Anyone "Handy" interested in a DIY Turntable Project?

Well lets say it was a major upgrade from my Bush stacking record player (also a Garrard - but possibly a a bit better built ). It was a fine bit of kit for an 11 year old. I upgraded it two years later when my Dad gave me his old Trio 1033/VMS20E and I sold the Garrard to my mate Mikey for a fiver (thus making a £1 profit as I'd bought it off a mate of my Dad's for £4).

The platter was tinny, the arm was flimsy, the plinth was tacky and the idler wheel had a flat which gave every record a DSOTM style heart beat and DSOTM a Time Lord heartbeat. I thought it was cool.

 

Hi Tony
Any news on motor pods etc? I will try to send you some drawings this week, for you to look over and confirm dimensions.
can you let me have an address ?
Is the bearing fitted to a commercial design or is it to be made to your spec.
Also wondering Tony why you are going the diy route when you have access to so many decks, is there nothing out there to float your boat ? Or do you perhaps, feel as I, that a lot of equipment is over priced ? I would be very interested in your views.
regards

 

Hi Granville,

I'll pm you the postal address.

Should have more news re the motor pod and bearing Monday or Tuesday.

The bearing is a commercial design yes - basically the running gear off of a Pro-Ject RPM9. I wouldn't go to the expense of having my own fabricated. Having had a good poke around with one I was very impressed with the quality of the parts and having ready access to the spare parts bin got my mind ticking over.

Why is a good question. It isn't so much that the commercial designs don't float my boat - more that those I have access to don't meet my particular (and maybe unusual) requirements.

I really do need a flexible design which will easily accept two arms, and easily swap arms of differing geometries because I need to be able to try out and demonstrate a lot of different cartridge and arm combinations. I've yet to come across a commercial design which meets that particular requirement which I find aesthetically pleasing as well - especially at an affordable price - remember even when you sell the things, you've still got to buy them .

The NAS I have does the job admirably from a practical point of view and sonically it does a great job but aesthetically I personally find it a bit challenging - sounds a bit shallow perhaps, but aesthetics is one of the boxes I would rather have ticked.

That and the fact that turntable design is something which has fascinated me for years. Electronics has never been a big interest - I've owned all of 3 amps and 2 CDPs in the last 20 years and apart from one time have only ever upgraded because kit has failed.

Mechanical engineering however has been an interest since I was a lad and got my first meccano set. I still find it almost miraculous that vinyl and turntables actually work, let alone as beautifully as they do (telescopes, binoculars, motors, steam engines, bicycles, clocks and watches etc. all have an oddly hypnotic effect on me - odd I know).

I figured what better way to find out about the ins and outs of DIYing a TT than to actually help design one. Having had a large number of new and second hand TTs through my hands and in many cases in bits (the second hand ones I'll hasten to add ), over the past year or so has certainly given me a few insights into the various approaches and materials used and has heightened my curiosity as to how well one could build a DIY job.

Some equipment is overpriced I think - moreso when you get into the higher reaches. I don't mean that the prices don't reflect the production costs, but that the production costs for such small runs don't necessarily justify the small improvements in sound quality. On the TT side I also think that some of the very expensive designs are far more complex than the job requires. Precision engineering is a requirement for quality vinyl replay and precision engineering isn't cheap - those are givens. BUT overcomplex designs add to that expense considerably and don't necessarily make major sound quality improvements - I don't know if that's true but that's the theory I'd sort of like to test. My gut feeling is to make it simple and make it right.

We may succeed or we may make an heroic failure. One would hope that lessons learned on my TT build will be lessons applied on yours and that anyone else inspired to have a go will learn from them too. I think it will be tremendously satisfying to drop the needle on a TT that I've made a major contribution to and which hopefully will sound good too (even if the running gear was off the shelf) ... but hey, I've yet to come across a DIY speaker or amp builder who built there own drive units or valves

Hope that makes sense.

