The Gramophone, December, 192&
I f .one has to choose between the two, a steady " G-r-r-r " is much to be preferred to a less audible but more unsteady " Chug-chug". Sometimes a motor may be noisy when running free and practically silent when i t ha,s work to do. After a t ime every motor becomes more noisy owing to the wearing of the moving parts and bearings. In this connection the Collaro Company have given a commendable lead to other manufacturers; all their bearings a,re bushed and easily accessible, so that a faulty part can be readily replaced.
vVe propose to deal more fully with questions of motor design and upkeep in ·a future article. But there are three points which we think i t well to mention now :-
1. I t is advisable not to use the motor to i ts full capacity; three-quarter wound to one-quarter wound is a good rule; what this means in the number of records the motor can play can only be found by trial.
2. I t is a good plan to let the motor run down nearly, but not quite, to the bottom after playing; this tends to preserve the temper of the springs. I f you run i t quite to the bottom or wind i t quite to the top there is a danger that the spring will come unfastened and in any event some of the grease will probably be forced out of the spring barrels.
3. The bearings and the governor plate against which the governor brake presses should be frequently oiled with light, non-sticky oil, and not with vaseline or heavy grease. "Three-in-One" oil is very good for this purpose.
* * * lII.-H.M.V., MODELS 25 (HORN) AND
In view of the remarks in our first article concerning the virtues of external horn machines we have thought i t well that our first report should deal with a standard instrument of that type. For this purpose we have coupled together H.M.V. Models 25 and 27, since their principles, of construct ion are almost identical. Both models are fitted, as a standard, 'with sheet-iron horns of the flower or petalled type built up by seaming sections together. The horns are about 2 feet long with a bell of nearly 2 feet. No. 25 has a quadruple spring motor-probably the finest in existencewhilst No. 27 has a double-spring motor of not dissimilar pattern. No. 25 is supplied with an Exhibition sound-box and is sold at £8 lOs. (oak) or £9 (mahogany). No. 27 is in the form of a cabinet of rather cheap design and material, is fitted with a No.2 sound-box, and costs £12. The tone-arm in both cases is beautifully made of stout drawn brass and is of the short goose-neck variety. Owing to the length of the tone-arm the needle-track alignment is rather better than has been usual with H.M.V. machines, but i t still leaves a good deal tobe desired.- We note that in the new "No.4" models which the Gramophone Co. have just put on the market this question has received the attention which i t deserves. ,;Ve hope that this sign of grace will appeal' in their horn models as well.
Both machines have a strong forward tone, of ample volume for the majority of listeners, even when fibre needles are used. Indeed, the power and quality of the reproduction with fibre needles is quite a revelation to those unfamiliar with the possibilities of good external horn machines . . In our last article we mentioned the special virtues of the horn machine so we need not particularise here. I t is sufficient to say that these models aretwo of the best examples of their class. Both the Exhibition and the No. 2 are, in our opinion, . sound-boxes which have been la,ndmarks in gramophone history; like other "commercial" soundboxes they vary a good deal in qua,lity but the best· of them are in the very front rank. With fibre needles the average Exhibition box is better than the avera,ge No. 2 on these machines; but readers who use steel needles will probably find that theExhibition box, as supplied, coupled with a metal horn will be rather too shrill in quality. Many " steelites " use a wooden horn with the Exhibition box, but these horns are rather smaller than the· metal horns. Those who wish to use steel needles: would probably be well advised to obtain a No.2 box for use with the metal horn. I f they can afford to get a Virtz box all the better.
We have no hesita,tion in saying that theseH.M.V. horn models give much superior results toany of the other old H.M.V. models and theirprices are satisfactory even to the modest purse. This article has been written before we have had an opportunity of full comparison with the nc\v "No.4" models, but on a first hearing we a.reconfident that the external horn machines will hold their own very well.
Apart from the matter of alignment referred to' above, there is one other point to which we would ask the Gramophone Co. to give their attention. The majority of the metal horns sent out from thefactory have a tendency to buzz and rattle at theseams which seriously detracts from the quality of the reproduction . This should not be. I t is surely but a small matter for a company with such facilities at their command to make certain of curing a fault like this, whilst for the private owneri t may be rather a messy affair. There are twosimple methods which we have found to b e quite effective. The first is to paint the seams liberally with black enamel; "Ripolin," being a flexibleenamel, is very good. Particular attention should be paid to the joint a,t the narrow end of the horn ;. we find that the tendency to rattle often occurs