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 The Outer Limits of Analog Audio

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Sonic Voyager



Posts : 60
Join date : 2018-05-25

PostSubject: The Outer Limits of Analog Audio   Fri Jul 13, 2018 8:57 am



An Unusual 78rpm Sound Box Needle

Sonic found this in Thomas Mayer’s Vinyl Savor blog – within his report on the 2014 European Triode Festival:



Look at the close-up and notice the needle.  I have never seen anything like this!

Sonic did a bit of research. There is a thing called a “trailer needle” – see here:
  https://www.youtube.com/watch?v=dF3WUrP-75g

But if this video is correct from the way the trailer needle is mounted, then the needle in pix from Mayer’s blog cannot be a trailer needle. What might it be?  Perhaps something handcrafted – then again given that you use one needle per side of a 78 rpm record, you will have to make an awful lot of them.

Anyway the best way to play 78 rpm records is to use a suitable phono (MM or MC) cartridge.  Sonic uses a Stanton with a 2.7 mil stylus and has heard how these old records can sound more real than even their LP counterparts and definitely better than digital – as I have learnt to great happiness and to the amazement of many of my audio-friends!

I wonder if the engineers who recorded those 78s all those decades ago in the last century knew what realistic and dimensional sound they were capturing in those grooves? What would the look on their faces be like if we could time travel a group of them and the artistes to 2018 into Michael Green’s listening room and hear their 78s played in that tuned room/system with a Garrard 301, SME 3012 with an Ortofon mono MC cartridge made to play 78s, through the right phonostage EQ?

For Thomas Mayer’s blog, go here:
http://vinylsavor.blogspot.com/

Sonic


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Sonic Voyager



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PostSubject: Re: The Outer Limits of Analog Audio   Sat Jul 14, 2018 10:41 am

For Zonees who might be unfamiliar with 78 rpm sound boxes and the needles, here is a picture of the conventional steel needle design and playing angle for 78 rpm records:



This would show in what way the needle in the picture from Thomas Mayer's blog is unusual.

Sonic


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Sonic Voyager



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PostSubject: Re: The Outer Limits of Analog Audio   Fri Jul 27, 2018 9:46 am

Baerwald Alignment Geometry for 78 rpm Record Playback

Till now, the cartridge alignment geometry that Sonic uses on my Audio Technica AT LP120 with the Stanton 500/5127 has been the Technics SL1200 variant of the Stevenson alignment.

Here is how the Technics/Audio Technica set up is done with a jig or a ruler:



I used this because the logic was that the Stevenson set up has the lowest tracing distortion at the inner grooves at the end of a side.



Source: stereonet.au

The sound I got has been so good that Sonic is now focusing more effort on collecting the old SPs and improving the playback as much as I can (short of buying a new turntable like a Lenco L75).

When properly equalized, the sound of the old mono 78s, particularly voices is eye-poppingly real!

Sonic has recently heard tell of people using the Baerwald geometry for 78s instead of Stevenson. Curious, I changed the set up using the excellent Dr Feickert Protractor



Note from Sonic: here is yet another reason why I like MM cartridges.  Their styli are replaceable. Sonic does not throw away the worn stylus when changing to a new one.  When I change to a fresh stylus, Sonic marks the immediately previous one and keeps it for set up/ alignment purposes as long as the cantilever is straight and the diamond is intact. This is for things like geometry alignments and any that does not involve actually playing a record. So if during the alignment process, an accident happens, it is no big deal.  You cannot do this with your $20,000 Moving Coil cartridge….

And The Improvement in Sound....
The Baerwald setting (compared to the quasi-Stevenson used by Technics and Audio Technica) has the stylus about 3mm further forward in the headshell and slightly more inward twist of the cartridge body…..and what an improvement in sound!

The tone improved, playback is cleaner and there is even further reduction of record noise.

