Linear Tracking Turntable

[julianE]

My Technics linear tracking turntable from the late 80's needed a new belt, the old one worked but made slight noise and i also wanted to check the lubrication. took a little doing to take it apart but once open everything was accessible. Looking at it I got a hankering to make a linear tracking arm of my own tho it's more than likely too big a project. A gentleman on the board built an entire linear tracking turntable, here is the post. After a few hours of research I still have a lot of questions and hopefully some of the brilliant minds on this board can shine a light. I have found two methods of moving the arm one of them nudges the arm every so often, my technics does that, motor turns on every couple seconds but i really should time it. From what i understand the arm moves when an error is detected using a photo electric method, there is an IR source and detector but i haven't found any details of operation. Sony top of the line linear table moved the arm continuously, i'm guessing at very tiny increments. i would think that should be a cinch with precision motor/gear assemblies available to us. something like the cd positioning assembly for computer optical drives.

if i do build my own, i would use another turntable to spin the record and have some sort of an assembly that sits above the record.

I would think a picaxe could easily control the arm movement.

Thanks in advance for any help on understanding linear arm control.

 

[hippy]

From what i understand the arm moves when an error is detected using a photo electric method, there is an IR source and detector but i haven't found any details of operation.

I never owned a linear deck but, if one starts from a traditional fixed arm perspective, we know and can see the arm rotates about its pivot as the cartridge and needle progresses along the track.

What a linear deck does in principle is move that fixed pivot across the record so the arm is always more tangential than angled.

Wherever the pivot is on a linear deck it's effectively a fixed arm so is rotating about that point. I would guess there's a sensor which determines what the angle is and then moves the pivot to keep that angle minimised.

You can role play that with an outstretched forearm, your finger the stylus, the pivot your elbow held against your body With your elbow fixed your forearm moves angularly as your finger tracks the invisible record. groove. If you move your elbow out, while keeping your finger in that grove, your forearm will be more tangential to your body, less angular than it was.

Your Technics seems to have the pivot point move a step whenever the arm exceeds some angle which should be simple enough, the Sony I guess is the same but much finer control or some sort of base speed of movement adjusted by whatever the angle is.

It then seems to come down to 'doing it'. I am guessing it is pretty much like the CD or floppy 'lead screw' mechanism which tracks the heads there. I would guess a direct or geared-down stepper would do the job. The hard part knowing when to turn it. I'm assuming it's stepped whenever the pivot angle exceeds some value.

Making an angle sensor with high resolution could be challenging. A disc below the pivot with a slot in it could be used with an IR sensor so the pivot steps whenever the slot isn't over the sensor, a typical rotation sensor. A pointer rather than disc and slot can do the same. If the pointer mirrors the arm under the platter, is long, you'll get a lot more movement towards the cartridge end which is where the sensor could be placed.

 

[julianE]

Thanks Hippy, I can see how the system works better, my mistake was thinking that the cartridge arm is rigid and only moved up and down as it went across. Maybe I'm wrong but the arm is allowed to pivot left and right and as it moves across the record and that's what's sensed and corrected, very elegant. When i had the belt off i tried manually turning the drive gear and it worked i could keep the music sounding correct. I looked at the service manual and it looks like the pivot sensor is on the base of the arm.

I'll have to see what i have in stock as far as motors, i would like to make something that tracks 5 minutes of a record just to see if it can be done.

 

[Buzby]

I've got a linear tracking turntable, Technics something or other.

The main body of the arm is driven by a pully-and-belt, a bit like a print head moves in a printer.
The short arm with the stylus pivots a few degrees either way, and there is some kind of sensor to detect this.
( I'm not taking it apart to find out what kind of sensor it is ! )

However, you can see when it is running, the main body moves a step when the angle of the short arm is too great.
It does this repeatedly to keep the stylus in line with the groove.

It should be easy to design a similar mechanism, probably better than my old Technics.

Designing is the least difficult part, but building it will need a lot of effort.
All all the bearings will need to be fiddly delicate things, tracking weight will need to be set, vibration designed out, etc.

It's a challenge, but doable if you keep at it.

