Garrard 301 motor and rumble


I had my 301 restored but I still complain about rumble at high volume. Iv'e been bitching about the plinth I made, but I just lifted the platter to see if perhaps the motor was the issue. when you engage the idler and apply a little pressure to engage fully, I feel the vibration. Either the brass speed selection post is not true or its the motor transmitting the vibration, but the motor seems very smooth.

 

What steps should I employ to figure this out?

128x128famoej

There are any number of gurus who claim to have mastered the art of perfecting the workings of a Garrard 301.  Artisan Fidelity are one of those, but there are others.  It's not cheap.  If you want to try to do it yourself, you've come to the wrong place for detailed instructions, but some of the other 301 aficionados here may be able to direct you to a source of the information you need. For example, if I wanted analogous information about my Lenco, I would go to the Lenco Heaven website.

Ah, the joys of idler/rim drive! Proponents claim a more forceful sound but with a higher noise floor! So a tradeoff there! 

@jasonbourne71 A nice measured answer. Thank you. As you modify the 301 with a such things as a precision machined brass bearing assembly and a heavier platter along with the many other steps to get the best of the 301 (like a complete motor rebuild) the 301 becomes less noisy but also loses some of that forcefulness. The Shindo 301 is a good example. The platter weighs more than 20 lbs whereas the original platter weighs 2.2 Kg, about 4.7 lbs.

I appreciate your frustration, but isn't complaining about the high volume rumble of a vintage Garrard 301, kind of like buying a vintage British sports car like a Lotus Super 7, then complaining that you can feel every bump in the road?

Isn't it just inherent in the idler wheel technology?

FWIW, a high quality PS like the LDA made by Fidelity Research (see the other thread) will almost certainly reduce motor noise, and also make it run smoother thereby reducing idler noise as well.  How much benefit is for an end user to say.  The Walker Audio Precision Motor Controller made a huge difference to the sonics of my Nottingham Analog Hyper, even though the Notts is of course a BD, not an ID, and even though the Walker is a crude device compared to the LDA.

I would like to give you the unmeasured answer but it will upset Fsonicsmith and you know the answer already along with the solution.

Idler wheel drives do not have a more forceful presentation. That is lay intuition and a psychological bias. All turntables with identical speed stability and identical cartridges and tonearms have the same "forcefulness." 

Mijo, I don’t argue with what you say, but it could be that certain drive systems are more capable than others in making incremental corrections in speed to maintain a more constant 33.333 rpm. Because of less compliance in the drive system compared to a BD or even a DD. That capacity for rapid short term acceleration might be heard as forceful performance. After all, there has to be something beneficial about ID. Which might be why putting a 20 or 40 lb platter on a 301 is heard to be counter productive by listeners who key on that sense of drive.

You won't anger me mijostyn. Seriously. Have at it and if I respond at all, it will be polite and measured. I promise. 

I don't agree with much of what you have to say but when there are legions of respected audio writers who disagree with you, I don't have to defend the praises of a good idler drive. 

Ralph Karston loves his Technics 1200's. There are legions of VPI fans. You love your Sota. And the divergent tastes and opinions go on and on. It is interesting that we accept that our taste in loudspeakers is different than one another's, and yet we somehow expect some degree of consensus as to turntable and arm combinations and turntable design philosophies. 

I have said it before and I say it again-I know that there are many turntables that are technically superior to my two hot-rodded idler's BUT I also know that my TD124 and Garrard 301 will be reproducing music just fine when my great great grandchildren are looking for a turntable. These decks were built to LAST. 

 

 

 

 

I would definitely replace the belt. You must order the belt from SOTA. Do not use generic replacements.

You might also have your serial number in hand and request a list of upgrades available for your unit. There have been many improvements over the years. For sure you should consider a new magnetic bearing and platter. 

If records have trouble sealing you will need to send your platter back and have a new mat put on. Records that are warped or dished and won't seal sometimes can be made to seal by starting up the table with the two finger nails pushing the lip of the record down at 180 degrees for three revolutions. records that are dished will seal on one side but not the other. 

If the pump makes enough noise that you can hear it from a distance of 10 feet it will need to be replaced with a new unit. The new ones are much quieter. 
 

@mijostyn  No such worries or anything even remotely similar apply to either of my idler turntables. If there is such a thing as a vacuum hold down system that does not fail, sooner or later, color me surprised. 

If a Vacuum Platter Mat is desired for the 301, the AT 665 or 666 will both be able to offer Vacuum Clamping to the LP.

