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If I'm not mistaken, the last post on this NG, was waay back in
5/16/2025???
Are Usenet Newsgroups FINALLY dying off??-a FOR GOOD?????
SAD TIMES!!!
:(
On 29/07/2025 3:32 pm, Paul Dorman wrote:
If I'm not mistaken, the last post on this NG, was waay back in 5/16/2025???
Are Usenet Newsgroups FINALLY dying off??-a FOR GOOD?????
SAD TIMES!!!
:(
I still check it out daily. In vain....
Geoff <geoff@nospamgeoffwood.org> wrote:
On 29/07/2025 3:32 pm, Paul Dorman wrote:
If I'm not mistaken, the last post on this NG, was waay back in
5/16/2025???
Are Usenet Newsgroups FINALLY dying off??|e-a FOR GOOD?????
SAD TIMES!!!
:(
I still check it out daily. In vain....
I check it but i haven't done much original audio work recently and
there hasn't been anything here to reply to.
I could start a thread on an analogue declicking computer for 78s,
which I am currently designing, but the number of participants would
probably be very limited.
I could start a thread on an analogue declicking computer for 78s,
which I am currently designing, but the number of participants would
probably be very limited.
I could start a thread on an analogue declicking computer for 78s,
which I am currently designing, but the number of participants would probably be very limited.
You might be surprised. Is it working? How does
its performance compare to digital solutions.
If I'm not mistaken, the last post on this NG, was waay back in 5/16/2025???I continue to drop in now and then, I'm happy to find audio friends who do so as well. Here's a conundrum in quest of ideas:
Are Usenet Newsgroups FINALLY dying off?? FOR GOOD?????
SAD TIMES!!!
:(
On 29/07/2025 3:32 pm, Paul Dorman wrote:
If I'm not mistaken, the last post on this NG, was waay back in
5/16/2025???
Are Usenet Newsgroups FINALLY dying off??-a FOR GOOD?????
SAD TIMES!!!
:(
I still check it out daily. In vain....
On Mon Jul 28 20:32:44 2025 Paul Dorman wrote:
If I'm not mistaken, the last post on this NG, was waay back in 5/16/2025???
Are Usenet Newsgroups FINALLY dying off?? FOR GOOD?????
SAD TIMES!!!
:(
I continue to drop in now and then, I'm happy to find audio friends who do
so as well. Here's a conundrum in quest of ideas: Like many, I have a decades-old accumulation of "Audio Stuff". Mics, processors, cables, connectors, one-off gadgets etc. eBay, done well, takes more time than it should. I guess I might be seeking someone who knows audio gear and
wouldn't mind splitting the rewards of unloading some interesting relics.
I wont need help with the NOS RCA 77DX. Words like T4B, QGP and KEPEX are familiar. All the 'stuff' is analog, mostly useful and generally of meaningful quality.
=3d?UTF-8?B?Um95IFcuIFJpc2luZw=3d=3d?=3d <rwrising@dslextreme.com> wrote:
On Mon Jul 28 20:32:44 2025 Paul Dorman wrote:
If I'm not mistaken, the last post on this NG, was waay back in 5/16/2025???
Are Usenet Newsgroups FINALLY dying off?? FOR GOOD?????
SAD TIMES!!!
:(
I continue to drop in now and then, I'm happy to find audio friends who do so as well. Here's a conundrum in quest of ideas: Like many, I have a decades-old accumulation of "Audio Stuff". Mics, processors, cables, connectors, one-off gadgets etc. eBay, done well, takes more time than it should. I guess I might be seeking someone who knows audio gear and wouldn't mind splitting the rewards of unloading some interesting relics.
I wont need help with the NOS RCA 77DX. Words like T4B, QGP and KEPEX are familiar. All the 'stuff' is analog, mostly useful and generally of meaningful quality.
If you can keep it in good condition and hang on to it for a few years,
it will become 'cult' and then you can sell it for a fortune.
--Thanks, Liz. In a sense I've already done that. What could be more 'cult' than a NOS UREI T4B? Has anyone here used a KEPEX to introduce a "very different, yet pleasing" 'snare' sound?
~ Liz Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk
I could start a thread on an analogue declicking computer for 78s,
which I am currently designing, but the number of participants would probably be very limited.
