The necessity for absolute tt speed control

[jdza]

Sorry, fortunately I have to disagree on all you said. If the capstan motor produces a whooshing noise it would result in miserable sound and poor measurements. Well cared Studer capstan motors (something that happens less frequently than people think) are completely silent - happily Fred Thal is not reading this thread ... BTW, poor mecanical adjustment of the tachometer assembly will result in the type of noise you refer, we need a scope to adjust it properly.

Surely the quality of the movement also depends a lot on the controller,

You describe motors that seem to have been taken from waste and two of them look like reel motors, not capstan. And the Studer capstan motors can be disassembled provided we know how to do it and no one with proper knowledge has tried to it before.

Absolutely Micro. Shoot from the hip as always.

We abdondened the project 3 years ago and the motors were tossed on an open shelf in a garage,hence their appearance now. It was abandoned because we were not getting anywhere with it.The we were me as cheerleader and owner of the problem turntable. The other was someone who worked for our National broadcaster. When in 1970 they bought such a huge amount of A 80s that unique features were included and the machines even got their own model number- Studer A80R-SABC. He was trained by Studer and looked after these machines till the last ones were withdrawn in the early 90s-more than 20 years. I'd say he knew at least half of what you know from reading the Studer List?. His wife begged me to stop the project as he was frail and dying at the time and showing way too much dedication to this. The other was an engineer who developed 2 systems for the 2 types of motors used. Do you really think we cannot distinguish a capstan motor from a voltage dependent spool motor?

Btw even I can distinguish the high pitched whine produce by a malaligned capstan reader from the sound created by these motors at high speed.

Of course the capstans can be rebuilt by someone trained to do so-not by any of us

This was the turntable involved. maybe you can also pass judgement on its sound quality your armchair too?


I have no further intention to discuss this any further. A thousand apologies,Lagonda.

 

[Lagonda]

Absolutely Micro. Shoot from the hip as always.

We abdondened the project 3 years ago and the motors were tossed on an open shelf in a garage,hence their appearance now. It was abandoned because we were not getting anywhere with it.The we were me as cheerleader and owner of the problem turntable. The other was someone who worked for our National broadcaster. When in 1970 they bought such a huge amount of A 80s that unique features were included and the machines even got their own model numbers,. He was trained by Studer and looked after these machines till the last ones were withdrawn in the early 90s. His wife begged me to stop the project as he was frail and dying at the time. The other was an engineer who developed 2 systems for the 2 types of motors used. Do you really think we cannot distinguish a capstan motor from a spool motor?

Btw even I can distnguish the high pitched whine produce by a malaligned capstan reader from the sound created by these motors at high speed.

Of course the capstans can be rebuilt by someone trained to do so.

This was the turntable involved. maybe you can also pass judgement on its sound quality your armchair too?


I have no further intention to discuss this any further.

Sure looks like an interesting project !
And thank you again for your input.

 

[microstrip]

Absolutely Micro. Shoot from the hip as always. (...)

Jdza,

No, my post was meant to be mainly technical and carefully though - I have been exchanging PM's with Laconda saying similar things before the thread started.

Anyway, my two thousand apology, the post was not directed to you or people you know, just to comment the few facts you refer. I wanted mainly to say that this approach is IMHO an extremely good one and should be taken and carried with great possibility of success. The idea was not mine - I took it from the original Apolyt.

https://www.r-l-x.de/forum/showthre...Thread-Schallplatten-Plattenspieler-etc/page2

It has been discussed several times in forums such as diyaudio.com and lencoheaven.net and many others in languages I can only check with google translator. It is not rocket science and does not need engineers or specialized knowledge - the basics of it are described in the bible of applied electronics, Horwitz and Hill, The Art of ELectronics.

I also read and learn most of what I know about the A80 from the now vintage Fred Thal Studer list - Fred enthusiastically explained the why's of the A80 capstan motor. My collection of Studer capstan motors includes mint ones, but also a few total wrecks.

BTW, my armchair knowledge has supported me developing such system for my Forsell airbearing flywheel turntable some years ago. I tried to post about it sometime later on an interesting thread about the famous AS2000 / ThecDas AirForceZero motors, but as no one seemed really interested in such matters, I gave up.

