Because of the way this works it requires no RIAA equalization. One of its many advantages over the conventional approach.
@mijostyn @millercarbon This statement is false. While it is true that the cartridge has an output that seems to complement the RIAA de-emphasis curve, from 500Hz to just above 2KHz (75uS) in the RIAA curve there is a bit where it flattens out. This causes an unequalized strain gauge device to be a little off. So they do need equalization to be correct but not nearly as much as a regular constant velocity device.
Its correct to say that it roughly approximates the needed de-emphasis.
Take a look at the RIAA curves- you'll see a 'zero' at 500Hz (318uS) (where the math says 'flat'- that's why its a 'zero' instead of a pole) and a pole above 2KHz (75uS) which re-introduces the slope. A strain gauge doesn't have that zero so what happens is it has the same slope across the band. This causes the highs to be and sound wrong. Its not glaring but if you know the recording its easy to hear.
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RIAA EQ is +20dB at the bottom, -20dB at the top. SG does not require this so the statement is true.
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@atmasphere , Have you heard the cartridge? Theoretically it should out track any other cartridge but his MI cartridges track anything I can throw at them. I can correct frequency response problems but I won't get involved if there are not significant advantages in the design.
@rauliruegas , I have no experience with the Lino C. I have an ARC PH3 SE which I really like for high output cartridges. It is a simple unit with just one switch in the signal path. It is a hybrid tube unit with a FET front end. It really does not have enough gain for cartridges with output < 0.5 mv. It is 30 some odd years old and still in perfect working order but it is time to move up. I do not like complex phono stages. It is too easy to damage the low level signal coming from a LOMC. The Lino C is a minimalist unit which is balanced throughout which I really like. Loading adjustments are not required and it is battery operated, another big advantage. I can use the ARC for high output cartridges which I prefer to MCs with certain music. The other candidate is the Sutherland Phono Loco.
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RIAA EQ is +20dB at the bottom, -20dB at the top. SG does not require this so the statement is true.
@millercarbon
Not really... The problem is that by the time you get to 20KHz you're not going to be 20dB down. Please look at the actual RIAA de-emphasis curve:
See that flattening out part in the middle? That's what I'm talking about. A strain gauge simply bypasses the flattened out part and continues rolling off the output following the 6dB slope as seen on the left side of the curve- so the highs simply won't be right. Imagine that red line just continuing down at 500Hz instead of flattening. You can see the error that is introduced. In reality it won't be as far off as the red line would be as I just suggested since were talking about a curve using analog filter theory.
To properly EQ a strain gauge, a pole (seen at 500Hz) has to be introduced (a rising response) and then a zero (seen at 2100Hz) going back to flat, so the strain gauge can do its thing.
So imagine an EQ curve that is flat from the bass up to 500Hz, then rises for 2 octaves at 6dB/octave and then goes back to flat. That's the math of it; the actual curve won't do that- it would be smoother of course in a way that is similar to the smoothness of the de-emphasis curve you see above. If this is not done the EQ won't be right.
@mijostyn Have you heard the cartridge? Theoretically it should out track any other cartridge but his MI cartridges track anything I can throw at them. I can correct frequency response problems but I won't get involved if there are not significant advantages in the design.
I don't know if its the same one but I have heard Soundsmith SG cartridges before. Tracking isn't what I'm talking about- I'm sure it tracks fine as the one I heard did. I'm talking about equalization. I provided the information you need to set the EQ right above. Can you dial that sort of thing in? If you do it in the digital domain, be sure to include an algorithm that includes the phase shift and frequency bump of analog filters.
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So what we have here is a perfect example of knowledge and facts (compliments of atmasphere) vs. ignorance and alternative "facts" (untruths).
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Lots of smart EE with ears have tackled the SG equalizer equation and sonics, Iverson comes to mind…
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Thanks, Ralph. All Atma is saying is that a strain gauge needs a little EQ in order to correct for the RIAA pre-emphasis standard used to cut all LPs. I don’t know whether the SS SG phono stages account for this but I’d be surprised if they don’t incorporate some corrective filtering in the 500 to 2000Hz region.
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@lewm , It is a good question I plan to ask Mr Ledermann. I have not seen him mention this. I can do it digitally although replicating the phase shift Ralph talks about won't be easy.
@rauliruegas , I viewed Channel D's web site last night. The Lino C 3.0 is now out and it has both MM and Voltage Mode MC capabilities among circuit improvements. It is also up to $6000 if you option it up. It has also lost the simplicity I like. Makes the Loco look better to me.
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Dear @mijostyn : You need to go for the one that match your way of thinking. No one of both phono stages you named are my cup of tea but this is me and that's all.
Look, when I want to listen analog everything that's below my system control must be analog and does not be digital manipulated in any way.