You might be surprised. Is it working? How does
its performance compare to digital solutions.
The basic principle is to split the sound spectrum into ten bands, each
about an octave wide. In each band a click or crackle is identified by comparing the vertical and horizontal vectors of the stylus movement -
if there is more than a certain proportion of vertical movement, a
switch opens and momentarily disconnects the signal. The band is then filtered again, so that the harmonics due to switch clicks are removed
and damped resonance in the filter covers any short gaps in the sound.
All ten bands are then recombined to restore the original spectrum.
My previous attempt (the MkII) used inductors in the resonant circuits
and became so cumbersome and difficult to align that I abandoned it.
The latest version uses 'state-variable' filters based on op-amps and a cascade filter configuration that makes the centre frequiencies far less critical and allows the use of ordinarly 5% tolerance components. The overall pass band is within 2 dB of flat from 20 c/s to 20 Kc/s and the ripple due to filter overlap is less than 0.5 dB.
Tobiah <toby@tobiah.org> wrote:
I could start a thread on an analogue declicking computer for 78s,
which I am currently designing, but the number of participants would
probably be very limited.
You might be surprised. Is it working? How does
its performance compare to digital solutions.
I'm pleased to report that the MkIII version which I have been working
on recently has now worked for the first time. The results are very >promising and it is extremely easy to operate.
Unfortunately, in trying to track down a common-earth hum problem, I >accidentally blew up one of the power supply regulators and I didn't
have a spare. A new one is on order, so I hope to resume testing in a
few days.
The basic principle is to split the sound spectrum into ten bands, each
about an octave wide. In each band a click or crackle is identified by >comparing the vertical and horizontal vectors of the stylus movement -
if there is more than a certain proportion of vertical movement, a
switch opens and momentarily disconnects the signal. The band is then >filtered again, so that the harmonics due to switch clicks are removed
and damped resonance in the filter covers any short gaps in the sound.
All ten bands are then recombined to restore the original spectrum.
Liz Tuddenham <liz@poppyrecords.invalid.invalid> wrote:
Tobiah <toby@tobiah.org> wrote:
I could start a thread on an analogue declicking computer for 78s,
which I am currently designing, but the number of participants would
probably be very limited.
You might be surprised. Is it working? How does
its performance compare to digital solutions.
I'm pleased to report that the MkIII version which I have been working
on recently has now worked for the first time. The results are very >promising and it is extremely easy to operate.
Unfortunately, in trying to track down a common-earth hum problem, I >accidentally blew up one of the power supply regulators and I didn't
have a spare. A new one is on order, so I hope to resume testing in a
few days.
The basic principle is to split the sound spectrum into ten bands, each >about an octave wide. In each band a click or crackle is identified by >comparing the vertical and horizontal vectors of the stylus movement -
if there is more than a certain proportion of vertical movement, a
switch opens and momentarily disconnects the signal. The band is then >filtered again, so that the harmonics due to switch clicks are removed
and damped resonance in the filter covers any short gaps in the sound.
All ten bands are then recombined to restore the original spectrum.
That's not a declicker! That's a broadband noise reduction system!
Compare with the Dolby Cat 43 system.
The declicker has a delay and looks at the first derivative of the input signal, and when it is too high it replaces the signal with the delayed signal or it holds the existing level, or it fades from one to the next,
in order to blend around a single impulse. Compare with the SAE 5000.
I think that the Audio Cyclopedia has schematics of both designs, both
pretty primitive but showing the techniques.
Scott Dorsey <kludge@panix.com> wrote:
Liz Tuddenham <liz@poppyrecords.invalid.invalid> wrote:
Tobiah <toby@tobiah.org> wrote:
I could start a thread on an analogue declicking computer for 78s,
which I am currently designing, but the number of participants would >>>>> probably be very limited.
You might be surprised. Is it working? How does
its performance compare to digital solutions.
I'm pleased to report that the MkIII version which I have been working
on recently has now worked for the first time. The results are very
promising and it is extremely easy to operate.
Unfortunately, in trying to track down a common-earth hum problem, I
accidentally blew up one of the power supply regulators and I didn't
have a spare. A new one is on order, so I hope to resume testing in a
few days.
