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Vintage Audio (record players, hi-fi etc) Amplifiers, speakers, gramophones and other audio equipment. |
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14th Jul 2018, 11:37 am | #21 | |
Nonode
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Re: Re-mastered 78s
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Andy G1HBE. Last edited by Andrew2; 14th Jul 2018 at 11:45 am. |
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14th Jul 2018, 11:21 pm | #22 |
Nonode
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Location: Papamoa Beach, Bay of Plenty, New Zealand
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Re: Re-mastered 78's
Given that the original question was about what was done (or not done) in the pre-digital era, some timeline information might be appropriate.
The consumer level noise blankers appear to date from 1977. The SAE 5000 was announced, reviewed and advertised in Audio magazine 1977 June. The Garrard MRM101 was mentioned as being forthcoming in Wireless World 1977 November p.57. The first Packburn professional unit, the Model 101, was introduced in 1982, see: http://www.packburnelectronics.com/history/. Cheers, |
14th Jul 2018, 11:36 pm | #23 |
Octode
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Location: Stevenage, Herts. UK.
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Re: Re-mastered 78's
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15th Jul 2018, 1:10 am | #24 |
Hexode
Join Date: Mar 2018
Location: Bishop Auckland, County Durham, UK.
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Re: Re-mastered 78's
Thanks to everyone who has replied. It seems the answer to my question is that record companies either had or looked for excellent copies of the 78rpm discs, then applied minimal analogue filtering.
Ted, you are clearly an expert in this field. I think I have one of those Columbia "silent surface" pressings. A very young Doris Day singing "Canadian Capers" with one of the 1940s Big Bands. My copy looks like new and when played on a 1950s radiogram (upgraded by fitting a Garrard SP25 turntable and ceramic cartridge) sounds nearly as good as vinyl. Some record companies pressed vinyl 78s around 1958. I have one on the Pye label, Lonnie Donnegan's "Does your chewing gum lose it's flavour". My record has seen better days but still plays well without the hissing surface noise associated with most shellac discs. I was never impressed with the 45rpm singles from the 50s and 60s. Many sounded rough and distorted, especially as the record got near to the end. They improved in later years though. Chris Isaak's "Wicked Game" from 1990 sounds as good as a CD when played on a half decent turntable and magnetic cartridge.
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Regards Martin Last edited by martin.m; 15th Jul 2018 at 1:13 am. Reason: Typo |
16th Jul 2018, 4:51 pm | #25 |
Pentode
Join Date: Mar 2013
Location: Norfolk, UK.
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Re: Re-mastered 78's
i remember seeing a program back in the late 80s something about "nipper" the dog and they were transfering rare 78's onto reel 2 reel tape turning fast then during the playback everytime a click appeared they would splice the tape and cut the click out, now its computers and so much quicker
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16th Jul 2018, 5:35 pm | #26 |
Dekatron
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 13,998
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Re: Re-mastered 78's
"De-clicking" of records is in some ways similar to the issue of reducing ignition-interference that plagued TV/radio-reception.
The fundamental issue is that a 'click' can drive electronic circuitry into saturation - coupled with the extremely fast rise-time you then have what amounts to a square-wave, and as the good Mr. Fourier showed us, that means a slew of harmonics - all of which can trigger 'ringing' in the signal path so the effects of the click can be noticed even after the click has ceased. The simplest 'noise limiters' - things like back-to-back diodes - just clipped the peaks. Good ones used 'soft' clipping [the old 'westector' diodes were strangely good for this] to reduce the harmonic-generation. Smarter 'blankers' rather than clipping the peak actually clamped the signal to zero during the click - essentially punching a 'hole of silence' into the audio for the duration of the click. The probloem was that, though this was less-noticeable than the click itself, there was still a level-discontinuity across the 'hole'. There were various analog-attempts at using things like PAL-TV glass 64uS delay-lines so that when a 'hole' was created after a click had been removed, the audio from either side of the hole could be 'stretched' to fill in the gap. All with variable levels of success. These days, a cheap PC, soundcard and suitable software can achieve things earlier restorers could only dream at. My greatest 'annoyance' in restored/remastered audio is crude hiss-reduction, where in the silent/quiet periods the hiss is removed, but in passages where the volume's higher the hiss re-emerges. It's like imagining the band performing on a beach, with the waves coming in behind them when they play loud! |
16th Jul 2018, 9:07 pm | #27 |
Hexode
Join Date: Mar 2018
Location: Bishop Auckland, County Durham, UK.
