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Floyddroid
12-04-2016, 21:34
As with other elderly Garrard turntables i have been experiencing speed instability. A visit from my mate Dougie turned out to be a blessing. Dougie himself is now onto his third 401 and makes gorgeous plinths for them and a trusted fettler of said devise. He suggested to me that i order a Kokomo bearing from Germany as he had fitted one to his and he loved it. Hopefully this will sort out the speed stability problem. On inspection the bearing presently in situ was bone dry which can't be helping the situation.
Dougie braved a hernia and picked up my monster 401 this evening and taken it to his gaff for surgery. I will update yawl when Gigantor comes home. For now i will dust the cobwebs from my Pioneer PL71.:scratch:

Kember
12-04-2016, 22:04
I have no experience of this upgrade (my 401 is Bastin through and through) and also have no wish to pee on your bonfire but wasn't there a bit of a hoohah a few years ago on pfm about Kokomos and what they did to the 401's spindle?

P

Floyddroid
12-04-2016, 22:17
There was indeed Peter. They have now sorted it and the bearing is it's Mk 3 guise.
I have no experience of this upgrade (my 401 is Bastin through and through) and also have no wish to pee on your bonfire but wasn't there a bit of a hoohah a few years ago on pfm about Kokomos and what they did to the 401's spindle?

P

Woodsong Audio
13-04-2016, 00:08
Please describe 'speed instability'. Are you speaking of variance during running while warm? Or the variance between the speed at cold startup, and running temps after 10 minutes or so? The Kokomo wont make a lick of difference to the variance in speed between cold startup, and when it reaches operating speed.


What I really dislike about the Kokomo, much more than the wear that it puts into the thrust end of the spindle, is that when the bearing is removed, the very slight bit of difference in concentricity at the re-install of said bearing, due to it not going backj in exactly the same, sets it up for some very rapid wear, on both the spindle and the ball of the Kokomo.

I have rebuilt many Garrards, 301 and 401. When I see a Kokomo on a deck, I remove it.


The stock Garrard bearing is a well engineered piece of machinery. It is not the best bearing, but it is well engineered as a whole.

That said, I do believe that there is a LOT of room for improvement for the 301/ 401, in a bearing.


I have heard it...

Tom-Brown
13-04-2016, 06:45
Sorry...but it would seem that a re-lube of the bearing assembly would have cured the problem. I also have heard nothing but bad things about these bearings.

Sent from my SM-T810 using Tapatalk

Floyddroid
13-04-2016, 07:38
Oh dear.

PaulStewart
13-04-2016, 08:33
Steve, the best thing to do in my opinion, is send the bearing or better still the whole deck to Garrard, i.e. Loricraft Audio for a service to new factory spec they can fit a 501/601 which has better tolerances.

Wakefield Turntables
13-04-2016, 08:44
Steve,

I talked at great length to Terry at Lorricraft and basically says the Kokomo mod in any guise is shit (sorry mate). I was originally going to book my bearing in for a full upgrade to 501 specs and was basically told that my bearing was perfectly upto standard, Terry essentially talked himself out of £500. I think that the general consensus of opiniopn is that the kokomo mods wreck your bearing, and that the 401 bearing is probably the best engineered (that's not to say that it's the best). I have spoke to and emailed various Garrard gurus (Bastin, NWA, Matt @ Audio Grail, Terry @ Lorricraft) on the subject of bearings and all essentially say that same thing in that Garrard knew best and just simply get the bearing serviced. I have a self fettled 401 bearing fitted to my 301 and I think it's better than the Bastin modified 301 bearing that I ran previously. Hope this helps.

Ali Tait
13-04-2016, 10:00
Yes, would echo the above Steve. Just dismantle and clean the bearing, and add new oil.

A.Grail
13-04-2016, 16:57
Consider the costs of manufacturing and then consider the R&D....

Garrard were well versed in ball bearings. The contemporary (and less expensive) offering of Garrard 4HFs for example feature a captive ball bearing in the base of the spindle (a la Thorens 124s') Indeed the motors of all but the very first 1000 or so Garrard 301's all feature ball bearings.

