Need help converting TT from 100v (JP) to 120v (US)

[Recaptcha]

Finally got the matching turntable for my Kenwood ROXY W7 midi system. The turntable works great, but I had to import it from Japan so it is 100v. I do not want to use an external convertor, I want to install a new transformer to allow it to work in US natively.

So, it’s 100v to two outputs, 12V and 9.6V. I need a transformer that’s 120v to 12v and 9.6v.

can anyone offer me some advise in this?

thanks a lot!

 

[WaynerN]

What is wrong with the external converter? Modifying a unit nullifies any safety ratings that have been issued to the unit (what ever testing service Japan uses). Hide the converter and call it a day.

 

[Recaptcha]

What is wrong with the external converter? Modifying a unit nullifies any safety ratings that have been issued to the unit (what ever testing service Japan uses). Hide the converter and call it a day.

I just don’t like external conversion. I wouldn’t mind it so much if it was one stand alone component, but this TT belongs in a set, and all of the other components in the set are native 120v, so this one needs to be as well.

I’ve had many components that had been converted from European voltages to American voltages by replacing the transformer. It can be done safely, and work properly. I just have to find a transformer that matches the specs in the service manual. Easier said than done!

 

[WaynerN]

Well, I have experience with UL and altering a product will null the listing on it. The problem is this (more then likely) is now a custom transformer, and unless you can find one with all the right voltage taps, you might be SOL. Putting 120 volts into a 100 volt transformer wouldn't be the worst thing, but then the 12 volt would turn into 14.4 volts and the 9.6 volts would turn into 11.52 volts. Of course, there are voltage regulators........

 

[Bone Yard]

Hello Recaptcha, I've got a bunch of JDM stuff, some of it I just plug in and some I use an external wall wart. I bought a "high-end' metal wall wart in Japan (made in Japan), they do come in different sizes, (amperage?) and this is fairly big. I can't find it right now but it has a small cord, maybe 12". It works great, I also have a smaller version that was about $20 from ebay (made in China). I use the big one for my mini-stereos, AIWA, Sanyo, AKAI and the little one for smaller electronics like boomboxes.

My buddy in Tokyo says their power grid has a ton of fluctuations so they might see 10-15% spikes and the electronics are built to handle it. I have no problem plugging into my US Voltage but a lot of this stuff can't be replaced so I don't chance it with most of it. Personally I'd leave those screws on and not worry about it, get the wart. I understand about the added bulk but it looks like there's a lot of other cords behind that unit.

Hopefully you posted some photos of your system, I have a soft spot for all-in-ones and there were some cool ones that never made it over here or are very rare.

 

[stratokaster]

There are companies that will build a custom transformer for you. The price usually depends on the total power output, I guess the original transformer is about 15-25 VA at most. It should be under 50$ I think.

(At least in the EU I can order a 25VA custom transformer from France for 27€.)

 

[Montycat]

I would just use an external transformer. I get why you are trying to do what you what said but these things can be really small and unobtrusive. The turntable only needs around 7 to 10 watts or so. I've happily used ones about like this:



Even without the voltage conversion the table might be fine too though I agree with the why risk it theory.

 

[Recaptcha]

Hello Recaptcha, I've got a bunch of JDM stuff, some of it I just plug in and some I use an external wall wart. I bought a "high-end' metal wall wart in Japan (made in Japan), they do come in different sizes, (amperage?) and this is fairly big. I can't find it right now but it has a small cord, maybe 12". It works great, I also have a smaller version that was about $20 from ebay (made in China). I use the big one for my mini-stereos, AIWA, Sanyo, AKAI and the little one for smaller electronics like boomboxes.

My buddy in Tokyo says their power grid has a ton of fluctuations so they might see 10-15% spikes and the electronics are built to handle it. I have no problem plugging into my US Voltage but a lot of this stuff can't be replaced so I don't chance it with most of it. Personally I'd leave those screws on and not worry about it, get the wart. I understand about the added bulk but it looks like there's a lot of other cords behind that unit.

Hopefully you posted some photos of your system, I have a soft spot for all-in-ones and there were some cool ones that never made it over here or are very rare.

Good to know. I imagine we get some spike here in the us as well. I will post pictures soon.

There are companies that will build a custom transformer for you. The price usually depends on the total power output, I guess the original transformer is about 15-25 VA at most. It should be under 50$ I think.

(At least in the EU I can order a 25VA custom transformer from France for 27€.)

I will try this, thanks! I did not know this was possible.

I would just use an external transformer. I get why you are trying to do what you what said but these things can be really small and unobtrusive. The turntable only needs around 7 to 10 watts or so. I've happily used ones about like this:

View attachment 1732177

Even without the voltage conversion the table might be fine too though I agree with the why risk it theory.

Yeah, I might HAVE to do this, since the transformer I need is not showing up ANYWHERE online...

 

[WaynerN]

Most transformers are built to 250 volt standards.

 

[rothwellaudio]

Finally got the matching turntable for my Kenwood ROXY W7 midi system. The turntable works great...

How do you know it works great? Have you plugged it in and run it from 120V?
It's quite possible, though not certain, that Kenwood used the same transformer for 100V and 120V mains and just relied on the regulators within the equipment to handle the difference. There's a +/-6% tolerance on US mains and probably a similar tolerance on Japanese mains and maybe Kenwood fitted the same transformer for both countries.
If Kenwood fitted different transformers for the US market you are unlikely to find an original example and a replacement of the correct size/shape would be difficult or impossible to find.
You could just run the turntable as it is on 120V and monitor the temperature for a while. If it stays cool it will probably be ok.

