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General Vintage Technology Discussions For general discussions about vintage radio and other vintage electronics etc. |
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17th Nov 2018, 5:35 pm | #41 |
Rest in Peace
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Re: Why both 33 and 45 ?
Before the 'maxi-single'. Concert Hall issued a series of 7" 33.333rpm records in the 1960s. These contained some of the shorter Classical works, such as the 'Peer Gynt' suite, the 'William Tell' Overture, and several others. Some were Mono, others Stereo.
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17th Nov 2018, 5:58 pm | #42 | |
Heptode
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Re: Why both 33 and 45 ?
Quote:
What K-Tel did was cut out mostly the second verse of a single. If a single ran for about 2 minutes then you would get the lot on. Singles at 4.30 would be reduced to say 2.35. In some cases the editing was very poor. Of course they were a lot quieter than most LP's. They also got around racism by using graffiti artwork covers on acts that were all black. As shown in this best seller LP Soul Motion. |
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17th Nov 2018, 11:25 pm | #43 |
Dekatron
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Re: Why both 33 and 45 ?
Variable pitch has been around since the dawn of LP, although some Siemens 78s were so cut post-war. It can be done manually with rehearsal or a score and nerves of steel. If the disc is being cut from tape, it is a fairly simple matter to arrange an advance playback head a turn before the main playback head and use the amplitude envelope to open or close the pitch. Neumann and Lyrec used this system. Later after-market systems used memory to map the previous turn's envelope in several segments, permitting tighter packing.
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18th Nov 2018, 5:32 pm | #44 |
Octode
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Re: Why both 33 and 45 ?
I can confirm that K-Tel sometimes cut down tracks. I have one on which Isaac Hayes' Shaft is very crudely chopped. I have a Ronco compilation LP with 50s/60s tracks and I don't remember many issues with it but it's probably 40 years since it was last played! I only have a few K-Tel/Ronco type LPs. The worst one seemed to be off centre on one side. I even took a needle file to the hole (!) to try to get it back on centre which sort of worked but there remained a couple of noticeably bad tracks so perhaps this was down to the cutting. It does date from around the the time of the three-day week so perhaps they were running the cutting lathe with a treadle! I didn't waste pocket money on 'TV ad cheapy' labels after that.
The Motown Chartbusters LPs used to cram in eight tracks a side but the quality always seemed okay to my ears, and the sound levels didn't seem that different from an average single, though my system at that time couldn't be described as brilliant. I noticed that in some instances they used (slightly) alternative mixes from the singles. Sixties Motown singles were designed to be two and a half to three minutes but as they got longer in the 1970s some editing went on to get in the required sixteen tracks. IIRC Gladys Knight's Help me make it through the night and Look of Love got heavily edited. I have a Beatles A Hard Day's Night 45rpm EP which, of course, dates from 1964 with two tracks from the album a side. I think it's a mono recording. One of the Beatles' gripes with UK single pressings (I think it was John Lennon doing the complaining) was that they weren't as loud as American records. I always found the Music For Pleasure and Classics For Pleasure labels more than acceptable and I have a few World Record Club LPs and they're on quite heavyweight vinyl. The latter were mainly my mother's but I have played them from time to time recently. It's interesting how your tastes change as you get older (or perhaps one's just happier to own up to enjoying 'music for squares'!) |
18th Nov 2018, 6:29 pm | #45 |
Dekatron
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Re: Why both 33 and 45 ?
I once had a compilation LP from Music For Pleasure that had more tracks than normal.
They were just faded out early. It was very cheap though. |
18th Nov 2018, 6:41 pm | #46 |
Administrator
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Re: Why both 33 and 45 ?
I think Music For Pleasure was part of EMI or at least connected in some way, which may have helped keep the standards that bit better than K-Tel, Ronco and Pickwick etc.
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18th Nov 2018, 7:29 pm | #47 |
Hexode
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Re: Why both 33 and 45 ?
I have a 45RPM 12" copy of ELO's "Don't bring me down" which is identical to the 7" single. I have always wondered why this was even made. I bought it in error thinking it was an album.
I also have 2 U2 singles that have the normal 45RPM A side and 2 tracks on the B side, which runs at 33RPM. Again this seems a bit odd. |
18th Nov 2018, 7:50 pm | #48 |
Heptode
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Re: Why both 33 and 45 ?
12 inch singles were made for the DJ and club market. They were generally long versions of the single. But I think some of the marketing people cottoned on the fact DJ's wouldn't play the 7 45 and issued the same track on 12 inch.
However you should find the quality should be better than a 45. Apparently the worse quality records were the picture discs. Probably good for looking at but rubbish at playing. DJ's often complained about them. |
18th Nov 2018, 9:21 pm | #49 |
Nonode
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Re: Why both 33 and 45 ?
I've seen a few picture discs with slight warps, possibly from bring displayed on a wall for ages & being exposed to sunlight. Also they were packaged in clear plastic sleeves which is probably more abrasive than paper.
I have a Queen EP No-one but you that plays of but is cut at 33rpm, something not stated anywhere on the disc or packaging. This means most times I've played it I have set the turntable to 45rpm by accident, making Roger Taylor sound even higher pitched than normal!
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18th Nov 2018, 11:26 pm | #50 |
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Re: Why both 33 and 45 ?
