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#1 DIY Linear Tonearm

Posted: Thu Oct 17, 2019 9:15 pm
by Ray P
I posted a link to this DIY Audio thread in 'Nothing in Particular' - maybe not the best place for it.

Just wondering if it was of interest to any of you who still do vinyl. If I still had some I would give building one a go.

https://www.diyaudio.com/forums/analogu ... nearm.html

Maybe I'll have to look out for a turntable just so I can.

#2 Re: DIY Linear Tonearm

Posted: Fri Oct 18, 2019 10:54 am
by izzy wizzy
It's a massive thread. I've read the lot on and off which took forever. Very interesting in how it develops over time.

I always wonder where people's references are in these types of things. Gee, hope that doesn't sound snobby but one person's terrific is not so much for someone else. In this thread there are so many positive contributers, it looks like a good basis for a design.

Cheers,
Stephen

#3 Re: DIY Linear Tonearm

Posted: Fri Oct 18, 2019 7:32 pm
by Ray P
I can't claim to have read every bit but reached a similar conclusion; at first I was concerned that it might have jut been one over-enthusiastic builder but the level of constructive participaton dispelled that and there are some great novel ideas in there. Part of me wants to build one but I wouldn't be able to make use of it.

#4 Re: DIY Linear Tonearm

Posted: Fri Nov 08, 2019 8:07 pm
by Ray P
I still find this fascinating as a possible project, even though I doubt if I have more than half a dozen LPs in the house. An even more fundamental problem is not having a single turntable in the house!

To that end I've been digging around a little and found this box of tricks and wondered if it might be interesting to put a turntable together too. Anyone any experience or thoughts?

https://www.ebay.co.uk/itm/The-Phainn-D ... 1438.l2649

#5 Re: DIY Linear Tonearm

Posted: Fri Nov 08, 2019 11:56 pm
by Greg
Can’t see the point, Ray. You spend £200 quid on a drive unit, not knowing how good it really is and still have to fork out for what will be the expensive stuff such as platter and plinth and cover. In my view better option is go for a well performing tried and tested TT and build around it. I have settled, probably forever with Denon DP-80. However, today I visited the guy who bought my 401 and helped him set up the geometry. Have to, say, I could happily have settled here. Sometimes there is no need to move on. In your case, it would be madness to go wild with purchase if you don’t have a library. I would go for an affordable direct drive or idler drive and be done with it.

The arm is a different matter and if you want to go diy, good for you. Remember there are good arms out there that don’t cost an arm and a leg and generally, set up is the key to good sound. You also need a cartridge and a phono stage. It’s starting to look expensive. Unless you want to do it for the hobby value, I’d knock it on the head and continue perfecting your streaming system.

#6 Re: DIY Linear Tonearm

Posted: Sat Nov 09, 2019 7:59 am
by Ray P
Well, this is a hobby Greg and my interest is in buiding a linear arm - buying a commercial turntable and conventional arm holds no interest for me, been there, done that!

Even a reasonable DD turntable is going to cost me more than the £200 the kit would cost me; BTW, the kit includes a platter (there's a cheaper kit sans platter if one was inclined towards, say, an acrylic platter, whuch are available for about £100). I've found some references to the DD kit being used in build projects and it seems to work OK so might be a reasonable basis for a motor unit. Here's an example;

https://ashleycox.co.uk/projects/direct ... turntable/

A potential fly in the ointment regarding the kit is that it has a tapered spindle on which the platter sits so any platter, other than the one they supply, might need some precision machining - not sure how doable that is.

I don't plan to expend an extravagant number of cider coupons, otherwise I might buy one of these;

https://www.tnt-audio.com/sorgenti/langer_7_e.html

We'll see.

#7 Re: DIY Linear Tonearm

Posted: Sat Nov 09, 2019 9:28 am
by shane
To my eye, this is all about the electronics. The motor looks pretty puny, and although you can’t see it, I doubt that the bearing is up to much.