So why did Garrard go to the expense of (In the case of the 301 / early 401's) a flat self centering and self lubricated die molded piece of sintered bronze seated on a Delrin type base framed in a bronze case? ) Or in later 401's a molded domed piece of sintered bronze in a plastic base (Slightly cheaper to produce in large numbers but designed as an improvement of the unit for STEREO application)

Small ball bearings are / were very inexpensive and in plentiful supply - indeed, Garrard as stated, were well aware of their application. Garrard noted that spin down times are far from the last word in a good bearing, in fact some drag can be useful in terms of speed stability. Damping is also useful as noted by Garrard when you consider the pressures grinding away between spindle base and thrust arrangement)

The EMT 930 uses a very large ball bearing the profile of which presents to the base of the spindle very similar profile to the 'domed' shape of the 401. The Shindo bearing shares much with the EMT bearing and again presents the base of the (Much larger) spindle with a dome as opposed to a small ball bearing.

The damage over time with small ball bearings can be easily noted in the base of the spindle. We see it time and time again.

Floyddroid
14-04-2016, 21:38
Well, got me 401 home tonight with the Kokomo bearing in situ. Had a good chat with the kind gentleman who fitted it for me and passed on the comments made here. What he pointed out was that most of the points made have been addressed by Analog Tube Audio in this Mk 3 version. On removing my old bearing Dougie found that it wasn't a Garrard bearing anyway shock horror and it was pretty much Donald Ducked. Despite the informed opinions above i also trust my mate Dougie implicitly and i know he wouldn't put me onto a bum stear.
We installed the Garrard back into my system and rocked it onto 78 RPM and let it spin for a while whilst we had a cuppa and numerous Fox's chocolate cookies. Once the Firebottle 2 had warmed up we spun Bird land by Weather Report and i shit you not honcho's, what ever your view on this i am very happy with the result. Moving onto Dire Straits album the presence was stunning! Listening to the Police confirmed that my 401 had indeed been poorly. Timing was almost metronomic and had the whole system dancing. I turned up the volume a notch and even more music spilled out and i found myself listening to the whole of Goldfrapp's gorgeous Felt Mountain album. So, my view is that what ever you may have found from an engineering point of view especially compared to the Mk1 and Mk2 Kokomo bearing, the Mk3 is doing the business in my 401 and without sounding too clichéd instead of the hi-fi speak it is just playing music. That's my thoughts on the matter anyway.

RichB
14-04-2016, 21:42
If you bring nowt else I think this deck definitely needs a showing on the 21st May.

Floyddroid
14-04-2016, 21:50
It's too f.....g heavy Rich. It's the size of a garden shed.

If you bring nowt else I think this deck definitely needs a showing on the 21st May.

Wakefield Turntables
15-04-2016, 07:58
Glad to hear your upgrades hit the mark.

Kember
15-04-2016, 11:27
Glad to hear your upgrades hit the mark.

+1. Sorry to have started such a flurry but glad you're happy with the change.

Peter

Floyddroid
15-04-2016, 19:10
+1. Sorry to have started such a flurry but glad you're happy with the change.

Peter

No worries. All useful input.

Andy831
16-04-2016, 08:50
Steve

Strip the bearing again in a few months (say no more than 6) just to check that premature wear is not occurring to the spindle just to be on the safe side.:)

YNWaN
16-04-2016, 09:13
Hmm... as my interest is peaked I have just looked on the Analog Tube Audio website and the KoKomo mod seems to consist of just the bearing thrust pad (am I missing something here?). In the product description the following is written:


The construction is changed to a hydraulic design, the means the spindle axis runs on a oil film and has no mechanical contact to the thrust plate.

Now I realise (having read the rest of the blurb on the page) that English translation is an issue here but you can't convert this type of bearing to a 'hydraulic design' just be changing the thrust pad. In fact you can't inherently alter the manner of bearing operation in any way just by changing the thrust pad!

----------
On further examination it seems the KoKomo is a silicone nitride ball set into a bronze end cap. If this is the case then the SN ball will be significantly harder than the bearing shaft and is bound to drill its way in to the tip of the shaft over time (this much is basic engineering).

Wakefield Turntables
16-04-2016, 09:15
Steve

Strip the bearing again in a few months (say no more than 6) just to check that premature wear is not occurring to the spindle just to be on the safe side.:)

This was my orig al worry.