Let us move to the important matters - Laconda project - again.

 

[Lagonda]

Jdza,

No, my post was meant to be mainly technical and carefully though - I have been exchanging PM's with Laconda saying similar things before the thread started.

Anyway, my two thousand apology, the post was not directed to you or people you know, just to comment the few facts you refer. I wanted mainly to say that this approach is IMHO an extremely good one and should be taken and carried with great possibility of success. The idea was not mine - I took it from the original Apolyt.

https://www.r-l-x.de/forum/showthre...Thread-Schallplatten-Plattenspieler-etc/page2

It has been discussed several times in forums such as diyaudio.com and lencoheaven.net and many others in languages I can only check with google translator. It is not rocket science and does not need engineers or specialized knowledge - the basics of it are described in the bible of applied electronics, Horwitz and Hill, The Art of ELectronics.

I also read and learn most of what I know about the A80 from the now vintage Fred Thal Studer list - Fred enthusiastically explained the why's of the A80 capstan motor. My collection of Studer capstan motors includes mint ones, but also a few total wrecks.

BTW, my armchair knowledge has supported me developing such system for my Forsell airbearing flywheel turntable some years ago. I tried to post about it sometime later on an interesting thread about the famous AS2000 / ThecDas AirForceZero motors, but as no one seemed really interested in such matters, I gave up.

Let us move to the important matters - Laconda project - again.

I am looking forward to the project, not expecting miracles, i have a couple of PS Audio regenerators that can change both voltage and frequency and deliver sufficient wattage, size of pully can also be used for speed adjustment. I would prefer to use the Phoenix Roadrunner for speed regulation, but the power supply is probably not powerful enough To me it is a low cost fun project with potential improvement of my TT, it is already very speed stable both with and without feedback loop, but a 4W motor driving a 100lbs platter must have a limiting factor torque wise

 

[analogsa]

Studer A80R-SABC

Wow. Having spent half of my life within the SABC broadcast range, much to my shame i have no knowledge of this. Otoh, still remember the SABC developed turntables.

 

[jdza]

Wow. Having spent half of my life within the SABC broadcast range, much to my shame i have no knowledge of this. Otoh, still remember the SABC developed turntables.

Yes ,when Harman unceremoniously got rid of all the Studer documentation it was given to a Swiss person,whose name I unfortunately cannot recall. When I was looking for a part he informed me that he came across documentation and engineering drawings for this unusual model. From that he could help me with the upgrade from mechanical to digital counters for this specific model .

As I understand it he subsequently withdrew from things Studer( can't blame him) and handed all the documentation to someone in China.

 

[Lagonda]

It's a shame that this tt drive system can't be modified to rim drive. I'd have certainly been very interested.

Marc, i just read the instruction manual for the Sota Condor controller, it can be adjusted to be used with rim drive, i think it reverses the direction of the spinn.

 

[spiritofmusic]

Keep me posted on that, maybe send me pertinent info.

 

[Lagonda]

Keep me posted on that, maybe send me pertinent info.

Here is the link for the manual. https://sotaturntables.com/wp-content/uploads/2019/05/condor-c-small-manual.pdf
i’m thinking this could actually be used to run my Studer motor with the right amplifier module. It does everything i need, but adjust the voltage from 3V -24V, i need around 130 V. Maybe i am wrong , Fransisco or Bill please correct me if i am wrong, i am about as technical as Tango

 

[Kingrex]

Joe Pitman told me years ago the PS for a TT motor made a difference. With my new better TT I heard it myself. When I first installed the table I was out of receptacles in my audio power strip. I plugged it into a crap strip that fed my Rocu, TV and other junk. When I rebuilt the power to my preamps I ended up with spaces in my audio power strip. I then plugged my TT PS into my audio power strip. Dammed if I didn't hear a change.

