING OF PHONOGRAPH RECORDS Original Filed May 12, 1930 3 Sheets-Sheet 5 ar a? L86 g 3 I o: 114 g avwentoz 351 Aw Gwen W13 Patented July 23, 1935 UNITED STATES PATENT OFFICE] a .REEDITING F PHoNoGitAPn nscoans John Hays Hammond, Jr., Gloucester,'Mass. l

Application May 12, 1930, Serial No. 451,661

Renewed October-5, 1934 a 3 Claims. (01. 179-1004 This invention relates to the art of acoustics and more particularly to an improved methodof reediting phonograph or other records.

This invention relates more particularly to a 5 system of reediting a recordedphonograph record the'several figures or the drawings." ,7

in which the intensity of the later recording is varied at the will of an operator.

The invention provides a method for the ,re-

editing of phonograph records in which the quality of the reedited record can be varied. at will.

The invention further provides arecording system for phonograph or' other records with in-, dependent control of the upper and lower harmonics 'so as to vary the quality of the reedited record. a

"The invention also .provides a method of reediting of phonograph records in which the up per harmonics may'be increased at the same time that the lower' harmonics are decreased'and vice versa.

The invention also consists of a system for the reediting of phonograph .records in which the louder tones are amplified to a greater extent than thelweaker tones.

The invention also consists in certain new and original features of construction and combinations iof parts "hereinafter set forth and claimed.

'Al'though'the novel features which are believed to"be"characteristic or this invention will be particul'arlypointed out in the claims appendedhereto, the invention itself, as to its objects and advantages, .the mode of its operation and the manner of its organization may be better understood by referring to the following description taken in. connection with the accompanying drawings forming a part thereof, .in which I Fig. 1 illustrates diagrammaticallya system' of m volume 'jcontrol for the re-recording 10f phono-' 4"0 graph records; a Fig. 2 illustrates diagrammaticallya systemof volumeandquality control for'the re-recording of phonographrecords; and

, Fig.'f3.illustrates diagrammaticallya system of 7 volume controlin which the amplification isautomatically varied in accordance withthe signal strength. 1 Like 'reference'charac'ters idenoteilike parts-in ilnitheifollowing description and'in the claims parts'w'illbe identified'by specific namesfor con- Nenience; but they are intended to be i as generic in their application to similar part's' as the art ,Will. .permit.

'This device is connected by two flexible iconductors H and 18 to a potentiometer resistance I9. One side of this resistance ,is connected by conductor 2| to a battery 22, the other side ,of

which 'is connected to the filament of a space dischargedevice 23. The other sideofsthis filament is connected to a battery 24 which inturn is connected to the primary of a transformer 25, the other side of which is connected to the plat e of the space'discharge device 23. The grid of this device is connected by a flexible conductor 26 to a contact 27 which slides over the resistance I9. This contact is mounted on, but insulated from, a shaft28, to the end of. which issecured aknob 29. g

The secondary of the transformer 25- is con} nected to an amplifying systemin the casingQB-l. The output of this amplifier is connected by two conductors 32 and 33 to a loud speaker 34. aThe conductors 32 and '33 are connected by branch conductors 35 and 36 to a double pole switch 31, the other side of which is connected by two flexible conductors 38 and 33 toanengraving-mechanism M which is provided with an engravingtool 42. The mechanism AI is mounted on the end of an arm 43 which is pivoted to a member 44, which is mounted for rotation on a casing .45, which contains a driving mechanism; provided with a shaft '46 to which is secured. a plateAl. Resting on this plate is the phonograph tablet 48 on which is to be engraved the reedited sound record by the tool 42. The member 44 -may b e slowly'rotated by mechanism inthe casing .45; so asto causethe tool-42 to form a spiral groove-.on the top of the tablet 48. q a In the operation of thissystem a phonograph record M is placed on the plate [3 andthemechanism in thecasing ll is-started-rotating. ELhe needle of the pick-up device is then placedin'the groove of therecordil l. The music or other Se,-

lection'from this record is then amplified by "the amplifier 3land reproduced by the loudspeaker Afterthe record has been p ay d once, he: op

inal record I4 is played, the music from it will be picked up by the pick-up I6, amplified by the amplifier 3I, and sent to the engraving mechanism 4 I thus making a record of the music on the blank tablet 48.