I have the AT 666 and have heard a pristine functioning model prior to making my purchase.

The AT 666 is a Metal Mat and is the one out of Three owned Metal Mats that creates the leanest of the Mats in their presentation. If this sonic is transferred to being perceived on a 301, the tightening of the Bass might be a interesting alternative presentation.  

I also know a individual with the 665 version and they are quite impressed with its Vacuum capability, I'm not sure how they view it as a sonic influence.    

@fsonicsmith 

No, you just have to replace a noisy idler wheel every couple of months or so. 

The actually pump Sota uses is child's play to replace and readily available. If you can come up with a better way to perfectly flatten a record and mate it to a mat of the same mechanical impedance color me surprised. 

It appears you are an antique collector and not interested in the highest levels of performance. I have an old Nagra Tape Machine on display, beautiful thing. I never use it.  

One key to really good LP playback is a robust drive in the turntable. That is why the Garrard has a following, along with the Lenco, Empire and Technics.

No matter how speed stable with no LP, a wimpy drive will have speed variation when you set the needle down and could have more when there is heavy modulation since the drag on the arm is increased.

When there is a slight speed variation, IME you hear it as a slight shimmer in the soundstage. I suspect this is because the variation is so slight that you dont hear it as pitch, rather you hear the tonearm tracking force on the groove walls change as the arm oscillates slightly left to right as the skating force changes with the speed.

If this Garrard were my machine, I’d grease the main platter bearing, make sure the motor has a good lubricant (automatic transmission fluid works well) and finally has a good idler, whose bearing also has a touch of light grease.

You can get idlers rebuilt by Russell Industries on the east coast. They do an excellent job. Most of the rumble you get is from the idler, so the more precision you can get out of it the lower the rumble. Its also worth it to make sure the inside of the platter where the idler bears against it is clean, since any dirt/buildup there can add to rumble too.

If the idler has a sloppy fit on its axle, all bets are off. But IME that’s pretty rare.

@atmasphere 

Speed instability is certainly a problem. Most of it is caused by record warping and eccentric spindle holes. The very same irregularities that cause rumble also cause speed irregularity.  The old idler wheel turntables are less speed stable than any high end belt drive table primarily because of the older motors. You could substitute a modern electronically controlled motor so you can have more accurate rumble. Even if you could create an idler drive that were as quiet as a belt drive it would not last long as components wear. 

The point is, unless you are an antique collector do not buy an old idler wheel drive table. There are many excellent modern turntables, either belt or direct drive that are quieter, more speed stable and better isolated. This is not an opinion. It is a matter of fact.  

@mijostyn 

I previously thought that you were knowledgeable and just needlessly argumentative. Now I see it is much worse-you are entirely ignorant. 

No, you just have to replace a noisy idler wheel every couple of months or so. 

Garrard and Thorens experts have stated repeatedly in their writings that it is not uncommon to find thirty year old idler wheels that remain perfectly true. 

You could substitute a modern electronically controlled motor so you can have more accurate rumble.

Are you going to blame this on your dyslexia again or will you just admit that you are awful (and dumb)  with your native language? 

 

There are many excellent modern turntables, either belt or direct drive that are quieter, more speed stable and better isolated. This is not an opinion. It is a matter of fact.  

Not opinion? Hooboy! Who let the inmate out of the cuckoo's nest?

You could substitute a modern electronically controlled motor 

You clearly are incapable of comprehending Ralph's point and it again shows that you know nothing about turntables. I am shocked. Speed control for a relatively weak motor will do nothing to address the micro-level (instantaneous) speed changes that Ralph is talking about. 

@mijostyn Your Sota is a fine turntable. It is nowhere close to being perfect and is no more state of the art (pun) than a top level modified and updated TD124 or 301.

Leave me out of the equation-read the S'Phile review of the newly released version of the 301and then tell all of us that it is not a matter of opinion, it is a fact that the reviewer is wrong. Tell all of us that it is not a matter of opinion, it is a fact that Art Dudley was wrong. 

Last, I will bet dollars to donuts that my Reed 3P arms easily outperform whatever arm you have installed on your Sota.

@fsonicsmith 

Thank you for the compliment.

This is not a competition. You are obviously an antique collector, I am not. The OP's case is typical. 

As for arms, the best Reed offset, pivoted arm is the 2G. The 2P's bearing arrangement is IMHO inferior. The arm I use on the Cosmos is a Schroder CB and the cartridges are the MSL Signature Platinum, The Ortofon MC Diamond and the Lyre Atlas Lambda SL. 