The basic principle is to split the sound spectrum into ten bands, each
about an octave wide. In each band a click or crackle is identified by
comparing the vertical and horizontal vectors of the stylus movement -
if there is more than a certain proportion of vertical movement, a
switch opens and momentarily disconnects the signal. The band is then
filtered again, so that the harmonics due to switch clicks are removed
and damped resonance in the filter covers any short gaps in the sound.
All ten bands are then recombined to restore the original spectrum.
That's not a declicker! That's a broadband noise reduction system!
It was primarily intended to de-click and de-crackle 78s, but it can
also de-thump cracked ones, so I suppose it is more broadband than I originally suggested.
Compare with the Dolby Cat 43 system.
The declicker has a delay and looks at the first derivative of the input
signal, and when it is too high it replaces the signal with the delayed
signal or it holds the existing level, or it fades from one to the next,
in order to blend around a single impulse. Compare with the SAE 5000.
I think that the Audio Cyclopedia has schematics of both designs, both
pretty primitive but showing the techniques.
Finding the clicks and crackle is realtively easy on a mono recording:
they show up in the vertical component (which obviously wasn't
recorded). The big problem is what to do about them. The Marantz and
other noise-reduction systems simply faded out a click - which
substituted a 'bloop' instead; cross-fading between before and after
could be better if it is done well.
The only system that seemed to do it really effectively and in real time
was Cedar: it claimed to synthesise a 'gap-filler' from the Fourier
transform of the sound before and after the click. Even that wasn't
really intended to handle the continuous crackle of some of the worst
gritty solid stock material (particularly inter-wars U.K. HMVs).
I wondered if some sort of resonator could 'ring' and fill the gap, but
it would need quite a lot of them to cover the whole audio band.
Octaves seemed the logical way to go but that involved either a large
number of ferrite pot cores or a lot of op-amps in state-variable
filters. I tried the pot-core approach many years ago and gave up
because it was becoming too unweildy.
This time I opted for state-variable filters and my design finished up
with 170 op-amps and several other I.C.s. It was a bit of a gamble
whether it would be worth building it, as the principle was untested, as
far as I knew. It has paid off, the results are stunning; as the
sensitivity is increased, the crackle just fades into the background and
the music comes through absolutely unaffected.
There are still a few things that need attention, as I can hear residual artefacts at a very low level - but I exhibited it to a group of
gramophone enthusiasts at the weekend and they were completely bowled
over by the sound quality.
On 16/09/2025 7:25 am, Liz Tuddenham wrote:
Scott Dorsey <kludge@panix.com> wrote:
Liz Tuddenham <liz@poppyrecords.invalid.invalid> wrote:
Tobiah <toby@tobiah.org> wrote:
I could start a thread on an analogue declicking computer for 78s, >>>>> which I am currently designing, but the number of participants would >>>>> probably be very limited.
You might be surprised. Is it working? How does
its performance compare to digital solutions.
I'm pleased to report that the MkIII version which I have been working >>> on recently has now worked for the first time. The results are very
promising and it is extremely easy to operate.
Unfortunately, in trying to track down a common-earth hum problem, I
accidentally blew up one of the power supply regulators and I didn't
have a spare. A new one is on order, so I hope to resume testing in a >>> few days.
The basic principle is to split the sound spectrum into ten bands, each >>> about an octave wide. In each band a click or crackle is identified by >>> comparing the vertical and horizontal vectors of the stylus movement - >>> if there is more than a certain proportion of vertical movement, a
switch opens and momentarily disconnects the signal. The band is then >>> filtered again, so that the harmonics due to switch clicks are removed >>> and damped resonance in the filter covers any short gaps in the sound. >>> All ten bands are then recombined to restore the original spectrum.
That's not a declicker! That's a broadband noise reduction system!
It was primarily intended to de-click and de-crackle 78s, but it can
also de-thump cracked ones, so I suppose it is more broadband than I originally suggested.
Compare with the Dolby Cat 43 system.
The declicker has a delay and looks at the first derivative of the input >> signal, and when it is too high it replaces the signal with the delayed
signal or it holds the existing level, or it fades from one to the next, >> in order to blend around a single impulse. Compare with the SAE 5000.
