Advice re upgrading a Gyrodec MkII

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browncow68
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Advice re upgrading a Gyrodec MkII

Post by browncow68 » 26 Jan 2018 20:51

Hi everyone,

First post here by a long time lurker (I was active in VinylAsylum some time ago).
I've recently been tempted to upgrade my Gyrodec MkII (black/bronze, half height housing, AC motor, aluminium bearing) with QC power supply.

My first thought was to upgrade the AC motor to DC, but that upgrade is not only expensive, but some folks here (or maybe just Werner) seem to feel it's a shame to give up on the very reliable AC Papst motor.

So then I figured maybe I should upgrade the following:
- aluminium bearing to inverted bearing
- the decoupled suspension tower upgrade
- tonearm decoupling kit

But I'm unsure if these upgrades are:
- easy to DIY?
Can the old aluminium bearing just be unscrewed out easily?
Similarly, are the old suspension turrets easily unscrewed out?
Why does the tonearm decoupling kit come with a grounding wire? Where does that go? Any drilling of the armboard required?
- worth the trouble/effort?
If the consensus here is that any of the above upgrades only offer a minimal (if any) improvement in sound, then I might just skip it.

Your collective wisdom/experience much appreciated!!
Thanks all!

ben

https://lh3.googleusercontent.com/ah1Na ... 80-h653-no

blakep
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Re: Advice re upgrading a Gyrodec MkII

Post by blakep » 28 Jan 2018 03:03

I have a very old Mk I that I've upgraded over the years. I've done platter, bearing and suspension turret upgrades over the years as well as the tonearm decoupling kit.

Improvements from the tonearm decoupling kit were there but were quite subtle IMO but it is not an expensive upgrade.

I would definitely recommend doing the bearing and suspension turrets-the sonic improvements are noticeable and the table is much, much easier to set up and dial in with the new suspension turrets. I'd also recommend replacing the steel ball in the bearing with a silicon nitride Grade 3 ball from Boca Bearings (7/32 inch is the correct size) for about $7. I've been running one for about 6 months now. Just my opinion but that will make an improvement almost as significant as the new bearing itself for next to nothing. Maybe I had a lousy steel ball?

The old bearing/turrets are very easy to remove and the new very easy to install.

I still run the AC motor (manufactured in 81 or 82 I believe on my table) and will run it into the ground. A very cheap and effective upgrade (if you can stomach another "step" in terms of playing a record) is to power the AC motor with a variable output transformer and dial voltage down to around 65 V (I'm in North America) after startup. This results in significantly lower motor vibration (it is similar in operation and one of the things that power supplies like the Linn Lingo and VPI SDS do) which in turn results in better detail retrieval and blacker backgrounds.

If my motor dies, I'll probably modify my plinth and take my chance with something like this:

https://www.ebay.com/itm/Jasmine-TM-R50 ... SwtnpaHlTG



http://img.canuckaudiomart.com/uploads/ ... /19556.jpg

browncow68
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Re: Advice re upgrading a Gyrodec MkII

Post by browncow68 » 28 Jan 2018 16:26

Many thanks Blakep.

That Jasmine standalone motor sure looks tempting, but I've just measured - it's wider than my Gyrodec's AC motor housing, so it wouldn't fit through the 'mickey mouse' ear of the sub-plinth!
No problem for your Gyro, but unless I decide to run 2 tonearms AND cut a hole at front left of my Gyro's acrylic base, it's not going to work for me!

Will probably upgrade the bearing then....or maybe call time on the AT33ANV cartridge and get one of those Hana cartridges that everyone's been raving about!!

ben

Werner
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Re: Advice re upgrading a Gyrodec MkII

Post by Werner » 28 Jan 2018 16:47

You could go for the Michell DC motor, but then to do it properly you'd have to purchase a standalone housing and have the plinth drilled. Instead I would have the Papst AC motor services (essentially cleaning and lubricating), and then as BlakeP said get the bearing and the towers. Then strip the deck and build it slowly and perfectly up again.