As for whether or not the Cosmos is equaled in performance by any old turntable? The Cosmos is fully suspended, Has a 1" thick aluminum chassis, has a magnetic thrust bearing and the Eclipse drive, one of the best in the industry. The others here can make up their own minds as to whether and old idler drive table mounted on a chunk of wood, stone or whatever is likely to come close in performance. They might look sharp, but that is about it. 

The makers of the finest turntables made today shun idler drive, I wonder why. It was necessary back in the old days to change speeds because we did not have electronically controlled motors yet and nobody had subwoofers. Then the little AR XA came along and blew them all away from a performance perspective. I had a TD124II at the time and a friend's AR was much quieter. Idler drives disappeared from the market and all the radio stations dumped their old tables for the hot direct drives. You can't slip cue most belt drive tables. All those old tables were available for pennies on the dollar and the myth begins. All this is not my opinion. It is historical fact. Today there are much better ways of changing speed than a stepped capstan and a spring loaded rubber wheel. 

For the love of God, can someone else denounce the man that keeps issuing proclamations of fact like some decrepit Medieval king from his throne for the bag of hot air that he is?

He seems to know just enough to be dangerous and no more. Much of what he says about all things vinyl-related is demonstrably incorrect and yet I seem to be the only one to object. Are the rest of you afraid of him? Why?

To Ralph Karsten; this person absolutely misunderstood your point about powerful motors eliminating stylus drag-induced speed variation and yet you refrained from correcting him. Why? Because he owns two of your amps?

I suppose if I had the time and inclination to identify and list ALL of his false proclamations of fact I could, but why bother? All one needs to do is take a cursory look at his posts. Such as his recent post that all who opt to purchase low output MC cartridges are misguided and doomed to inferior S/N ratio. This in his shameless-and yet successful- effort to publicly shame MoFi into extending a free repair/extended warranty (rather than blame himself for not reading the warranty prior to purchasing).

He clearly does not have a clue as to matching cartridges with suitable phono stages nor a clue as to the importance of investing in a good phono stage to begin with. His phono stages are digital sound processors. He is a contradiction of claiming to love analogue while refusing to surrender digital manipulation.

His sound system, which he seems to think is inarguably perfect, more resembles a HT system with a turntable connected to it.

I vow to never engage with this "gentleman" in this forum again. He is a forum bully but a toothless one. And no one else here dares call him out for the self-perceived emperor with no clothes that he is. If the mods choose to exercise censorship here, so be it, but calling out a forum bully should not be grounds for such.

And to you, good Sir, the subject of this post, belt drive is not perfect. This may come to a shock to a you but it too is true. As the motor pulley turns the belt, the belt is stretching and contracting at the micro-level at all times. This is why some have tried multiple motors, pulleys, and belts and others have tried thread and floss instead which again don't solve all problems with belts. Some listeners hear the effects and deficiencies of belt drive and some don't. This is not a matter of "superior hearing" but simply a matter of sensitivity and personal taste. As with so many things in life where there are analogous arguments and yet no "absolute truth", e.g. the attributes of aluminum, carbon fiber, titanium, and steel for bicycle frames, a human being with higher levels of cognition and consciousness comes to the awareness that the scientific method only goes so far when human subjectivity is involved.  

Out.

 

To Ralph Karsten; this person absolutely misunderstood your point about powerful motors eliminating stylus drag-induced speed variation and yet you refrained from correcting him.

@fsonicsmith I missed his comment.

FWIW, We stopped making our model 208 when Technics came out with the entirely revamped SL1200. I regard it as a better machine and have one in my home system. With a different platter pad...

@mijostyn

The old idler wheel turntables are less speed stable than any high end belt drive table primarily because of the older motors.

I don’t think this statement is accurate. The synchronous motors on some of the vintage machines are excellent as long as the AC mains frequency is stable. If the machine is properly serviced out, there isn’t any stretch between the drive and the load. So they should be more speed stable (and in practice this is borne out), but a lot depends also on the platter mass. The Empire machines got their speed stability from both the motor and the platter being very effective flywheels. Only a few of the idler drive machines had platters of that kind of mass.