Again, that's me and I'm way different to you with different targets and MUSIC priorities.
R.
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Whatever you decide, my advice would be not to try to introduce the filtering externally with your digital filter device. It has to happen in conjunction with transduction of the cartridge signal.
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Interesting experience you have. I don’t like my dust cover to be next to my system at all when I listen, I even keep it in different room when it’s long listening. Maybe it’s too much, but I think my cover is very reflective as it pretty big put on-of style and covering whole tt.
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Dust cover is a kind of ''self explaining'' expression. Dust is everywhere but
we don't wan't them on our records. So even a kid can grasp the
''connection''.
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I don’t know whether the SS SG phono stages account for this but I’d be surprised if they don’t incorporate some corrective filtering in the 500 to 2000Hz region.
@lewm The last time I heard one, it had no eq. The claim was that it didn't need it- which is misleading. And sure enough, the LP I used for reference (which I recorded) didn't sound right. I heard months later that EQ was being offered, but apparently that is incorrect??
The thing is, a strain gauge has really high output; some of them I've seen can drive an auxiliary level input. The parts needed to execute the EQ are inexpensive and small, and could be installed in a very small box that is part of the interconnect cable, since it can be done entirely with passive components. So it puzzles me why this isn't done.
It has to happen in conjunction with transduction of the cartridge signal.
Why is that?
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That statement was probably incorrect. Apologies to Mijo. But I still don’t think he should attempt it before acquiring a thorough understanding of RIAA.
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Hold on Guys! I have not bought one yet. I'm just going to listen. I am equally enthralled by low impedance MCs and transimpedance phono stages. Unfortunately, the price of admission is going up in leaps and bounds.
I see what the problem is with strain gauges unequalized. Most rooms create more error but that should not be an excuse.
On the other hand I am still greatly enjoying The Voice on my ARC PH3 SE. They match up well and SS guys would never know it was a tube phono stage except maybe rauliruegas who is just claire voyant and really has no idea what he is listening too:)))
I bought a large piece of Macassar Ebony which should be big enough to do the whole plinth. Should I do dovetails or finger joints? What do you think would sound better?
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Dear @mijostyn " has no idea what he is listening too "
That is all my knowledge level I'm and my friends totally sure.
To my quality level standards your phono stage is totally out of question even with your Voice..
At this time all your statements in this thread tells me that your overall quality MUSIC level targets are way lower that what you showed in other threads. If this is your reality then you are not a gentleman that really want to help analog lovers in this forum through your posts.
Your technical knowledge level is way superior to.
R.
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@mijostyn
I'll let you in to a little dirty little secret - its the arm.
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@rauliruegas , I hope you realize Raul that I was joking. That's what the smiles were supposed to convey.
I am here because I still play records just like everyone here. We all enjoy music in our own way. You have no idea what my listening capabilities are and I yours. I have no idea what you are listening too and you I. It make more sense on these forums to talk about the way things work, much more concrete. We both dislike unipivot arms for the exact same reason. They do not function the way the ideal tonearm should. We both have probably used and listened to examples we did not like.
@dover , Are you saying the Schroder is causing my feedback problem? If so that would fly in the face of the obvious. If I lift the dust cover or close off the bottom the feedback stops. I did nothing to the arm. It is perfectly capable of playing at outrageous volumes without any difficulty at all. It is tuned right where I like it. If you are saying it is just a bad arm I and many others will disagree with you. Thanks for your input.
@lewm , I think that is an argument for a different day.
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Like you, Mike, I was joking. I wouldn’t have a chance trying to change your point of view.
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@lewm , and I was just about to buy one of those Oswald Mills Audio K3's. Actually, it is the only way you can get one of those arms. I plan on tossing the turntable and sticking that arm on an AR XA just for spite.
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@mijostyn
I was just about to buy one of those Oswald Mills Audio K3’s. Actually, it is the only way you can get one of those arms.
Actually you can build it yourself, it’s an old audio amateur design, here is an example
Its all a parody - I call the arm "a bridge to nowhere", nowhere being the TT - its a con.
Its similar to the Linn Sondek - comes from the land that gave us haggis, well the Linn like the Haggis is a bag of bits that nobody wants.
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@mijostyn
@dover , Are you saying the Schroder is causing my feedback problem? If so that would fly in the face of the obvious. If I lift the dust cover or close off the bottom the feedback stops. I did nothing to the arm.
The feedback is being amplified by the cartridge, which is mounted on the arm, which is mounted on the TT subchassis.
The closed lid changes the environment, but the arm/cartridge is what is getting excited at a particular frequency.
I would have tried a couple of things -
Bypass the suspension and see if any changes occur.
Increase the arm effective mass by 2g
You might find the problem disappears.
Also I agree with @atmasphere - locating the TT in a corner or niche is the worst possible location for the sort of issues you have.