Sonic got out my most difficult 78s – a few 12” broadcast records of classical music with soft passages where record noise sometimes swamped the music – and played them.  Schubert’s Unfinished Symphony and Rossini’s William Tell Overture.  They sound much better now, the ear has an easier job separating out the music from the noise and the old “played to bits” broadcast disks have lower distortion than Sonic imagined.



Sonic


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Sonic Voyager



Posts : 60
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PostSubject: Re: The Outer Limits of Analog Audio   Mon Jul 30, 2018 9:26 am



My Experiments with Cartridge Alignment Geometries

Sonic has to tell you that my experiments with alignment geometries led me through an adventure across this last weekend with different conclusions from what I posted here on July 27, 2018.

My cheering the Baerwald setting for 78 rpm and SP replay was premature. Playing more 78 rpm records, the Baerwald alignment indeed sounded clean but the extraordinary lifelikeness of the 78s was gone.  What I got was a clean but artificial sound. Sonic next switched to Stevenson which took me back in the direction of the realism I enjoy from SPs but in the end Sonic started to hear more distortion from this geometry compared to Baerwald.  

What to do?

I then tried the Lofgren B geometry on the Audio Technica and found it a promising middle ground – lower distortion from SPs with a good naturalness especially in voices.  It appears Sonic will have to make some small adjustments in the playback EQ for the 78s in the 250 Hz region. After listening to a larger number of SPs, this alignment is appearing better than the Baerwald setting and cleaner than the Stevenson.  

While I was at it, Sonic next experimented with the geometry of the Rega P5/RB700/Ortofon 2M Blue.

In the case of the Rega/Ortofon, it turns out that Lofgren B sounded preferable over the Baerwald giving a slightly a fuller and better extended sound. So after settling for a couple of days and playing a number of LPs, Sonic is sticking with Lofgren B and this updates my earlier posts on the cartridge alignment geometry I use (see for instance “Tuning and Musical Adventures” June 30, 2017).    

Again a happy thing is I can do my set up with (one generation) older styli of my cartridges so I can get as painstaking as I like without fear of accidentally damaging a fresh stylus. In all these adjustments over the last few days, did Sonic bump anything?  Not at all with the Ortofon, though I did inflict a thump with the Stanton 500 that might set me off wondering if I needed to get the microscope out and see if something broke. But this is a DJ cartridge and a stylus built to DJ standards so this thump was possibly akin to a pat on the head.

In the end, all the cartridge alignment geometries are compromises round the reality of pivoted tonearms swinging in an arc across the record surface while record cutter heads are driven in a straight line across the radius of the disc.  Given that the playback arm tracks in an arc across the record surface, you will have two null points where tangency of the stylus corresponds with the cutting radius thereby creating two Null points where tracing error/distortion is ZERO.

Everywhere else on the record surface the stylus is “in error”.  All the geometries do is to play with overhang and cartridge offset angle (the angle it is mounted in the headshell) to shift the Zero/Null points about distribute the amount of tracing distortion across the surface of the record.  Baerwald (also called Lofgren A) tries for an even distribution, Lofgren B has the least tracing distortion in the middle area but higher tracing distortion at the inner grooves compared to Baerwald/Lofgren A.  Stevenson optimizes for lowest tracing distortion at the inner grooves but is the tracing distortion is higher mostly everywhere else on the record (except the Stevenson Null points) compared to Baerwald and Lofgren B.

What we should however remember that tracing distortion is not necessarily audible as “distortion” as in mistracking.  Whether with Baerwald or now Lofgren B, Sonic does not hear the tracing or any other distortion changing across the groove and I get none of the Inner Groove Distortion that many audiophiles lament about.

The geometry of tonearm/cartridge alignment is a complex topic and because of the inherent compromise involved there are many views about.  There are more set up geometries in addition to the “traditional” (Michael Fremer’s term) geometries of Baerwald, Lofgren B and Stevenson.  There is Uni-Din plus more around including esoteric set up geometries from manufacturers like Japan’s SAEC. In the case of SAEC, their WE-308 arm starts from the outer grooves at something like 6% tracing distortion falling to Zero in the inner grooves. It is a curious system with no Null points. The recommended overhang is 5 mm (typical geometries are twice or three times this) and a small offset angle for the cartridge (around half of what is commonly used elsewhere).