As the part of the music is reached which should be increased in intensity, the operator rotates the knob 29 in a clockwise direction, thereby increasing the amount of current sent to the engraving tool 4I, which increases the intensity of the record at this point. If a point is reached where the record should be decreased in intensity, the knob 29 is rotated in a counter-clockwise direction thereby decreasing the current sent to the engraving mechanism 4I, thereby decreasing the intensity of the record made on the record disk 48.

, In this way the intensity Values of any, record may be varied at will so as to produce entirely different and more pleasing effects than those from the original record, which may be either an old record or a new one.

Referring to the modified form of the invention shown in Fig. 2, the phonographic reproducing mechanism is the same as that shown in Fig. 1. In this case, however, the conductors I1 and I8 are connected to the primary of a transformer 55, the secondary of which is connected to two filter circuits 56 and 51 each comprising a group of condensers and inductances as shown. The filter circuit 56, which is a high pass filter, allows high frequency currents to pass, such as those of the upper half of the voice and music range, and the filter circuit 51, which is a low pass filter, allows low frequency currents of the lower half of this range to pass. The filter circuits 56 and 51 are connected to two space discharge tubes 58 and 59, the outputs of which are connected to two transformers BI and 62.

The secondaries of these transformers 6| and 62 are connected to two potentiometers 63 and 64, the movable contacts of which are moved by means of a handle 65. The potentiometers ,63 and 64 are connected to two filter circuits 66 and 61, the condensers of which are variable and are controlled from a handle 69. These condensers are so connected to this handle that, as the capacity of one set is increased, the capacity of the other set is decreased. The filter circuits 56 and 51 are connected through tubes H and 12 to a transformer 13. The secondary of this transformer is connected to a push pull amplifier 14, the output of which is delivered from transformer 15.

The secondary of this transformer 15 is con nected to the conductors 32 and 33 which go to the loud speaker 34. The conductors 32 and 33 are connected by the branch conductors 35 and 36 to a double pole switch 31, the other side of which is connected by two flexible conductors 38 and 39 to the engraving mechanism M.

The operation of this system is similar to that shown in Fig. 1, the intensity of the re-recording being controlled by the handle 65. By moving this handle in a counter-clockwise direction the intensity is increased due to the increased energy which is picked up by the potentiometers 63 and 64, and by moving the handle in a clockwise direction the intensity is decreased.

The energy from the pick-up device I6 passes through the transformer 55 to the filter circuits 56 and 51, the former allowing the higher frequencies' to pass and the latter thelower frequencies.' These currents are then amplified by the space discharge tubes 58 and 59 from which they Pass through the transformers 6| and 62 to the potentiometers 63 and 64. Here any desired proportion of the energy from the lower and upper sound ranges may be picked up depending upon the setting of the handle 65.

The energy from the potentiometers 63 and 64 then passes through the filters 66 and 61. These are normally in such a position that the frequen cies passing through these filters are unaltered and, therefore, the relative intensities of the treble and bass harmonics are the same as those in the original music. If,-however, the handle 68 is shifted in one direction, it will increase the capacities in the circuit 66 and decrease the capacities in the circuit 61. This will cause less of the harmonics to be passed in the circuit 66 and more of the harmonics to be passed in the circuit 61. In this way the brilliance of the bass notes is increased and that of the treble notes decreased. If the handle 68 is moved in the opposite direction, the capacities in the circuit 66 will be decreased and those in, the circuit 61 increased,

thereby making the treble harmonics richer and cutting down on thebassharmonics. l

The energy from the circuits 66 and 61 isthen amplified by the space discharge means H, and 12 from which it is fed to the push-pull amplifier 14 where it is still more amplified and fed to-the loud speaker 18 and engraving mechanism 4I thus making a record of the music on the blank tablet 48 in a manner similar to that described in connection with Fig. l.

Referring to the modified form of the invention shown in Fig. 3, the phonograph mechanism is the same as that shown in Fig. 1. In this case, however, the conductors I1 and I8 are connected to the primary of a transformer 8|, the secondary of which is connected to a potentiometer 82, the movable contact of which is operated bya handle 83. The input current is taken from this potentiometer and applied to the input circuit of a space discharge tube 84.