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@dover , I believe you are analyzing the problem incorrectly dover. Increasing the effective mass would make things worse by giving the the tonearm more inertia. The bass gets the suspension bouncing at 24 Hz. Life not being perfect, the tonearm has more inertia at the cartridge end and it is bouncing also enough to generate a 24 Hz signal that keeps things going. If the suspension does not bounce there is no problem regardless of volume. I can peg it no problem. I'm quite sure this would happen with any tonearm mounted as it is just along for the ride.
The bass response is pretty much the same across the shelf. It does not increase appreciably in the corner because the side wall is only 1 foot deep. It is not much of a corner from an acoustic standpoint, not at all like the corner of a room. This was one of the first things I measured.
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Dover, The next arm I get will be a Schroder LT. I am already looking into mounting it on a modified Sota base since I plan on making a new one. As long as the suspension can handle the greater weight I should be able to make it fit.
I am in total agreement on the Linn having owned two many years ago. They do seem to have everyone hooked on the upgrade mania. Good business.
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@lewm , @rauliruegas @atmasphere The skirt is finished and installed. It is lined with felt which makes a good seal. It works perfectly. I can no longer induce any feedback with the dust cover closed. I can sleep at night now:)
I
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Dear @mijostyn : Good ! !
Now is time to enjoy it: just do it !
R.
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@mijostyn
Thats great news - perhaps you could play Reference Recordings RR12 "Gates of Dafos" at 120db and post it on youtube.
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@mijostyn ,
Glad you have things started out and now you are able to "rock out" again and play your music at listening levels that only a few appreciate...I get it. I also like to play loud every once in a while. Well, perhaps, more lately;). The work you did to your system and room to ensure that you can enjoy playing music loudly without problems is what makes this hobby fun. Your subwoofer builds are intriguing to me because customized them to take advantage of using DSP, which you already use for your system. I use SVS (4 each) with the limited DSP they have, but it works.
Like you, I have lots of mass for my turntable. It is already 120 plus pounds, sitting on top of a 275 pound Clearaudio MontBlanc stand, on top of bamboo floor with anti-vibration and sound absorbing adhesive (that's what the special glue container says (275 per 5 gallon), on top of concrete. No resonance issues in this system even with 100db plus levels, which is not part of my loud norm. only once in a while.
Back to the main topic. Of course, you realized this symptom was some form of resonance emanating from the dust cover based on increasing the loudness of your music. I experienced that once with my old (still is use for living room) Denon DP62L sitting between a pair of Polk Audio SDA2's being driven by Carver M1.5Ts.
This was in the early 80's when I first joined the military and lived in the barracks, so no thought of treating room acoustics. Whenever I played Def Leppard or AC/DC really loud, I would hear that resonant feedback that you mentioned. My trick to eliminate this resonant feedback was to prop the dust cover up so that it was not entirely touching the turntable base, about a 45 to 55 degree lift. I forgot what I used, but I am sure it was some crude and rudimentary fix that only Soldiers would figure out when you wanted to make things 'happen" or accomplish the mission.
Back then I was a novice and knew virtually little about tweaking, only, plug and playing and treating issues if they were gross, bass to boomy,.move speakers away from walls, too little bass, move back to walls, not loud enough, get bigger amps, and bigger speakers, and so on and on it went for years. I have learned a lot since then...hence, my moniker, which has philosophical meaning to me, the journey will never end. We will always learn something new as we grow older or experience new things, in this hobby, other hobbies, or in life.
Hmm, now I want to dig out some Rush 2112, Three Blind Mice, and Miles Davis, talk about eclectic tastes in music, LOL. Low level listening sometimes, in the room live feeling most of the time. It is all enjoyable.
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@audioquest4life , Glue always makes that claim:)
Yes, what I did when I was young is quite comical looking back on it. Learning in the school of hard knocks. But, experience is always the best teacher and after 55 years of it you usually gain enough to have some idea what you are doing. The big leap was when I started out with DSP in 1995. Seeing is believing and when you start measuring the lights come on.
Rock On, Mike
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@mijosyn,
LOL, they sure do.
This excerpt from your statement is so true ""But, experience is always the best teacher." Excellent point.
Speaking of dust covers, after our last move, my Denon dust cover ended up shattered, in pieces, and missing hinges. How that happened is just weird. I had to order a replacement dust cover from that company on e-bay who makes replacements for a variety of turntables, but, it did not have the mounting hardware to connect to the turntable hinges. It is a perfect match and has the hinge slots, just no hinge mounting hardware. So, now I have to lift the dust cover and set it down when changing out records in our living room system. I keep the dust cover on otherwise to control dust from settling and keeping the cleaning lady from polishing the wood veneer on the Denon. I have found the tonearm a few times moved to the center from its resting place.
