DIY TURNTABLE : ideas and comments.

[Hiten]

Friends,
as said in other thread I have a Jelco Tonearm. So started thinking about building a turntable around it. Will I make it or not is difficult to tell due to work pressure and few commitments. But posting some ideas which may help others or atleast spark their imagination. Feel free to comment or criticize if I go overboard or idea is just plain silly.
Ideally I was wondering if solid one block of metal would be a good base to setup a turntable on as it being heavy and least resonant. But it is not practical. So here goes...

Tonearm Base : Tonearm base would be solid metal cylinder with cavity to fix tonearms. This will reside in sidepanel like Thorens TD124. the panel will have phonostage etc. electronics inside.

Platter Shaft : Salvaged from good vintage turntable as I guess this being most important part engineering would be difficult.

Motor Base : Totally isolated base OR Motor will be well damped and hidden below the platter and will serve as a third feet (2 feet being in front). Not sure about this.

Platter : Ideally would like something as shown in following pic. This platter (Patent pending :lol only touches record label part and circumference of the record, so less area contact will result in to less resonance and vibration energy transferred to the cartridge. This will also insure that non playing music part of the record will not touch the platter. Will need center weight to press record on the platter.
cross section of the platter :

Platter at the top edge is slanted inside to make it stable. Record lable part and circumference of the platter will have some kind of rubber mat to dampen it further.

Motor : Good quality DC motor (Just to have different speeds) with speed regulation circuits.

Plinth : Hollow Wood plinth with compartments filled with fine sand or other damping material as I have read at some place that sand absorbs vibration and resonance and transfers in to heat.

More as I think.

Regards

 

[sachu888]

You can use a floppy drive for TT motor.It has a high quality bearing and can be powered by batteries.See this Audio Origami - ReWires
PDF version http://www.blueculture.com/floppyproject3.pdf
I also want to DIY a TT.I have even sourced a Floppy Drive and hard drive for DIY Tonearm.
Turntable Forum • View topic - Low Cost DIY Tonearm

Regards,
Sachin

 

[sbg]

Friends,

Platter : Ideally would like something as shown in following pic. This platter (Patent pending :lol only touches record label part and circumference of the record, so less area contact will result in to less resonance and vibration energy transferred to the cartridge. This will also insure that non playing music part of the record will not touch the platter. Will need center weight to press record on the platter.
cross section of the platter :

Platter at the top edge is slanted inside to make it stable. Record lable part and circumference of the platter will have some kind of rubber mat to dampen it further.

Regards

Me thinking "LOUD"...hyeah:
I was under the assumption that using heavier platter would mitigate this issue. "The" platter (Patent pendinghyeah may act like a durm/tabla where in the record itself will excite for more sound / resonance.

...I may be wrong.

 

[Hiten]

@Sachin : Floppy Drive motor is good idea, but I dont know electronics to control it. Actually AC motor is very sturdy and have stable speed as it is AC frequency dependent but to have different speed will require pulley which will need mechanism to shift belt so I prefer DC motor. Lets see.
@sbg : As said earlier I have used center weight . Also these are vogue ideas one can always add weight by making the plate thicker and platter wall can also be made thicker. Me thinks will also increase inertia so DD motor can also be used. good suggestion.

 

[arj]

Hiten, by platter shaft did you mean Bearing ? you will need to get the bearing and platter spot on..motor has quite a few options if you got for a good DC motor which you can give a speed control.

What is the drive system you are planning ? direct/idler/belt

 

[arj]

Platter : Ideally would like something as shown in following pic. This platter (Patent pending :lol only touches record label part and circumference of the record, so less area contact will result in to less resonance and vibration energy transferred to the cartridge. This will also insure that non playing music part of the record will not touch the platter. Will need center weight to press record on the platter.
cross section of the platter :

Platter at the top edge is slanted inside to make it stable. Record lable part and circumference of the platter will have some kind of rubber mat to dampen it further.

not quite the expert, but since the LP is not that rigid..i think if you do have a gap between the Record and the platter, it will only cause tracking problems for the cartridge (like a trampolin !) should you not be planning a Platter mat throughout ?

