Rega P9 specs Re: spacers


Hi: could anyone tell me if the Rega specs on spacers are a good starting point to tell how many spacers I will need with a certain cart.

For instance Rega says their carts are 14 mm. Therefore if I have a cart that is 16 mm I would need one 2mm spacer. If I have a cart that is 19 mm I would need a total of 5 mm in spacers.

Is this is correct? If so, does anyone know if the height measurment is to be taken with the cart,mounted on the arm, and sitting on a record (i.e suspension engaged) or if the measurment should be taken without the action of the suspenion. I guess the question here is: does anyone know how rega get the 14 mm measurment, so that I can measure potential new carts the samy way, and gauge the spacer requirements.

Also, how do I short list potential carts for the RB1000 tonearm with regards to calculating resonance frequency. I cannot find specs for effective mass on this tonearm.

I'd appreciate it if any P9 owners out there could give me some tips on using this table with anything other than a Rega cart.
wfsf75d
Doug:
I won't be drilling any holes in the table that's for sure. I think I will have to work out a formula of my own in regards to the shims.

Miner42:
Thanks for replying. Yes, Rega says to measure from top top of cart (where it sits against the headshell) to tip of stylus. Theirs are 14mm. Mine is 19mm. 5 mm spacing does not give the correct arm height, so it's back to the drawing board to try to figure out a formula that gets me close, or figure out why something that is supposed to be so simple isn't.

...
I think you are getting way to caught up in measurements or specs. Rega doesn't publish specs for spacers needed with specific cartridges or cartridge height. Nor do cartridges publish these specs (at least any cartridge I have used). There is no spec for VTA. It is up to personal taste. Level is the starting point.

Just put in spacers to get it to somewhere near level. Then measure the height of the arm (or cart) with respect to the a record with a small one or two inch ruler (you can make your own). Fremer explains this in his DVD. You can use this as a starting point. Then, add or remove spacers as necessary according to your listening tastes keeping in mind your initial, measured reference to a level arm. With the Rega, this requires some bit of audio memory due to the task of replacing spacers is not immediate.

I think you should be more concerned with aligning your cartridge, getting your cartridge loading correct into your preamp, and VTF.

For most cartridges, you simply want it level or slightly up or down from there.

Finally, you don't need to figure out height and spacers needed before you order a cartridge. Get the cartridge and if you run out of spacers, use $2 washers from your hardware store. If those make you uncomfortable, then order more $30 spacers.

Btw, I have two tables, one of them is a Rega P5. I am using a 1mm brass washer with my Denon 103R. Many people like 2mm. There are no set rules to this.

Thanks Plinko: I understand what you are saying, and it is exactly what I plan to do.

Initially, I was trying to follow the instructions (from the REGA website) for calculating spacer requirements. They say. All REGA carts measure 14mm. The height specs for my cart are not published, but I got them from the distributor (which I double checked myself) and thought i could go from there.

Unfortunately it did not work out as planned, so Yes, I am going to have to play around to find the correct height instead of being able to calculate it beforehand.

I think I have found what works, but the mismatch got me to wondering if something else could be wrong, which is why I asked the original question. It seems no one else is gettng tied up in knots over the measurments, I guess I'm just funny that way.

Thanks for your reply, I'll try to relax a bit. :/
Hey wfs, forgot about your question about resonant frequency. try the cartridge database at vinylengine: http://www.cartridgedb.com/

You can look up cartridges or plug in your own arm mass and will tell you what range of dynamic compliance is suitable for your arm. But remember, it is not 100% accurate and you can listen to carts on the out range of specified acceptability. The Rega arm should be decent or very good with most cartridges.
Do you know the effective mass of the Rega RB1000 arm. I can't find that information.