Now for a really off-the-wall idea, build one of these ....

https://en.wikipedia.org/wiki/Laser_turntable

or just buy one off eBay .....

Elp Laser Turntable High-End Model Lt-Master | eBay

Find many great new & used options and get the best deals for Elp Laser Turntable High-End Model Lt-Master at the best online prices at eBay! Free delivery for many products.

www.ebay.co.uk

 

[julianE]

Designing is the least difficult part, but building it will need a lot of effort.
All all the bearings will need to be fiddly delicate things, tracking weight will need to be set, vibration designed out, etc.

Mechanical part is a nightmare and way beyond my skill. If i were to make one i would start with a broken top of the line yamaha linear tracker and replace a few bits, make the arm control motor a direct drive one eliminating belt slip but unfortunately losing vibration damping. Another idea i was toying with is to have the turntable play the record and record all the corrections it makes to flash memory. Next time the record is played there is no need for a feedback loop instead the turntable would know when to move the arm from pre stored data. the problem i always had with linear trackers is that there is an error and then it's corrected but with saved datapoints the turntable would know ahead of time where the stylus should be.

i was certain that laser turntables would have been common place with the resurgence of vinyl, i no longer think people buy turntables for the sound but more for the "coolness" factor.

there definitely is something special about vinyl and i think it's due to the mechanical reproduction. i've spoken to musicians and they tell me something happens from the transfer from a master tape to vinyl. the theory i subscribe to is that the stylus/cartridge is itself a musical instrument, in effect you are listening to a live performance every time you listen to a record, the vinyl grooves plucking the stylus.

this forum has the smartest most helpful people on the web, it's truly a gem.

 

[hippy]

Designing is the least difficult part, but building it will need a lot of effort.

Having had a read of what people are doing I would suggest it's reasonably easy to produce a proof of concept which does what one wants. Getting it as good as a commercial system will likely be hard, getting it better, audiophile quality, will be extremely difficult.

Once one's past the 'it's actually quite simple in principle' it quickly gets into 'how to make that perfect in practice', superior to what most manufacturers created.. Most people are happy with a fixed pivot system and you will be trying to minimise or remove quite small discrepancies to start with. It will be a labour of love of micro-optimisations to get towards perfect.

There was at least one deck which used a fixed pivot system and an extra bar which rotated the cartridge as it tracked across the record. Maybe something more adjustable than a fixed bar to improve the alignment of the cartridge is an alternative to consider ?

I am not convinced that recording the stepping and repeating those subsequent times will work but that's just gut feeling. To me it would be like walking through a forest then trying to repeat the path with your eyes closed. I would expect small deviations to what went before would eventually add up and have you walk into a tree. But, as it's not perfect the first time anyway, it doesn't have to be perfect subsequently, so it may be good enough and not actually worse.

The nature of it all falls into 'try it and see', testing theory as practice.

 

[hippy]

Thought - Two cartridges. The lead determines the error and correction needed, the following adjusted so it's correct when what the first tracked arrives ?

 

[julianE]

There was at least one deck which used a fixed pivot system and an extra bar which rotated the cartridge as it tracked across the record

I have seen the pivot system that rotates the cartridge it's very impressive and expensive.
I have never seen a two cartridge system. if it were on the same arm it would add too much weight, I'm imagining you'd have two arms on the same carriage with the leading arm lifting up once reaching end of the record.
Yea, the storing of data point has issues, the starting point has to be identical for both runs which is very difficult to do tho I think the system would still work because the difference would be smaller than the errors introduced by the flexing stylus.
The only really innovative turntable was the Nakamichi effort where they identify the center hole on the record to contribute most of the distortion. The hole varies from record to record and the nakamichi compensated for that i'm not aware of anyone else going to the trouble.

I do have a very good conventional pivot turntable and the difference between it and the linear tracking is negligible far outweighed by the quality of the cartridge. The linear is very tiny and convenient, perfect for the bedroom system, the huge pivot table sits in the listening room. I went and ordered a broken linear tracker on ebay I'll open it up and examine in detail how it operates my current one looks brand new and I have had it for over 30 years i hate to break it now that it's working perfectly after the belt change. BTW, it was a little off sounding until the new belt wore in.

