High compliance cartridge recommendations for jelco ts-350s arm? (Under 500 usd)

[flavio81]

So would a 6Hz resonant frequency be acceptable?

Really, the rule of thumb is that between 8-12Hz is OK, however there have been different opinions on this and I think it was Joe Grado or another well-recognized name in audio that was advocating for a much lower frequency. My view is that it's all about the Q-factor and the Q-factor will depend on the cartridge itself. For example shure cartridges are often fitted with suspensions with low Q factors thus work better with various arm masses; whereas Grado cartridges in general are notorious for having sharp (high) Q suspensions and thus being picky and difficult to get right.

All in all, i'd say that if you are not having any flutter, wow, or mistracking problems when hitting a warp, and if there is no problematic subsonic frequencies moving your speaker cones, and no feedback problems, then call it a day and leave it as it is.

A good reference is the magazine "The B.A.S Speaker", Volume 8 Number 5, February 1980, page 25, they test about 24 turntable/tonearm/cartridge combinations. There were combinations with less then 5Hz resonant frequencies that worked fine.






Now, if you want to go for a cartridge suited for high mass tonearms, that's OK too, but you'll have to state your budget. Cheapest ones would be DJ cartridges like the Ortofon VNL. For MC cartridges the Denon 103 would be a start.

If you want to diminish the tonearm effective mass, the easy way is to replace the headshell for a light one (IIRC the lightest there is is the SME headshell at 6.5 gram or so), and the other useful advice is to use a heavier counterweight. Heavier counterweight means the counterweight sits closer to the pivot and thus the inertia of the system is diminished.

 

[flavio81]

Here's an opinion on resonant frequency by Pritchard inventor of the ADC cartridges, on an interview on the "B.A.S speaker".

This mentions also that the intended optimium resonance frequency for the (very-high-compliance) ADC cartridges was 6Hz.

 

[TrevorBarten]

It all makes sense to me.

You have a heavy headshell, with the cartridge and headshell alone the combination is a high mass one (21gr). The M97xE is a rather high compliance cartridge, 5Hz sans-brush is not surprising. The Shure brush acts a hydraulic damper -because it does have silicon fluid on the bushings- and thus changes the results. The Stanton brush has no silicone fluid, it is there just for cleaning the record.



All of these formulas for compliance are questionable and shouldn't be relied upon, because of many reasons, one reason is that cartridge suspensions are different and some have narrower (high) Q-factors other have low Q-factors.

There are other reasons and the best explanation and tests are here in the Korf Blog. Required reading!!

Interesting read. It seems to make a lot of sense as well.

 

[TrevorBarten]

Really, the rule of thumb is that between 8-12Hz is OK, however there have been different opinions on this and I think it was Joe Grado or another well-recognized name in audio that was advocating for a much lower frequency. My view is that it's all about the Q-factor and the Q-factor will depend on the cartridge itself. For example shure cartridges are often fitted with suspensions with low Q factors thus work better with various arm masses; whereas Grado cartridges in general are notorious for having sharp (high) Q suspensions and thus being picky and difficult to get right.

All in all, i'd say that if you are not having any flutter, wow, or mistracking problems when hitting a warp, and if there is no problematic subsonic frequencies moving your speaker cones, and no feedback problems, then call it a day and leave it as it is.

A good reference is the magazine "The B.A.S Speaker", Volume 8 Number 5, February 1980, page 25, they test about 24 turntable/tonearm/cartridge combinations. There were combinations with less then 5Hz resonant frequencies that worked fine.

View attachment 3041789


View attachment 3041790

Now, if you want to go for a cartridge suited for high mass tonearms, that's OK too, but you'll have to state your budget. Cheapest ones would be DJ cartridges like the Ortofon VNL. For MC cartridges the Denon 103 would be a start.

If you want to diminish the tonearm effective mass, the easy way is to replace the headshell for a light one (IIRC the lightest there is is the SME headshell at 6.5 gram or so), and the other useful advice is to use a heavier counterweight. Heavier counterweight means the counterweight sits closer to the pivot and thus the inertia of the system is diminished.