 

[microstrip]

I am looking forward to the project, not expecting miracles, i have a couple of PS Audio regenerators that can change both voltage and frequency and deliver sufficient wattage, size of pully can also be used for speed adjustment. I would prefer to use the Phoenix Roadrunner for speed regulation, but the power supply is probably not powerful enough To me it is a low cost fun project with potential improvement of my TT, it is already very speed stable both with and without feedback loop, but a 4W motor driving a 100lbs platter must have a limiting factor torque wise

Well, although I do not know the characteristics of your current motor, I would expect that the smoothness of the Studer motor due to the high moment of inertia can be a very positive factor.

Since you are going DIY you can start today using the modern version of The Art of Electronics recipe. Get an USB soundcard, some free software to generate two sinusoidal signals in quadrature (nice name to say 90º phase difference ), an old 50W stereo amplifier - Quad 303's are perfect for this purpose - and two 230/24V 20W power transformers to step up the amplifier output.

Just using the software to control the amplitudes tune for minimal noise using a stethoscope, or better use a cheap piezzo to see the spectra of vibration. This software does it all for free during 30 days. https://www.spectraplus.com/

Then be sure that we are not considered armchair experts we can get a prototype pulley made by 3D printing locally , smooth it using the motor axe as a lathe axe and listen! If we find that the preferred sound does not mach the best measurement we get extra points in WBF ...

 

[microstrip]

Probably everyone knows about it, but perhaps it is the time to remember, as we are addressing Studer motors. The Studer FTP site with all Studer operating and service manuals as well as all other type of information, such as brochures, technical and service notes, has been down since long but we can access of mirror of it at https://www.reeltoreel.nl/

 

[Lagonda]

Well, although I do not know the characteristics of your current motor, I would expect that the smoothness of the Studer motor due to the high moment of inertia can be a very positive factor.

Since you are going DIY you can start today using the modern version of The Art of Electronics recipe. Get an USB soundcard, some free software to generate two sinusoidal signals in quadrature (nice name to say 90º phase difference ), an old 50W stereo amplifier - Quad 303's are perfect for this purpose - and two 230/24V 20W power transformers to step up the amplifier output.

Just using the software to control the amplitudes tune for minimal noise using a stethoscope, or better use a cheap piezzo to see the spectra of vibration. This software does it all for free during 30 days. https://www.spectraplus.com/

Then be sure that we are not considered armchair experts we can get a prototype pulley made by 3D printing locally , smooth it using the motor axe as a lathe axe and listen! If we find that the preferred sound does not mach the best measurement we get extra points in WBF ...

Fransisco if i can make the Phoenix work, it does it all. Slow startup( minimum belt wear), feedback for adjustments (if wanted) and counters if i want to keep track of usage. I don’t want to reinvent anything The pulley part is the only part i have experience with. But a capacitor and simple two phase action would maybe be a good way to gouge the potential.

 

[microstrip]

Fransisco if i can make the Phoenix work, it does it all. Slow startup( minimum belt wear), feedback for adjustments (if wanted) and counters if i want to keep track of usage. I don’t want to reinvent anything The pulley part is the only part i have experience with. But a capacitor and simple two phase action would maybe be a good way to gouge the potential.

Oops, I was preparing for the true three phase driver ... Does the Phoenix have power enough for the Studers?

 

[Lagonda]

Oops, I was preparing for the true three phase driver ... Does the Phoenix have power enough for the Studers?

No probably not the one i have, but i have PS Audio supplies that can be adjusted for both frequency and voltage, and if results are good, a 3 phase supply is next. I should be able to hear improvements even with 2 phase, or it is not worth the hassle.

 

[analogsa]

does the Phoenix have power enough for the Studers?

It has plenty of power, just needs step up transformers at output.

 

[Lagonda]

It has plenty of power, just needs step up transformers at output.

That is what i am hoping. I have the 5 watt Falcon.

 

[analogsa]

Oh, didn't know there was a 5W version...probably won't do.

 

[Lagonda]

Oh, didn't know there was a 5W version...probably won't do.

The Condor puts out up to 24 watt in 3 phases, maybe that will work with a step -up ? But it is only up to 24 V.

 

[microstrip]

It has plenty of power, just needs step up transformers at output.

Good. But we should not forget that step up transformers at low power usually are not very efficient.

Do you have a value for power and voltage?