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JayDC
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Location: Philadelphia

Test tone for cutter head calibration

Post: # 13460Unread post JayDC
Fri Mar 18, 2011 12:50 am

I made a series of test tones to cut and figured i'd share them. It goes 20hz to 20khz, each tone is -11db (sine). It's spaced out one tone per groove, with a silent groove between each tone.

1000, 20, 30, 40, 50, 60, 70, 80, 90, 100, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900, 950, 1000, 1500, 2000, 2500, 3000, 3500, 4000, 4500, 5000, 5500, 6000, 6500, 7000, 7500, 8000, 8500, 9000, 9500, 10000, 11000, 12000, 15000, 20000

Made one for 33 1/3 rpm, and 45rpm.
33: www.djjaybird.com/TEST_TONES-33RPM.wav
45: www.djjaybird.com/TEST_TONES-45RPM.wav

Very surprised to find out that my presto 1-C cut the 20khz tone.

I plan on using this cut to balance my cutter head, by cutting it, playing it back, and recording it to my computer. Then I can see how even each tone is reproduced, and eq to compensate. I'm going for the flattest response i can get, trying to reproduce each tone exactly.

I hope this helps someone out. If anything the groove pattern looks cool! :D
generally its for reproduction.. but i like to play wif it sometimes.. :P

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subkontrabob
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Location: Helsinki, Finland

Re: Test tone for cutter head calibration

Post: # 13466Unread post subkontrabob
Fri Mar 18, 2011 4:37 am

Hi Jay,

Good effort with the test tones, thank you for sharing! I've been thinking about doing something similar.
JayDC wrote: I plan on using this cut to balance my cutter head, by cutting it, playing it back, and recording it to my computer. Then I can see how even each tone is reproduced, and eq to compensate.
It's good to keep in mind that in your proposed method the frequency response and distortion of your pickup will have an influence on the outcome.

To avoid this, Buchmann & Meyer developed an optical method to precisely measure levels of signals cut to disks. I started a thread on this topic to find out if people use this method, and maybe get some practical advice, but it didn't really pick up....... :(

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JayDC
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Joined: Sat Jan 13, 2007 5:45 pm
Location: Philadelphia

Post: # 13477Unread post JayDC
Fri Mar 18, 2011 12:04 pm

I got the idea from the presto 1-D manual. The correct way to do this test Visually would be to not use the riaa encoders. Just cut the grooves with no EQ at all, and you should see your heads true frequency response in the grooves.
generally its for reproduction.. but i like to play wif it sometimes.. :P

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subkontrabob
Posts: 284
Joined: Fri Oct 30, 2009 5:40 am
Location: Helsinki, Finland

Post: # 13481Unread post subkontrabob
Fri Mar 18, 2011 12:51 pm

JayDC wrote:The correct way to do this test Visually would be to not use the riaa encoders. Just cut the grooves with no EQ at all, and you should see your heads true frequency response in the grooves.
I'm going to do that as a test next time I'm there.... :D

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JayDC
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Joined: Sat Jan 13, 2007 5:45 pm
Location: Philadelphia

Post: # 13483Unread post JayDC
Fri Mar 18, 2011 1:38 pm

be very careful, these tones are all one level.. don't blow your head..
generally its for reproduction.. but i like to play wif it sometimes.. :P

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JayDC
Posts: 849
Joined: Sat Jan 13, 2007 5:45 pm
Location: Philadelphia

Re: Test tone for cutter head calibration

Post: # 13484Unread post JayDC
Fri Mar 18, 2011 1:53 pm

subkontrabob wrote: It's good to keep in mind that in your proposed method the frequency response and distortion of your pickup will have an influence on the outcome.
I understand this, but I do not plan on using this cutter to produce recordings for the general public, I want to set this up to the type of playback pickup I'm using, and the DJ mixer I request in my contract.
generally its for reproduction.. but i like to play wif it sometimes.. :P

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