I think the main reason you don’t see idler drive machines in production now is the cost of making the idler and speed change mechanism (since they are not made in large quantities). They require more service to keep them running properly. Its a lot easier to engineer a belt drive with only two moving parts which is also easier to fix since most of the time its just a belt replacement, plus anyone who wishes to be a turntable manufacturer has to compete with Technics, whose direct drive system is competent, reliable, well-priced and overall excellent.

fsonic, I too am in disagreement with Mijostyn's  bald pronouncements, on some occasions, first because he is sometimes (but not all the time) wrong, and second because he fails to include three little words, after delivering a broadside, "in my opinion".  That in itself is a bit provocative. However, it is his intention to drop bombs, which is what just happened with respect to idler drive.  Just take it with a grain of salt; you are one of many audiophiles who prefer idler drive turntables, which in itself is testimony to their virtues.  He dislikes direct drive, as well. This does not deter me one iota from my chosen preference for same. In fact, he ONLY likes suspended belt drives.  I wouldn't have one in my system, if the suspension consists of springs. I would also take issue with the notion that no one ever contradicts Mijostyn. That is simply not the case. He usually takes it well.  He is actually quite knowledgeable and experienced, so it is folly to criticize him on that basis alone.

As regards idler drive motors, and particularly the Garrard motor, Mark Kelly, a definite 301 aficionado, used to point out regularly that although the motor does consume Watts, compared to other TT motors, it is in fact not that high in torque output.  Audiophiles confuse power consumption with power output. What accounts for the immediacy and dynamics of the 301 sound is I think the directness of the idler drive, the very low compliance of the drive system, rather than the essential power of the motor.

I too am in disagreement with Mijostyn's  bald pronouncements ...he fails to include three little words, after delivering a broadside, "in my opinion".  That in itself is a bit provocative. However, it is his intention to drop bombs ...

That is my impression as well. Indeed, some people enjoy dropping these rhetorical "bombs," finding some satisfaction in them. I generally avoid that kind of engagement, whether online or in person.

Thanks Lewm and Ralph. Ralph for your candor and integrity and Lewm for giving me some needed perspective and advice to settle down. 

Ralph is a prime example of what is good on this Board-sharing information and assisting others when asked. 

It is unfortunate that some take delight in playing at or being the provocateur. Others feel that this a forum for verbal combat and I am not blameless in that regard. 

For what it is worth Lewm, I don't prefer idlers. I fell into them. My TD124 was my Dad's. He bought it in a NYC audio shop the same year that I was born, 1959, while on a work related trip for Wright Patterson AFB. After deciding that several different VPI decks were not for me, I took on the project of having his mothballed and non-operational 124 first repaired and then modified and hot-rodded to the nines. The custom stainless steel bearing assembly utilizes two ball bearings rotating on top of each other and was designed and custom made (IIRC) by Greg Metz and is no longer in production. The platter is much heavier than standard and also supplied from Greg. I don't recall his source. Much of this is detailed in my profile with photos. After being amazed at the results of this project, I again "fell" into buying a near NOS early grease bearing 301 and again having it modded to the max with parts mostly sourced from Ray at Classic HiFi in the UK. However, after trying his hugely massive brass platter along the lines of the Shindo I ended up happiest with the custom copper topped alloy 301 platter sold by Steve Dobbins.

I will readily admit that the beauty of the custom plinth options that are integral to an all-out effort at making an idler perform at its best was part of my motivation and remains a large part of my pride of ownership. You won't find that kind of aesthetic with virtually any DD or belt drive deck. This of course being a matter of taste and purely subjective. 

When Brian Walsh of TTsetup.com first laid eyes on the plinth to my 301 his comment was "this belongs in a museum-I have never seen such a beautiful plinth" (yes, the "gentleman" referenced above will quip it belongs in a museum as an historical relic). .

I believe the Reed 3P's with their German made "Firewire" continuous wiring from RCA's to cartridge clips-along with the all of the other attributes of the tonearm design-contribute to a large degree to my overall happiness with the result. I would go so far as to say that is very likely that the same Reed 3P's mated to a very good belt or direct drive table would result in equally pleasurable though slightly different sound. 

And for the record (pun intended), everything I ever say in this forum and on this Board is just my humble opinion and I almost always say so. 

