The best alignment for 7 inch singles?

Dear Downunder, interesting request - 7" singles .....
I will design an UNI-template for 7" and ( while we already at it ....) one specific for 10" records too.
Will ship both to you in mid september after my return from holiday.
Cheers,
D.

Thanks John

Interesting that no one has ever designed an alignment for 7 inch singles, or that Loef/Baer ever thought of it.. Given how popular they have been over the years and how manhy squillions have been sold.

me, I am not really a 7 inch collector.I do have a few Elvis 7 and 10 inch box sets, as well as a couple of Raadiohead albums on 10 inch.
When I was playing the Motown box set, it got me wondering as the re was great presence and prat in every performance, however you could tell the alignment was not up to the same performance level.

Daniel. Sounds like an interesting project for you to look at. Not sure if a compromise 7 / 10 inch alignment is worthwhile.
Trouble is I would need a seperate turntable just to play my 7 inch singles, or seperate hadshells for 7 and 10 inch.

Downunder,

Interesting that no one has ever designed an alignment for 7 inch singles, or that Loef/Baer ever thought of it.. Given how popular they have been over the years and how manhy squillions have been sold.

Interestingly, all arms at one time would have been designed for 10" records when dimensions were in inches. So when 12" records arrived, they presumably worked acceptably with the existing alignment.

You can see the history in the dimensions. A 78rpm 10" disc has an outside recorded radius of 9 1/2", which is 120.65mm, and an inner of half that, 4 3/4" which is the basis of the familiar IEC 60.325mm.

A 10" LP is the same. (So if you have a Uni DIN which has nulls suitable for a Lof/Baer A alignment with recorded radii at 58.4mm and 129mm that should work well for 10" records.)

Both 33.3 and 45rpm 7" records have the same nominal recorded radii, namely, 4 1/4" (53.975mm) and 6 5/8" (84.1375mm), which isn't such a good match, but must have been an acceptable compromise in the opposite direction. I don't know if juke boxes were optimised for 45s. I would hope so

(The metric conversions are of course unnecessarily precise, and make no practical difference should they be rounded to the nearest millimeter. )

However, using a specific 7" alignment should bring the best out of the records, as the distortion is markedly reduced. Chopping a cheap headshell and using a cheap cartridge would be worth the experiment...

One other point to consider is that using an LP alignment for 7" will need more antiskate, but a 7" alignment will need much less, as the overhang and offset are much reduced, especially if you have a 12" arm you can use.

That's a good question.I play my vintage 45's on my lower grade TT's and they sound pretty good,in fact a lot are great,like my Beatles "I Saw her standing there"blows away my 33 vinyl and new CD even on my old Dual TT.The Stereo ones in the 80's sound awesome too.I'm afraid to play them on my $875.cartridge,a far cry from my Admiral foldout from early 60's.