In my latest comment I did actually attempt it with a sme headshell that weighs in at around 7 grams including wires. Looking at the spectrum that would bring it to around 7Hz, just barely atleast. I wonder if that is something that is preferable to having a (much) higher quality headshell with azimuth adjustment. With the shure cartridge I did see tracking errors, this hasn't happened with the ac-2 yet. I have not tested the w&f. I did recently buy the stereo analogue test record so when I get home checking the w&f is the first thing I'll do. I am aware that using a heavier counter weight could help, however this isn't an option for the current cartridge since with a 7 gram headshell I am only just able to get +- 2 grams of tracking force before it bottoms out. Are the subsonic frequencies something I can measure, or do I just have to look out for specific movement of my speaker cones?

 

[mr_petit]

There are other reasons and the best explanation and tests are here in the Korf Blog. Required reading!!

Koft makes some stupid mistakes in his explanation and his calculator.
Yes, damping of the cantileversuspension is a real factor in how strong the resonance is (so... how high that peak is), but somehow Korf thinks he can make a calculator based on that....without q factors being available as data from manufacturers.

He jokes about Hooke's law (as that 'old formula'), but that has stand the test of time for over 300 years. The problem is, that he (and maybe many others) read more from it's outcome that that there is.
Indeed, it doesn't claim anything about damping, and anyone who think it does, is a fool.
So lets ook at what korf does...
If you look at the math he's using...he uses the same Q factor for every cartridge...
This is his mathematical reasoning:

Dropbox

www.dropbox.com

And the conclusion of it is........Q>0,707 (some who do some speakerbuilding will probably recognize this)
There's nothing in that file that wasn't known in 1954 too, so this is all 'old formula'....
That Q factor pretty much a given for a non actively damped system.... IT's bound to be above 0,5 right (underdamped).
So there is nothing news here, and there is nothing cartridge specific here
And if you start to play with his calculator, you come to the conclusion that every resonance frequency above 10,25Hz gives an unacceptable acceleration in his calculator.
To me, 10,25Hz is fine though....
Regarding anyone who recommends the korf calculator, haven't any of you seen that above 10,25Hz the acceleration becomes acceptable?

So what korf did... to me it's completely meaningless.
Also funny that he uses the vertical resonance track from the HFNR.
Everyone who has that...record that track, look at it's waveform. 20Hz....19Hz....bit loud isn't it? 18Hz is suddenly very quiet....he turned the volume down. It's not a resonance you see, its the recorded wave. 18Hz and lower is so soft and deformed that it's pretty much useless. There are better records with vertical resonance tracks. Korf clearly didn't do a source analysis here. He just saw something and accepted it as the truth without a plausibility check or a check of the track itself.

If you want to investigate the damping capabilities of your cartridge suspension, get a test record with a very soft resonance track (firato for example that also has no pilot tone) and compare it's amplitude to the reference amplitude. That's a good start.


And regarding korf's calculator, he doesn't actually say something about resonance, but if you look at what the excursion calculates, it's pretty safe to say that where the excursion is highest, there's a resonance, right?
Just go and test is. His calculator is off by a mile. Not only regarding Hooke's law, but also what you see happening in reality.

 

[flavio81]

Are the subsonic frequencies something I can measure, or do I just have to look out for specific movement of my speaker cones?

Being a practical person, i just look at the speaker cones...

 

[tabarddn51]

Hi, 6 hz is generally considered to low, but only just & it depends on what type of floor your system is situated on. I wood you may hear feet walking across the room, if someone moves around. however on concrete it is unlikely. I am using a AC-2 in my system at present & it does go down very low, I hear organ low notes from LP's never hear before. This is what you would expect as it is equivalent to a now-a-days $6000 cart. But on the other had I feel the bass is a little light in impact.
It is all about arm & cart matching & looking back I cannot see what arm you are using. (may have missed it)
It is also about your perception of music & whether or not you listen to live music. Normally you will find bass levels of live music to be much more prominent that you get from even top level carts.
It looks to me from the resonant graph you have a problem with your speaker output at 30hz, which you will hear. If you are using base reflex speakers of a ported sub. Fill then with drinking straws & that should get rid of that peak.

