DC motors and outboard power supplies...


For those of you with analog rigs that utilize a DC motor and outboard power supply....I'm wondering:

1. How often do you check to see if the platter is at correct speed?

2. How often do you have to fine tune the speed adjustment?

3. Once fine tuned, does it stay throughout the listening session, or do you need to make adjustments throughout?

4. Would you be willing to comment on which table you are using?

Thank you for your comments.
no_regrets
Post removed 
Along the lines of what Palasr suggests, can you swap another DC source for the battery? I am able to do this with my controller by using a 12-vdc wall wart. The wall wart isn't as quiet but it is great for emergencies and troubleshooting. It does sound like the controller is fine, but the supply is questionable. What battery are you using? How often do you charge it?
I'd have to guess that you have a thermally related issue - power on, current draw, and component 'X' drifts out of spec. Tracking this proverbial needle in a haystack can be very frustrating without a working knowledge of electronics. That said, in most cases semiconductors either work or they don't; it is pretty rare to see a fixed regulator, for example, start drifting wildly on its own - if that occurs they simply self-destruct. I'd look to passive components first - capacitors and carbon comp resistors, especially on the raw power supply/rectification side of things. Good luck.

-Richard
Hi Lewm,

I just got home from listening to a 17 piece jazz band playing charts from Count Basie, Duke Ellington, and the like. Great fun! I'm going to spin a few albums now and try and take some measurements as you suggested and see what happens.

I appreciate your words of caution as well.

No Regrets
No regrets, This is just my 2 cents, but if you don't know how the motor control circuit works, I would advise against random parts replacement. That can lead to confusing the issue, if you make an error. Anyway, I am sticking with the idea that you should measure some voltages during full function vs during problematic moments. It sounds like the problem IS localized to the motor or its upstream circuit.
Hi Dan ed,

"No_regrets, how do you get the controller to work properly again after one of these slow down episodes?"

I shut the supply down, pour myself a drink to calm my frustrations, and after a period of time, sometimes a couple of hours later or the next day I go back turn and turn it on. Many times it works just fine, but sometimes not. That's the thing about it. I don't do anything to it.

One of my thoughts was that something may be drawing too much current and causing one of the many regulator chips to go into thermal overload. But then why is it that I can literally listen for up to 8 strait hours without a problem one day and the next day not even make it 1 hour?

Raul brought up the trimmer pots may be going out of spec. I don't know a lot about electronics but that could be an option. I can't seem to find the exact model number anymore, but I would think as long as I replace with like values it should be fine. I found some for as little as 79 cents. Worth a try at least.

Thanks for your question. I'm sorry I don't have a more technical answer for you though.
No_regrets, how do you get the controller to work properly again after one of these slow down episodes?
Hi Raul,

Thank you so much for your suggestion about the variable pots. To be honest, I never thought about them going out of spec. That's a great idea. I'm not sure if I have the problem in 45 speed as I don't often listen to 45's as I do the 33's. My next listening session I will dedicate to 45 issues and will see if the problem presents itself. Thank you Raul and to all for trying to help me with this. It means a lot to me.

No Regrets
Dear No regrets: Ok, check what Lew suggest.

+++++ " My supply does have variable pots to fine tune the speeds for 33 and 45. I can get the table to spin correctly, but then for no reason at all it justs slows way down. " +++++

I don't know which kind of pots your TT has but from what are my experiences about and taking in ount what you posted: +++ but then for no reason at all it justs slows way down... ++++, maybe there is something wrong there because that kind a problem is a sign that a pot could be going out of specs and with the working time in the future that problem could be worst.

Btw, have you the trouble in both speeds?, if yes then I think that maybe is not a pot because it is almost imposible that both suffer a damage at the same time.

Now, for any one could to have a precise diagnosis it is desirable that the check-up on your TT have to do it when the failure is present.

I can't say nothing more except: good luck.

Regards and enjoy the music.
Raul.
Syntax, thank you for sharing your experiences with me.

Raul, the people at Linn are of no help to me because the motor and powersupply are not from Linn. I have talked with the people of Pink Triangle who is now known as the Funk Firm. They no longer have schematics for this supply nor parts or replacement motors. I have even reached out to the designer of the supply who frequents a different forum, but to no avail as of yet. My supply does have variable pots to fine tune the speeds for 33 and 45. I can get the table to spin correctly, but then for no reason at all it justs slows way down. You never know when its going to happen. That's why I think it may be a regulator chip or capacitor going bad. I am going to try measuring the output of the supply today and see if I can in fact isolate the problem to the supply as lewm had suggested.

Thank you,
No Regrets
Dear No regrets: Normaly a speed TT has to be fix ( by design ) on 33/45rpm on the electronic circuit in the PS and normaly too this could be through a " pot " ( variable )that is the part that makes that job and for check about you need the diagram or a technician if you can't do it. I don't know how this works in your TT but you can contact to Linn and Pink Triangle and ask about.

Regards and enjoy the music.
Raul.
Since Adjust+ is available, I heard from lot of users, that their - expensive - Turntables are drifting. That's more common than most of us think.

