@dbxdx5 

While it is not necessary to bias the power amplifier after voltage conversion, I thought it would be a good idea to record the rail and bias voltages before conversion for future reference.

 

Thanks for confirming. Do you tweak the bias after doing a voltage conversion?

@dbxdx5 

Yes, switch the voltage from 100V to 120V, leave jumpers J1 and J3 unchanged.

 

@imhififan 

 

Just confirming that for the E-470, switching the voltage from 100V to 120V requires only moving the connectors from K3 to K5 and K4 to K6, with no change to the jumpers J1 and J3.

https://ibb.co/4fT3dys

https://ibb.co/WWfHVj6

 

Hello, I would like to request advice regarding changing the voltage of Accuphase A75 from its Japanese 100V model to 230V. While I have experience with voltage conversions, this is my first time working on an A75 model, so your assistance is greatly appreciated.

The basic modification plan involves rewiring the main transformer wires in parallel, replacing the fuse with an 8A slow-blow fuse, and changing the relay jumpers from J1 and J3 to J2. I intend to include circuit photos for reference. I have already measured the resistance allocation of the main transformer wires using an LCR meter.

https://drive.google.com/drive/folders/1jEZNpgb04ZSw6yBU3Tum0yNrq4RdXZ6P?usp=sharing

1. Orange - 120V Red - 100V Grey - 0V

2. Yellow - 120V Brown - 100V White - 0V

To achieve 230V, I believe I need to connect Orange to Grey and Yellow together in parallel, leaving White as it is. If you have any advice or suggestions, please share them. Thank you!!

The Transformer is tiny 2VA, such of high resistance.

The brown and blue line is from same source, meaning hot wire.

@leecc73

I think the fuse is non reset-able and able to withstand till 300v. here the model i find

Littelfuse 36911000000 369 T1A 300V Fuse micro fuse Time-Lag Radial Lead Square Fuse.

Thanks for the info, in that case, the fuse will blow if exceed its power rating. However, IMO, 1A fuse is too high and unable to protect this transformer.

The funny part is i was not able to measure any resistance after the fuse, meaning the 2 legs of the transformer, i suppose it have few milli ohms.

That’s weird! unless the primary winding is shorted (due to over voltage?), it should has more than 10 of ohms resistance for such a small transformer. I got reading of 24ohms on primary winding of a 24VA transformer and 36ohms on a 12VA transformer. You should measure it with the blue and brown cable disconnected to get accurate reading.

 

I think the fuse is non reset-able and able to withstand till 300v. here the model i find

Littelfuse 36911000000 369 T1A 300V Fuse micro fuse Time-Lag Radial Lead Square Fuse.

The funny part is i was not able to measure any resistance after the fuse, meaning the 2 legs of the transformer, i suppose it have few milli ohms.

 

Sorry, I don’t know what kind of miniature transformer is it. Measure the size, lead spacing and the output voltage and see if you can find a replacement for 230V.

If i turn it on with higher voltage, will it burn? or the fuse will gone.

or i just simply not able to turn on?

The fuse (F1) will trip open circuit if connected to higher voltage, it will reset itself when that voltage removed. So it’s unable to turn on at all!

what is see the red wire kind of link (by pass) from this board and go over to the next board which allow for the main transformer to have the voltage change.

You can remove F1 ( just to be safe) and bypass the RELAY1’s contacts to allow the main transformer to have voltage change. However, the front power switch will be bypassed as well! You also need to check where is K3 connected to and see if it can work without power supply to this board.

Relay is 18VDC power by transformer (from K2) thru smd Z622.

Im not sure what is z622? , i assume its rectifier to supply 18VDC to relay.

I believe D3 (Z622) is a full bridge rectifier.

BTW, perhaps you can try remove F1 and add a small transformer with 120V primary in series to the existing transformer primary winding to make it work for 220V mains.

 

 

 

i remove the board out.

Here what i understand, K2 input (brown) will switch to K1 (red) after relay turn on once power button press in and direct the current to sec board .

Relay is 18VDC power by transformer (from K2) thru smd Z622.

Im not sure what is z622? , i assume its rectifier to supply 18VDC to relay. or any double voltage will damage the z622?