I think that the Audio Cyclopedia has schematics of both designs, both
pretty primitive but showing the techniques.
Finding the clicks and crackle is realtively easy on a mono recording:
they show up in the vertical component (which obviously wasn't
recorded). The big problem is what to do about them. The Marantz and other noise-reduction systems simply faded out a click - which
substituted a 'bloop' instead; cross-fading between before and after
could be better if it is done well.
The only system that seemed to do it really effectively and in real time was Cedar: it claimed to synthesise a 'gap-filler' from the Fourier transform of the sound before and after the click. Even that wasn't
really intended to handle the continuous crackle of some of the worst gritty solid stock material (particularly inter-wars U.K. HMVs).
I wondered if some sort of resonator could 'ring' and fill the gap, but
it would need quite a lot of them to cover the whole audio band.
Octaves seemed the logical way to go but that involved either a large number of ferrite pot cores or a lot of op-amps in state-variable
filters. I tried the pot-core approach many years ago and gave up
because it was becoming too unweildy.
This time I opted for state-variable filters and my design finished up
with 170 op-amps and several other I.C.s. It was a bit of a gamble
whether it would be worth building it, as the principle was untested, as far as I knew. It has paid off, the results are stunning; as the sensitivity is increased, the crackle just fades into the background and the music comes through absolutely unaffected.
There are still a few things that need attention, as I can hear residual artefacts at a very low level - but I exhibited it to a group of
gramophone enthusiasts at the weekend and they were completely bowled
over by the sound quality.
Isn't this all now trivial to do, better, in software ?
Or is the
project more of an intellectual exercise ?
Geoff <geoff@nospamgeoffwood.org> wrote:
On 16/09/2025 7:25 am, Liz Tuddenham wrote:
Scott Dorsey <kludge@panix.com> wrote:
Liz Tuddenham <liz@poppyrecords.invalid.invalid> wrote:
Tobiah <toby@tobiah.org> wrote:
I could start a thread on an analogue declicking computer for 78s, >>>>>>> which I am currently designing, but the number of participants would >>>>>>> probably be very limited.
You might be surprised. Is it working? How does
its performance compare to digital solutions.
I'm pleased to report that the MkIII version which I have been working >>>>> on recently has now worked for the first time. The results are very >>>>> promising and it is extremely easy to operate.
Unfortunately, in trying to track down a common-earth hum problem, I >>>>> accidentally blew up one of the power supply regulators and I didn't >>>>> have a spare. A new one is on order, so I hope to resume testing in a >>>>> few days.
The basic principle is to split the sound spectrum into ten bands, each >>>>> about an octave wide. In each band a click or crackle is identified by >>>>> comparing the vertical and horizontal vectors of the stylus movement - >>>>> if there is more than a certain proportion of vertical movement, a
switch opens and momentarily disconnects the signal. The band is then >>>>> filtered again, so that the harmonics due to switch clicks are removed >>>>> and damped resonance in the filter covers any short gaps in the sound. >>>>> All ten bands are then recombined to restore the original spectrum.
That's not a declicker! That's a broadband noise reduction system!
It was primarily intended to de-click and de-crackle 78s, but it can
also de-thump cracked ones, so I suppose it is more broadband than I
originally suggested.
Compare with the Dolby Cat 43 system.
The declicker has a delay and looks at the first derivative of the input >>>> signal, and when it is too high it replaces the signal with the delayed >>>> signal or it holds the existing level, or it fades from one to the next, >>>> in order to blend around a single impulse. Compare with the SAE 5000. >>>>
I think that the Audio Cyclopedia has schematics of both designs, both >>>> pretty primitive but showing the techniques.
Finding the clicks and crackle is realtively easy on a mono recording:
they show up in the vertical component (which obviously wasn't
recorded). The big problem is what to do about them. The Marantz and
other noise-reduction systems simply faded out a click - which
substituted a 'bloop' instead; cross-fading between before and after
could be better if it is done well.
The only system that seemed to do it really effectively and in real time >>> was Cedar: it claimed to synthesise a 'gap-filler' from the Fourier
transform of the sound before and after the click. Even that wasn't
really intended to handle the continuous crackle of some of the worst
gritty solid stock material (particularly inter-wars U.K. HMVs).