 

[Hiten]

@ arj : Yes I meant turntable bearing and centre spindle. Yes would be tough to get that right, but if taken from good old turntable will save some precision DIY and one will only have to be terribly precise when mounting. But me thinks can be done. Regarding drive system, wanted an idler drive but for speed change will require some mechanism to shift pulley. So belt or DD will do. As making things simpler will be a benefit.

Yes you are right about LPs not being rigid. Some Indian vinyls are paper thin. But your comment gave me an idea. One can fill the space with mat as shown below. The idea is to have least contact. Silly me. I can use turntable mat to have least contact with record too. Following pic. is of half side of the cross section. (proportions are little exaggerated to give an idea).

OR as seen on some High End turntable one can use acrylic platter with felt mat which have their own advantages. But then will have to skip the DD motor option.
Regards

 

[sachu888]

Turntable main bearing and spindle

@ arj : Yes I meant turntable bearing and centre spindle. Yes would be tough to get that right, but if taken from good old turntable will save some precision DIY and one will only have to be terribly precise when mounting. But me thinks can be done. Regarding drive system, wanted an idler drive but for speed change will require some mechanism to shift pulley. So belt or DD will do. As making things simpler will be a benefit.

Yes you are right about LPs not being rigid. Some Indian vinyls are paper thin. But your comment gave me an idea. One can fill the space with mat as shown below. The idea is to have least contact. Silly me. I can use turntable mat to have least contact with record too. Following pic. is of half side of the cross section. (proportions are little exaggerated to give an idea).

OR as seen on some High End turntable one can use acrylic platter with felt mat which have their own advantages. But then will have to skip the DD motor option.
Regards

Hi Hiten,
See here for main bearing The Altmann DIY Turntable

Regards,
Sachin

 

[arj]

@ arj : Yes I meant turntable bearing and centre spindle. Yes would be tough to get that right, but if taken from good old turntable will save some precision DIY and one will only have to be terribly precise when mounting. But me thinks can be done. Regarding drive system, wanted an idler drive but for speed change will require some mechanism to shift pulley. So belt or DD will do. As making things simpler will be a benefit.

Yes you are right about LPs not being rigid. Some Indian vinyls are paper thin. But your comment gave me an idea. One can fill the space with mat as shown below. The idea is to have least contact. Silly me. I can use turntable mat to have least contact with record too. Following pic. is of half side of the cross section. (proportions are little exaggerated to give an idea).

OR as seen on some High End turntable one can use acrylic platter with felt mat which have their own advantages. But then will have to skip the DD motor option.
Regards

The acrylic platter is a great idea. only problem is they are much more prone to Static. but an antistatic mat should be good.

you should not have any problem with speed change for an Idler as well...in the end it is about controlling the speed of the motor electrically

 

[navin advani]

"The" platter (Patent pendinghyeah may act like a durm/tabla where in the record itself will excite for more sound / resonance.
...I may be wrong.

You are right. I tried this using a Garrad table given to me by my aunt in the early 80s. The best option is to have a well damped mat below the platter.

Ideally I was wondering if solid one block of metal would be a good base to setup a turntable on as it being heavy and least resonant.

Motor Base : Totally isolated base OR Motor will be well damped and hidden below the platter and will serve as a third feet (2 feet being in front). Not sure about this.

Motor : Good quality DC motor (Just to have different speeds) with speed regulation circuits.

Plinth : Hollow Wood plinth with compartments filled with fine sand or other damping material as I have read at some place that sand absorbs vibration and resonance and transfers in to heat.

Just some ideas.

All Metals ring. Think Granite for the base.

Isolate Motor from everything. Let the Base have it's own support.

some links.
Turntable Basics Advice Page
REFERENCE COMPONENTS-TURNTABLES
HIGH-END PALACE - Analogue Turntables
AudioFederation - Catalog of High-End Audio Turntables
Thorens TD 124 / TD124 Mk2 and TD-224 Legendary Vintage Turntables

OR as seen on some High End turntable one can use acrylic platter with felt mat which have their own advantages. But then will have to skip the DD motor option.
Regards

I thought the felt mat was there to prevent static from the acrylic transferring itself to the record.

 

[jls001]

Re: Turntable main bearing and spindle

Hi Hiten,
See here for main bearing The Altmann DIY Turntable

This Altmann guy is brilliant, and has good sense of humour to boot.

