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- Feb 24, 2021
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Hey Everyone!
This last year I've been on a mission to complete maintenance items to my 1977 Technics SL-23. I've depended largely on the use of Google Gemini to help guide me in this process. Long story short, I've exhausted everything I can and now have, according to my measurements, the table as close to Factory Specs as possible, at least I think so.
My goal in this post is multifaceted. I want human verification that the AI model I've been using is accurate in it's data points and calculations. I also want some additional human feedback on where these numbers lie from a quality perspective. Par for that era? Good for vintage equipment? Should sound great! Horrible in any era? And PLEASE don't with the DIGITAL IS WAY BETTER. I understand, this isn't that conversation.
I'm mulling on whether I need to pay a tariff tax on a Technics SL100c and have much better performance, or if the data below points to the point of diminishing returns. I recently fitted my SL-23 with a re-tipped Ortofon MC3 turbo from Groovetickler, and am honestly very pleased with the output. That said, "am I missing performance" is front and center here, particularly in the IMD category.
Google Gemini suggests keeping this as a "casual" listening table, but for critical listening and digitization, recommends I move on to something like the Technics SL100c. Of course I have triggered it's "sell you something" algorithm in the AI model, so that's all it recommends now and is why I am here.
For listening, my setup is below:
SL-23>Darlington Labs MP-7>KAB RF-1>THX AAA 789> Dan Clark Aeon RT closed/Truthear x Crinacle Zero IEM's
or
Digital rips through Topping E2x2 served on NAS/MoOde Audio front end/>Rpi Audiophonics DigiPi+I2s>Topping D30>Denon 4700H>RSL CG23s/10sMKII
Now the data:
Using the Ultimate Analogue Productions Test LP:
Side 1 Track 1: 1khz mono tone:
Unweighted SNR of 36dB
DIN B SNR of 81.4 dB
THD was measured at 1.1% (Left) and 1.3% (Right)
IMD was measured at 1%
Thanks for taking the time to review and weigh in!
David
This last year I've been on a mission to complete maintenance items to my 1977 Technics SL-23. I've depended largely on the use of Google Gemini to help guide me in this process. Long story short, I've exhausted everything I can and now have, according to my measurements, the table as close to Factory Specs as possible, at least I think so.
My goal in this post is multifaceted. I want human verification that the AI model I've been using is accurate in it's data points and calculations. I also want some additional human feedback on where these numbers lie from a quality perspective. Par for that era? Good for vintage equipment? Should sound great! Horrible in any era? And PLEASE don't with the DIGITAL IS WAY BETTER. I understand, this isn't that conversation.
I'm mulling on whether I need to pay a tariff tax on a Technics SL100c and have much better performance, or if the data below points to the point of diminishing returns. I recently fitted my SL-23 with a re-tipped Ortofon MC3 turbo from Groovetickler, and am honestly very pleased with the output. That said, "am I missing performance" is front and center here, particularly in the IMD category.
Google Gemini suggests keeping this as a "casual" listening table, but for critical listening and digitization, recommends I move on to something like the Technics SL100c. Of course I have triggered it's "sell you something" algorithm in the AI model, so that's all it recommends now and is why I am here.
For listening, my setup is below:
SL-23>Darlington Labs MP-7>KAB RF-1>THX AAA 789> Dan Clark Aeon RT closed/Truthear x Crinacle Zero IEM's
or
Digital rips through Topping E2x2 served on NAS/MoOde Audio front end/>Rpi Audiophonics DigiPi+I2s>Topping D30>Denon 4700H>RSL CG23s/10sMKII
Now the data:
Using the Ultimate Analogue Productions Test LP:
Side 1 Track 1: 1khz mono tone:
Unweighted SNR of 36dB
- (According to Gemini, DIN 45 500 spec was 35 dB unweighted to be considered "HiFi")
DIN B SNR of 81.4 dB
- Gemini states the DIN B spec for this table was -65dB and I've confirmed this in the original literature. My 81.4 was calculated by the AI model with the main "noise" in my 1khz profile is a 19hz motor noise at 33rpm @ -59dB. The math was as follows: Noise: -58.95 dB (19hz peak) - 45 dB (weighted <20hz adjustment) = -103.95
Weighted SNR: (-22.55)(1khz peak) - (-103.95) = 81.4dB
THD was measured at 1.1% (Left) and 1.3% (Right)
IMD was measured at 1%
- This is where most of my concern is based. If the 19hz/25hz (33/45rpm) motor noise is causing stylus interruption and disruptive IMD, I'm okay moving on and selling this table.
- The math is below:
| Channel | 1 kHz Tone Level | Sideband Level (approx. 982 Hz) | Relative IMD |
| Left | -22.55 dB | -63.19 dB | -40.63 dB |
| Right | -23.35 dB | -64.76 dB | -41.42 dB |
Thanks for taking the time to review and weigh in!
David