Once the ebay table comes in I think I'll solder a couple sense wires to the carriage motor feed it to a picaxe and collect data of when the carriage motor is on as the record plays.

 

[erco]

Cool project! IMO no picaxe is required, just a motorized leadscrew and 2 microswitches on the traversing tonearm carriage. Tonearm rotates slightly, hits switch, blips motor to move carriage, restoring tonearm alignment. Done.

 

[Alien]

can't really compare the tracking to a hard drive head or a cd player because these units go in search of the track number and then drive to the next track data identifier. I was under the impression that the early Technics linear turntable had a sychronizing ring on the platter and this would coincide with an optical sensor which incremented the stylus mechanism across the vinyl disk. The stylus arm could be raised off the lead screw and positioned at the start track and then it followed the synch signal throughout the music tracks.

 

[hippy]

I was under the impression that the early Technics linear turntable had a sychronizing ring on the platter and this would coincide with an optical sensor which incremented the stylus mechanism across the vinyl disk.

Does that work though if the pitch, distance between grooves, is not fixed ? I would have thought the groves would be far closer on the 6 minute Bohemian Rhapsody single than a normal 3 minute track, and I recall hearing they used variable pitch anyway.

 

[erco]

Variable pitch? Nice but I'm just a poor boy nobody loves me, Galileo!

 

[julianE]

Technics linear turntable had a sychronizing ring on the platter and this would coincide with an optical sensor which incremented the stylus mechanism across the vinyl disk.

I have seen a sensor made out of pc traces that likely measures the platter spin tho it might just be used for speed regulation.
There also is a speed encoder on the carriage drive motor so the table knows exactly how much it's turned the screw,

Mine is one of the last technics made, i do remember having a CD player at the time i was gifted the turntable. if my recall is correct the table was less then $200 which now seems like a bargain considering all the technology and research it took to bring it to market.

 

[julianE]

In case anyone else finds linear turntables interesting here is a link that explains the progress of linear tables. There are instances of simple limit switches correcting for errors as suggested by Erco. The Pioneer maglev is particularly fascinating, I never gave Pioneer the credit they deserve, they had so many innovative products but they also made a ton of affordable equipment tarnishing their image among the snobs.

 

[wapo54001]

There is a website where I am a member -- diyaudio -- where there are folks who build entire linear tonearms of very high quality. I think you would find very useful information there. They are audio amateurs and don't use digital control very much but they know an awful lot about the mechanical aspects of turntable and tonearm design and construction.

 

[julianE]

folks who build entire linear tonearms of very high quality.

it's very impressive the mechanical work done by diyaudio community. i am running out of life so little chance i could ever build a high quality tonearm.
my ebay purchased linear table should be here this week, i'll have to repair it and hopefully will learn a lot in the process. the plan is to buy a top tier linear table and perhaps improve on it.

 

[wapo54001]

work done by diyaudio community. i am running out of life so little chance i could ever build a high quality tonearm.

I totally get that -- I got involved there by combining an interest in audio and my (then) newly-acquired Picaxe capabilities. I designed a lovely-sounding volume control using LDRs in lieu of resistors or mechanical potentiometers with a 28x2 first measuring and calibrating then controlling 4 ill-matched LDRs to operate as a tightly-matched stereo potentiometer then integrating an OLED display and relay controls, etc. That was ten or more years ago, and I've thought about updating the system but time truly is getting short and it's necessary to prioritize and I'm having too much fun with photography and some things are never going to get done.

 

[julianE]

but time truly is getting short and it's necessary to prioritize

It's one of the many things that makes this forum exceptional, we are most of that age where a lot of life is behind us and we have learned what matters and what does not.
The ebay turntable came in, the seller packed it well. more than worth the $65 spent. It's an early panasonic/technics belt driven platter. I had the belt on hand and once i replaced it the table came to life, a little contact cleaner and the cartridge worked. i'm playing a Van Cliburn record of approximately same vintage as the turntable. The linear mechanism needs lubrication but it's playing well, i'll wait a little before opening up that section, it has tricky plastic rivet type system and the old plastic tends to break. I'll play a few records before opening it. the unit is almost cosmetically perfect, did not expect that. came with a shure cartridge, never had one of those before, sounds really nice, i used to drive by Shure factory back in the day when things were made in usa, the turntable was made in japan.