The ground wire for the armboard mod is there because with the mod the board standoffs are plastic, no longer metal. Thus the subchassis and bearing become isolated from the arm and its ground wire. These piece can/will charge and the violently discharge via the shortest path, the cartridge. So the wire is needed. Installing the wire is also a royal pain. So I would steer clear of it.

browncow68
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Re: Advice re upgrading a Gyrodec MkII

Post by browncow68 » 28 Jan 2018 17:05

Hi Werner!!
Good to hear from you again - I used to be active on the Vinylasylum forum!

I understand there's now a kit that can just replace the old AC Papst motor and top plate with the new DC motor and new top plate. That will however render my QC useless. Not cheap too.
(I had bought my QC brand new when it was first released, so when they switched to DC a few years later, I was mighty pissed!!)

ben

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Re: Advice re upgrading a Gyrodec MkII

Post by gwernaffield » 28 Jan 2018 17:19

hi i have used the plastic standoffs but added a second earth to the base off the deck , i now dont use the standoffs and went for a plastic ring bought off eBay for £20 , so now the arm board is bolted to the deck via the 3 screws,
also i have put some cheap upgrade ideas on art of sound, all work to one degree or another , best one was the trick with the toilet doughnut seal in the motor housing ,
as for the bearing michell now use a ceramic one in the new orbe SE R, no problems with the earthing on the deck as the earth wire is held onto the chassie vai the thumb screw that came with the deck ,
peter

browncow68
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Re: Advice re upgrading a Gyrodec MkII

Post by browncow68 » 28 Jan 2018 17:38

Blakep, you have me intrigued here...
Would you happen to know the size of the ball in the old aluminium bearing?
Maybe changing that to a ceramic ball would suffice to curb my 'upgraditis'?
It'll certainly be a cheaper option!! =P

ben
blakep wrote:I'd also recommend replacing the steel ball in the bearing with a silicon nitride Grade 3 ball from Boca Bearings (7/32 inch is the correct size) for about $7. I've been running one for about 6 months now. Just my opinion but that will make an improvement almost as significant as the new bearing itself for next to nothing. Maybe I had a lousy steel ball?

gwernaffield
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Re: Advice re upgrading a Gyrodec MkII

Post by gwernaffield » 28 Jan 2018 19:05

should be the same size, but werner would know,

7/32 is what is in the gyro and orbe,

peter

blakep
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Re: Advice re upgrading a Gyrodec MkII

Post by blakep » 28 Jan 2018 19:12

browncow68 wrote:Blakep, you have me intrigued here...
Would you happen to know the size of the ball in the old aluminium bearing?
Maybe changing that to a ceramic ball would suffice to curb my 'upgraditis'?
It'll certainly be a cheaper option!! =P

ben
blakep wrote:I'd also recommend replacing the steel ball in the bearing with a silicon nitride Grade 3 ball from Boca Bearings (7/32 inch is the correct size) for about $7. I've been running one for about 6 months now. Just my opinion but that will make an improvement almost as significant as the new bearing itself for next to nothing. Maybe I had a lousy steel ball?
Just took the ball out of my old aluminum bearing and measured it with a steel ruler-sorry I don't have calipers so cannot be entirely sure.

Ball is larger in the aluminum bearing. I am pretty sure but not entirely that it is 1/4"; to be absolutely safe (we are not talking a lot of money here), I would think that you would be sure to have it covered if you order a 1/4" and a 9/32" at the same time.

You could always cut a hole for the Jasmine motor at the front left of your Gyro and mount a phony tonearm back left (or just leave it as is back there) :lol: Would be way cheaper than going DC through Michell!

If my AC motor dies, I will probably just angle off the front corner of my plinth and be done with it :lol: I ended up modifying the plinth and the custom dustcover I had fabricated many years ago when I mounted the 2nd arm so it wouldn't be the first time my Gyro went in to the surgeon. :wink:

browncow68
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Re: Advice re upgrading a Gyrodec MkII

Post by browncow68 » 29 Jan 2018 03:08

OK, I've dismantled my Gyro again.

I can indeed unscrew the aluminum bearing, so yup, I'll go ahead to order the new inverted bearing.

But try as I might, I can't seem to unscrew the metal spindle that extends vertically upward from under the deck where the 3 feet screw into - so maybe I'll just raincheck on the suspension upgrade for now.

