Jump to content

Converting AC power for my TT


greg928gts

Recommended Posts

I was given a beautiful TT setup about a year and a half ago, but I have not been able to use it. The power supply is 230V/50Hz and I need 230V/60Hz or 120V/60Hz.

The TT is a Transrotor, and I asked Transrotor about this and they suggested that I purchase another power supply from them, which would cost $1000 plus shipping. I don't really want to spend $1K on this right now, and I can't help thinking that the parts inside the $1K box probably cost about thirty bucks. I already have a power supply and I wonder if it could be modified to work.

I'm hoping someone out there might be able to help.

Greg

post-11090-13819488731314_thumb.jpg

Link to comment
Share on other sites

  • Replies 45
  • Created
  • Last Reply

Top Posters In This Topic

Why does T/R require a different power supply, and not, for example, just a different size pulley? Is it a DC motor? If it's just a belt drive and synchronous motor, one would think a different size pulley would do the trick, but somehow I doubt it.

Some 'tables require a very specialized, complicated power supply designed to reduce or eliminate things like eddy currents and minute speed variations. Basis and Clearaudio make them as options, I believe. Maybe that's one reason Transrotor is special.

My PS audio P-300 can vary the line frequency, and I suppose I could change it to 50 Hz (I'm limited to 60 Hz because it powers motors). But that's not any cheaper than T/R's.

Link to comment
Share on other sites

I think Michael might have an idea. Look at it backwards. Whats the voltage spec. requirement of the motor/turntable and provide a solution. Maybe you can go with out eddy current elimination.

Might just be a real stable 12v dc which I suspect you can makeup for a whole lot less than a thou.

Link to comment
Share on other sites

I'll take a look tomorrow and see if I can find out what the voltage is. I can't imagine it's listed on the motor or the power supply, but it might be in the manual.

I think "New Classic" is the model, but I'll check that as well.

Greg

WAIT! Lookie what I found?

Of course, that's no guarantee that the voltage isn't stepped down again between this plug and the wires to the motor.

Greg

post-11090-1381948873472_thumb.jpg

Link to comment
Share on other sites

So was that part of your Transrotor package? I hope that solves it.

If not, I guess I still suggest you ask Transrotor (or Axxis, its distributor) to make sure you're OK with using that. There still might be a problem if your motor was designed for 50 Hz electricity, since 60 Hz might make it run 60/50 = 1/5th faster than it's supposed to, and that can be hard to tell if you aren't used to the music.

Does your package have one of the T/R "motor controllers"? -- http://www.axissaudio.com/turntables/KM1.htm. If so, maybe a transformer is all that's needed instead of an expensive motor controller.

Transrotor KM-1 One Motor Controller features:
Output voltage: 2 x 18 V AC two phase -- 18 V = same as your adaptor
Output current (max): 0,2 amps
Speed correction range: +/- 5%
Max voltage draw: 30 VA
Enclosure: 6 mm aluminum
Front plate: 8 mm aluminum

Dimensions: 7" w x 8" d x 2-3/4" h

Transrotor KM-1 One Motor Controller

Link to comment
Share on other sites

Yes, that came with the package. What I found was a picture that showed the voltage, not that adapter. The adapter shown in the picture plugs into European 230V outlets, at 50Hz.

No, I still don't have a solution to this. I think it's going to take an electrical engineer to draw something up for me to build, or to figure out how to modify what I have. Or I just have to shell out a thousand bucks.

Greg

Link to comment
Share on other sites

Well I'm not a EE. I'm also not a TT expert. If it were me I would be very tempted to try what you have on your home 230v 60hz. I don't really see where the extra 10hz is gonna hurt anything other than speed control being out of range. I guess its possible to puff the existing PS which you can't use anyway. Boy if you could borrow the correct PS and compare it to the one you have........

Link to comment
Share on other sites

Well I'm not a EE. I'm also not a TT expert. If it were me I would be very tempted to try what you have on your home 230v 60hz. I don't really see where the extra 10hz is gonna hurt anything other than speed control being out of range. I guess its possible to puff the existing PS which you can't use anyway. Boy if you could borrow the correct PS and compare it to the one you have........

I am tempted, I just don't want to burn up the TT motor. I can imagine what that costs! I was told this TT was in the $10K range new. Don't know if that's true or not.

Greg

Link to comment
Share on other sites

The Wallwart ps shows 18 Volts AC at 50 Hz. Going from 50 to 60 Hz is a big jump. A pulley change could take care of that.

Or bult a small amplifier and feed in a 50Hz signal. You would need the correct load impedance, but could measure the output and change the osc. gain to get the desired voltage.

That's how the original 2" tape decks adjusted the speed. A massive amp fed by a VSO.

The $1k is starting to look pretty good...

Bruce

Link to comment
Share on other sites

Is it as simple as finding the correct adapter? Why did Transrotor tell me I needed a new power supply then? I don't know . . . .

I don't know a lot about this, but I'm leary of simply changing the adapter or just running it off of 230v/60hz.

Greg

Obviously they want your $ 1K.

Supply at the wall is different than what the motor needs. Obviously it's 18v, but is it actually AC or a DC motor? If you have a DC motor, you will be on easy street.

If it's AC, it will turn the wrong speed. Next best is to take the motor off and into a supply house, see if there is an RPM listed on it, and see if you can get a different motor that turns the same RPM. Guessing it is AC, and they are varying the frequency for speed control. (+-)

Link to comment
Share on other sites

I'm sounding like a broken record here, but rather than trying to take apart a delicate and expensive motor or giving it the wrong voltage or current, you need to find a Transrotor tech nerd who can trot out all the answers from the tip of his tongue. He could be at Transrotor or Axiss, or a dealer who really knows his stuff. Like, can you use that wall wart, what happens if you try it, is the "power supply" that T/R motor accessory, etc. The wall wart may only put out 18 volts at 230 volts in, not 120 -- dunno if that would hurt or not. That motor might cost hundreds of dollars to replace!

Bruce is right about your possibly slipping into costly work anyway, and 60 Hz being a big jump over 50. If the motor RPM is based directly on line frequency, 60 Hz gives you 40 RPM instead of 33, over half way to 45 RPM. Someone else may have been right that the extra pins are to feed back info, which suggests a specialized interaction.

See if you can find an Answer Man!

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×
×
  • Create New...