 

PS. I think I think about turntables more than is perhaps healthy. This much I confess. :JPS:

 

Hi Tony
Thanks I received your message and will send over the plots as soon as.
I can fully understand your love of things mechanical, microscopes are a particular interest of mine, and if I had sufficient funds and space I would have collected many by now, as it is I only have four. I also have to admit to a deep affection for stationary engines, you know, the strange lumps of iron with one cylinder and a huge flywheel. Standing and watching them run with that 'PHUT' every 20 seconds is very hypnotic. I would very much like to have one at home in the garden, up to now however I have resisted the urge. In truth it's probably the wife who curbs my strange habits more than anything else. If I came home with one, I would end up living with it in the garden.

I agree with your comments re building something yourself, that's partly why I built my own speakers and amp, that and the fact I didn't have the money available to purchase a commercially built design of the quality I wanted. It does make using them all the more enjoyable though.
I would hope we could arrive at a simple design, aesthetically pleasing to you and with very high reproduction quality, that fulfils all of your requirements.

I have been thinking about the arm boards and I would suggest that we settle on one particular arm to start with, your choice. That we then make a number of arm boards to suit, in a range of materials to test suitability , I don't know but would imagine it's possible that different arms would suit different materials for the arm board ?

What do you think of the Tabriz ? I purchased one some time ago on e-bay for another project
I was thinking about making. I also purchased a 'The Source' turntable, I had little knowledge about it at the time, but was told that it was similar quality and design to the LP12. I will admit I was shocked by the general build quality and design and decided not to proceed at the time.
Do you think the arm is of sufficient quality to bother with ? Or should I put in back on e-bay ?
I also have a brand new Shure V15XMR. It has had good reviews but I don't always believe what I read. In your opinion is it any good ? your views would be much appreciated.
regards

 

Hi Granville,

I was PMing you as you were responding here .

You have a PM with pictures of the bearing and measurements. which will help. No need to bore everyone with the details here, but a quick pic of the bearing and platter together. I took it so as to better imagine how it might attache to the plinth:

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Remember that brass bearing housing is integral with the platter, so it rotates with the platter, so the hole in the plinth needs to be a bit wider to provide clearance.

Arms for testing? Well if you have a Roksan Tabriz, then we are in luck. I have a Roksan Nima and a Rega RB250 we can use. All have the same spindle to pivot distance and the same diameter arm base (i know it to be the case for my two, and that's what the spec sheet for the Tabriz says). In other words one board pattern will do for all three arms. That would give us one unipivot and two gimballed arms from two different manufacturers to try out.

The Tabriz is by all accounts a good arm, though I haven't tried one - I wouldn't ebay it yet. From my own personal experience the V15VxMR is an excellent cartridge. I have a few other carts we could throw into the mix as well.

 

Have you chaps spotted this site for complete and partial DIY turntable builders?
Bits of it may be of interest.

http://www.teresaudio.com/index.html

 

I've come across it before yes. Some very nice things here - though I guess the looks are going to be a matter of taste

The bearings look very tasty (1" spindle :MILD: ) and that VTA adjuster looks very interesting - on the fly VTA adjustment even with the RB250 - not cheap though.

 

Motor Pod

Hi Granville,

Some piccies - measurement in PM.

The stand for the pod. The pod sits on this. Its pretty heavy and has three little squishy feet:

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The motor pod itself with the stand separately:

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and together:

​

Tony

 

Hi Tony
I haven't died ! just been very busy with 2 dead PC's and a nearly dead 48" plotter. I will be sending you something this week.
regards.

 

No worries. Been a bit hectic here too. I have the parts now anyway (or at least one set of them).