 

[Recaptcha]

How do you know it works great? Have you plugged it in and run it from 120V?
It's quite possible, though not certain, that Kenwood used the same transformer for 100V and 120V mains and just relied on the regulators within the equipment to handle the difference. There's a +/-6% tolerance on US mains and probably a similar tolerance on Japanese mains and maybe Kenwood fitted the same transformer for both countries.
If Kenwood fitted different transformers for the US market you are unlikely to find an original example and a replacement of the correct size/shape would be difficult or impossible to find.
You could just run the turntable as it is on 120V and monitor the temperature for a while. If it stays cool it will probably be ok.

Yes, I have run it off of 120v. It runs very cool. I ran it for quite awhile on 120v, and it didn't have any issues with the motor or playing.

The transformer is definitely different in Japan than in the US. the part number for the US transformer is L01-3721-05, and the one in this Japanese example is L01-3720-05. The European one is L01-3723-05. So the part numbers are different.

Now WaynerN previously mentioned that the 100v transformer that outputs 12v and 9.6v would go up to 14.4v and 11.52v if the transformer was fed 120v. This is correct, the voltages are right about that if checked while plugged in. That is my concern.

 

[Recaptcha]

Ok, I posted the pictures of the system to the member's system pics media folder.

 

[BilboBaggins]

Here’s the thing. If that unit is ever involved in a fire, the first thing they do in an investigation is check the electrical devices. If any of them are not rated for your power, the investigation stops and the finger points to your device. Insurance companies love it when they find out about something like that. Just saying as I went through a fire some years ago and it was an electrical fire.

 

[rothwellaudio]

Yes, I have run it off of 120v. It runs very cool. I ran it for quite awhile on 120v, and it didn't have any issues with the motor or playing.
The transformer is definitely different in Japan than in the US. the part number for the US transformer is L01-3721-05, and the one in this Japanese example is L01-3720-05. The European one is L01-3723-05. So the part numbers are different.

Ok, one possibility for you is to remove the transformer and then have someone rewind the primary for 120V, if you can find someone to do it. At least you'll know that it will physically fit the turntable and give you the correct voltage.

Here’s the thing. If that unit is ever involved in a fire, the first thing they do in an investigation is check the electrical devices.

Yes, that's true.

 

[Bone Yard]

Very nice! Thanks for posting the photos, I did find your earlier thread and checked it out. The Japanese had a ton of the smaller systems and they are a nice part of audio history, and some are very nicely built. For some reason the US only got the crappy Fisher/Sanyo that seemed to be everywhere. I also think we liked big things over here so a monster stereo is much cooler than a micro stereo and the smaller systems didn't sell as well. AIWA built a plant in the UK just for micro stereos, at one time they thought that was the future, you can find (on auction sites) "Made in UK" stamped equipment.

 

[Recaptcha]

Very nice! Thanks for posting the photos, I did find your earlier thread and checked it out. The Japanese had a ton of the smaller systems and they are a nice part of audio history, and some are very nicely built. For some reason the US only got the crappy Fisher/Sanyo that seemed to be everywhere. I also think we liked big things over here so a monster stereo is much cooler than a micro stereo and the smaller systems didn't sell as well. AIWA built a plant in the UK just for micro stereos, at one time they thought that was the future, you can find (on auction sites) "Made in UK" stamped equipment.

Yeah, we did like bigger stuff over here, and the smaller stuff was overlooked. Strange enough, all of these components (except the TT) are the US version. I got them at a local Goodwill, with the tape deck on eBay. And these components (once again leaving out the TT) have switches on the back to take 230-240v as well.

In japan, during this time, the bubble period was beginning, and that was when housing prices went up and the price of everything was very high as well. Many could only afford small places during this time, and they had to have smaller stereos of good quality to match... here's a chart:


You can see that raw land prices were completely blown up by the end of the 80s.

...anyways, I have contacted Heyboer transformer, and that say they can clone the transformer for 120v. Hopefully not for a small kings ransom.

 

[rothwellaudio]

...anyways, I have contacted Heyboer transformer, and that say they can clone the transformer for 120v. Hopefully not for a small kings ransom.

You haven't posted a picture of the transformer so I don't know how it fits inside the turntable. Having a transformer with the correct primary and secondary voltages isn't much use if it won't fit in the existing space.

 

[Recaptcha]

You haven't posted a picture of the transformer so I don't know how it fits inside the turntable. Having a transformer with the correct primary and secondary voltages isn't much use if it won't fit in the existing space.

I can/will post a picture of it. Hmm... do you rewind transformers? Heyboer wanted too much cash.

I will take that picture today.

 

[Bone Yard]

The Japanese love small stereo systems, they perfected the all-in-ones. The good news is they hate equipment that looks used or old (unless it's a classic), my buddy says he sees curb finds all of the time but the living spaces are so small they have to be very picky about what they bring home. Their action sites have a ton of equipment and the price drops to nothing if there's corrosion or scratches on it, if it's mint they tend to get more than over here but who knows where it's shipping to.

That's interesting about the land prices, Tokyo's seem to still be very high and going up.

 

[rothwellaudio]

I can/will post a picture of it. Hmm... do you rewind transformers? Heyboer wanted too much cash.

Sorry, I don't rewind transformers but it should be possible to find who does. Btw, I'm in the UK, so the shipping costs would be prohibitive anyway.