Regarding that 7/32 ball bearing - so many options out there....silicone nitride, delrin, teflon, PTFE...what's best?!?
I suppose it's most important to get the highest grade ball around, ie a Grade 3?

Gwernaffield - I've just read your theartofsound post - wow, you have done quite a bit of fiddling about with your Gyrodec indeed!! I'm impressed!!

Blakep - what are those 2 arms on your Gyro? A Zeta and a Jelco?

ben

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Re: Advice re upgrading a Gyrodec MkII

Post by blakep » 29 Jan 2018 03:34

Jelco 750D at the front and a Sumiko FT3 at the rear.

Do the suspension posts. You will not believe how much easier it is to set up the table properly with them. If they are tight you might have to take a pair of pliers and loosen them from above if I recall correctly.

Silicon Nitride makes the most sense to me (but everyone has an opinion) and the improvement in sound quality/reduction in surface noise etc. is apparent immediately and gets better IMO over the course of a month or two (as the older steel ball did as well).

I've used both Grade 5 and Grade 3 SN balls. For the extra buck or so, the Grade 3 is a no brainer.

browncow68
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Re: Advice re upgrading a Gyrodec MkII

Post by browncow68 » 29 Jan 2018 05:44

Success!!
No finesse here, just brute force rather gingerly with a pair of pliers!!
Inverted bearing, suspension posts and Silicon Nitride ball bearing upgrades, here I come!!
Thanks everyone!

ben
blakep wrote:Do the suspension posts. You will not believe how much easier it is to set up the table properly with them. If they are tight you might have to take a pair of pliers and loosen them from above if I recall correctly.

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Re: Advice re upgrading a Gyrodec MkII

Post by watchnerd » 04 Mar 2018 23:51

browncow68 wrote:Success!!
No finesse here, just brute force rather gingerly with a pair of pliers!!
Inverted bearing, suspension posts and Silicon Nitride ball bearing upgrades, here I come!!
Thanks everyone!

ben
blakep wrote:Do the suspension posts. You will not believe how much easier it is to set up the table properly with them. If they are tight you might have to take a pair of pliers and loosen them from above if I recall correctly.
Did you end up getting the ball bearing upgrade? If so, which one?

watchnerd
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Re: Advice re upgrading a Gyrodec MkII

Post by watchnerd » 05 Mar 2018 00:02

blakep wrote: I'd also recommend replacing the steel ball in the bearing with a silicon nitride Grade 3 ball from Boca Bearings (7/32 inch is the correct size) for about $7. I've been running one for about 6 months now. Just my opinion but that will make an improvement almost as significant as the new bearing itself for next to nothing. Maybe I had a lousy steel ball?
So I assume you're using one of these?

https://www.bocabearings.com/products/7 ... -pc)-10694

I know nothing about bearings, really, so wondering in what why grade 3 is different than grade 5?

https://www.bocabearings.com/products/7 ... 1-pc)-1929

Or the pros / cons of a ceramic bearing, grade 10?

https://www.bocabearings.com/products/7 ... 1-pc)-4198

blakep
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Re: Advice re upgrading a Gyrodec MkII

Post by blakep » 05 Mar 2018 00:50

watchnerd wrote:
blakep wrote: I'd also recommend replacing the steel ball in the bearing with a silicon nitride Grade 3 ball from Boca Bearings (7/32 inch is the correct size) for about $7. I've been running one for about 6 months now. Just my opinion but that will make an improvement almost as significant as the new bearing itself for next to nothing. Maybe I had a lousy steel ball?
So I assume you're using one of these?

https://www.bocabearings.com/products/7 ... -pc)-10694

I know nothing about bearings, really, so wondering in what why grade 3 is different than grade 5?

https://www.bocabearings.com/products/7 ... 1-pc)-1929

Or the pros / cons of a ceramic bearing, grade 10?

https://www.bocabearings.com/products/7 ... 1-pc)-4198
Yes, I'm using a Grade 3 ball from Boca. You can order one for less than $4 U.S.

Google is your friend.

https://en.wikipedia.org/wiki/Ball_(bearing)

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