@Hiten: start hunting for Royal Enfield intake valve and guide If you already ride one, then you can always cannibalise! Nothing comes in the way of a good audio quest:lol:

But I am doubtful of the way he has fixed the valve to the platter with what looks like 8 pins. There ought to be a more permanent way of fixing it.

Personally I think a solid top platter will make more sense than something that is hollowed out. Also, it will be much easier to fabricate/machine/cast. Acrylic should be easier to source and work with.

Metal base may not be a good idea as it will ring. A composite of aluminium, acrylic, baltic birch, MDF, etc layers glued together seems to be the flavour these days in high-end TTs (e.g this, or this.

 

[Hiten]

@arj : I wanted the idler drive and yes speed will not be the issue but since it will require the mechanism to move the wheel on pulley to select the speed I doubt it. Didn't know Acrylic platter generates static. Thanks.
@ Navin : Some nice links there. I like Technics SP-10 Design in High End Palace Link. Simple low profile, no bells and whistles. Isolating the motor is first priority.
@joshua : I don't have any vehicle as my office is near my home. I think as said earlier salvaging bearing (And now thinking of platter too) from High quality turntable. Thanks to clarify on Metal base thing. I too had my doubts. But as you said sandwich of different layer will not resonate or ring.
In over enthusiasm I almost forgot. Need to have 78rpm speed also (Have couple of them, and have different sound from vinyls). Lets see will have to work on that too.
Regards

 

[stevieboy]

Reso-Mat - Trans-Fi Audio

If you want to minimise the area the LP touches the platter, you can DIY something like the above As for the platter like Joshua I think filled and solid might be better too.

Seems like a mighty project! Will be following this to see how it goes! All the best Hiten!

regards

 

[Hiten]

Reso-Mat - Trans-Fi Audio

If you want to minimise the area the LP touches the platter, you can DIY something like the above As for the platter like Joshua I think filled and solid might be better too.

Seems like a mighty project! Will be following this to see how it goes! All the best Hiten!

regards

Thanks for the link Stevie. That links tells me atleast I am thinking on the right path and not going overboard .
Yes only crazy enough would try to build a TT around a tonearm :lol: have to get rid of laziness and start something soon.
Regards

 

[omishra]

Friend, don't bother about electronics. You decide on the motor and let us know details of same. I can design some speed controls to it. There could be standalone speed control or speed control locked with some feedback/error correction. Decide where you want to go.

Hmmm... But counting 33rpm and 45rpm need to be done separately.

 

[Hiten]

Friend, don't bother about electronics. You decide on the motor and let us know details of same. I can design some speed controls to it. There could be standalone speed control or speed control locked with some feedback/error correction. Decide where you want to go.

Hmmm... But counting 33rpm and 45rpm need to be done separately.

wow! the person I was looking for. Thanks bro. Let me gather things. Will post soon.
Thanks again.
Regards

 

[navin advani]

@ Navin : Some nice links there. I like Technics SP-10 Design in High End Palace Link. Simple low profile, no bells and whistles. Isolating the motor is first priority.

best way to isloate motor is belt drive but you are looking at a direct drive na?

Hmmm... But counting 33rpm and 45rpm need to be done separately.

How about the old fashioned strobe like on the original SL1200?

 

[bhaskarcan]

Re: Turntable main bearing and spindle

This Altmann guy is brilliant, and has good sense of humour to boot.

@Hiten: start hunting for Royal Enfield intake valve and guide If you already ride one, then you can always cannibalise!

IMHO intake valve & valve guide from any heavier bikes(bcos of their bigger size) can be used for this purpose.

:clapping::clapping:Very good initiative Hiten:clapping::clapping:

This thread going to be a hit :yahoo:

 

[arj]

One way is to buy an Old lenco off fleabay..(i got mine for 17K landed from UK much cheaper than its sold here) ! use the standard Idler wheel/motor , bearing and platter as a start and keep innnovating piece by piece !
if you can play around with the position of the Motor you can make it like Altmans Rim drive as well.

 

[sachu888]

I like this design
DIY MICRO SEIKI RX 5000 TURNTABLE - diyAudio

Regards,
Sachin