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#81
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45 to 78
Scott Dorsey wrote:
Adrian Tuddenham wrote: That's interesting. We don't get many Red Seals this side of the pond, but it would be helpful if you could let me know the turnover frequencies (or time constants). There have been several attempts to draw up definitive tables of turnovers for different makes at different times, but they always seem to be incomplete, in dispute or inaccurate. It's a two pole filter. F1 is specified at 500 Hz, F2 is 1590 Hz and set for 13dB at 10 Khz. Maybe. Even wackier is the Columbia stuff! Columbia used a three-pole filter like the modern RIAA curve on some of their later 78 and early LP pressings. F1 at 100 Hz, F2 and 500 Hz, F3 at 1590 Hz, and something like 16dB boost at 10 Khz. None of these numbers are guaranteed, and the might be totally wrong. But they aren't any worse than the ones in the McIntosh preamp book. Thanks for that. Now you have reminded me, I'm think I remember reading something about those turnovers some years ago. My recollection is that they didn't apply to pre-WWII recordings, so there was no need to remember them. There are a couple of strange curves that turn up in the U.K. from time to time. Early recordings by P.G.A.H. Voigt were approximately constant velocity up to at least 1Kc/s; but the microphone response has to be taken into account too. Luckily he published an account of his experiments in Wireless World. The B.B.C. used 2dB per octave for their 'Type D' transcriptions. That was a particularly difficult curve to synthesise in an analogue system, but I eventually succeeded with a cascade of three RC networks. The U.K. National Sound Archive used my circuit, as did Ted Kendall's 'Mousetrap' processor - then one day the B.B.C. rang up and asked if they could also use it, as they didn't have any original playback equipment left in working order! -- ~ Adrian Tuddenham ~ (Remove the ".invalid"s and add ".co.uk" to reply) www.poppyrecords.co.uk |
#82
Posted to rec.audio.pro
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45 to 78
On Apr 11, 11:40*am, (Adrian
Tuddenham) wrote: Scott Dorsey wrote: Adrian Tuddenham wrote: That's interesting. *We don't get many Red Seals this side of the pond, but it would be helpful if you could let me know the turnover frequencies (or time constants). *There have been several attempts to draw up definitive tables of turnovers for different makes at different times, but they always seem to be incomplete, in dispute or inaccurate.. It's a two pole filter. *F1 is specified at 500 Hz, F2 is 1590 Hz and set for 13dB at 10 Khz. *Maybe. Even wackier is the Columbia stuff! *Columbia used a three-pole filter like the modern RIAA curve on some of their later 78 and early LP pressings. F1 at 100 Hz, F2 and 500 Hz, F3 at 1590 Hz, and something like 16dB boost at 10 Khz. None of these numbers are guaranteed, and the might be totally wrong. *But they aren't any worse than the ones in the McIntosh preamp book. Thanks for that. *Now you have reminded me, I'm think I remember reading something about those turnovers some years ago. *My recollection is that they didn't apply to pre-WWII recordings, so there was no need to remember them. In North America they did, from early days of electrical recording. And every label was different. Record dealer Kurt Nauck has compiled what is probably the most accurate directory of 78 EQs. It's certainly the most exhaustive. All that said, one still needs to use one's ears. Despite the "official" numbers, I find that (for example) turnover frequencies of 50Hz, 500Hz and 3180Hz sound excellent on many electrical US Columbias. The extra octave of bass boost and the extra extension of treble response may be compensating for losses in the system -- whatever, they sound good to my ears. The recommended curves make a good starting point, but you still need to use your ears and judgment. Peace, Paul |
#83
Posted to rec.audio.pro
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45 to 78
All that said, one still needs to use one's ears. Despite the
"official" numbers, I find that (for example) turnover frequencies of 50Hz, 500Hz and 3180Hz sound excellent on many electrical US Columbias. The extra octave of bass boost and the extra extension of treble response may be compensating for losses in the system -- whatever, they sound good to my ears. With a playback pole at 50Hz, there will 6dB /less/ overall boost during playback than with a 100Hz pole. I think. |
#84
Posted to rec.audio.pro
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45 to 78
среда, 11. април 2012. 11..34.01 UTC+2, Adrian Tuddenham је написао/ла:
I have tried it in Pro-Tools and Audacity, but neither of them allows a graph to be drawn. in cubase you can draw tempo (speed), and make audio "sync" to that, so to change pitch accordingly. |
#85
Posted to rec.audio.pro
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45 to 78
On Apr 11, 3:53*pm, "William Sommerwerck"
wrote: All that said, one still needs to use one's ears. Despite the "official" numbers, I find that (for example) *turnover frequencies of 50Hz, 500Hz and 3180Hz sound excellent on many electrical US Columbias. The extra octave of bass boost and the extra extension of treble response may be compensating for losses in the system -- whatever, they sound good to my ears. With a playback pole at 50Hz, there will 6dB /less/ overall boost during playback than with a 100Hz pole. I think. Depends how you look at it. *Relative to 1kHz*, bass boost starting at 500Hz and continuing +6dB/octave as you move downward will produce more level in the 50-100Hz octave when the lower pole frequency is 50Hz than when it's 100Hz. Draw the picture, but draw it referencing 1kHz. With a passive circuit a 50Hz turnover will give more loss from 50Hz on up than a 100Hz turnover, but since that also includes the ref. frequency of 1kHz, it's not relevant. Ref. 1kHz, a 50Hz turnover boosts the bass more than a 100Hz turnover. Peace, Paul |
#86
Posted to rec.audio.pro
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45 to 78
Luxey wrote:
среда, 11. април 2012. 11.34.01 UTC+2, Adrian Tuddenham ј е написао/ла: I have tried it in Pro-Tools and Audacity, but neither of them allows a graph to be drawn. in cubase you can draw tempo (speed), and make audio "sync" to that, so to change pitch accordingly. Thanks for that. I'll look around for a copy of Cubase 5 which I shall need for Mac OS 8/9 -- ~ Adrian Tuddenham ~ (Remove the ".invalid"s and add ".co.uk" to reply) www.poppyrecords.co.uk |
#87
Posted to rec.audio.pro
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45 to 78
On Friday, April 6, 2012 10:01:05 PM UTC-4, Trevor wrote:
You could do it, but it would take more time than doing it at normal speed, and with 850 records I would think you would want to be working as fast as possible. Now THAT is the reason I'd want to do it at the correct speed with less post processing. Given that many records, and time needed, surely buying a proper turntable/cartridge/pre-amp is worthwhile. But then I can't think of 850 78's I'd ever want to record :-) Trevor. I would like to thank everyone who answered my post...great discussion and quite enlightening. As Trevor points out, after giving a listen to the records on my old RCA, there are clearly three piles: 1) Must record 2) Would like to record and 3) not worth the effort. Pile 1 and 2 add up to maybe 300 discs, but about half are single sided, so maybe 450 x4 minutes or 30 hours of recording...big but manageable. As I'm more interested in melody than in sonic fidelity, I've used the 45rpm route and recorded as flat as possible and did not bother acquiring or building anything fancy. I followed Paul's suggestions pretty closely (as to sequence of events) but rather than buying a new DC preamp, I'm using a pretty flat Presonus box). I did use a mild detergent to clean them first and after a few tests, I did not listen to the tracking much...As Scott pointed out, they all sound like Beelzebub on qualludes with a funeral dirge playing in the background. I'm using Nuendo for the post-processing (dehiss, click, speed and EQ) and should be done in a few months. The results are not perfect (I'm not sure any process could give me that), but I am happy with the results and grateful for everyone's help and guidance. Kind regards, CS |