SAEC's rationale, quoted by Phonomac at vinylengine.com, is  “The SAEC WE-308SX arm design is based upon research done by the Sansui Electric Co. The AES preprint 1390 (D-5) derived the optimum pivot position from a kinematic point of view, with the mass of the arm, the location of the center of gravity, and the moment of inertia around the system's center of gravity. Resonance was the engineering problem being solved. For this particular arm, it is not advised to optimize the geometry, or the resonance of the system will change to such an extent that the arm will not track properly.”

For Sonic, I am happy that my tonearms’ set up have been improved on, and I am not going to obsess too much with the arcane geometry of cartridge alignment.  

Sonic


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Sonic Voyager



Posts : 60
Join date : 2018-05-25

PostSubject: Re: The Outer Limits of Analog Audio   Fri Aug 10, 2018 11:36 am

Work to Improve the Audio Technica Turntable - Part 1

Sonic got started on some work to improve my Audio Technica AT-LP 120. Given that I am playing more SPs and 78 rpms as part of my regular listening, Sonic needs to make certain that this cheap 'n' good turntable stays good because that way I can preserve the growing number of 78 rpms and SPs in my collection.

The quality control of the AT-LP 120 is at best adequate, actually not very good (designed in Japan, made in China).  For instance the collar that mounts the headshell to the tonearm is often machined slightly off so that the azimuth of the cartridge is wrong,  and the stylus therefore not vertical to the grooves as seen from the front of the cartridge.



Here is a picture where you can see the locating slots and the tonearm wire contacts slightly rotated clockwise (I shot the picture from an angle that exaggerates the degree of rotation).  Till now, Sonic has compensated for this by mounting the Stanton 500v3/D5127 cartridge used on this arm with a tiny thin washer on one mounting screw between the cartridge top and headshell to bring the stylus back to the perpendicular. This is not a solution I like because it affects the mechanical grounding of the cartridge. Sonic might shortly be using more than one cartridge on this turntable and it means I have shim every headshell and cartridge for this turntable.  The washer on one mounting screw also makes the cartridge hard to align -- the setting runs because the cartridge rotates when you tighten the screws. Very annoying. So its time to try to get this right.

Next, here is a picture of bottom of the arm pillar.



I need to improve the damping of the cueing lever to make it more predictable in its action, rather than working sometimes and other times threatening to slam the cartridge onto the record surface. Which is why Sonic just cues my records by hand. But the cueing level that works is always more convenient and safer.

That will take some work on the square assembly in the upper middle of the circular mount.  In some AT-LP 120s, the tonearm lead-out wires are also badly dressed and that causes horizontal drag on the motion of the arm.  In Sonic’s turntable this wire dressing seems to have been done properly.

And this is a wider picture of the underside of the turntable.



With the AT-LP 120 open, there are a few things that can be done get better sound such as improving the quality of the cable that takes the signal from the tonearm to the phonostage. See the black twinlead snaking through the oblong clip in the lower of the turntable.

Running parallel to this twinlead is a red wire – that is the turntable earth.  I used a heavier gauge earth cable because the original was thin and did not do a good job of grounding the system and a slight hum could be heard.  With the red earth cable, the system is extremely quiet.

More reports to come as work progresses.  

Sonic  




Last edited by Sonic Voyager on Sun Aug 12, 2018 11:37 am; edited 1 time in total
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Sonic Voyager



Posts : 60
Join date : 2018-05-25

PostSubject: Re: The Outer Limits of Analog Audio   Sun Aug 12, 2018 11:36 am

Work to Improve the Audio Technica Turntable – Part 2

Sonic made a good start with this project to improve my Audio Technica AT-LP120!