Cheers

 

[TrevorBarten]

Hi, 6 hz is generally considered to low, but only just & it depends on what type of floor your system is situated on. I wood you may hear feet walking across the room, if someone moves around. however on concrete it is unlikely. I am using a AC-2 in my system at present & it does go down very low, I hear organ low notes from LP's never hear before. This is what you would expect as it is equivalent to a now-a-days $6000 cart. But on the other had I feel the bass is a little light in impact.
It is all about arm & cart matching & looking back I cannot see what arm you are using. (may have missed it)
It is also about your perception of music & whether or not you listen to live music. Normally you will find bass levels of live music to be much more prominent that you get from even top level carts.
It looks to me from the resonant graph you have a problem with your speaker output at 30hz, which you will hear. If you are using base reflex speakers of a ported sub. Fill then with drinking straws & that should get rid of that peak.

Cheers

I don't entirely understand what you mean with my speaker output. I recorded this directly from the tape out, I didn't record my speaker output. As for the arm, I am using a jelco ts-350 arm, I also just picked up a sa-250 (transrotor version so with slightly better tolerances) and I just mounted the ac-2 on my ps-x75 as I get a resonant frequency of around 10 Hz on my ts-350 with my newly acquired ortofon black. With my ac-2 on my ps-x75 I get 8-9 Hz depending on the recording. Seems like the better option.

 

[tabarddn51]

Yes I understand that, but that 30hz bump obviously will get through to your speakers. The 6hz will not.

Cheers

 

[Blue Shadow]

Yes I understand that, but that 30hz bump obviously will get through to your speakers. The 6hz will not.

Cheers

most gear will get a 6Hz signal through to the speakers. Unless one is using the subsonic or low filter or both. Most gear easily does 6hz.

 

[TrevorBarten]

Yes I understand that, but that 30hz bump obviously will get through to your speakers. The 6hz will not.

Cheers

So what do you think caused that bump? Is that even something that unnatural or is it recording dependent?

 

[tabarddn51]

Hi, It depends, frequency measurements should be done on quiet grooves from a test LP or LP with a long run out groove. So should not be LP dependent.
However it is most likely a resonance between your arm & cart, if you can change your head-shell to a lighter one, that will bring the 6hz up also may change the 30hz hump. (for better or worse, I do not know)

Cheers

 

[JP]

So what do you think caused that bump? Is that even something that unnatural or is it recording dependent?

Can you provide the file?

 

[TrevorBarten]

Hi, It depends, frequency measurements should be done on quiet grooves from a test LP or LP with a long run out groove. So should not be LP dependent.
However it is most likely a resonance between your arm & cart, if you can change your head-shell to a lighter one, that will bring the 6hz up also may change the 30hz hump. (for better or worse, I do not know)

Cheers

I did the recordings using non test records. I was under the impression that it did not matter for determining the resonant frequency, and it seems to not have been a factor so far as my results among different records have been pretty consistent. I have two measurements of a 3.15khz test tone, one with a ps-x75 and ac-2 and the other with the pd121a and ts-350 + ortofon black combo. I wanted to use these to measure the w&f, but have not been successful in doing so via software. I could only find 'real time' w&f meter software. I have an old school w&f meter so I was able to get rough estimates, but due to how this meter works (with a vu-meter) it does not reset fast enough for accurate measurement of a record player. So on this part I'd love a suggestion for software that allows me to analyse the w&f over already recorded files instead of a real time signal.

As for the headshell, I ordered a lighter hs-50 headshell, which is supposed to come with the arm anyway. I also am going to be buying a jelco sa-750d tonearm in a few days, no clue how I ended up getting two jelco arms in the same week but the prices are too good to pass up, especially considering how hard these arms are to find for sale. Seems to me to be somewhat of a buy now, think later situation. I will be pretty busy the next few days but after that I'll take some more measurements.

 

[cafe latte]

So conclusion, get a lighter headshell and find something medium to low compliance or if it's high compliance it needs to have a brush ? Any recommendations for low compliance carts in the 500 usd range in that case?

Denon 103r, bargain MC.
Retipped later on it is stunning