Not loving my AT740MLx

[JP]

Bummer on the 80BK is even if it measures well, it's a crude elliptical.

 

[Thomas_A]

Bummer on the 80BK is even if it measures well, it's a crude elliptical.

Yes I know. MP-500 is the champ to test but still interested though. I have not figured about Nagaoka; do they cut and polish their own diamonds?

 

[dlaloum]

What is required to get resonance above 20k for cantilevers of a more typical length? I assume the beryllium and boron tubes of yesteryear accomplished this. How about solid beryllium (I think my ATN152LP styli use solid)? Solid boron (very common today)?

The Rivertone ADC XLM Improved MkII (3x7 Diasa) looks to have a peak of about 5db @ 18.7k according to my crude measurement capabilities. I only mention this model because ADC touted the shorter cantilevers and Rivertone is assembling them from old OEM components. This is the second time I've mentioned this stylus in as many days, but I'm not obsessed with it (I'm not even using one at the time), I'm just lately curious about these resonant frequency issues.

It is very hard to separate a MM cantilever resonance from the sum of the performance of the entire setup - you need to model the electrical EQ (including its resonance) and deduct it from the measured performance - which then expose the "actual" raw needle performance - allowing the resonance identification.

All the high performing setups with resonances well above 20kHz (and given the rise to a resonance, you need to get it up above 30kHz to minimise impact below 20kHz...) - used tube/pipe cantilevers.

I do have an ATN152LP... and I will have to look up my archives to see what it measured as (assuming I measured it!)

MC's are much easier as there is minimal EQ impact from loading - so you can see the raw performance

 

[mfalcon]

Yes I know. MP-500 is the champ to test but still interested though. I have not figured about Nagaoka; do they cut and polish their own diamonds?

What kind of tests do you want done to the MP-500? Something besides the phono measurement script?

 

[Thomas_A]

What kind of tests do you want done to the MP-500? Something besides the phono measurement script?

Just a couple more to see possible variations, and perhaps a glimpse above 20 kHz.

 

[Thomas_A]

And if someone has the MP-500 and a JICO SAS/B. Is there any difference in cantilever length? Possible to measure this?

 

[mfalcon]

I have an MP-500 that I can measure in a few days if you still need it. No Jico Sas.

 

[Thomas_A]

I have an MP-500 that I can measure in a few days if you still need it. No Jico Sas.

It would be appreciated. I have a JICO SAS and the boron rod measures 3.8-4.0 mm.

 

[Bob from Florida]

And if someone has the MP-500 and a JICO SAS/B. Is there any difference in cantilever length? Possible to measure this?

View attachment 408601

If you change the length of the cantilever, aside from changing any resonances, aren't you also affecting the voltage output?

 

[Thomas_A]

If you change the length of the cantilever, aside from changing any resonances, aren't you also affecting the voltage output?

You change quite many things with cantilever length. The Obray boron rod is 6 mm so any manufacturer may mount it with different length. Perhaps the range varies between 3-4 mm. Having a resonance of 16 kHz with 4 mm should be shifted to 21 kHz if 3 mm. Most cartridges seem to get a rise and decline 10-20 kHz, while others seem to rise just before 20 kHz. I just wonder if it is due to cantilever length.

 

[dlaloum]

You change quite many things with cantilever length. The Obray boron rod is 6 mm so any manufacturer may mount it with different length. Perhaps the range varies between 3-4 mm. Having a resonance of 16 kHz with 4 mm should be shifted to 21 kHz if 3 mm. Most cartridges seem to get a rise and decline 10-20 kHz, while others seem to rise just before 20 kHz. I just wonder if it is due to cantilever length.

Are you measuring cantilever length from needle point to suspension pivot?

Styli like the SAS are composite constructs, with the boron rod being on the needle end, then inserted into what I assume is an aluminium tube, and the suspension pivot point is on that tube...

So the resonance of the stylus "system" is determined by the overall cantilever length - pivot to needle - for a compound structure there will most likely be subsidiary resonances for each of the components but they are both an order of magnitude (or more) lower, and difficult to measure! (Grado are also famous for using compound structure cantilevers)

 

[Thomas_A]

Are you measuring cantilever length from needle point to suspension pivot?

Styli like the SAS are composite constructs, with the boron rod being on the needle end, then inserted into what I assume is an aluminium tube, and the suspension pivot point is on that tube...

So the resonance of the stylus "system" is determined by the overall cantilever length - pivot to needle - for a compound structure there will most likely be subsidiary resonances for each of the components but they are both an order of magnitude (or more) lower, and difficult to measure! (Grado are also famous for using compound structure cantilevers)

Yes it is the system in total. But to know resonance diff. we need to know if there are differences in the boron rod length.

 

[dlaloum]

Yes it is the system in total. But to know resonance diff. we need to know if there are differences in the boron rod length.

Sorry I feel like I am missing a step in the logic here...?
to know the resonance we measure it (with all its concomitant difficulties in measurement)
Knowing the length may help us in predicting what the resonance might be for an unmeasured stylus, but won't help us with resonance differences?

 

[Thomas_A]

Sorry I feel like I am missing a step in the logic here...?
to know the resonance we measure it (with all its concomitant difficulties in measurement)
Knowing the length may help us in predicting what the resonance might be for an unmeasured stylus, but won't help us with resonance differences?

Look at the results in the database thread. The Ortofon OM40, 2M black and the Nagaoia MP-500. Why >20 kHz resonance? We need to know cantilever length. If boron rod lengrh is 3.2 mm for the MP-500 and 3.8 mm for the JICO sas we most likely have the answer. That is why I ask.

 

[JP]

Exposed rod, with calipers under 8x magnification, I get 2.75mm.

 

[Thomas_A]

Exposed rod, with calipers under 8x magnification, I get 2.75mm.

That’s short indeed!

 

[JP]

 

[Thomas_A]

View attachment 408961

 

[JP]

I have V SAS/B, but not Vx SAS/B.

 

[Thomas_A]

I have V SAS/B, but not Vx SAS/B.

And length?