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Nice finger joints. Dogged determination, for sure.
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@audioquest4life , you tossed the old hinge hardware? Sota uses some really nice hinges with adjustable friction. I'm sure Donna would sell you a pair. You can mention my name if you like. Having to lift the cover off al the time is a recipe for disaster.
@lewm , Thanks Lew. I'm not sure about "dogged determination." Setting up the jig is the hardest part. It takes a lot of test cutting to get the tolerances right, but once that is done you can knock these out all day long with minimal effort. Now hand cut dovetails is dogged determination. But, this is not a $10,000 coffee table and I'm not exactly getting paid for it. After all, it is just a turntable:)
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Having read through this old thread, and as someone who listens infrequently to vinyl, I have the following question:
If I don't get an artifact such as the OP in this thread describes, what are the reasons one typicaly doesn't use a dust cover while playing the record?
I recently picked up an lp of Julian Bream playing Spanish Guitar Music when I was visiting out of town. It sounds great but for the first time since buying this turntable a few years ago I experimented with cover on/cover off and could detect no difference. I'd always just imbibed the dogma that the cover should be off while playing. I love this pristine and really quiet sounding lp and would like to prevent as much dust as possible and so I will continue to use the cover since I don't hear any difference at all. Am I doing something that will effect the outcome of the election or contribute to Global Warming or committing some other unforgiveable sin?
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@mahler123 Avoiding the dust cover is old audiophile dogma, the fear being that the dust cover resonates and affects sound quality. In some cases this might happen. Most people like yourself can not hear a difference. Dust covers that sit directly on the chassis that the plater and tonearm sit on might cause trouble. If they are not hinged taking them on and off during play can be dangerous. Ideally a dust cover should be hinged to the plinth of a suspended turntable. The dust cover does not have direct contact to the important chassis, it is isolated. A good example are the Heritage and Cosmos Sota tables. Using a dust cover that is hinged and isolated poses no danger and actually improves sound quality by attenuating sound around the cartridge by up to 10 dB at some frequencies. I have actually measured this.
Dust is the enemy of records and fine mechanical devices. I will never use a turntable without an isolated dust cover in my system. I will never use a turntable that is not properly isolated by a tuned suspension.
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Jeez. That’s only two Commandments from Mijo. Do you suppose a dust cover can be isolated from the TT, if it’s firmly attached with hinges to the TT? Especially a spring suspended TT where induced vibrations of the cover are easily transformed into activation of the suspension? Anyway, if you hear no difference with vs without, then do what floats your boat.
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@rauliruegas Glass is a bad material to use for a dust cover as it can ring. Have you ever made a wine glass sing? If it is thick enough to prevent ringing it will be very heavy and difficult to manage even if hinged.
The dust cover I use now is 1/8" thick Lexan which like wood is self damping, it does not ring. It rests on a thick felt gasket and is sealed all the way around. You can see the felt gasket and the dust cover on my virtual system page. I can drop the dustcover during play and it won't affect play in any way, you can't even hear it even if the volume is maxed out.
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I apologize to Mijo for being facetious, but I don't like dust covers anywhere near the turntable when I am playing records. When the TT is not in use, a dust cover is a good idea.
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@lewm And that is why Howard Johnson's made 28 flavors. Best Hot Dogs ever.
The idea behind a suspension Lew is to isolate the cartridge from all environmental mechanical vibration including anything coming from it's own plinth including the dust cover. I can turn the volume all the way up and tap all over that dust cover and you can not hear a peep. If I give it too hard a lateral blow the table will skip because I provided an impulse below the suspension's cut off frequency. Anything above will be filtered out. Now in your case, you have a slate plinth and no hinges. We are both old men, but as you previously related you are 10 years older which makes you REALLY old. Any really old man trying to put an unhinged dustcover on a running turntable is a recipe for disaster. It is not such a great idea for just a plain old man never mind a young man with an essential tremor.
@rauliruegas Pardon for the late reply. I stumbled over an old post of yours. Forgot to push the "LAST" button.
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I’m not your average old man, old man.
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@lewm Keep up that attitude Lew:-)
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@mijostyn : No rpoblem and that was many years ago, not any more and as you I'm not anal about LP surrounded dust so my TT has no dust cover and NO I have not any trouble at any SPL.
R.
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Perhaps aerosolized sawdust leaks from your workshop into your listening room. Or perhaps the workshop IS a listening room. In either case, I do understand the obsession with dust covers.
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@lewm I'm pretty good at keeping the dust out of the house. The workshop is indeed a listening room......of a different sort. It is powered by 4 Mirage speakers and an old Adcom amp that refuses to die. The music is shipped down to the shop by a Sonos connect system. Anything playing on the main system can be sent down. It will also stream Qobuz from my phone. Can't work without music.
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