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Phono Cartridge Response Measurement Script

DrCWO

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I do it manually…
I edit the file myself, visually in cooleditPro.
1 . Mark the signal just where 1000hz ends ,easy to see the shift in the silent channel.
2. Drag sweep length 51 seconds.
3.Copy selection by CopyToNew.
4.save under a file name. DONE
Repeat for second track, swap channels and save.

takes 8 click and 30 seconds to do both files.
Not all audiophiles that like to know more about their cartridge are skilled like you ;)
 
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JP

JP

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The threshold detection worked fine for the end of the sweep and the beginning if no pilot tone was present. It became problematic when I adjusted the script to plot from 20Hz rather than 1kHz on something like STR-100 as the adjustment for <500Hz, and of course the various RIAA configurations combined with that.

Being able to see your script would help. Regardless, this would be a winter project - I try to limit my indoor and screen time when the weather is decent.
 

DrCWO

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The threshold detection worked fine for the end of the sweep and the beginning if no pilot tone was present. It became problematic when I adjusted the script to plot from 20Hz rather than 1kHz on something like STR-100 as the adjustment for <500Hz, and of course the various RIAA configurations combined with that.

Being able to see your script would help. Regardless, this would be a winter project - I try to limit my indoor and screen time when the weather is decent.
Sent PM with the script and the filters.

I understand that your focus is wider than CA-TRS-1007. I wonder if all the other test LPs can still be bought :oops:
 

badboygolf16v

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Thanks for this great script, it's really useful tool. I wondered if I could get some input on a measurement anomaly I've found with my setup?

I've got a Technics SL-7 and a couple of carts: a Technics EPC-310MC and an Ortofon OM-5 body with OM-30 stylus. I have an RME ADI-2/4 Pro SE, so I run the OM directly into the ADI-2/4's ADC using the RIAA mode. I have a Reisong 1:20 MC SUT which I use with the 310MC. I'm using the CBS STR-100 Mk3 disc.

The ADI-2/4 has a DSP feature called RIAA Mono Bass. According to the manual "For this purpose, only the bass frequencies below 150 Hz are summed to mono." When enabling the RIAA Mono Bass feature I am seeing a bass roll off in the script measurements starting at 300Hz. I don't see this roll off when I disable the Mono Bass feature.

Here are some plots to show what I'm seeing. I've included a measurement taken with a NAD phono pre that uses the ADI-2/4's ADC only with no RIAA functionality enabled.

Is it possible that the bass roll off when RIAA Mono Bass is enabled is a measurement artefact? Or is it a problem with the ADI-2/4's DSP? Or have I just messed up my measurements? :) Any help greatly appreciated.

EPC-310MC_NAD PP 2e - RME ADI-24 Pro SE (ADC Only)_CBS STR-100.png
EPC-310MC_Reisong SUT - RME ADI-24 Pro SE (RIAA Mono Bass OFF)_CBS STR-100.png
EPC-310MC_Reisong SUT - RME ADI-24 Pro SE (RIAA Mono Bass ON)_CBS STR-100.png
OM-30_RME ADI-24 Pro SE (RIAA Mono Bass OFF)_CBS STR-100.png
OM-30_RME ADI-24 Pro SE (RIAA Mono Bass ON)_CBS STR-100.png
 

Thomas_A

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Thanks for this great script, it's really useful tool. I wondered if I could get some input on a measurement anomaly I've found with my setup?

I've got a Technics SL-7 and a couple of carts: a Technics EPC-310MC and an Ortofon OM-5 body with OM-30 stylus. I have an RME ADI-2/4 Pro SE, so I run the OM directly into the ADI-2/4's ADC using the RIAA mode. I have a Reisong 1:20 MC SUT which I use with the 310MC. I'm using the CBS STR-100 Mk3 disc.

The ADI-2/4 has a DSP feature called RIAA Mono Bass. According to the manual "For this purpose, only the bass frequencies below 150 Hz are summed to mono." When enabling the RIAA Mono Bass feature I am seeing a bass roll off in the script measurements starting at 300Hz. I don't see this roll off when I disable the Mono Bass feature.

Here are some plots to show what I'm seeing. I've included a measurement taken with a NAD phono pre that uses the ADI-2/4's ADC only with no RIAA functionality enabled.

Is it possible that the bass roll off when RIAA Mono Bass is enabled is a measurement artefact? Or is it a problem with the ADI-2/4's DSP? Or have I just messed up my measurements? :) Any help greatly appreciated.

View attachment 308386View attachment 308387View attachment 308388View attachment 308389View attachment 308390
The problem as I see it is what loading you get with the RME. OM cart likes 150-200 pF and 43 kOhm. Also, the crosstalk shows odd pattern
 
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badboygolf16v

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The loading is identical. The ADI-2/4's RIAA Mono Bass is implemented in DSP only.

The loading is almost ideal for the Ortofon.

I would expect to see poor crosstalk with RIAA Mono Bass on, as the stereo signal is summed to mono below 150Hz.
 
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JP

JP

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Thanks for this great script, it's really useful tool. I wondered if I could get some input on a measurement anomaly I've found with my setup?

I've got a Technics SL-7 and a couple of carts: a Technics EPC-310MC and an Ortofon OM-5 body with OM-30 stylus. I have an RME ADI-2/4 Pro SE, so I run the OM directly into the ADI-2/4's ADC using the RIAA mode. I have a Reisong 1:20 MC SUT which I use with the 310MC. I'm using the CBS STR-100 Mk3 disc.