I just ignore him now…. i made errors of engagement along the way… 

@fsonicsmith I have my Dad’s 1961 MC240….. immeasurable joy

 

@atmasphere 

And there you have it. AC synchronous motors particularly the three phase ones are the best turntable motors because they automatically apply corrective torque. The older motors had to rely on the AC lines frequency which is held within limits but is not as stable as an electronically applied signal which can be changed to adjust speed. The old idler drives might be accurate to lines frequency for a short period. Watch one start up. There is so much initial slippage in the drive as it fights to get the platter up to speed which is why the idler wheel wears irregularly causing speed irregularity and rumble. If you use boosted subwoofers it is virtually impossible to stay ahead of it. The cost of a modern electronically controlled three phase motors is not cheap and may well cost more than an idler drive especially the older ones which when manufactured in numbers where cheap. A CD transport is more complicated and they are dirt cheap. Belt drives are certainly simpler which is perhaps the main reason they are so effective. If you have a thing against belt drive tables Direct Drive is a much better way to go from a raw performance perspective. And, no the belt on the SOTA does not slip as the Eclipse Drive has a soft start up feature. Torquey bastard too. It is hard to stop it. If a record does not seal (warped too much) I hold the rim of the record down with two fingernails at 180 degrees during startup and usually will get it to seal. Am I making the belt slip then? Good question. Next time I start it up like that I'll take the motor cover off and have a look. I have not seen any deterioration in the wow and flutter yet. I am also fortunate in that I can see the speed of the turntable down to 1/1000th of an RPM and it does not waver. 

@tomic601 

Getting cold feet? 

@fsonicsmith 

Wood bases can be a beautiful thing. Might I suggest Macassar Ebony? 

My Dad had this HUGE Rek-O-Kut  turntable with a HUGE ESL tonearm on it, very impressive. No antiskating. Some fool mounted it in a fancy custom cabinet right on the veneered plywood. Talking about feedback and footfall on top of the rumble. Fortunately, he also had an Ampex R2R. That was heaven, a lot of hiss, but heaven none the less.  My first table was a used TD 124II with an ADC Pritchard tonearm soon to be exchange for an SME. That required shoveling a lot of driveways. The TD124 as you are probably well aware had a hybrid drive. The AC synchronous motor drove the stepped pully via a short belt. I guess the thinking was to isolate the drive from motor noise? Then of course it had two platters, one on top of the other with a clutch for cueing.  I never used it.  After a few more Winters of shoveling and a little subversion I managed to procure a Revox A77 Dolby. I guess the Apples do not fall far from the tree. Not that I did not buy or play records, But I was never happy with turntables and I had a bunch of them, After the TD there was a Sony, a Micro Seiki, two LP12s, a Transcriptors , an Oracle and finally the first turntable that actually worked really well The SOTA Sapphire I bought in 1981. It worked so well I kept it for 40 years. Like most of us young lions, children put a lock on the audiophile budget. I might add that all those tables I was unhappy with were belt drives. Direct drive tables at the time were not good. They worked well but for whatever reason did not sound as good as belt drives of the day. Nobody did anything with idler drives back then except maybe a changer or two.

There is more to a car than raw performance. There are the looks, how it talks to you, how it smells and the silly little things it does like unexpectedly opening it's Frunk as if it is giving you a smile. I see no reason why a turntable can not be as such for some people. So, enjoy your turntable, put it in a nice plinth (Macassar Ebony) and be happy. It is what you like.  I would keep a stash of spare idler wheels.

Big fish get to be that way…by at the very least..not rising to every ineptly cast fly…

What is overlooked when it comes to the usage of different drive mechanisms for creating the rotation of a TT's Platter. Is that all drives are able to produce a rotation that is absolutely correct to enable recorded music to be replayed as per the requirement for a recording.

Where the differences are to be discovered is pretty much limited to three alternatives for how the Speed is controlled. There has to be an interface that connects the Drive to a surface belonging to the Platter. Along with this connection there is the Electro-Mechanical Mechanisms in use to control the Speed of the Platters Rotation.

Taking producing sonic being produced out of the equation, each drive mechanism is able to produce an accuracy in the Speed Rotation to meet the requirements of replaying recorded music. This is pretty much set in stone, or Tech savvy enthusiasts for Vinyl Replays, would be spouting there protests endlessly, as this is not seen, it can be assessed that any Drive used for a TT, produces acceptable rotation speeds for the platter.

The Tonearm (TA) > Cart' being used in conjunction with a LP are the next ancillaries required to produce the Trilogy that enables Vinyl LP Recording Replays.

It is the introduction of the TA > Cart' that creates a New Interface and one that can be assessed as a result of being able to encounter a produced sonic.

