INSTRUCTIONS for the “Retor ” DISC-TALKING APPARATUS
for self-recording and sound reproduction by means of
ORIGINAL “Retor” disc records.
(Patented in Germany and Internationally protected.)
Comments in red are by NF. The instructions, generously provided by Rolf Rekdal, have been scanned and translated from German into English on-line, then re-written extensively, and rather loosely. It is to be hoped that nothing important has been omitted or misinterpreted.
The Retor apparatus includes:
- The tonearm (Fig. 1).
This consists of the arm a with the articulated pivot b, the rubber coated guide rod c, the weight at its end acting also as a handle. Furthermore, the connecting joint with counterweight e, the rotatable diaphragm carrier f, the larger replay diaphragm g, the smaller recording diaphragm h and the horn i.
- The central driver unit. (Fig. 2).
The base j, with spring clamping k, bearing l, the rotary gear m, (a horizontal spiral gear inside the housing), a gearwheel n, take-up roller o, and support roller p. The lower part rotates, including the horizontal spiral m; the upper section remains stationary. The spiral drives the gear n and the take-up roller o (actually a single assembly), thus drawing the guide rod across the disc, and the arm with it.
- The arm pivot block (Fig. 3 – 4).
The baseplate q, swiveling carrying sleeve r, retaining springs s, and adjusting screw t, together with fixing screws u; Fig. 4 shows the carrying sleeve in rest position.
One would have thought that the ‘rest’ position would have been as in Fig. 10, with the entire assembly hinged backwards. The term ‘rest’ must refer to the position when the arm is actually in use.
- The original Retor record, (Fig. 5).
Fixing the pivot block.
A template is supplied free of charge for each device, to ensure the correct attachment point for the pivot block. With this, one proceeds as follows:
Put the template (according to Fig. 6) over the centre spindle. With a bradawl mark the position of the three holes on the motor-board of the gramophone. Remove the template, pre-drill with a small drill, offer up the pivot block and insert and tighten the fixing screws.
It is important to ensure that the lower part of the template contacts the surface of the motor-board. If, due to the design of your gramophone, there is a still a gap, use a packing piece or spacer of wood or stout cardboard, so that the bearing block is screwed to the turntable at the proper height.
It seems evident from the above, that the ‘stencil’ was of thin sheet metal. Also, the instructions have nothing to say in the event of your turntable being too low, rather than too high.
The diaphragm(s) must be parallel with the turntable. Side-to-side adjustment is by the screws securing the pivot block. Small front-to-back differences can be adjusted by the screw t on the pivot block, which makes it possible to raise or lower the tonearm slightly. Make sure that the apparatus assembled according to Fig. 7 is adjusted so that the guide rod not only lies horizontally, but points slightly downwards after passing through the driver!
The last sentence is slightly ambiguous, but the diagram makes the requirement plain.
Place a “Retor” disc over the centre spindle on the turntable. Press the central driver unit firmly onto the record, the clamping sleeve fitting over the centre spindle. Insert the tonearm into the bore of the support sleeve r of the pivot block, registering the pin b in the slot. Place the guide rod into the follower pulley, then insert the horn into the tone arm. If the recording diaphragm (the smaller one) is not facing downwards, pull on the front knob on the tonearm to disengage the dual head, and turn the knob to set the recording diaphragm downwards. Carefully re-engage the turn-over head into the arm. See next paragraph for the recommended method of doing this.
The result is as shown in Fig. 8. which illustrates the arrangement. Make sure that the stop supporting roller of the driver is engaged with the coupling rod. (See Fig. 7.) The pin on the pivot must be engaged in the slot in the support sleeve. The recording diaphragm is then solidly seated, and only capable of up-and-down movement. When changing over the sound boxes, the safest way is to take the whole apparatus with the left hand, pull the knob with your right hand to disengage the heads, then turn the knob so that the desired diaphragm is downwards. Then, carefully re-engage the head assembly in the arm.
Fig. 8 above shows the correct way of speaking into the horn. Unfortunately, the larger replay head is seen in contact with the disc, instead of the recording head. This is simply a small error in these otherwise meticulous instructions.
Be careful that sapphire diaphragms and points are not damaged by shock, impact, or are allowed to fall! Raise the head, then start the turntable. Slowly lower the recording diaphragm onto the Retor disc. After a few turns, speak calmly, loudly and informally into the horn. During recording never come into contact with the horn!
The rotation of the turntable should be the usual one for gramophones (about 70 – 90 r.p.m.).
To ensure perfect recording, speak or sing &c. as close as possible to the horn. (See fig 8). If the sound is too far away from the horn you get a vague, quiet, inferior playback. (See fig. 9). When recording with musical instruments, because of their strong sound waves, a lot of swarf or chip may be produced. It is advisable to remove this during recording, by brushing or blowing it from the disc. Furthermore, it is advantageous to clean the sapphire points on the sound boxes with a soft brush between each recording.
Lift up the device, pull out the turnover head, change to the large replay diaphragm, place the guide rod into the central drive boss, and set the turntable in motion. Carefully lower the replay head just outside the first groove.
Apart from the fact that it is advantageous, after completion of the recording, to remove the disc and to clean it by turning and tapping or brushing of all residues, no further treatment is necessary. The records are ready to play immediately and can be played many times without losing any of their sonic purity.
As you can see, the large replay diaphragm (as opposed to the laterally fixed recording diaphragm) can also be moved sideways to and fro. …as well as up and down; a true floating reproducer, and a very impressive piece of design. The recording and playback sapphire cutters are durable and need not be replaced. For changing discs, the apparatus is folded back into the position shown in Fig. 10. If the apparatus is to be used on other gramophones, it can be stored in the delivery carton when not in use.
It is recommended to use our paper protection discs to catch the swarf. Wax swarf is indeed very difficult to remove from turntable felt. Normally, it is sufficient to put portable devices on a paper pad. Interleave wax discs with paper? If there is any difficulty in assembly or operation, consult the seller of the apparatus or the General Sales Office of “Retor”, as in the brochure.
First draft, 2nd April 2018.