Funny thing is I was talking to the Henley rep about this (he's quite interested in the whole exercise from a purely personal, fascination with TTs point of view) and he told me that there had been an experimental Pro-Ject RPM12, which was a twin arm deck ... problem was that aesthetically it absolutely minged

 

Hi Tony
Can you let me have the dimensions of the arms you want to use, base of arm pillar to centre of arm etc. even better if you have any working schematics.
Does part of the bearing housing pass through the platter and form the record spindle, or is there another part set in the top ?
what is the exact dia of the platter ?
regards

 

Hi Granville,

I'll measure it tomorrow, when I get a chance. The bearing housing, platter and the spindle the record hole goes on are effectively one piece. On the pic above, you can see the bronze bearing housing extending down out of the platter - in fact I think you see it better on one of the pics I PMed you but here is is again:

​

That's the platter upside down.

Arms - spindle to pivot (ie. the centre of the hole that needs to be cut for the arm) is 222mm for the Rega arm and both of the Roksan Arms we have available, and the hole needs a diameter of 22mm.

Other arms I would maybe like to consider vary in spindle to pivot distance from 210mm to 242mm, so the hole in the plinth underneath the arm board needs to be long enough to cope with these and also wide enough to accomodate the fixing nuts that fix the arm to the armboard.

Hope that makes sense. Good evening to you now. Its time nearly for a sit down and a relax. I'll be back sometime tomorrow with some measurements.

Cheers

Tony

 

More questions

Hi Tony
Some more possibly stupid questions for you to answer.

Are you using any type of mat between platter and record ?

I have drawn up the deck to check out the thickness of the plinth, against the motor, and we could sink the platter up to just below the ceramic ball, we can then run the belt at the balance point of the platter. However the final design will require you to decide on your feet ! otherwise we will have to pack up the deck
or the motor depending on their thickness.

What do you think about making the whole of the back part of the deck ( devided into two halves) as the arm board rather than having another piece set into it. This would give a superior fixing for the arm and also allow you to change arms with greater ease.
Each arm having a bespoke armboard built for it.

I have drawn it up like this and will send you the plots in the post on Wednesday.


regards

 

Not stupid, no. But the answer is no. Records go directly onto the acrylic platter.

Granville,

Send me the plots - if its not going to work, I'll soon know, I think Just got in from a long evening of chatting to a man about record decks, so a bit too tired to even think right now.

Time for a beer and then :SLEEP:

I'll post in the morning when I can say something sensible.

PS. I measured the platter (as best I could - its not easy to get a to the nth degree accurate measurement as on one side there is a spindle sticking out and on the other the bearing but it looks to be somewhere between 296mm and 298mm in diameter.

 

Hi Granville,

Back in the land of the living now

This might take a little testing. As far as I'm aware on the deck we've pinched the bits from the belt when on the 33 pulley runs a few mils below the balance point and at 45 a few mils below that, but I don't know how critical it is tbh.

If we buried it a fair way, I suspect we would definitely have to think about using a Speedbox which is not necessarily a bad thing. The Speedbox is a regenerating power supply that allows push button speed change with the belt running on the 33 pulley. It goes to 45 by upping the regenerated "mains" frequency to 67.5 Hz, making the AC motor run faster. It would mean we wouldn't need to worry about ever running the belt on the 45 pulley even if we wanted to play 45s. Auntie couldn't live without 45s.

I'm not sure (I'll have to wait til I see the plots) but I think this is sort of what I had in mind

Cheers

Tony

 

Tony
Plots in post today

 

Excellent, cheers.

Edit: Plots received this am. Thanks. Will look at later

 

Hi there,

Very interesting TT design banter going on here. I'm starting my own scratch build very soon (I'm a mechanical engineer, so I should find it quite easy), based on an LP12 motor/DIY Geddon psu, with a 25mm acrylic platter and the motor mounted beneath this in an isolated pod.

One question, though it may sound stupid as I've not read all the posts fully in this thread- Does your platter have a recess for the record label? I fear that if not you may run into some nasty problems!

As for mine, I've got to save some pennies and buy a load of bits from here and there.

 

FIrstly apologies to Granville for not spending some time looking at the plots ... I will I promise

Yes it has a recess and also comes with a heavyish (over a pound anyway) record puck that optionally sits over the record on the spindle.

Are you going for a rim drive or subplatter?