Thanks for your comment but I don’t think channel balance on the cartridge has much to do with the two sides of the airpump. However both sides of the pump work. I am not sure but even if one aide doesn’t work all the tonearm cares is that sufficient pressure is being supplied
To the slider for the carrier to move freely and allow the cartridge to track.
Let me know in case I understood your comment incorrectly.
To the slider for the carrier to move freely and allow the cartridge to track.
Let me know in case I understood your comment incorrectly.
Theoretically open air bearing arms like the terminator should work at their best at the lowest possible air pressure, when there is only just enough to prevent the slider from fowling. The open type bearing is a constant pressure bearing, the air pressure in the gap is equal to the weight of the carriage divided by the area of the slider. Increasing supply pressure will make the gap bigger and reducing it makes the gap smaller. The air in the gap act like a spring. A shorter spring, of the same type, is stiffer than a longer one. Making the air gap smaller is the same as making a spring shorter. Therefore lower supply pressure results in a stiffer bearing. I think the general consensus among terminator users is that they sound at their best at low pressure, which is handy as low pressure pumps are cheaper and quieter than high pressure ones.
Low air pressure will only cause mistracking if the slider snags due to the air gap being too small.
Niffy
Low air pressure will only cause mistracking if the slider snags due to the air gap being too small.
Niffy
This is correct. The sound improves as you lower the airpressure for the same reasons you described.
However it is possible that the cartridge starts being misaligned before it even mistracks thus causing channel imbalance. I wonder if this is possible.
ok this is very, very interesting. Have you measured the misalignment in output imbalance or the image was getting skewed to one side?
I will try to measure using a much higher source of air pressure to see if there is any difference just as a curiosity.
Sorry for my inactivity but I have been really busy trying to finish up other things and also to measure resonance frequencies in the current terminator arm to gather more info on what would be optimum to build for proper match with my cart..
In order to have a better understanding I have also acquired another test record: the ultimate analogue test to try to grasp what’s going on with my goldfinger and terminator arm. The vertical midulated test 10Hz-1khz sweeep I have detected a resonant frequency of 30hz which is extremely high.
Trackeability is ok but cannot track the torture track on the HiFi test record and he goldfinger accordingly to its specs can track 100um grooves.
However I have detected problem getting the azimuth right so I decided to switch from carbon fiber light armwand to the aluminum version and I have installed my other clearaudio titanium V2 which is almost half as heavy as the goldfinger.
With this cartridge I was able to achieve perfect azimuth using the hifi test track for azimuth and surprisingly I can track the inner torture track with very minor distortion equally distributed on both channels. Vertical resonance is now below 10hz and so is the lateral one.
But I have a question for people here about azimuth setup.
Using the test record HiFi test, the azimuth is within 0.1db between the two channels with the cartridge completely horizontal which would indicate a very accurate diamond installation for this unit. Nevertheless when I play other tracks in the same test record, for example the different tracking test tracks, one channel is always consistently higher than the other.
I can’t explain the reason for it other than L and R ch are mastered at different levels.
But the situation becomes even darker, in fact, if I use the two azimuth mono test tracks on the ultimate analogue test record, there is a difference of 1dB between the two channels on the same azimuth setting that produced less than 0.1db on the HiFi test record. Also the residual crosstalk using the mono tracks seem to be different on the two channels no matter how I set the azimuth for the cartridge in both directions.
Nevertheless when I play music I have very well centered image with most of the vinyls and fantastic stereo image on all theee dimensions.
I would like to understand why the two test records don’t seem to agree on the azimuth test.
Is anybody here that can help to guide me through this quest have been bugging me for the last few weeks to the point that I have sent my goldfinger back to clearaudio for inspection because I didn’t seem to be able to find proper azimuth setup.
Thank you in advance for your patient.
In order to have a better understanding I have also acquired another test record: the ultimate analogue test to try to grasp what’s going on with my goldfinger and terminator arm. The vertical midulated test 10Hz-1khz sweeep I have detected a resonant frequency of 30hz which is extremely high.
Trackeability is ok but cannot track the torture track on the HiFi test record and he goldfinger accordingly to its specs can track 100um grooves.
However I have detected problem getting the azimuth right so I decided to switch from carbon fiber light armwand to the aluminum version and I have installed my other clearaudio titanium V2 which is almost half as heavy as the goldfinger.
With this cartridge I was able to achieve perfect azimuth using the hifi test track for azimuth and surprisingly I can track the inner torture track with very minor distortion equally distributed on both channels. Vertical resonance is now below 10hz and so is the lateral one.
But I have a question for people here about azimuth setup.
Using the test record HiFi test, the azimuth is within 0.1db between the two channels with the cartridge completely horizontal which would indicate a very accurate diamond installation for this unit. Nevertheless when I play other tracks in the same test record, for example the different tracking test tracks, one channel is always consistently higher than the other.
I can’t explain the reason for it other than L and R ch are mastered at different levels.
But the situation becomes even darker, in fact, if I use the two azimuth mono test tracks on the ultimate analogue test record, there is a difference of 1dB between the two channels on the same azimuth setting that produced less than 0.1db on the HiFi test record. Also the residual crosstalk using the mono tracks seem to be different on the two channels no matter how I set the azimuth for the cartridge in both directions.
Nevertheless when I play music I have very well centered image with most of the vinyls and fantastic stereo image on all theee dimensions.
I would like to understand why the two test records don’t seem to agree on the azimuth test.