I wondered if some sort of resonator could 'ring' and fill the gap, but
it would need quite a lot of them to cover the whole audio band.
Octaves seemed the logical way to go but that involved either a large
number of ferrite pot cores or a lot of op-amps in state-variable
filters. I tried the pot-core approach many years ago and gave up
because it was becoming too unweildy.
This time I opted for state-variable filters and my design finished up
with 170 op-amps and several other I.C.s. It was a bit of a gamble
whether it would be worth building it, as the principle was untested, as >>> far as I knew. It has paid off, the results are stunning; as the
sensitivity is increased, the crackle just fades into the background and >>> the music comes through absolutely unaffected.
There are still a few things that need attention, as I can hear residual >>> artefacts at a very low level - but I exhibited it to a group of
gramophone enthusiasts at the weekend and they were completely bowled
over by the sound quality.
Isn't this all now trivial to do, better, in software ?
In real time? In a portable record player?
On 16/09/2025 8:23 pm, Liz Tuddenham wrote:[...]
Geoff <geoff@nospamgeoffwood.org> wrote:
On 16/09/2025 7:25 am, Liz Tuddenham wrote:
Scott Dorsey <kludge@panix.com> wrote:
Liz Tuddenham <liz@poppyrecords.invalid.invalid> wrote:
The only system that seemed to do it really effectively and in real time >>> was Cedar: it claimed to synthesise a 'gap-filler' from the Fourier
transform of the sound before and after the click. Even that wasn't
really intended to handle the continuous crackle of some of the worst
gritty solid stock material (particularly inter-wars U.K. HMVs).
I wondered if some sort of resonator could 'ring' and fill the gap, but >>> it would need quite a lot of them to cover the whole audio band.
Octaves seemed the logical way to go but that involved either a large
number of ferrite pot cores or a lot of op-amps in state-variable
filters. I tried the pot-core approach many years ago and gave up
because it was becoming too unweildy.
This time I opted for state-variable filters and my design finished up >>> with 170 op-amps and several other I.C.s. It was a bit of a gamble
whether it would be worth building it, as the principle was untested, as >>> far as I knew. It has paid off, the results are stunning; as the
sensitivity is increased, the crackle just fades into the background and >>> the music comes through absolutely unaffected.
There are still a few things that need attention, as I can hear residual >>> artefacts at a very low level - but I exhibited it to a group of
gramophone enthusiasts at the weekend and they were completely bowled
over by the sound quality.
Isn't this all now trivial to do, better, in software ?
In real time? In a portable record player?
OK, I missed the 'real time' bit.
But wonder what the circumstances are for real-time. Demonstration of
vinyl (or shellac !) playback for historical or sentimental purposes ?
Geoff <geoff@nospamgeoffwood.org> wrote:
On 16/09/2025 8:23 pm, Liz Tuddenham wrote:[...]
Geoff <geoff@nospamgeoffwood.org> wrote:
On 16/09/2025 7:25 am, Liz Tuddenham wrote:
Scott Dorsey <kludge@panix.com> wrote:
Liz Tuddenham <liz@poppyrecords.invalid.invalid> wrote:
The only system that seemed to do it really effectively and in real time >>>>> was Cedar: it claimed to synthesise a 'gap-filler' from the Fourier
transform of the sound before and after the click. Even that wasn't >>>>> really intended to handle the continuous crackle of some of the worst >>>>> gritty solid stock material (particularly inter-wars U.K. HMVs).
I wondered if some sort of resonator could 'ring' and fill the gap, but >>>>> it would need quite a lot of them to cover the whole audio band.
Octaves seemed the logical way to go but that involved either a large >>>>> number of ferrite pot cores or a lot of op-amps in state-variable
filters. I tried the pot-core approach many years ago and gave up
because it was becoming too unweildy.
This time I opted for state-variable filters and my design finished up >>>>> with 170 op-amps and several other I.C.s. It was a bit of a gamble
whether it would be worth building it, as the principle was untested, as >>>>> far as I knew. It has paid off, the results are stunning; as the
sensitivity is increased, the crackle just fades into the background and >>>>> the music comes through absolutely unaffected.