Theinput circuit of a control space discharge tube is connected in parallel'with the input circuit of the space discharge tube 84, through condenser 86 and the common grid return 81. This lead 81 is connected to the movable con-tact of a potentiometer 9| which is across the common filament battery 92. This potentiometer 9| is operated by a handle 93. A high resistance 9.4.may be connectedbetween the grid of the space discharge tube 85 and the grid-return 81, to provide the necessary leakage path. A resistance is lo cated in the grid return of the space discharge tube 84 and is shunted by a condenser 96. In series with the resistance 95 in the grid return 81 are batteries 91 and 98. v

The output circuit of the control space discharge tube 85 includes the primary of a transformer IIII and a source of power I 82. The sec.- ondary of this transformer is connected in series with a rectifying device I 93 and a battery I04 all across the resistance 95. The rectifying device I03 may be of any suitable type, as for example, a three electrode spacedischarge tube havinga filament which maybe energized by a battery I05. The output circuit of the main space discharge tube 84 comprises a transformer I06 which is shunted by a high resistance IIITin order to ob tain the proper fidelity curve. The secondary of this transformer is connected to 'a potentiometer I I I, the movable contact of which is controlled by a handle II2. Thispotentiometer is connected through a transformer I I3 to the input circuit of a push-pull amplifier I I4. The output. circuit of this amplifier is connected through a transformer recording being controlled by the handle I I5 to the conductors 32 and 33 which go to the loud speaker 34. The conductors 32 and 33are connected by branch conductors 35 and 36 to a double pole switch 37, the other side of which is connected by two flexible conductors 38 and 39 to the engraving mechanism ll.

The general operation of this system is similar tothat shown in Fig. l, the intensity of the H2 which controls the amount of energy fed to the push pull amplifier H4 and, therefore, to the loud speaker 34 and engraving mechanism at. The handles 33 and 93 control the dynamic range and quality, the former controlling the amount of energy fed to the dynamic multiplier, so that it will operate in its proper range and not cause an overloading of the space discharge tube 84 and the latter controlling the initial setting for the space discharge tubes 84 and 85, thus determining the dynamic range.

The amplifying characteristics of the space discharge tube 8d are determined by its grid potential. This in turn is determined by the batteries 91 and 98, the voltage drop in the resistance 95 and the setting of the potentiometers 82 and 9!. The voltagedrop of the resistance 95 is governed by the amplitude of the impressed signals, which are applied to control the tube 85 and determine the space current in that tube, which is passed through the primary of the transformer Iiil. The current in the secondary of this transformer is applied through the rectifier H33 to the resistance 95. An unidirectional current is thereby produced in this resistance which is proportional in value to the average amplitude of the impressed signal, thus controlling the amplification characteristics of the space discharge means 86.

It is thus seen that in the form of the invention shown in Fig. 3, the intensity of recording may be controlled by one handle while the quality and dynamic range may be controlled by the other two handles. This form also has the advantage of the dynamic multiplication in which the amplification ratio is varied in accordance with the strength of the impressed signal, being greater for strong signals than for weak ones.

Another advantage of the system disclosed in Fig. 3 is that it can be used for re-recording records without the manual operation of handles 83, 93 and H2. In this case the inherent performance of the circuit will cause the louder notes to be amplified to a greater extent than the 1. In a reediting system, a primary tablet having a record of a sound selection thereon, a secondary tablet for recording the reedited selection, a pick-up device cooperating with said primary tablet, a recording device cooperating with said secondary tablet, a path between said devices, said path including an amplifier tube, variable means for controlling the energy fed to said tube, variable means for controlling the energy delivered by said tube, variable means for controlling the dynamic range of the tube, and. means for causing said tube to amplify the weaker tones less than the stronger tones.

2. In a re-editing system, a primary record member having a record of a sound selection thereon, a secondary record member for recording the re-edited selection, a pick-up device 00- operating with said primary record member, a recording device cooperating with said secondary record member, a path including an amplifier between said devices, and means controlled by the change in average intensity of the sound energy produced by said primary record member for controlling the amplifier to impress the selection with modified dynamics on said secondary record member.

3. In a re-editing system, a primary record member having a record of a sound selection thereon, a secondary record member for recording the re-edited selection, a pick-up device cooperating with said primary record member, a recording device cooperating with said secondary member, a path including a modifier between said devices and means controlled by the average nature of the sound energy produced by said primary record member to control the modifier to impress the selection in its modified form on said secondary record member, whereby sound reproduced from said secondary record has different characteristics from sound reproduced from said primary record.

JOHN HAYS HAMMOND, JR.

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