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Re: Re-mastered 78's
The problem I have with most of my 78rpm records is not clicking but the continuous hissing surface noise of the shellac. I have Magix Audio Cleaning Lab 2005 for transferring vinyl to WAV files (they want the user to pay extra for converting to MP3). There is a de-clicker but I don't find it very effective. I have never tried removing background hash from 78s though. Perhaps other members have experience of this program.
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Regards Martin Last edited by martin.m; 16th Jul 2018 at 9:08 pm. Reason: Punctuation error |
16th Jul 2018, 9:24 pm | #28 | |
Retired Dormant Member
Join Date: Dec 2007
Location: Shropshire, UK.
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Re: Re-mastered 78's
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It surprised me when I was first fortunate enough to own a high-quality turntable, arm and cartridge how noise-free reproduction was compared with run-of-the-mill systems. |
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17th Jul 2018, 6:44 am | #29 | |
Dekatron
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Location: Kington, Herefordshire, UK.
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Re: Re-mastered 78's
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Hiss is difficult to treat, not least because it has a spectrum which is not white. The noise peaks in the low kHz region, and in some ways this is fortunate, because sufficiently good software (such as CEDAR NR-5) allows the operator effectively to equalise the surface noise, by reducing it in the frequency bands which are most troublesome whilst leaving the rest of the spectrum intact. Basic, broad band hiss reduction falls over with shellac noise - if you use enough to tackle the mid-range noise, all the low level information is sucked out of the LF region, where the reverberation and ambience live, giving rise to the disembodied "there's no there there" effect. It is as well to remember that all hiss reduction algorithms are essentially dynamic filters - careful design and use can render their applcation transparent, largely by exploiting the masking characteristics of human hearing, and only treating the most troublesome parts of the spectrum is a very effective masking technique, as Ray Dolby showed in his Dolby A system, which is completely inaudible in operation when properly aligned. There is a lot to be said, even now, for picking up a Packburn, if you can find one - it really was quite a good instrument in its day for improving the music to muck ratio of shellac. It still arguably makes a better fist of it than cheap software, whose designers do not understand that shellac is different from vinyl in kind, not degree. |
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17th Jul 2018, 8:59 am | #30 | |
Heptode
Join Date: Feb 2010
Location: Duffort, Gers, France
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Re: Re-mastered 78's
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which produces very good results for a reasonable price (no connection, just a satisfied customer). It does most of what I need to do. Every now and again I find a record with a stubborn click and it's much cheaper to buy a second copy of the record which doesn't have a click there than spend thousands on CEDAR. (One one occasion I discovered that an annoying thump was actually recorded on the record where apparently something had fallen on the floor during the recording). Even CEDAR isn't infallible. For example I have a CD of Charlie Kunz piano medleys which boasts that it was processed with CEDAR and some of them are very noisy whilst others are comparatively quiet. Presumably it's a function of the original record which brings us back to an earlier comment that the most important thing is to get a good quality copy in the first place. Having said that, retouch sounds like a useful function to have.