 

[wapo54001]

came with a shure cartridge, never had one of those before, sounds really nice, i used to drive by Shure factory back in the day when things were made in usa, the turntable was made in japan.

Is it a V15 Type II cartridge? It would be about the right vintage, a top dog in the day and my favorite "sound."

 

[julianE]

s it a V15 Type II cartridge?

it's not a "track anything" V15, unfortunately. Closer to the bottom of the range SHURE PRO TRACK 4.

I opened the arm tracking portion, well constructed for an entry level table, it's a panasonic version of more popular Technics SL-3. Replaced the motor drive belt cleaned old lubricant off and applied fresh lubricant, almost silent operation now. Uses some sort of hall effect circuit on the motor and still figuring out how the control mechanism works to keep the arm perpendicular. looks to be optical. eventually plan to attach some wires to the control motor and use a picaxe to measure when the signal is sent.

 

[rq3]

My Technics linear tracking turntable from the late 80's needed a new belt, the old one worked but made slight noise and i also wanted to check the lubrication. took a little doing to take it apart but once open everything was accessible. Looking at it I got a hankering to make a linear tracking arm of my own tho it's more than likely too big a project. A gentleman on the board built an entire linear tracking turntable, here is the post. After a few hours of research I still have a lot of questions and hopefully some of the brilliant minds on this board can shine a light. I have found two methods of moving the arm one of them nudges the arm every so often, my technics does that, motor turns on every couple seconds but i really should time it. From what i understand the arm moves when an error is detected using a photo electric method, there is an IR source and detector but i haven't found any details of operation. Sony top of the line linear table moved the arm continuously, i'm guessing at very tiny increments. i would think that should be a cinch with precision motor/gear assemblies available to us. something like the cd positioning assembly for computer optical drives.

if i do build my own, i would use another turntable to spin the record and have some sort of an assembly that sits above the record.

I would think a picaxe could easily control the arm movement.

Thanks in advance for any help on understanding linear arm control.

Not an audiophile, but your intriguing project had me looking though the old Columbia Microgroove information, which as far as I can tell is THE standard for 33-1/3 RPM LP mastering to this day, except for very rare and outlier pressings.

The disc is 30 centimeters in diameter, turns at precisely 33-1/3 revolutions per minute, and has a track spacing of 150 microns (75 micron groove width). This implies that a gear ratio of exactly 1200:1 between the turntable and the linear arm would always keep the arm tangential to the groove, no matter the stylus position in relation to the disc diameter.

 

[julianE]

This implies that a gear ratio of exactly 1200:1 between the turntable and the linear arm would always keep the arm tangential to the groove, no matter the stylus position in relation to the disc diameter

I have been researching as well and found a very old article saying that some of the linear trackers move the arm every two grooves which i'm guessing equates to every 2 revolutions, nothing about the distance arm was bumped. I'm planning to read some of the patents for linear tracking, i know bang and olufsen have patents on their beogram tables.
As an aside, i spent a good part of the evening comparing 3 of my turntables. two pivot based and the linear that i repaired. in the end, you get what you pay for, my high end pivot was able to track and sound better than the cheaper tables. to keep things somewhat equal i had same brand cartridges installed in my best table and the linear tracker. there are arguments that a cartridge suited for a pivot table may not be the best for linear.
audiophile community is complicated. to the credit of linear tracker there were some quiet passages that i would say sounded better on the linear but when the full orchestra came on the pivot did better. i was listening to a piano concerto with lots of dynamic range.

the difference between all the tables i have is very subtle nothing to fret about but it's fun. i am shocked when people spend as much on a stereo system as what an average automobile costs. i have heard some of these systems and as good as they sound it's nowhere as good as hearing a live orchestra from a good seat. relative to an audiophile approved system symphony season tickets are a bargain

 

[erco]

One of the more memorable audio shootouts.

https://www.engadget.com/2008-03-03-audiophiles-cant-tell-the-difference-between-monster-cable-and.html

 

[julianE]

One of the more memorable audio shootouts.

as crazy as the speaker wire is the power cords are crazier still, they actually believe that higher quality power cables improve the sound despite the fact that many more feet of home wiring is just plain copper. i built an A/B switch using a picaxe, relays and an IR sensor so i could switch between sources from my chair. i was gonna go so far as to add random switching but there was no need, some things the difference was very obvious and others there was no difference. i could not discern between different cd players but i could tell a difference between a super audio CD and a regular one, it was very subtle tho worth it. I am completely convinced cables make a zero difference.