It is the outcome of assessments, especially the extreme end, where analysis of the sonic is taking place, where a sonic being produced from a System Source is exposed as being an attraction or detraction to the individual only

Hence, following analytical assessment, certain individuals end up on a quest, sometimes very costly, to discover interfaces that are much more aligned with their own unique and preferred tastes. 

In my own Case, I have used in my system over a 30 Year Period in chronological order, BD (8yrs), ID (15yrs) and DD (8yrs).

For 15yrs with a ID and for 3yrs of the DD usage I used TA's from Brands SME IV and for a period with the ID and DD I also used a Audiomods Series V Micrometer.

Today on DD only I use a different TA, it is no longer based on Geometries introduced by Rega, and has a thought for the mechanical interfaces that have shown through as extremely attractive when in use contributing to the produced sonic.

At this time and place, I have found a method to produce Vinyl Replays, that in my opinion does not surpass any other I have used, all used over the years have been totally capable of producing music that has been thoroughly enjoyable as an entertainment.

As an individual, what my quest has enabled, is that the the present situation, is where the replays that are being encountered in my System and Listening Environment, are to myself as an assessment much more aligned to my own unique preferences.

It is each to their own, I find it very difficult how anyone can suggest an individual is not contented with their Source and System.             

@mijostyn The Pabst motor used by Empire is one of the best synchronous motors I've seen for a turntable. That motor was used in one of the Rek-O-Kut turntables and its probably the only one to mess with. Rek-O-Kuts had a pretty massive platter though but can't be damped easily due to the idler drive. Most of them I've seen don't use the Pabst motor and seemed to need some time to warm up before they would play on speed. I've not sorted out why but its something to do with the motor. 

The older motors had to rely on the AC lines frequency which is held within limits but is not as stable as an electronically applied signal which can be changed to adjust speed.

As you can imagine, this really isn't true anymore- there are devices which feed a very frequency stable 60Hz output for older motors like that- people are doing that for the Empire machines. But the AC line frequency has been traditionally very stable regardless- I'm not sure on the Empire if going electronic wins anything. 

 

@atmasphere 

I do not know what my dad's old Rek-O-Kut had in it. I'm sure you can upgrade old turntables with more modern drive systems and materials. But there is no way around the noise produces by the idler drive. You can lower it for a time perhaps but it will be back with a vengeance. Granted as a subwoofer user I am more sensitive to this problem but I have never used or listen to an idler drive turntable that did not rumble. Many systems are not capable of projecting a frequency that low but you can see it in the motion of the woofer. Why were rumble filters so popular in the old days?

Any low frequency noise is poison for a system with boosted subwoofers. With my current turntable and I'm sure there are many others, I do not have to use a rumble filter. I do program an 18 Hz very steep filter to protect the subwoofers in case of a mishap.

But there is no way around the noise produces by the idler drive. You can lower it for a time perhaps but it will be back with a vengeance.

@mijostyn My phono section cuts off at 2Hz; the mechanical resonance of the tonearm/cartridge combo describes the LF bandwidth limit. I don’t see my woofers moving except for bass notes. I don’t do anything in particular to flatten my LPs.

Its not hard to keep an idler drive system working with low rumble. Once a year, make sure the platter bearing is clean and properly lubricated. Do the same for the motor and idler bearing. Clean the idler surface at the same time and you’re good to go.

An idler will get noisy because it can perish and get hard (and so go out of round) or the motor is allowed to grind against it while the platter isn’t moving. So its always a good idea to give the platter a spin before starting it.

Cheap idler drive machines often have more noise because the platter is able to resonate. A more massive platter, espicially one that has been damped, will be quieter.

One of the reasons our Atma-Sphere 208 was so quiet was because we damped the platter. Not only did that help the bass out, you could twock the platter with your index finger while a record was playing and not hear it in the speakers. One of the reasons the Technics SL1200 works so well is Technics bothered to damp the platter. Anyone with a turntable can take this as a clue.

The Empire 208 platter, which we used in the Atma-Sphere 208, was particularly well suited to a damping treatment. Idler drive machines might be tricky in that regard, but often if there is the will there is a way.

I had Nottingham Spacedeck and moved to a heavy plinth Lenco 78 with SME 3009mk2 tonearm.
Lenco won in terms of PRaT, piano and organ tone, better bass, better instrument separation, more musical. No rumble, very quiet idler drive.

Most belt drive turntables are not accurate in rhythm nuances and play separate divided not connected sounds. The general meaning of music, the essence of interpretation itself disappears. They are also sensitive to the belt condition and bearing maintenance. Rubber belt should be changed each couple of years.