In your position, I’d go for something like this:

https://rover.ebay.com/rover/0/0/0?mpre ... 3787064970

These decks have really horrible plinths and arms, but the motor unit is solidly made, and cries out to be built into something solid and beautiful.

I’ve have a similar project on a back-burner for some time: http://www.audio-talk.co.uk/phpBB3/viewtopic.php?t=6889

I’ll try to sort out the broken picture links later, but meanwhile, compare this Vestax motor to the one your advert: https://rover.ebay.com/rover/0/0/0?mpre ... 2692736124

#8 Re: DIY Linear Tonearm

Posted: Sat Nov 09, 2019 11:08 am
by Ray P
Thanks Shane, that's a really useful steer. I will have a look at some DJ turntables.

#9 Re: DIY Linear Tonearm

Posted: Sat Nov 09, 2019 1:05 pm
by shane
Going back to your comment about tapered spindles, the taper on the Vestax motor is formed by a brass sleeve pressed onto the spindle. Removing that leaves the spindle projecting from a “sub-platter” about 30mm diameter which has three tapped M4 (I think) holes for attaching the platter. That enabled me to drop a spare sub-platter from a Heybrook TT2 straight onto the motor and bolt it down.
I then found that the motor had so much torque that the TT2 sub-platter would spin inside the main platter on start-up, so I had to drill and tap them to fit a couple of retaining bolts.

#10 Re: DIY Linear Tonearm

Posted: Sat Nov 09, 2019 5:21 pm
by Ray P
Useful to know, thanks again Shane. I'll be interested in the images of your project if you can resolve the broken links.

Doing a bit of reading, some of the Stanton DJ decks are talked about as having good torque, which I assume implies a good motor, so a used one of them looks like a possibility.

I was thinking of an acrylic platter - I know you can buy them as upgrades for Project turntables at a reasonable price - but I guess I would need to get hold of a motor unit first to check compatibility.

#11 Re: DIY Linear Tonearm

Posted: Sat Nov 09, 2019 6:47 pm
by IslandPink
Acrylic is a good material , go for that if you can get it at a reasonable cost.
On the motor, just think about what you need from this. It needs to be smooth for HiFi, low-cogging, it's not just about torque.

ps. if you want any bits from an old air-bearing arm I used, early version of Vic's trans-fi arms, you can have those for nothing. There's a pump too.

I do think direct-drive + air-bearing linear tracked would be great, but there's plenty of work to do- which may suit you :)

#12 Re: DIY Linear Tonearm

Posted: Sat Nov 09, 2019 7:09 pm
by shane
Just re-posted the relevant bit of the first post in the Bastard thread with the photos restored.

http://www.audio-talk.co.uk/phpBB3/viewtopic.php?t=6889

#13 Re: DIY Linear Tonearm

Posted: Sat Nov 09, 2019 7:31 pm
by Ray P
shane wrote: Sat Nov 09, 2019 7:09 pm Just re-posted the relevant bit of the first post in the Bastard thread with the photos restored.
Yes, just been taking a look. Thanks for doing that.

Are you tempted to resurrect the Bastard project now?

#14 Re: DIY Linear Tonearm

Posted: Sat Nov 09, 2019 7:43 pm
by shane
Yes, once I’ve finished a project to restore an old pair of Stax headphones.

Unfortunately the PSU board was damaged during a shed tidy-up a while ago, so I’m going to have to do some major troubleshooting before I take it any further. Possibly out of my depth, but we’ll see...

#15 Re: DIY Linear Tonearm

Posted: Sat Nov 09, 2019 7:46 pm
by Ant
IslandPink wrote: Sat Nov 09, 2019 6:47 pm I do think direct-drive + air-bearing linear tracked would be great, but there's plenty of work to do- which may suit you :)
it is great.
ImageJbe series 3 transfi terminator by anthony cresswell, on Flickr

The arm wasn't mine unfortunately,but i would have liked to use it for longer apart from the frustrating finickey setup of the air bearing. I have a design in my head for a magnetic bearing. wether it will work is another matter