Is anybody here that can help to guide me through this quest have been bugging me for the last few weeks to the point that I have sent my goldfinger back to clearaudio for inspection because I didn’t seem to be able to find proper azimuth setup.
Thank you in advance for your patient.
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in theory track 2 and track 3 are meant to measure balance and crosstalk. Adjust should be perform to obtain perfect channel balance and minimum/symmetrical crosstalk.
In my case no matter the azimuth angle I set, the channel balance is off and crosstalk seems to be almost identical.
I haven't connected my spectrum analyzer to it, but visually on the scope they are very different in magnitude.
Nevertheless with the other test record "HiFi" I can achieve azimuth BUT the other test tracks on the same vinyl have asymmetrical amplitude.
This is very confusing to me and I wanted to know if anybody here had gone down to the same analysis detail using scope and the two test records mentioned here and can help me answer my questions.
In my case no matter the azimuth angle I set, the channel balance is off and crosstalk seems to be almost identical.
I haven't connected my spectrum analyzer to it, but visually on the scope they are very different in magnitude.
Nevertheless with the other test record "HiFi" I can achieve azimuth BUT the other test tracks on the same vinyl have asymmetrical amplitude.
This is very confusing to me and I wanted to know if anybody here had gone down to the same analysis detail using scope and the two test records mentioned here and can help me answer my questions.
Member
Joined 2019
The air bearing arm Niffy was talking about is Terminator's style air bearing arm. There are serval different styles of air bearing arms so far.
The air gap is supposed to be constant during the travel. Obviously the smaller the stiffer the less variations but also the more the drag the stylus has to overcome.
Not sure what gap are you referring to, if you are talking about terminator if I had to gauss keeping the air pressure close to the min it probably has 50-100um gap.
Not sure what gap are you referring to, if you are talking about terminator if I had to gauss keeping the air pressure close to the min it probably has 50-100um gap.
Member
Joined 2019
Dear Sir, thank you for the assistance. Please note that I have a good knowledge of all types of tonearms, after reading carefully a lot of articles during the last 50 years. I am not against air bearing arms, I know that air bearing per se is inherently superior to other types of bearing. I want to know numerically what is considered, by different people, as an acceptable level of tonearm displacements. "As low as possible" is not an answer for me.
I am talking about this type of air bearing you are familiar with. If I take your lower value, 50 microns, I perfectly know that during the disk playback the effective tonearm length will NOT vary within ±25 μm, but within ±A μm, where A<25. So, what is, approximately, the value of A ?
Even the air gap is 50 microns, it doesn't mean the slide will make small movements in 50 microns in all directions as your floating arm. On your arm, the vibrations are not well damped. A scientific analysis doesn't necessarily be numbers. Using numbers doesn't always mean it is a scientific analysis.
Member
Joined 2019
I am not defending Terminator arm and other open air bearing arms. Personally, I am not fond of this kind of constructions. Even if the air gap is 50 microns, the air gap is filled with compressed air. The high the air pressure is, the stiffer the bearing is, the better the arm is damped. Terminator arm has low air pressure so its bearing isn’t damped as well as my arms.
I want to do some trackability tests for my latest air-bearing arm for a while but I never had the chance to do it until recently. The arm is with 0.75” air bushing and the cartridge is Benz LPs.
The first two tests I did were 1 kHz square waves. One square wave was from Stereo Review’s Stereo Test Record.
This is the ideal waveform.
These are the results of my arm.
Left Channel
Right Channel
The result is great.
I also used CBS Technical Series STR 112. There is a 1 kHz square wave on the LP, too. However, the result isn’t what I expected. I am not sure why it looks like that. Here is the result.
If anyone has an answer to the result, I will appreciate it. Here is the info about 1 kHz square waves.
I also did a burst response test. This is the ideal wave form.
Here is the result. It looks very good, too. There are very little of ringings.
The first two tests I did were 1 kHz square waves. One square wave was from Stereo Review’s Stereo Test Record.
This is the ideal waveform.
These are the results of my arm.
Left Channel
Right Channel
The result is great.
I also used CBS Technical Series STR 112. There is a 1 kHz square wave on the LP, too. However, the result isn’t what I expected. I am not sure why it looks like that. Here is the result.
If anyone has an answer to the result, I will appreciate it. Here is the info about 1 kHz square waves.
I also did a burst response test. This is the ideal wave form.
Here is the result. It looks very good, too. There are very little of ringings.
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Very good results
The peak 1 kHz overshoot on the right channel in comparison to the left, are you using the silicone damping on this measurement ?
The first fig 1(a) squarewave shows a slight high frequency phase shift ( lead) and not perfectly flat like it should be , nonetheless the cartridge follows it fairly well
Tone bursts look excellent with quick returns. Not sure what is causing the slight double image
Regards
David
The peak 1 kHz overshoot on the right channel in comparison to the left, are you using the silicone damping on this measurement ?
The first fig 1(a) squarewave shows a slight high frequency phase shift ( lead) and not perfectly flat like it should be , nonetheless the cartridge follows it fairly well
Tone bursts look excellent with quick returns. Not sure what is causing the slight double image
Regards
David
Your triangulated looking 1 kHz square wave looks like it is bandwidth limited. If the RIAA response dropped off rapidly above 2 kHz, I would expect this shape waveform. Translating that into the mechanical domain assuming you are not going through an RIAA EQ stage), and reading the test record notes, it seems the cart<>arm system track-ability might be limited at high velocities
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