Whats the error on the 300Hz tone on HFN test LP ?

[GUILHERME]

Does anyone know what is the max deviation on the 300Hz test tone on the HiFi News Test LP ?

If it where played on an imaginary perfect TT with 100% accuracy what would be the error ? would we be able to measure 300.0 Hz or 300.000 Hz or what ?

Does anyone know where I can get this information ?

Thank You.

Guilherme.

[fdegrove]

Hello Guilherme,

Does anyone know what is the max deviation on the 300Hz test tone on the HiFi News Test LP ?

I think the best thing for you to do is search their archives,I remember that this record was part of their Accesories Club offerings.

If that doesn't turn out to be useful then you could e-mail mr.Ken Kessler.He described it in one of his colums for that mag.

Given even the most perfect TT an error smaller then 1% should be possible with the best MC's currently available.
Stylus drag can be minimized by using a product such as Stylast which really works as claimed.

You would still see spurious resonances of the stylus/cartridge/arm interface:10 to 12Hz overtones depending mostly on the properties of the tonearm in use.

Other then that you should come close enough for it to be a good tool for measurement purposes.

Hope this helps,

[GUILHERME]

I guess you know where this is all heading

I'm trying to find out the error at the source, when it was recorded. Thats why I said "an imginary TT", because there is no TT that does not introduce some speed error no matter how small.

Do you have Mr. Kessler email ? I've already tried to email Steve, but got no reply.

Why do you talk about the quality of the MC ? agreed, bad quality will bring distortion in the wave form but not on the wave length. If you're measuring the period it will still be the same even if it has a slight distortion caused by resonance.

1% ?? why would you have such high error ? even my entry-level TT has a (claimed) speed variation of 0.08% (which I have not measured yet). I submit that if the test tone has been recorded with good enough precision, then it is a very good way of asserting the speed of the TT.

Or am I missing something ?

Guilherme.

[fdegrove]

Hello,

I guess you know where this is all heading

I guess.

Actually I don't have anything usefull on Ken,it's been years since I last had a chance to talk to him.

I also discovered they don't have any archives online either,too bad.

Why do you talk about the quality of the MC ?

Well I assume you're going to have to use a cartridge sooner or later and that's why I also mentioned the <1% distortion levels.
That info comes from Ortofon and is related to their MC 5000.

No direct relationship with what you're trying to measure.
At this moment you're focussing on speed stability but I was painting a broader picture so you can take more factors into the equation.

See you,

[fdegrove]

Hello,

Think these people may be able to help you with the testrecord:

http://www.britishaudio.co.uk/proaud...iesothers.html

Also check this out:

Pure Cycle - Turntable power supply, ultra quiet & stable

http://www.britishaudio.co.uk/proaud...ssoriesbd.html

See you,

[GUILHERME]

British Audio were the people I got the LP in the first place! Now why didnt I think of that
I just sent them a mail and also Ben Duncan. Hope any of them can help me.

The Pure Cycle looks very nice.

PS: been busy with my design. Just got hold of a 2.5 ppm oscillator and I'm expecting my circuit to perform at least with 3 digit accuracy. Biggest problem now is to deal with EMI since the design is mainly digital.

Again, Thanks.

Guilherme.

[fdegrove]

Hi Guilherme,

Although I admire your search for perfection I believe there isn't much point in surpassing the precision of the cutting lathe.

I feel that if you get a reasonable stability with respect to that you're in very good company.

And I will pump the net on info on the Neumann cutters tomorrow.

See you,