The ADI-2/4 has a DSP feature called RIAA Mono Bass. According to the manual "For this purpose, only the bass frequencies below 150 Hz are summed to mono." When enabling the RIAA Mono Bass feature I am seeing a bass roll off in the script measurements starting at 300Hz. I don't see this roll off when I disable the Mono Bass feature.

Here are some plots to show what I'm seeing. I've included a measurement taken with a NAD phono pre that uses the ADI-2/4's ADC only with no RIAA functionality enabled.

Is it possible that the bass roll off when RIAA Mono Bass is enabled is a measurement artefact? Or is it a problem with the ADI-2/4's DSP? Or have I just messed up my measurements? :) Any help greatly appreciated.

View attachment 308386View attachment 308387View attachment 308388View attachment 308389View attachment 308390

It's not a measurement artifact. Perhaps @MC_RME can shed some light?
 

badboygolf16v

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Thanks JP. As you've confirmed it's not an anomaly with the measurement script, I think I should raise it on the RME forums so as not to derail this thread.
 

Balle Clorin

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Thanks for this great script, it's really useful tool. I wondered if I could get some input on a measurement anomaly I've found with my setup?

I've got a Technics SL-7 and a couple of carts: a Technics EPC-310MC and an Ortofon OM-5 body with OM-30 stylus. I have an RME ADI-2/4 Pro SE, so I run the OM directly into the ADI-2/4's ADC using the RIAA mode. I have a Reisong 1:20 MC SUT which I use with the 310MC. I'm using the CBS STR-100 Mk3 disc.

The ADI-2/4 has a DSP feature called RIAA Mono Bass. According to the manual "For this purpose, only the bass frequencies below 150 Hz are summed to mono." When enabling the RIAA Mono Bass feature I am seeing a bass roll off in the script measurements starting at 300Hz. I don't see this roll off when I disable the Mono Bass feature.

Here are some plots to show what I'm seeing. I've included a measurement taken with a NAD phono pre that uses the ADI-2/4's ADC only with no RIAA functionality enabled.

Is it possible that the bass roll off when RIAA Mono Bass is enabled is a measurement artefact? Or is it a problem with the ADI-2/4's DSP? Or have I just messed up my measurements? :) Any help greatly appreciated.

View attachment 308386View attachment 308387View attachment 308388View attachment 308389View attachment 308390
What you are seeing with Mono Bass is the curve of the elliptic filter used to merge the two channels to mono bass. When one channel is silent it looks like that. ( the sum of one channel with signal and the other with very low signal sums to a lower value as the frequency goes down) I get the same if I use deRumble in Parks Audio Puffin
 

Thomas_A

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The loading is identical. The ADI-2/4's RIAA Mono Bass is implemented in DSP only.

The loading is almost ideal for the Ortofon.

I would expect to see poor crosstalk with RIAA Mono Bass on, as the stereo signal is summed to mono below 150Hz.
What I can see capacitance of the RME input is speced to 150 pF. To that you need to add tonearm cables of perhaps 120-160 pF. So in total too high for the Ortofon.
 
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JP

JP

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Thanks for the replies, do you have the frequency response of your 150MLX measured with trs-1007 so I can compare and correct with EQ.

I'd have to do a fresh layback of both - when doing something like that, you want consecutive laybacks or controlled conditions or there's a high likelihood of extra deviation. I'm happy to do that, but will be away watching some Tennis for the next couple weeks.

Someone should also think about the possibility of any non-linearity due to different loading between my cart and yours. I want to say it shouldn't be an issue, but I'm not in the headspace to think all the way through that at the moment.
 

aaaakkkk

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I'd have to do a fresh layback of both - when doing something like that, you want consecutive laybacks or controlled conditions or there's a high likelihood of extra deviation. I'm happy to do that, but will be away watching some Tennis for the next couple weeks.

Someone should also think about the possibility of any non-linearity due to different loading between my cart and yours. I want to say it shouldn't be an issue, but I'm not in the headspace to think all the way through that at the moment.
Thanks, I will wait. On my record, side 1 is better than side 2. On side 1, tracks 3 and 4 are better.

A few years ago I also watched tennis from morning to evening :)
 

Thomas_A

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Has anyone digged deeper into the CA-TRS1007 wiggling pattern. Three cartridges/stylii and it seems better with the bonded elliptical, worse with the Gyger stylus, and worst with the SAS stylus.

Ortofon super OM10 | 1.5 g | 36 kΩ | 140 pF | CA-TRS1007 side B.png

Ortofon super OM40 | 1.5 g | 47 kΩ | 140 pF | CA-TRS1007 side B.png

Shure V15Vx JICO SAS B | 1.4 g | 47 kΩ | 140 pF | CA-TRS1007.png
 
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JP

JP

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Have seen various manifestations on various records, usually a once or twice per revolution modulation. Haven’t dug in to what specifically causes it.
 

Balle Clorin

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I see the same with my AT33PTGii, but ONLY on that test record. Especially visual in the RIGHT channel. I use side A
No wiggling with other cartridges, ATOC9ML/II etc
 

Thomas_A

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One hypothesis is that the stylus is bottoming out. It will depend on the stylus geometry, asymmetric wear and stylus azimuth. I will test a couple of JICO SAS stylii.
 

Balle Clorin

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My PTG is less then 60hrs and azimuth optimized for beste crosstalk …
 

Thomas_A

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My PTG is less then 60hrs and azimuth optimized for beste crosstalk …
Yes. I made a similar opt where xtalk got more even but wobbling got worse. I wonder why. Also increased VTF 1.25 to 1.4.

Compare:


With

 

Thomas_A

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Yes. Strangely though in one channel and not when I play the L+R sweep. I'll do some further testing tomorrow.
 
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