See the two small screws in the tonearm just behind the headshell locking collar?  They hold the collar mounting assembly.  I removed the screws using a jeweller’s screwdriver and found if I removed the spring washers under the screw heads, the collar can be turned enough to get the headshell about parallel to the record surface.  Sonic tightened the screws (sans washers) as tight I could without stripping the screw threads and on replacing the headshell/cartridge, found the azimuth correct enough.

Next, I tackled the cueing mechanism. This involved applying thick motor grease with a coffee stirrer (used as a spatula) to the lever assembly -- see the square housing in the picture.



I got a cueing mechanism that can be lowered smoothly without crashing the stylus onto the record. Sonic has to control the decent by hand – but this is an improvement!

Finally, Sonic did a test between a rubber mat and a Rega felt mat.  The rubber mat gave a fuller sound possibly by better damping the ringy platter.

Now that the stylus is properly mounted and the stress of the twist from the incorrect azimuth has been removed from the system, Sonic will retest the tonearm alignment geometry again.

I will also get to changing the lead out wires to the phonostage to something that lets through more music.    
 
Sonic

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Sonic Voyager



Posts : 60
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PostSubject: Re: The Outer Limits of Analog Audio   Fri Aug 17, 2018 11:03 am

Work to Improve the Audio Technica Turntable – Part 3

Sonic soldered a higher quality cable leading from the turntable to the phono stage. What I had till now was a 24 AWG cable that comes free with a any of a thousand cheap DVD players.  My Audio Technica has reached the stage where Sonic could hear the need for something better.  For this, I found an inexpensive 24 AWG (two conductors) screened Belden cable with Teflon insulation, an 833 something – it is the white wire in this picture.



And Sonic found a Technics 52 mm set up gauge!



So I took some time to retest the arm alignment geometries after the azimuth of the cartridge was fully corrected. I tested Lofgren B vs Stevenson vs the Technics 52 mm setting. After all the recent revisions and improvements, the best sounding and cleanest in terms of perceived distortion and sensitivity to record noise that emerged is the Technics 52 mm setting.  

Sonic is staying with this.

Sonic

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Sonic Voyager



Posts : 60
Join date : 2018-05-25

PostSubject: Re: The Outer Limits of Analog Audio   Fri Aug 24, 2018 8:29 am

Zero-Offset Tonearms

Sonic has been occasionally posting pictures of Japanese tone arms that are absolutely straight with no visible offset angle (the angle the cartridge is turned inward towards the spindle).

I got enough info over time to figure what these Audio Mania Fans were doing.

They are part of a trend of using Zero-Offset Arms with Underhang.
 
Have a look at these pictures of a DIY Japanese tonearm with no cartridge offset angle.



This is from https://audiooyazi.exblog.jp/

The google-translate of the captions to these pictures say:

“Good evening, I made an arm base with a light old material which seems to be sawn lumber of the 1960's. When lightly struck with a finger, it sounds comfortably. I applied linseed oil. Is a nice feeling to check the under hang. Next is the output terminal production and wiring ♪”

Sonic asks “Underhang, Zero Offset Tonearms….what’s going on?”

Audiogon forumer William62 sums up the rationale for these unusual arms like this:


Yes, the alignment is not as good as an off-set arm, but there's the advantage of having no anti-skate problems, and also probably less stress on the cantilever.

Source:
https://forum.audiogon.com/discussions/tonearm-without-off-set

However, Zonees should have a look at the kind of tracing error and distortion an arm like design like this creates.  Notice too there is only one Null point instead of the usual two. If you would like a comparison to how this fares compared to the tracing errors/distortion of the conventional geometries (Baerwald, Lofgren B and Stevenson), have a look at Sonic's post of July 27, 2018 on this thread.

 

This is from
https://www.audioasylum.com/cgi/vt.mpl?f=vinyl&m=1140067

A 500 mm (approximately 19 inches) tonearm is being discussed and the underhang is 6.183mm to minimize distortion.

