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Post by hamish on Apr 15, 2023 16:33:33 GMT
Evening all, I need a little help setting up my turntable. I’ve just put a Jelco 750d (I think - it’s defo a jelco…) onto a technics SL1210. I want to get the cart aligned properly, so have printed off the technics one found on this page www.audioappraisal.com/free-cartridge-alignment-protractors-and-strobe-discs/It seems to want the cartridge to be very far forward on the headshell. Is that likely to be right, or do I need a chart that’s less specific to the standard techy arm…? Sorry, I suspect this is pretty basic stuff for you guys. I feel like I used to know this stuff… but it’s all evaporated out of my brain! |
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Post by MartinT on Apr 15, 2023 16:44:21 GMT
It depends a bit on the cartridge, Hamish. However, too far forward or backwards rather than somewhere in the middle of the slots doesn't sound too convincing.
Did you print exactly to scale and is the centre hole in exactly the right place - there's little room for error here.
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Post by hamish on Apr 15, 2023 17:48:56 GMT
How do add photos on here… is it just from a computer and not on my phone?
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Post by julesd68 on Apr 15, 2023 18:08:24 GMT
Your Jelco has its own geometry which you need to take into account - lots of info if you Google this as it has been an issue for plenty before you.
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Post by hamish on Apr 15, 2023 18:18:13 GMT
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Post by hamish on Apr 15, 2023 18:21:01 GMT
Your Jelco has its own geometry which you need to take into account - lots of info if you Google this as it has been an issue for plenty before you. Yeah, I came here after not finding anything ... I am very out of touch with hifi these days, so I struggle to even search the correct search terms it seems... |
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Post by julesd68 on Apr 15, 2023 18:29:47 GMT
No worries - if you try "sa-750d tonearm alignment" you will find discussions on other forums that have covered exactly this problem and the data you need.
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Post by julesd68 on Apr 15, 2023 18:34:18 GMT
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Post by hamish on Apr 15, 2023 19:06:38 GMT
That one on vinyl engine looks promising… I don’t suppose you could give me any tips on how to use it?
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Post by MartinT on Apr 15, 2023 19:47:46 GMT
How do add photos on here… is it just from a computer and not on my phone? Use a photo hosting service like Flickr. There's a help article in the help section. |
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Post by julesd68 on Apr 15, 2023 20:04:17 GMT
That one on vinyl engine looks promising… I don’t suppose you could give me any tips on how to use it? Sorry it's so long since I last set up a cart I will leave that one to current turntable users - good luck with it. |
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Post by MartinT on Apr 15, 2023 20:09:09 GMT
In this one, it looks like you have the alignment almost spot on. Cart just needs to go back a tiny touch.  |
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Post by petea on Apr 15, 2023 20:16:04 GMT
Hi Hamish, what strikes me from the Technics template and the Jelco specification (https://forums.stevehoffman.tv/threads/9-jelco-750d-tonearm-alignment.646768/) is that nominally the Jelco has a pivot to spindle difference that is 1 mm shorter than on the technics template. The overhang is the same as is the offset angle but the pivot to spindle distance is 114 mm rather than 115 mm on the Technics template. The first thing I would do would be to measure the pivot to spindle distance on your printed template to make sure it is correct. Then I would draw a new arc (or mark a point on the existing intersecting line) that is 114+15 mm from the pivot. That will bring your stylus 1 mm or so back into the headshell and seems a reasonable way to accommodate the geometry of the Jelco arm with the deck.
Funk arms are so much simpler to set up!
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Post by MartinT on Apr 15, 2023 20:18:36 GMT
Funk arms are so much simpler to set up! Hard to beat SME with their rack/pinion adjustable base. |
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Post by hamish on Apr 15, 2023 21:26:29 GMT
Hi Hamish, what strikes me from the Technics template and the Jelco specification (https://forums.stevehoffman.tv/threads/9-jelco-750d-tonearm-alignment.646768/) is that nominally the Jelco has a pivot to spindle difference that is 1 mm shorter than on the technics template. The overhang is the same as is the offset angle but the pivot to spindle distance is 114 mm rather than 115 mm on the Technics template. The first thing I would do would be to measure the pivot to spindle distance on your printed template to make sure it is correct. Then I would draw a new arc (or mark a point on the existing intersecting line) that is 114+15 mm from the pivot. That will bring your stylus 1 mm or so back into the headshell and seems a reasonable way to accommodate the geometry of the Jelco arm with the deck. Funk arms are so much simpler to set up! Hi Pete, I’ve read this about 15 times and I’m still not 100%… Could I just not use this as a guide but then mount the cart slightly further back that it suggests then…? I don’t even know how precise this sort of thing need to be really…? It certainly sounds pretty good now… |
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Post by petea on Apr 15, 2023 21:48:09 GMT
Yes. Moving the cartridge back 1 mm will be close enough I suspect using the slot lengths as a guide.
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Post by daytona600 on Apr 18, 2023 16:45:37 GMT
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