I am using
a, Basis Debut with Walker controller
b, Micro Seiki 5000

. How often do you check to see if the platter is at correct speed?

for both at the beginning but then I stopped that

. How often do you have to fine tune the speed adjustment?
a, never
b, never

. Once fine tuned, does it stay throughout the listening session, or do you need to make adjustments throughout?

a, stable
b, stable

. Would you be willing to comment on which table you are using?. How often do you check to see if the platter is at correct speed?

maybe 1x in 14 days
Hi Lewm,

Thank you for your response. My table is a Linn LP12 that was modified by Pink Triangle with a Pink Link DC Battery Power Supply. I take excellent care of the bearing assembly and really do not feel it is the cause of the problem. The inner platter and pulleys have been cleaned, the belt has been replaced with a brand new one so I don't think that is it either. What is confusing to me is that there are times when I can listen for up to eight hours strait with no problems. Other times it occurs within the first hour or two. I think that your suggestion about measuring the output of the supply is a great idea and should tell me if the problem is the supply or the motor. I will try to do that tomorrow. Thank you for that suggestion.

Hello Raul,

Believe me, I have done much research and have participated on many of the forums that Linn and Pink Triangle owners frequent. I have had many good suggestions but to no avail. I know I will most likely have to buy a new motor and power supply but I sure would love to try and fix what I have first because when it is running correctly, I do love the way it plays records.
Dear No regrets: +++++ " Literally around the world in just over 8 hours time thanks to my Linn LP12, Naim ARO, Wood bodied Benz, and Pink Link DC Battery Power Supply. " +++++

well, I'm not the right person to help you on that Linn configuration but I think that you could obtain a very good advice/support from either LINN directly or the LP12 owner " excited " community, good luck.

Regards and enjoy the music.
Raul.
No regrets, Are you absolutely certain that the belt is not slipping? If it's neither the belt nor binding up of the bearing assembly, then have you been able/are you able to measure the electrical output of the PS when it is running well as compared to when it is running too slow? That at least will pinpoin the problem to the PS. You might want to reveal the identity of your tt, so that others who own the same rig and might read this thread could relate their experiences. For example, measure the DC voltage at the output of the supply under both conditions (if you have a DC motor).
Hello Raul,

Yes, I am having issues with speed control in my rig. So, as I am trying to sort out these issues I am contemplating getting a new table but can't help but wonder if I might not have simalar problems with the new table. Therefore I ask questions of the fabulous members of this forum because I respect their opinions.

The problem that I am experiencing is that there are times that I can listen for hours without a problem, and then out of the blue my speed will slow way down. Other times I can't even make it through a single record.

I've changed the bearing oil, the belt, the battery in the power supply. I don't know if it is an issue with the motor or the supply. About a couple weeks ago, I cleaned the din plug that connects the power supply to the table and I had put on about 50 hours of listening without a problem. But now, here it is again. I'm getting stumped. Maybe I need to replace the capacitors and regulator chips in the supply. I don't know what the answer is but it is getting frustrating. I never know when it is going to happen except that it will probably happen for sure when I'd like to invite friends over for listening!

So do you have any ideas? Your thoughts would be greatly welcomed.
Dear No regrets: Looking at your thread and that in other one ( not yours ) you ask the same: Could I assume that you have speed " problems " with your TT?, do you? or which is the real subject: only curiosity?

Regards and enjoy the music.
Raul.
Thank you to all who shared their experiences with me regarding this. I greatly appreciate it.
No Regrets; I find that since my rig is in the basement there is a wide variation of ambient temperature. Being so affects the bearing oil temp until it has reached a stable temp. I live in the Colorado Mountains. I do find a more measurable need for checking speed accuracy during the winter months then I do the summer months (which are few)!
Peace
I use the Origin Live dc motor and controller on a Oracle turntable. I find that the temp. of the room has an effect on the speed. If i let the room cool off or heat up the speed will change slightly, but it is audible. Letting the motor run for 15-30 min. prior to listening helps warm up the motor and oil in the turntable bearings. If i maintain the temp. in the room and i check the speed before every listening session i usually never have to adjust the speed. The Origin Live motor and controller is very accurate and the strobe will vary the slightest amount at the very begining and very end of the lp. The instructions for the Origin Live say to adjust the speed when the stylus is in the center of the lp , this gives almost perfect speed throughout the lp.

The largest improvement came from removing the Oracle motor and making a motor pod for the Origin Live motor and allowing the motor to sit on the turntable stand instead of the plinth or base. This removed all the vibrations that the motor generated and now my turntable is extemely quiet. To see if your motor is generating vibrations and transmitting it to the turnable put your ear against the plinth with the motor running and if you hear noise this may be heard during playback.
Todd
Hi Santanaali,

Thank you for responding. Just so that I understand, if you go a few days between listening sessions, are there times when you first check the speed, that it is different from what it was at the last listening session?

Thank you again for sharing your experiences with me.
1. About once a week or after a long time off.

2. Very rarely.

3. It plays at speed during the listening session and for many, many days, but I check it from time to time anyways.

4. I'm using the Acoustic Signature Mambo. Its bearing is self-lubricated, so it does not use oil. The bearing is made of a material called Tidorfolon, which, as I understand it, is composed of offerrite, vanadium, teflon and titanium. The outboard Alpha power supply generates its own frequency and therefore is not affected by power fluctuations.

Best,

iSanchez
Here is what I do: I turn on all the equipment for at least 30 minutes; including my Galibier SE. I check and adjust IF necessary before the 1st LP. Then I recheck and fine tune if needed on the second LP. The bearing oil needs to warm up. I have never found that I have to readjust but I do occasionally re-check during a long listening session.