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17th Jul 2018, 11:03 am | #31 | |
Dekatron
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Re: Re-mastered 78's
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Well of course it isn't. It's a tool, not a panacea. Like any tool of sufficient power, it can completely louse up the sound if not properly used. I have the experience to drive my costly tools to their limits. Some don't. One dozy character did a whole album with the decrackle function set to "detect", which is only meant as an aid to adjustment. No surface noise - and precious little music, either. |
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17th Jul 2018, 12:11 pm | #32 | ||
Heptode
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Re: Re-mastered 78's
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I was surprised that it never really caught on. Quote:
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17th Jul 2018, 12:32 pm | #33 |
Nonode
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Location: Aberaeron, Ceredigion, Wales, UK.
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Re: Re-mastered 78's
Thank you Synchrodyne for the link to Packburn, I’ve just listened to some before and after recordings, wonderful stuff.
Cheers John |
17th Jul 2018, 8:59 pm | #34 |
Hexode
Join Date: Mar 2018
Location: Bishop Auckland, County Durham, UK.
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Re: Re-mastered 78's
Graham Foster, an English Folk Dance enthusiast, has achieved excellent results cleaning up old 78rpm recordings of folk dance music using very modest equipment. There are some before and after samples on his website.
www.gfoster.info
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Regards Martin |
18th Jul 2018, 8:57 pm | #35 | |
Octode
Join Date: Jul 2006
Location: Perth, Western Australia
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Re: Re-mastered 78's
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Trying to expand down unwanted noise at the playback end is doomed to failure if unlike double system NR the recording was never intended to be expanded on playback. The result will never be transparent. All we can do is use it very sparingly and hope that not too many people notice the artifacts. It's not the fault of the tool. It just has an impossible task. Last edited by TIMTAPE; 18th Jul 2018 at 9:08 pm. |
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18th Jul 2018, 10:09 pm | #36 | |
Nonode
Join Date: Aug 2015
Location: Cambridge, Cambs. UK.
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Re: Re-mastered 78s
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By 1930 Columbia and HMV had merged under the EMI umbrella and a new improved recording system was developed in EMI labs by one Alan Blumlein. Developed mainly to avoid paying licensing fees to Western Electric, this innovative system also had the advantage of a wider bandwidth - up to 8kHz I understand. Unfortunately, the merger also spelt the end of the New Process laminated quiet pressings. Quite why they were killed has always been a mystery to me because their audio quality was way ahead of its time. Perhaps they were too costly, or maybe they weren't suited to the mass-market HMV acoustic gramophones: the abrasive content in conventional shellac pressings was said to increase record life by sacrificing the needle rather than the record. Unfortunately it produced that familiar 'frying bacon' background that we took for granted until technology improved in the mid-1950s. A Blumlein Columbia disc is identified with an impressed tiny letter 'C' in a circle. It would be great to hear one on a quiet laminated pressing, but I've never managed to find one. Maybe there aren't any. Martin
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18th Jul 2018, 10:43 pm | #37 |
Rest in Peace
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Re: Re-mastered 78's
No doubt the best quality sound produced on 78rpm discs in the mid to late 1950s was that emanating from the vinyl 78s issued by the Pye group (Pye-Nixa and Mercury primarily) These had a virtually silent surface comparable to the 45s & LPs of the day, and a good condition copy of one of those pressings will still to this day have a very good S/N ratio. Not sure what the frequency response of vinyl 78s was, though it probably extended to at least 10kHz. Anyone know the exact figures?
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18th Jul 2018, 11:00 pm | #38 |
Dekatron
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Re: Re-mastered 78's
I listen to a lot of pre-war music sourced from digitally-enhanced re-mastered 78s, most of which has been very well engineered and I enjoy it immensely. However I also enjoy occasionally playing some of my own 78s on various reproducers, including mechanical ones. Somehow the associated surface noise is just part of the experience, and was the type of sound that people would have heard from records, certainly up to the 1950s.
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19th Jul 2018, 6:36 am | #39 | |
Nonode
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Re: Re-mastered 78's
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So I'd expect no less from the vinyl 78 type. Cheers, |
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19th Jul 2018, 7:15 am | #40 | |
Dekatron
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Re: Re-mastered 78's
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