There are still a few things that need attention, as I can hear residual >>>>> artefacts at a very low level - but I exhibited it to a group of
gramophone enthusiasts at the weekend and they were completely bowled >>>>> over by the sound quality.
Isn't this all now trivial to do, better, in software ?
In real time? In a portable record player?
OK, I missed the 'real time' bit.
But wonder what the circumstances are for real-time. Demonstration of
vinyl (or shellac !) playback for historical or sentimental purposes ?
Shellac* (what's this 'vinyl' of which you speak?) Mainly to accompany
live presentations on singers, musicians and other performers of the
past - and for entertainment in the evenings after the presentations.
The original purpose, which has now become secondary, was to be able to
take the playing equipment to collections of recordings which were too valuable to transport to a studio.
Something which I hadn't realised until recently, is that people are
finding it allows them to hear subtleties on the records in their
collection which they never heard before. It might be useful to loan or
hire out as a standalone analysis tool because it gives the ability to
just pop on a record and audition it quickly without a lot of faffing
about with digital computers.
* In the UK, particularly during the1930s, the 'shellac' material used
by the biggest group of record companies was appalling. If you have
never heard a British inter-wars HMV pressing you can have no idea of
just how terrible the sound was. Ordinary de-clickers which are
designed to deal with occasional scratches on vinyl discs or good
quality American or Australian shellac pressings simply cannot cope with
it
On 17/09/2025 8:26 pm, Liz Tuddenham wrote:
Geoff <geoff@nospamgeoffwood.org> wrote:
On 16/09/2025 8:23 pm, Liz Tuddenham wrote:[...]
Geoff <geoff@nospamgeoffwood.org> wrote:
On 16/09/2025 7:25 am, Liz Tuddenham wrote:
Scott Dorsey <kludge@panix.com> wrote:
Liz Tuddenham <liz@poppyrecords.invalid.invalid> wrote:
The only system that seemed to do it really effectively and in real time
was Cedar: it claimed to synthesise a 'gap-filler' from the Fourier >>>>> transform of the sound before and after the click. Even that wasn't >>>>> really intended to handle the continuous crackle of some of the worst >>>>> gritty solid stock material (particularly inter-wars U.K. HMVs).
I wondered if some sort of resonator could 'ring' and fill the gap, but >>>>> it would need quite a lot of them to cover the whole audio band.
Octaves seemed the logical way to go but that involved either a large >>>>> number of ferrite pot cores or a lot of op-amps in state-variable
filters. I tried the pot-core approach many years ago and gave up >>>>> because it was becoming too unweildy.
This time I opted for state-variable filters and my design finished up >>>>> with 170 op-amps and several other I.C.s. It was a bit of a gamble >>>>> whether it would be worth building it, as the principle was untested, as
far as I knew. It has paid off, the results are stunning; as the
sensitivity is increased, the crackle just fades into the background and
the music comes through absolutely unaffected.
There are still a few things that need attention, as I can hear residual
artefacts at a very low level - but I exhibited it to a group of
gramophone enthusiasts at the weekend and they were completely bowled >>>>> over by the sound quality.
Isn't this all now trivial to do, better, in software ?
In real time? In a portable record player?
OK, I missed the 'real time' bit.
But wonder what the circumstances are for real-time. Demonstration of
vinyl (or shellac !) playback for historical or sentimental purposes ?
Shellac* (what's this 'vinyl' of which you speak?) Mainly to accompany live presentations on singers, musicians and other performers of the
past - and for entertainment in the evenings after the presentations.
The original purpose, which has now become secondary, was to be able to take the playing equipment to collections of recordings which were too valuable to transport to a studio.
Something which I hadn't realised until recently, is that people are finding it allows them to hear subtleties on the records in their collection which they never heard before. It might be useful to loan or hire out as a standalone analysis tool because it gives the ability to
just pop on a record and audition it quickly without a lot of faffing about with digital computers.
* In the UK, particularly during the1930s, the 'shellac' material used
by the biggest group of record companies was appalling. If you have
never heard a British inter-wars HMV pressing you can have no idea of
just how terrible the sound was. Ordinary de-clickers which are
designed to deal with occasional scratches on vinyl discs or good
quality American or Australian shellac pressings simply cannot cope with
it
But surely the Kellogs factor is a main attraction ;- )