ViV Laboratories, a Japanese company sells zero-offset tonearms that have lengths of 7 inches to 13 inches.  They are reported to sound pretty good.



Source:
https://www.analogplanet.com/content/will-viv-audio-labs-tonearm-float-your-analog-boat

Fascinating isn’t this?

Sonic



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Sonic Voyager



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Join date : 2018-05-25

PostSubject: Re: The Outer Limits of Analog Audio   Sun Aug 26, 2018 8:20 am

Just as we are discussing zero-offset tonearms, Yamaha launches this – their Gigantic and Tremendous series GT-5000 turntable.


And look at the arm – it is an 8.77 inch long arm with a specified underhang of 17 mm.



Source:
 https://www.monoandstereo.com/2018/08/new-yamaha-gt-5000-turntable_24.html#more
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Sonic Voyager



Posts : 60
Join date : 2018-05-25

PostSubject: Re: The Outer Limits of Analog Audio   Fri Aug 31, 2018 7:40 am


A Mystery Unraveled by Sonic

Zonees will have noticed that Sonic went through a period of mental discombobulation round the alignment geometry for my Rega RB700 tonearm and Ortofon 2M Blue cartridge.  

My account of this was in Sonic’s post of July 30, 2018 where I arrived at the use of Lofgren B…..but there is more.

Background: this all started with Sonic carelessly moving the position of the Ortofon 2M Blue cartridge in the Rega tonearm then trying to aligning it with the Dr Feickert protractor only to find nothing quite got me the sound I enjoyed before the position shift.  

Sonic tried Baerwald (which sounds a little thin), Stevenson (gives a better balance, though with a higher level of distortion was always somewhat audible), Rega’s manufacturer protractor alignment (which was absolutely awful, the most distorted and noisy) and Lofgren B, (which is pretty good, though with perceivably higher end of side distortion is audible).  This was a step backwards from the set up Sonic used previously which was so clean from the first groove to the run-out grooves that even vinyl skeptics had to say “what did you do? I have never heard vinyl analog this distortion free. Your analog is as quiet as CD”

The Mystery Deepens:
a. My Rega RB700 tonearm was set up three years ago by a trusted set up man in one of the best (most reliable) stores in this town

b. I asked for Baerwald and he says he used the Original Dr Feickert Analogue Universal Protractor

c. Sonic has pictures of my Rega RB700 with the old setting and the pictures show where the mounting screws in the headshell were and after the recent attempts at alignment using a Next Generation Dr Feickert Protractor, not one setting of either Baerwald, Stevenson or Lofgren B shared the position of the cartridge mounting screws with the old/original setting! And none of them sound as good.

Look at this -- Baerwald and Lofgren B alignment have the mounting screws at the front of the headshell like this:



The position of the mounting screws of for both Baerwald and Lofgren B are about identical the only difference being the offset angle.

Stevenson on the other hand has the mounting screws just ahead of the halfway point of the slot in the headshell.



For Zonees who are wondering, the Rega manufacturer’s alignment was a little further back from the Stevenson setting, putting the cartridge screws at the mid-point of the slot in the headshell or perhaps a little behind that point towards the arm pivot compared to the Stevenson setting and sounds lousy….really lousy.

The original alignment that worked so well had the mounting screws about an mm or so ahead of Stevenson, slightly offset inward and visibly behind Baerwald/Lofgren B positions!

Sonic was mighty perplexed – what was that mystery setting that worked so good?

Sonic thought deeply into this problem, losing some sleep in the process.

Then as I kept researching (while minimizing Vinyl playback just in case I was damaging the records), Sonic realized that the Baerwald alignment has two variants – IEC and DIN, where the Null Points are (from the record centre): 67mm/122mm and 63mm/119.17mm respectively.  

