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Wanting To Import A Fostex HP-A8C From Japan; Voltage Concerns - Page 2

post #16 of 27

So a transformer is not needed at all since one can open the case and change hard wiring easily?

 

I am going to get one fro Japan as well. Thanks
 

post #17 of 27

It sounds like so but it still has some risks. My order will arrive next week, and will make a try firstly :-)

post #18 of 27

Thanks. You could consider take down that board and see what is attached to it before changing the plugs.
 

post #19 of 27
Quote:
Originally Posted by HiFan View Post

Thanks. You could consider take down that board and see what is attached to it before changing the plugs.
 

 

Sorry for the late response!

 

I opend the chassis but didn't try changing the voltage yet, for my USB cable is just sold today together with previous HP-A3 wink.gif

 

In the past weekend, I listened to HP-A8 using a 300W transformer (not a very good one, just 25 dollars). I'd like to say I didn't notice sound quality issue with a transformer, though I will be able to comment more after modifying the voltage of A8.

 

The overall layout after opening the top:

 

The right side has three slots with 230V, 120V and 100V respectively, that's the thing we need to change:

 

The screw is very special, according to Chinese standard, it's named as T10H type screw, where A = 2.8mm and B = 2.05mm.

post #20 of 27

I have just brought one of these units in Japan (81,000 yen) and have cracked it open and can confirm that they indeed do have the 3 voltage headers (100,120 and 230). All you need to do is find a security TP10 screwdriver which took about 2 minutes in Akihabara.

 

I still need to do the firmware update on the box but it sounds really good with my W4R's.


Edited by A_Man_Eating_Duck - 9/13/13 at 1:32am
post #21 of 27
Quote:
Originally Posted by A_Man_Eating_Duck View Post
 

I have just brought one of these units in Japan (81,000 yen) and have cracked it open and can confirm that they indeed do have the 3 voltage headers (100,120 and 230). All you need to do is find a security TP10 screwdriver which took about 2 minutes in Akihabara.

 

I still need to do the firmware update on the box but it sounds really good with my W4R's.

 

Did you notice any sound difference between directly connected (after modifying voltage) and using a transformer?

 

I notice that after modifying voltage, sometimes there is a few static electricity on the chassis even without powered on. I don't remember it exists when I'm using the transformer before modifying voltage to 230V though maybe I simply omit it. It may also be caused by the two pin power plug but I didn't heard other users compain about it.

 

The static electricity is just ok, but I feel a bit concern about whether it may affect the sound quality.

post #22 of 27

I'm still in Japan at the moment. I won't be in 230 volt land until the 19th. I'll let you know how I go once I get home but I plan on using a grounded power cord.


Edited by A_Man_Eating_Duck - 9/13/13 at 5:43am
post #23 of 27

Netmask 254 this  "static" is interesting.. Having repaired1000s of pieces of equipment with all types of power supplies -with all types of voltages and connections. I have found this to occur occasionally  when the mains input is connected the wrong way around. Especially  when there is no earth connection. Try reversing the mains input. This was completly removed when the chassis was earthed. This can be due to transformer  leakage .[although there are other causes] Make sure the toroidal transformer is isolated from the chassis by a rubber insulator between it and the chassis..--Add  if you are told not to reverse the mains connection then there is something wrong with it. It should be safe no matter what way round it is connected.That is an international safety rule.


Edited by duncan1 - 9/13/13 at 10:27am
post #24 of 27
Quote:
Originally Posted by duncan1 View Post
 

Netmask 254 this  "static" is interesting.. Having repaired1000s of pieces of equipment with all types of power supplies -with all types of voltages and connections. I have found this to occur occasionally  when the mains input is connected the wrong way around. Especially  when there is no earth connection. Try reversing the mains input. This was completly removed when the chassis was earthed. This can be due to transformer  leakage .[although there are other causes] Make sure the toroidal transformer is isolated from the chassis by a rubber insulator between it and the chassis..--Add  if you are told not to reverse the mains connection then there is something wrong with it. It should be safe no matter what way round it is connected.That is an international safety rule.

 

Duncan1, thanks a lot for your advice!

 

A8 is using a two-pin power plug, actually I tried swap the two-pin connection but no help. I think using a 3-pin power cord shall be helpful to this case but didn't try it yet since the user manual warned that not to change power cord :-)

 

I will check the tranformer connection later today.

post #25 of 27

If you hands can touch a piece of the chassis then you should-legally- be protected from any type of electric shock. And "static" is really a low current voltage leak. Thats why you just got a tingle . If your hands were wet from perspiration you would feel it more. .Therefore try a temporary earth  via small clips . The earth could be copper water pipes[make sure there is no plastic pipes in between] or even if you have a garden into the soil. If you are told --you cant do that as the chassis is isolated and it will blow your equipment then tell them --Then there shouldnt be any part of the equipment  bare to physical touch.capacitor leakage can also cause some microamps/milliamps  of voltage to appear on the chassis but again you should be protected from that and thats the Law.  ---Also there is a capacitor in a SMPS that is connected between the high voltage and-LOCAL earth in twin lead mains cable[no earth conductor] On power amp[loudspeaker]  amps this SMPS is "isolated" from the main PCB [by the Law] but all that means is it is a few inches away from the main layout[low voltage] part of it.Thats one reason I dont like them. You could easily when working on it come in contact with both parts so its NOT safe as far as I am concerned when compared to a non-switching transformer mains isolated  power supply. 


Edited by duncan1 - 9/14/13 at 4:40am
post #26 of 27
Ok I'm in 230v land now. The Fostex works fine using a aus\nz 3pin plug, no static or any shocks for the hour I used it for.

I can't comment on any sound difference since I'm still zoned from the 15hours of travel.

more testing tomorrow, I might upgrade the firmware to 2.13b and try out the v2 drivers (ASIO support now included).

EDIT: I seem to be having some slight crackling issues with the v2 drivers using ASIO and wasapi (both push and event modes). Rolling back to the 1.04 driver fixes wasapi. No problems with the 2.13b firmware though.

LAST EDIT: I have now been using it for over a week. I have had no shocks from this unit using a 3 pin AUS\NZ power cord. Also there is no change in sound signature by doing this voltage switch over. It also works fine with windows 8.1 using ether the v1.04 or v2 drivers.
Edited by A_Man_Eating_Duck - 9/26/13 at 3:40pm
post #27 of 27

Hi all.  this thread gave me the assurance to purchase a unit from Japan.

 

Would like to share that I have no issue using a unit from Japan (100v) in Singapore (230v) after changing the internal setting.

No static/ shocks.  Using a 3 pin power cord.


Edited by tropicana - 2/4/14 at 5:54am
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