Ali Tait
16-04-2016, 09:57
Hmm... as my interest is peaked I have just looked on the Analog Tube Audio website and the KoKomo mod seems to consist of just the bearing thrust pad (am I missing something here?). In the product description the following is written:



Now I realise (having read the rest of the blurb on the page) that English translation is an issue here but you can't convert this type of bearing to a 'hydraulic design' just be changing the thrust pad. In fact you can't inherently alter the manner of bearing operation in any way just by changing the thrust pad!

----------
On further examination it seems the KoKomo is a silicone nitride ball set into a bronze end cap. If this is the case then the SN ball will be significantly harder than the bearing shaft and is bound to drill its way in to the tip of the shaft over time (this much is basic engineering).

That was also my understanding.

YNWaN
17-04-2016, 08:27
Thinking about it I was briefly a member of a Lenco forum (I think it was) and I seem to recall a discussion of a bearing mod that used a ceramic or silicone nitride ball as the thrust pad - I wonder if it was this one. Anyway, the differing hardness issue was raised then and, as I recall, the manufacturer claimed that the specific ball used had been carefully chosen so that its hardness matched that of the bearing shaft. Now I'm not an expert on Garrard's but I would be very surprised if the bearing shaft is not made of tool steel. Whilst tool steel is very hard indeed, and an excellent choice, silicone nitride is very much harder and I'm not aware of any of these sintered ceramic materials that are as soft as tool steel. Rega will shortly be releasing their 'statement' turntable, the 'Naiad', and this uses a ceramic bearing (not as hard as silicone nitride), they have chosen to make both parts of the bearing from the same ceramic material. Those of you who are keen cyclists (not I as my gut will attest) will be aware of the range of wheel bearings available, steel, part ceramic and full ceramic ball races; the part ceramic that use ceramic balls in steel races are notorious for quick wear and noise.

Wakefield Turntables
17-04-2016, 08:47
You can have a chat with Terry @ Lorricraft he still knows one or two of the people who use to make the bearings and why they choose the materials they did.

YNWaN
17-04-2016, 10:51
I happen to have a 301 here now and that certainly uses a tool steel, or high- speed steel, main bearing shaft.

Wakefield Turntables
17-04-2016, 13:50
I happen to have a 301 here now and that certainly uses a tool steel, or high- speed steel, main bearing shaft.

New project? Sorry to thread drift.

Wakefield Turntables
17-04-2016, 17:46
Sort of, yes.....

Good luck!

337alant
19-08-2016, 18:23
Steve
I did the Kokomo mod on my 401 about 4 years ago and also found it had a better balance to the sound, whenever you have heard my Garrard at the Nebos it was with the Kokomo bearing
The 401 is sometimes criticized as having a veiled or rolled of treble but tremendous bass energy and with the standard bearing I would agree but its still a fantastic turntable.
The Kokomo on my turntable was indeed a silicon nitride ball and new end cap replacement for the the old thrust plate and IMO it tightens up the sound, the bass energy is still there but it doesent sound as bloated, there is better 3D image and fine detail IMO
I had a look at my bearing after 2 years and there is a tiny round shiny area on the middle of the end of the bearing shaft which to me doesn’t have any depth to it so I’m not concerned.

Speed instability can also be caused by a dry motor bearings worn springs, perrished gromets, a hardened idler drive roller, the inside of the platter should be polished as smooth as possible , the magnetic break being pooly positioned, and poor electrical contact on the crappy push to make mains switch on the 401.

https://c5.staticflickr.com/8/7324/9302181084_1dba8cc230_b.jpg (https://flic.kr/p/fb17mu)Garrard (https://flic.kr/p/fb17mu) by Alan Towell (https://www.flickr.com/photos/69508926@N05/), on Flickr
Alan

337alant
20-08-2016, 05:08
Some more info, looks like the Mk2 & 3 uses a shim or cap betweeen the ball and the bottom of to bearing spindle so there can be no wear on the original spindle.
Think I'll upgrade mine to the mk 3

A Review from TNT Mk 1
http://www.tnt-audio.com/sorgenti/kokomo_e.html

Mk2 review

http://www.tnt-audio.com/sorgenti/kokomo2_e.html

Mk3
http://www.analogtubeaudio.de/en/kokomo-kit-mk3-garrard-301-401/

Alan