Measuring the quality of DIY turntable

[Coolerooney]

Hi all,

Progressing nicely with my homebuild turntable
Cutting no corners, learning from fora, deep diving reviews etc etc

Its gonna be great, off course, but needs independent confirmation

How can this be done, preferably without buying scopes and other high €. items

Those that get listed are

Speed deviation
Speed drift
Wow & flutter
Signal to noise ratio
Rumble

Sure there are a lot more...

Thx

C

Btw, its interesting that a top of the line Clearaudio turntable, only lists speed variation as a spec...

 

[La 67]

I think it can be done on a decent budget, but some sort of investment is most likely required. There exist DIY measurement tools. Check the "Equipment & Tools" forum here. I would first be looking for a digital tachometer which can connect to a computer for long term speed measurement and analysis.

 

[Galu]

How can this be done, preferably without buying scopes and other high €. items?

Start by playing a solo piano recording. That will quicky show up problems such as wow & flutter.

 

[claudio]

For the first 3 measurements, various apps exist that uses you cellular accelerometer to calculate the turntable speed.
For S/N and rumble, a sound card+measurement program, plus a record with tones is needed. Maybe an AC voltmeter capable to measure till 1kHz Vac plus some calculations, with the tone record used as generator, could work too.

 

[Coolerooney]

Hi all,

Thx for the tips, should have found the thread myself....

However, still pretty abstract, and a lot of DIY
Amazon has a lot of stuff in this field, starting at 30 €

https://www.amazon.de/s?k=oscillosc...1&tag=googdemozdesk-21&ref=pd_sl_9cyxhmj3zo_e

————
Which brings me to the next question, what kind of specifications/ratings am I looking for and where are the measurements actually physically done?- on the TA output?- the RPM I get hahaha

Best

C

 

[claudio]

Not really abstract and DIY: take your smartphone, install this app: RPM Speed & Wow - App su Google Play
Start the app and put your cellular on the turntable paltter; turn on the turntable and voila'....you get the 3 measurements you asked for.......
For the specifications to look at as reference, check in the past: Pioneer PL-600 - Manual - Fully-Automatic Turntable - Vinyl Engine
The important thing to point out is that there are some way to perform rumble or S/N measurements, called STANDARDS: if you want to compare your measurement with the one published by Pioneer, for example, you must perform your using the same standard they did, otherwise it's nonsense. To do so, you need to spend money for calibrated instruments. Otherwise you can do "relative measurements", that is you can compare between your measurements only.

 

[billshurv]

Much easier way. see the thread Turntable speed stabilty


If you can record a 3khz or close signal off a test record then it can be analysed in seconds and gives you an output that allows you to work out what and where the problems are.

 

[Mark Tillotson]

Start by playing a solo piano recording. That will quicky show up problems such as wow & flutter.

Only upto a point - once its below the threshold of human detection you have to measure it with testgear.


And if you want to improve a design you need repeatable testgear to be able to tell if your changes are making improvements or not - the human ear won't be a reliable tool for confirming small improvements.


A good test disc is essential for checking tracking and cartridge issues as well as basic speed control.