I'm still researching the Linear tracker turntables, the issue with the powered designs is that the carriage motor pushing the cartridge across is putting more pressure on one side of the groove . My thinking to get around that issue is to allow a little more tracking error by letting the cartridge follow the groove freely just like a normal pivot table and make the correction less often. for instance let the cartridge follow the groove for let's say 30 seconds and then gradually get it back in a straight line. i'm not sure if my thinking is right or not. i'm still thinking of the easiest way to make a carriage assembly. Yamaha had an innovative way to move the carriage, they used what is essentially a rubber conveyor belt. the belt sat on two spools and one of the spools was powered. the carriage with the tube and cartridge is attached to the conveyor belt. they used the belt to dampen any mechanical vibrations from the motor.

There are manufacturers making linear arms that rely on low friction bearings and the cartridge follows the groove without power assist. I'm favoring the power method at this time.

 

[hippy]

a gear ratio of exactly 1200:1 between the turntable and the linear arm

That would make sense for LP's which are usually some 20 minutes per side, so the tail-out area is pretty much the same for anything in that ballpark.

From Wikipedia it seems they may have started with fixed pitch, then went to variable pitch, and presumably returned to fixed pitch when they introduced frequency curves and variable pitch didn't retain an advantage. Not sure what problems tangential fixed pitch playing of variable pitch would have but that's probably an outlier for most people.

Fixed pitch might be a problem for 7" or 12" singles.

 

[julianE]

I have been looking for a potential turntable to do modifications on, was outbid on ebay but will look around locally to see if i can find one.
I'm also waiting on parts for making a prototype. going to use skateboard bearings and a linear actuator, make the arm out of wood. very coarse mock up. i have a $3 cartridge and some horrible records that i don't care if i ruin. i will use an existing table to rotate the records.

i have a way of digitizing vinyl but it's an older unit that has at best CD quality sound. i used it this weekend to test various cartridges, i think they would throw me out of an audiophile club, just when i thought i heard a night and day difference between cartridges the digitized audio convinces me that the difference is very slight. i was using audacity with two cartridge samples loaded so i could compare passages with ease and also have a visual representation of the waveform.
there are very high quality analog to digital converters and i wonder if audiophiles compare equipment using that method. i'm sure they can rationalize that the test is flawed else how could they sell turntables for well over $100K.

 

[hippy]

just when i thought i heard a night and day difference between cartridges the digitized audio convinces me that the difference is very slight.

This is the problem; perception versus scientific analysis. One can perceive differences when analysis shows there is none, and not perceive differences when analysis shows one should. That makes it difficult to decide what the definition of "perfect" is.

 

[papaof2]

"Perfect" is when what you hear on recorded media matches your memory of a live performance ;-)

Your memory includes the acoustics of the venue where that memory was made and not all venues have "good" acoustics.

Consider the multi-million dollar renovation on the Sydney Opera House - with most of that reno being to correct some bad design choices (from an acoustic standpoint) by the original designers (such as the lengths of audio reflective surfaces and putting the orchestra pit at least partially UNDER the performance floor) and managers (swapping the two purpose-designed halls to have more seating for the performances they thought would draw bigger crowds and audio quality be damned).

No one country has a monopoly on stupid - all the designers, engineers and managers get things wrong occasionally. The Opera House happens to be a very expensive "got it wrong" that did not endanger anyone.

 

[inglewoodpete]

This is the problem; perception versus scientific analysis. One can perceive differences when analysis shows there is none, and not perceive differences when analysis shows one should. That makes it difficult to decide what the definition of "perfect" is.

