Correct
That's why I suggested 3 levels to get an even better picture of what is happening when increasing amplitude.
But may be an ever better idea instead of having 3 separate parts, is to have one part where in steps of 30 seconds each, amplitude increases in 3 steps ending in a locked groove.
This saves space, but you can also watch the step response, a suggestion already earlier made by Ray.
The possible effect of increased friction will be even more apparent.
Hans
Yes. But the announcement at beginning of each low frequency tells you what is your arm and cartridge resonance frequency. This is all you need.
I don't think we should make things unnecessarily complicated. All we need are vertical and horizontal arm and cartridge resonance frequencies. A 4-25 Hz with a pilot frequency is enough. Arm and cartridge resonance frequency is inherited in the combo of arm and cartridge. The goal is to make the resonance frequency away around 7 Hz. If your arm and cartridge resonance frequency is around 7 Hz, you need to change things in order to change its resonance frequency no matter its amplitude is low or high.
Very good, thanks! I remember that they can not turn off the top end of the RIAA, so we would just use their EQ. Hole centering is something we've not yet gotten any answer on.
I'm in conversation with a couple of mastering techs here in the USA. It's a slow conversation and I will report any progress.
I'm in conversation with a couple of mastering techs here in the USA. It's a slow conversation and I will report any progress.
As promised, added a Progress Tracking document to Test LP drive folder to provide a birds eye view of where we are at.
I expanded on lcsaszar's suggestions (Post #839), but left it kind of general so feel free to suggest fine tuning. Anyone with access can comment.
Access it here: Test LP Progress Tracking Doc
I expanded on lcsaszar's suggestions (Post #839), but left it kind of general so feel free to suggest fine tuning. Anyone with access can comment.
Access it here: Test LP Progress Tracking Doc
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Pano:
You could keep a catalogue of mastering and pressing information here rather than have to store it in your email / noggin.
Also, I think it helps keep everyone in the loop and efficient- we don't have multiple people doing the same thing. Of course also to provide commentary / feedback.
You could keep a catalogue of mastering and pressing information here rather than have to store it in your email / noggin.
Also, I think it helps keep everyone in the loop and efficient- we don't have multiple people doing the same thing. Of course also to provide commentary / feedback.
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If you could kindly include any info in the Pressing / Mastering doc here that would be very helpful, so the info doesn't get lost in the giant thread.
I also sent inquiries regarding a guarantee of center hole tolerance to:
Optimal (GR)
Pallas (GR)
RTI (USA)
Rainbo (USA)
United (USA)
Quality Record Pressings (USA)
MPO (FR)
Record Industry (NL) - [Furnacemfg in USA]
GZ (CZ)
Will update with their answers as they come in.
What is the margin of error we are willing to tolerate? Since this might impact all tests on the LP, it seems to me a critical area to get a definitive answer and run a hard line on... other test lps haven't managed this issue well.
also issue of tolerance of center hole diameter (i.e. the punching the hole it self: little small = will be pinchy to get on spindle..little large we have slack = contributes to off center issues. The eccentricity aspect involves the coordination of master and hole on the press, event when perfect hole diameter etc)
Yes but no one is defining what these tolerances should ideally be?
What is a reasonable improvement to request on the standard tolerance? Are standard tolerances even adhered to anymore?
The RIAA Dimensional Standards can be found here.
This is from a 33rpm 7" but the same standards apply:
What is a reasonable improvement to request on the standard tolerance? Are standard tolerances even adhered to anymore?
The RIAA Dimensional Standards can be found here.
This is from a 33rpm 7" but the same standards apply:
ok center hole diameter +1/40mm to -1/20mm maybe that is what is possible even today
but worse on page 3
"Runout of Recording Grooves Related to Center Hole " = "(0.41mm)"
well that is steep I'd say.. should be better than 1/10mm for usable performance, if much above that it gets 'criminal'..would like down in order sub 1/10mm
(don't think it is possible to align center hole and matrix to order 1/100mm ..but maybe I am wrong?)
anyway makes it even more important on-record to be able to assess eccentricity .. and possibly have remedies in post proc SW to compensate for it (as it is supposed to test cartridge/TT not the record it self)
IIRC we had a go earlier in the thread, trying to balance reality/achievability with ideals. Suggestion was +/- 0.05% of radius, to include centre position and hole size tolerance. If the track ends up on the record at 10cm that would be +/- 50µm as a target/starting point?
LD
That is what I am saying. Aim for quality precision record pressing but also compensate in measuring software inherent eccentricity and speed drifts. Otherwise both deficiencies (Turntable system's and record pressing's) will get mixed in results. If in software we can neutralize pressings minor defects the measurements of system will be accurate to be differentiated precisely.
Test signal
Not sure if that's the right place to present an idea for a test signal, but here it is:
I would like to have a track, best would be an endless one, with a series (20, 30, 36?) of evenly distributed sharp clicks. Purpose: the time between the clicks could be measured e.g. with an Arduino, and so we could check if the momentary rotation speed of the TT differs during one round. I hope this description is clear... English is not my first language.
Maybe someone finds such a test could be done otherwise... I'm open ears.
Kind regards,
Hansrudolf
Not sure if that's the right place to present an idea for a test signal, but here it is:
I would like to have a track, best would be an endless one, with a series (20, 30, 36?) of evenly distributed sharp clicks. Purpose: the time between the clicks could be measured e.g. with an Arduino, and so we could check if the momentary rotation speed of the TT differs during one round. I hope this description is clear... English is not my first language.
Maybe someone finds such a test could be done otherwise... I'm open ears.
Kind regards,
Hansrudolf