 

 

Thanks for the analysis, do you know what kind of miniature transformer is it?

If i turn it on with higher voltage, will it burn? or the fuse will gone.

or i just simply not able to turn on?

what is see the red wire kind of link (by pass) from this board and go over to the next board which allow for the main transformer to have the voltage change.

@leecc73

Thanks for the photos.

I think the brown and blue cables are "live and neutral" come from the AC mains IEC socket, the small transformer is connected to it via a resettable fuse (F1), and the K4 is connected to the front panel power switch.

When the front panel power switch engaged, RELAY1 energized and close the contacts to power the main transformer.

I believe Accuphase made three versions of this board for 100V, 120V and 220/240V mains. If you want to convert to different mains voltage, a new board or install a small transformer with correct primary winding for the applied voltage is needed.

 

 

If only shift the 2 row pin plug should be easy

This from E5000,  i think soft start.

as usual , if not wrong the plug need to shift for 230V, any suggestion?

 

@leecc73 

It look like a stand-by board, what is the amplifier model number? Can you post a photo of the back of this PCB? Where those brown, blue and red cable came from? 

 

HI, can anyone help to advice this device need to change anything, it seem like nothing i can shift here? does it work ? from 110 to 230V if turn on without changing anything?

 

 

@jsch9876 

Hi Jason, E-650 and E-800 are class A integrated amplifier, the E-380, E-4000 and E-5000 are class AB integrated.

Sorry I have no experience of E-5000 voltage conversion, I think its power board is different from E-650 and E-800. Maybe it's similar to E-370, E-470 or E-480 which is utilize jumpers. 

 

@imhififan

Hello Sir, is E-5000 same as 650, 800, etc...?

 

Thank you in advance, 

 

Jason

Victor,

I'm glad you figured it out.

👌✌👍

@imhififan 

I checked everything, the amplifier is working normally from 220V.  Thank you again!  Good luck! 

Sincerely, Victor 

Two possibilities:

1. The incandescent light bulb too low in wattage

2. Short circuit

@zeptul

According to the specs E-650 draws 168 watts @ idle. Please try a 250 or 300 watts bulb. If that does not light up the amplifier, you need to check the soldering of all connectors.

 

@imhififan Incandescent lamp power 100 watts

When the amplifier is turned on through an incandescent lamp, the amplifier indicators do not light up. It should be?

What’s the wattage of the incandescent lamp?

 

Hello @imhififan , thanks for your support of audio hobbyist!

I used your instructions and switched the E-650 to 220-240 volts:

I moved the connectors to the third row (K7, K8), disconnected the jumpers J1 and J3, installed the jumper on J2. When the amplifier is turned on through an incandescent lamp, the amplifier indicators do not light up. It should be?

Watch the video:

https://youtu.be/GRjwPxrW2sE

 

Just a hobbyist? One of the most knowledgeable “hobbyist” on this forum!

Perfect. Thank you!

@budburma

https://www.usaudiomart.com/details/649010738-accuphase_a46_class_a_power_amplifier/images/466883/

 

This is awesome. Is there similar conversions for their class A amps? Like the A36 or A46?

I think it makes sense to remove J5 and J6 but add J4.

Yes, you got that right.

This works as well for the soft start circuit:-)

Congrats! Thanks for letting us know.

 

This works as well for the soft start circuit:-)

@imhififan good question with J4, J5 and J6.

I recognized you have mention something similar for the E600 above in context of soft start resistor settings. Any idea if I have to change these jumpers, too?

 

I think it makes sense to remove J5 and J6 but add J4.

Then there is the maximimum resitor value set.

I have manual of ps510 and there is also a kind of soft start circuit like this.

works as expected:-)

Good job! @systemroot👍, thanks for sharing!

BTW, have you figured out what J4, J5 and J6 for?

 

works as expected:-)

Hi @imhififan

 

hope it works with the pics:

(link Icloud: https://www.icloud.com/iclouddrive/04bYXYU4boecaHce1E39q0HMA#Voltage)

(link dropbox:

)

My guessing:

DP900: just change the two black wires with the two brown wires.

DC901: As you said only change the jumper from J1 to J3

What do you think man:-)

I have manual of the DP800/DC801 looks bit similar.