That reminds me of an anecdote of an audiophile who went to a live orchestral concert and grumbled "Not enough highs!"

 

[wapo54001]

That reminds me of an anecdote of an audiophile who went to a live orchestral concert and grumbled "Not enough highs!"

One evening I visited an audio society meeting in Minneapolis, the guest speaker was a guy flogging $14,000-per-pair speaker cables. He brought with him a system to demonstrate his cables -- two huge tube amps so heavy that they had to be moved on dollies driving two towering top-of-the-line Magnepan speakers all driven via direct digital from a laptop through a superb external DAC.

That night I was enthralled, I could not get enough of the music coming from that system. That was also the night that I learned that music reproduction is not about the quality of highs and mids and lows, it is about whether the music grabs you and draws you in and makes you want to hear more. It is about the emotional impact it has on you. That experience gave me the exact opposite of the well-known "listener fatigue" syndrome, I wanted it to go on and on. And that is what experienced audiophiles strive for, and it's why vacuum tubes are still being used after all of these years.

 

[papaof2]

"it's why vacuum tubes are still being used after all of these years"
It seems that the best digital recording and reproduction may not have the almost unlimited range of analog audio ;-)

I have a small digital audio recorder - used when interviewing family members about people they remember for the family genealogy I maintain. It's small, has good voice quality and records for several hours but it's definitely a niche product - the music in the background at the coffee shop does not come through well ;-)

 

[julianE]

driving two towering top-of-the-line Magnepan speakers

I do love the sound of Maggie speakers, but they are utter garbage without $14K speaker wire...I jest.
BTW, after all these years I heard the full story of Mangnepan speakers that the Steely Dan people bought to use as monitors, I remember listening to the particular album at friend's house thinking I am hearing it as the artists heard it. Turns out no, the Magnepans could not handle the volume they used in the studio space, speakers blew up, they ended up reverting to the studio monitors.

I was enthralled, I could not get enough of the music

Last time I was that enchanted by music it was brought on by being in love with an auburn haired beauty

 

[papaof2]

"Last time I was that enchanted by music it was brought on by being in love with an auburn haired beauty "

An excellent reason for finding perfection ;-)

 

[wapo54001]

"it's why vacuum tubes are still being used after all of these years"
It seems that the best digital recording and reproduction may not have the almost unlimited range of analog audio ;-)

Actually, it's all about the harmonics. Tubes tend toward 2nd harmonic distortion, solid-state tends toward 3rd harmonic. Second harmonic is mellifluous to the ear, third harmonic gives you listener fatigue. Thus the preference for tubes.

Nelson Pass designed a circuit using the Korg dual triode tube which is about the size and rectangular shape of a pack of wrigley's gum with a pot that makes the 2nd harmonic level adjustable. I am using it, having dialed in just the right amount of harmonic to change my dry-sounding class-d power amp into a musical tube-like system. The discussion of this circuit is here.

 

[oracacle]

The bigger problem with digital is lossy compression, amoung other things.
There is a a lot of frequencies that are removed to make the music samller. Then bit depth. If you can get hold of a raw studio audio file before compression, or even a FLAC variant there is a massive difference to the digital audio that most people will experience daily.
The standard audio sample rate is 44khz, which gives a max frequency of 22khz. While this is enough for most testable situations, humans have been known to be able to detect up to 28khz (my ex could here up to 26khz). Generally speaking the upper range of hearing is lost us we age.
This frequency clipping for saving space and time happens to a more extreme amount on phone lines - this is why the "on hold" music always sounds so bad.

I spent some extra cash ona resonable sound card for my PC, went from a standard 44khz, 16 bit sample of the on board audio, to 96khz and 24 bit sample depth. There was an exremely noticable difference. You have to spend cash to get good audio, the motherboard was around £200, the creative sound card that i now use was £150. People aren't willing to spend that sort of cash when they have something that is good enough for what they are doing. They don't realise what they are missing.

 

[julianE]

humans have been known to be able to detect up to 28khz (my ex could here up to 26khz)

I had access at work to a lot of audio test gear and in my twenties I could easily hear 18 KHz, stayed pretty steady for many years, I checked a few weeks ago and best I can be sure of is 14 KHz, not that many instruments can reach that even with the harmonics so it's not much of a loss.