I've remembered that Marble Arch was the label putting out the blues compilations [post 39*]. It's hard to explain the difficulty in seeking out info re the blues then. I sort of assumed that what was on the cheap label wasn't the real thing that other [more knowledgeable] people accessed. Later I realised that these were all classic tracks. When my son was involved in a Birmingham Record shop [Jibbering Records Mosely] and running festivals [Shambala eco family friendly pioneers-still going, forerunner of the posh versions like Latitude!] to my surprise, he and his mates thought the Marble Arch stuff was amazing....and the quality was good as well!
Dave W Last edited by dave walsh; 18th Nov 2018 at 11:56 pm. |
19th Nov 2018, 9:58 am | #51 | |
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Re: Why both 33 and 45 ?
Quote:
Way back in time (1950's) many Jukebox manufactures had 2 speed playing systems that could play 45 discs with a large centre hole and also the 33 'mini albums' which had a small hole. The hole size was used to detect which speed to use. In the UK most 45 discs had centre knockouts to allow use of small hole used by most domestic record players/autochangers and the larger hole for American/jukebox players. |
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19th Nov 2018, 2:13 pm | #52 |
Heptode
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Re: Why both 33 and 45 ?
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19th Nov 2018, 2:47 pm | #53 | ||
Nonode
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Re: Why both 33 and 45 ?
Quote:
I've heard of some American labels releasing mini albums for jukeboxes with 3 tracks per side, which were 7" & played at 33rpm. Also some American labels used to send 12" 33rpm promotional albums to FM radio stations with 2-3 tracks per side, normally tracks from an album that hadn't been released. The size & speed was to make playing them on air an easier task.
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19th Nov 2018, 3:02 pm | #54 | |
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Re: Why both 33 and 45 ?
Quote:
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19th Nov 2018, 11:48 pm | #55 |
Nonode
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Re: Why both 33 and 45 ?
I was using gearing because I couldn't think of a better word of the time for the reduction using belts & pulleys.
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20th Nov 2018, 6:53 am | #56 |
Nonode
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Re: Why both 33 and 45 ?
Whilst 12" 45s could sound much better than the equivalent 7" version, they presented
a serious challenge for the dynamic range of the typical moving magnet pre-amp, this lead to hi-fi amps having different MM sensitivity levels, often selectable by a switch. |
24th Nov 2018, 10:49 pm | #57 | ||
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Re: Why both 33 and 45 ?
Quote:
The 33⅓ rev/min speed was originated for movie sound purposes, and it was chosen to allow turntables to be mechanically driven from film projector motors. So the speed needed to be a factor of 1800 rev/min, the speed of a 60 Hz 4-pole synchronous motor. Such a mechanism had a mention in a recent posting here, see: https://www.vintage-radio.net/forum/...2&postcount=15. With the LP, for domestic purposes Columbia might have chosen a different speed within the range that was acceptable for its purposes, but with 33⅓ rev/min evidently being within that range, it was a logical to use it given that it was an existing transcription standard. RCA could not avoid introducing a new speed for its small microgroove record, but notwithstanding the relative freedom of speed selection conferred by the “rubber” element in domestic turntables, it may have been mindful of mechanical-drive transcription turntables, and chose a number that was a factor of 1800. Cheers, |
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25th Nov 2018, 12:21 am | #58 | |
Nonode
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Re: Why both 33 and 45 ?
Quote:
That notion appears to be confirmed by this excerpt from the RCA 1950 Broadcast Equipment catalogue (available at: https://www.americanradiohistory.com...talogs_RCA.htm). RCA Broadcast 1950 p.87.pdf It shows a retrofit 45 rev/min adaptor available for its 70-C and 70-D transcription turntables, which basically inserted a ball-type speed reducer in the main drive shaft. Cheers, |
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1st Dec 2018, 3:20 am | #59 | |
Nonode
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Re: Why both 33 and 45 ?
Those RCA 70-C and 70-D transcription turntables in standard form had a horizontal-shaft synchronous motor in the base of the unit that drove the vertical shaft at 78 rev/min by a gear unit that looks to have been of the worm type. Assuming a 60 Hz 4-pole motor with a speed of 1800 rev/min, then the worm gear reduction would have been 23:1, to give a vertical shaft speed of 78.26 rev/min. The ball-type speed-reducer just under the turntable would then have provided a 54:23 speed reduction (54:1 overall from motor to turntable) to give the 33⅓ rev/min speed. The “add-on” speed reducer would have provided a 40:23 speed reduction, which with the turntable end speed-reducer in direct drive, would have given an overall reduction 40:1 for the 45 rev/min speed.
RCA also offered a 50 Hz version of those turntables. Possibly these had 50 Hz 4-pole motors running at 1500 rev/min. Thus they would have required a worm gear with a 19 1/6:1 ratio. They could have been addressed, for example, with a 6-start worm and a 115-tooth wormwheel, which seems mechanically reasonable for the application. If that were the case, then probably the 60 Hz version had a 5-start worm and a 115-tooth wheel. Quote:
Cheers, |
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1st Dec 2018, 2:52 pm | #60 |
Nonode
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Re: Why both 33 and 45 ?
The handbook for my Pioneer turntable mentions it was supplied with 2 different pulleys for 50 & 60Hz operation with different diameters.
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