Stevenson on the other hand has Null Points at 60mm/118mm,  that is closer to the record centre.  Stevenson was designed to minimize inner groove distortion while having somewhat higher tracking distortion elsewhere.  There is rational logic here – the groove speed is lowest at the inner grooves and distortion highest there, so optimize to add the least tracing error there.  SME, VPI and Rega as well as many Japanese manufacturers design their arms round Stevenson or some proprietary variant of it.

Now this set up man is too good a professional to make any gross error.  He must have aligned to something.

Looking at the Null Points of Baerwald IEC, DIN and Stevenson, I noticed the Null Points of Baerwald DIN falls between Baerwald IEC and Stevenson.  With the alignments of Baerwald IEC and Stevenson that Sonic did, I observed that with the same cartridge, a shift of Null Points closer to the centre of the records moves the cartridge back in the Rega headshell…..and noticing that Null Points of Baerwald DIN is between those of Baerwald IEC and Stevenson, Sonic had my “Aha!” moment.

Sonic asked myself “what if the trusted set up man did set up the tonearm for Baerwald as I asked but used Baerwald DIN instead IEC? This setting will put the cartridge in a spot between Baerwald IEC and Stevenson, exactly what Sonic is looking to do!"

The only protractor with a DIN variant for Baerwald (Lofgren B) I could find is the Acoustical Systems SMARTractor that gives both IEC and DIN settings…..and after a few moments, Sonic found that the Baerwald DIN alignment put the mounting screws right back where they were originally.  



The musical sound which Sonic was accustomed to came back, the distortion was lowered and normalcy returned.

Many things Sonic learnt from this:

a.          If something is working well, Do Not Touch It!  

b.          If you have to move something and you cannot afford to lose the setting, at least mark spots, make templates/jigs, take lots of pictures so you can minimize the time you take to get back – this wandering about for Sonic lasted a month!

c.          The different alignment geometries all sound different from each other – even between the IEC and DIN variants of the same geometry, in this case Baerwald. I have to add that Lofgren B have IEC and DIN variants too.

d.          Different protractors, if competently designed, will show proper alignment results where if you get alignment right on one protractor, the other will corroborate it – you will not be right on one and wrong on another

e.          Protractors can vary wildly in ease of use though.  The New Dr Feickert is very easy to use, the Rega card pretty bad (OK, it is alright if your cartridge is square like the Denon 103), while the SMARTractor is real wild given all the reflections though you only had to align to one spot

f.          What a difference a millimeter makes.  That was the difference between the Stevenson and Baerwald DIN (there is more offset angle turn in with the latter), and we talking about both alignments being spot on using precision protractors and magnifiers

g.          Close gets you no cigar.  You must be spot on as determined by magnifiers and not using the naked eye. A setting that is slightly off can increase record ticks and pops noticeably

Sonic has good sound again, and a throbbing headache from eyestrain of using the SMARTractor which is effectively a mirror with grid lines engraved on it.  Imagine linking all that up with a tiny stylus with all the reflections plus the occasional flash of the torchlight beam reflecting all over the place including into Sonic’s eyes.  The SMARTractor is probably the most accurate protractor but not easy to use

This episode has given me an understanding about alignments I did not have till now.  While Sonic loves analog music, I wonder how the future of vinyl playback will go with the need for painstaking set up with costly set-up gear like the protractors I used. No way will one get accurate alignment with a card printed with a few lines and squares.

For the new people entering the joys of analog, I notice they are buying inexpensive plug and play turntables like the Audio Technicas. If these tables come with the manufacturer’s cartridge (like the Audio technical AT95e) properly set up from the factory, then all is well but what happens on the day they change the cartridge for something better?  Where will they get competent help and set up?  I do not see many of the new vinyl fans will want to work to get the DIY skills to do what Sonic just did…..or go to the expense of buying protractors costing multiples of an entry level turntable…..what the future of turntable and vinyl playback then?      

Sonic




Last edited by Sonic Voyager on Fri Aug 31, 2018 10:12 am; edited 2 times in total (Reason for editing : Described the position of the cartridge mounting screws in the headshell for Stevenson and Rega settings more accurately)
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