To your argument there is value to higher quality audio, SACD is certainly better than regular CD's and of course, better than mp3.

I did A/B a tube preamplifier with a transistor one and tho i was certain that tube was better/different the A/B listen proved me wrong, if there was a difference it was very slight and I could not tell which one was which. Power amplifiers are a different case, the difference between tube and transistor is noticeable, I'm guessing tube is more pleasant while transistor more accurate.

As far as comparing live music with reproduced that's a night and day difference, I have never heard any audio system that's as good.
I have been fortunate to have known a number of classical musicians and audiophiles would be appalled by the middle of the road systems that musicians listen to. There are exception, I know a horn player that has a very impressive system.

I spent some extra cash ona resonable sound card for my PC, went from a standard 44khz, 16 bit sample of the on board audio, to 96khz and 24 bit sample depth.

I do need to get a better sound card.

 

[julianE]

Nelson Pass designed a circuit using the Korg dual triode tube

Thanks for that link, Pass projects are a lot of fun. Years ago I made one of his Zen amps, I still have them but they run very hot, my speakers are way too inefficient but every so often I give them a run. I like what he did with the Korg based preamp.

 

[wapo54001]

The bigger problem with digital is lossy compression, amoung other things.
There is a a lot of frequencies that are removed to make the music samller. Then bit depth. If you can get hold of a raw studio audio file before compression, or even a FLAC variant there is a massive difference to the digital audio that most people will experience daily.
The standard audio sample rate is 44khz, which gives a max frequency of 22khz. While this is enough for most testable situations, humans have been known to be able to detect up to 28khz (my ex could here up to 26khz). Generally speaking the upper range of hearing is lost us we age.
This frequency clipping for saving space and time happens to a more extreme amount on phone lines - this is why the "on hold" music always sounds so bad.

I spent some extra cash ona resonable sound card for my PC, went from a standard 44khz, 16 bit sample of the on board audio, to 96khz and 24 bit sample depth. There was an exremely noticable difference. You have to spend cash to get good audio, the motherboard was around £200, the creative sound card that i now use was £150. People aren't willing to spend that sort of cash when they have something that is good enough for what they are doing. They don't realise what they are missing.

OK, we are now in audiophile land and mostly no one ever agrees with anyone else.

Lossy compression does not lose entire frequencies, it removes detail. If the recording is 16-bit, the compression might remove the least significant bit. But you can have compression that has no loss of detail, it all depends on the compression. MP3 is the curse of good sound but FLAC, though compressed, is not lossy and does not lose detail.

The problem with all computer sound cards is that they are in the computer with all the electronic hash surrounding it. Some expensive sound cards do a good job of insulating themselves from that, but an effective and relatively cheap way to massively improve computer sound is to output the sound as a digital stream (USB, for example) to an external DAC and convert to analog outside of the analog hell that is a computer.

 

[oracacle]

Good sounds cards come with TOSLINK.
It has been a long time since I studied audio compression, and for that matter recording, but iirc lossy compression discrads uninportant psychoacustics - so frequencies that are outside of the normal hearing range (20khz for most) would be a good condidate for that. Dynamic range is something else that is also considered relatively unimportant and is altered with dynamic range compression. This will also make it harder to hear the high frequencies as humans are less sensitive to high frequencies and need the extra volume to hear them making them seem like they are (perseved) removed.

MP3 uses auditory masking, which is a big part of why its sounds so bad. I will always remember symbols sounding like some one was tickling a bee.

 

[julianE]

A kenwood linear table came from ebay today, if anything, i'm becoming very good at repairing these tables. This one was tricky to repair but I have it playing, used a belt from my parts bin, plan on ordering an authentic one soon. This table is a bit easier to work on since it's large and the mechanism is in the base unlike the technics variants. Once satisfied that it's working correctly I will be attaching leads to the motor terminals and gathering data. To add to the audiophile discussion, this table sounds really good, very silent. I can't be sure if it's psychological, I can also see how this works in the favor of merchants, seems like people always prefer whatever is newest/different. Than again, money can be spent on far worse things than audio equipment.