How to work out the correct size of drive belt to order 

You're welcome. Happy to help.

There is a link to the online shop in the description text above.

This turntable is A Marantz TT5005 and there is a link to the online shop in the description text above, where you will find the correct replacement belt.

Hi Mathieu, yes, the belt should be slightly shorter than the circumference of the platter hub. It should (just) grip on to the hub (not tight) when you replace the platter on the spindle. Then when you stretch the belt over the motor pulley, that gives it the correct drive tension so that it does not slip. Our best match for the KD2055 would be BELT45: gbaudioshop.co.uk/shop/index.php?rt=product/product&keyword=belt45&category_id=0&product_id=352

You're welcome. Happy to help.

www.gbaudio.co.uk/data/belts.htm

www.gbaudio.co.uk/data/belts.htm

Similar, but slightly different. For VCR, tape, CDs and cassettes you should measure the drive path with string or thread and then deduct about 7% to allow for drive tension. That will give you a good approximation to the belt length.

@@gbaudio1212 Awesome! thanks for the help!

Thanks for your praise. The total length of this belt (BELT41) is 640mm, so if you fold it flat it will measure 320mm.

It's a direct drive turntable, it doesn't have a belt 😉

www.gbaudio.co.uk/data/belts.htm

This is rare but some platters without access holes have a different system. Turn the platter upside down and look for a small hook or stud somewhere between the hub (where the belt sits) and the outside edge. Dress the belt onto the hub as normal, then hook it onto the hook/stud. Refit the platter with the hooked section of belt above the motor pulley. Now when you rotate the platter the belt should unhook itself and catch on the motor pulley. Good luck.

@@gbaudio1212 Because I had a loose belt I actually cut out a piece and spliced the two ends together with duct tape. I managed to finally pull the belt far enough out to hook it over the drive spindle (earlier today before you replied) and it works fine except for a slight wobble when the repair runs across the spindle, but at least I can play my vinyl again. It might not last but I see you are in Brunswick Road. I am in Tollcross, and if my temporary repair fails can I bring the platter to get a new drive belt (correct size) if you stock these?

Hi, we don’t have any previous sales recorded for your model but, from your measurement, we would suggest our BELT36 (192mm dia. / 603mm circ. x 4.2mm wide) should be a good match. gbaudioshop.co.uk/product_info.php?products_id=358

Thank you

To be fair, I gave the simple 'piece of string' method as well as the mathematical calculation so you can follow which ever method of measurement you feel most comfortable with. Regards GB

The closest matched belt we have is BELT435 which you can get from our online shop: gbaudioshop.co.uk/product_info.php?products_id=363 Yes the P325E uses a standard headshell so you have plenty of choice of headshell and any cartridge with 12.5mm (1/2") screw mounts. See our selection at: gbaudio.co.uk/data/cartridges.htm

Also, check our headshell/cartridge setup tutorial which shows a similar headshell to your NEC P325E: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-q6MSN4Gg_cs.html

@@gbaudio1212 thanks so much for the reply 😊

The diameter is the measurement straight across the centre of the drive hub or across the centre of the belt if were arranged in a perfect circle. If you fold the belt flat, ie doubled over, you get half the total length which is not the same thing. You could still work it out this alternative way: Fold the belt flat and measure it and then double it to get the total length or circumference. In this case, the old belt measured 328mm when folded flat, so x2 = 656mm. Then deduct 10 - 15mm to give the correct drive tension = 641 - 646mm.

I Mean technics-sl-bd22

@@ruitravanca9059 A tidy, entry level deck with a reasonable low-mass tonearm from mid-80s

Sorry, we don't have the VZ3000 on our database. Suggest you measure it, following the instructions at www.gbaudio.co.uk/data/belts.htm

You're welcome. Happy to help.

If you fold the belt flat, ie doubled over, you can measure it and then double it to get the total length or circumference. In this case, the old belt measured 328mm when folded flat, so x2 = 656mm. Then deduct 10 - 15mm to give the correct drive tension = 641 - 646mm.

Thanks for your feedback. As shown in the video (2 min, 12 seconds in), the calculation 3.14 (Pi) multiplied by Diameter gives you the total length (cirumference) of the hub. This simple formula works for all turntables. Or you can avoid the maths by using the string method if you prefer. Hope this helps make it clear.

GB Audio , yes the string method is easy enough and I think most people could fathom that out themselves in desperation. I’m honestly not being argumentative for the the sake of argumentation , but I think you you live in a technicality-minded world that is blind to the average mans grasp of “Pi” , what is it and how you would apply it. In all my 57 years I’ve never been asked nor needed to apply a Pi solution to any common mathematical problem dealt to me in the real world. I’m by no means dumb neither would I regard myself as advanced educated but your average guy in the street that had no aptitude nor reason to retain knowledge of PI , advanced trigonometry etc since school 40+ years ago. Your video scores a 10/10 for production values , it’s very nicely done , but you need to take a step backwards and a look at yourself before you throw (unworked out) PI values into a common man solution ..... 2/10 “Johnny has obvious capabilities and is good in General Science , however he likes to show off in Maths” Mr.Chips , deputy headmaster.

really? I have only elementary school and every therm in this video is very obvious. I dont know how easier you can explain that. maybe some math video for 3 yo kids with elephants and penguins everywhere. for me much bigger problem is, that shops which sell those belts (at least in my country) dont mention lenght of belts which they offer in e-shops. but that is quite OT

​@@davidheafield1436if you consider pi * D to be advanced maths then there's no doubt that you're an idiot. That's grade 8 maths mate. What a rude comment to this bloke who made a great video.

Hi Cathy, most tape measures and rulers have both metric and imperial measures on them. If not, here's a handy conversion site: goodcalculators.com/distance-converter/

You can also multiply what you measure in inches by 25.4. That will give you the equivalent in millimetres

I know this is an old comment but the turntable featured in the video uses a DC motor. Pitch control is through two holes at the bottom of the turntable. It is inconvenient but better than nothing. You may have been thinking of older 1970s-80s belt driven turntables, which do use an AC synchronous motor and simply change the position of the belt to change speeds. Modern Pro-ject turntables also happen to use this type of motor, requiring you to manually change the position of the belt to change speeds

that's not an option for many vintage turntables

Ya..I have a few obscure turntables I can't find much info on...this is simple math ...with a calculator 😊

You may be lucky and get the right size but I find some inconsistency from different online suppliers. Best to measure it to be sure.

Try that with vintage turntables, almost impossible to find the manufacturers let alone the belt

@@Dongfloppyso true I have a luxman pd-210 and I can’t find much to any information the unit it self so belt size is completely off the table

You're welcome. Happy to help.