 

@systemroot 

Thanks! I'm just a HiFi hobbyist, Not a specialist at all🙂!

Sorry I don't have any experience for voltage conversion of Dp900 or DC901. However, some Accuphase CD player utilize low power transformer with jumper setting, J1 for 100V, J2 for 120V and J3 for 220-240V, IIRC.

If you can post a picture of the power board, perhaps we can figure out how to convert the voltage.

 

HIi @imhififan,

you are a specialist as I understood:-)

I want to switch my Dp900 & DC901 from 100v to 230v. Any idea if thats already discussed here in an other post? Or do you have an explanation already?

In the older models it was much easier to do as it was described more or less in the device itself...

Thanks in advance.

@imhififan Many thanks!!!

Yes, Fill the empty holes in K3 and K4, it will increase the mechanical strength of the PCB especially holes with through hole plating. 

Hope this helps

@imhififan I'm sorry for my typo, please ignore my previous questions. What I meant is: after desoldering K3 to K5, K4 to K6, do I need to fill the empty holes in K3 and K4 with lead or they are ok to be empty?

@imhififan I really appreciate your sharing! This doesn't only help me but also those who have the same need in the future. 

Your answers address more than what I have asked!

I have another question though, after desoldering K3 to K5, do I need to fill the empty holes in K3 and K5 with lead or they are ok to be empty?

@quanghuy147 

To convert the voltage from 100V to 120V, Move K3 to K5 and K4 to K6 position.

Voltage conversion on E-600, E-650 and E-800 basically similar, first row of connections for 100V, second row for 120V and third row for 220/240V.

For 100V and 120V mains, soft start resistors jumpers and fuse value remain the same.

For 220/240V mains,disconnect jumper J1 and J3, install jumper wire on J2, change fuse accordingly.

Accuphase design those built in power transformer for worldwide voltage, I don't think voltage conversion will affect sound quality.

I hope I've answered your questions. 

@imhififan My amp is E-600 (not E-650 as others’ in this thread). I am trying to convert the voltage from 100V to 120V.

Could you check the 3 pictures below and advise where these K connectors need to be moved?

https://photos.google.com/share/AF1QipOJ7YKjzYGWVqR70tglZFofPXrJeFzNjQd6v0qq0eVNDXgSI5qqQB6fRQ7QBufIbg?key=Wm8xMlRzeklvbmg2c2JwOTl3STZUVTV3NUJzYTdR

Many thanks!

 

 

Hi everyone, 

I have the E-600 amp and I am thinking of converting the voltage for it. 

Does this conversion change the sound quality? 

If I don't have dim bulb tester, is there any other way to test?

Thank you.

Is there any guide how should 230v/240v label should be? I am eyeing for a 220v pre-owned unit but need to convert that into either a 230v or preferably a 240v version
Appreciate some advise

@eugene81
Congrats! Thanks for posting the photos.

I went ahead and did this myself and tested successfully with a dim bulb tester.

The amp sounds fantastic! It is somehow both crisp and clear, yet rich and slightly warm, with great texture and soundstage depth.

For others who might use this thread for reference, here are some more photos of the board removed, ready to work on, and post-conversion:

https://photos.app.goo.gl/7rQ1gaZM6zDN1E47A

Initially I thought it was one big board so I was going to take it to a pro. After being turned down by my usual tech (turns out they are an authorized Accuphase repair center and thus were told by Japan they couldn’t do it), I took another look under the hood and found that the connectors are actually on a smaller board secured by just 3 screws. I unplugged the 2 harnesses, 3 wires (blue, yellow, brown), and boom--easy access.

Thank you!

https://photos.google.com/share/AF1QipOGrOpMMqsYdBSgXH2RZ5WAQr8ECpSKQ9lZeFPP-kK9lqHx94MR8pkv-HWnDXZq...

connector K3 needs to be moved to K5 and connector K4 moved to K6 as pictured here?

Yes.

@imhififan Yes, that's the board.  Sorry, let's try this again:

https://photos.app.goo.gl/qknm4Js8Pe2t58rR9
https://systems.audiogon.com/systems/3753#&gid=1&pid=1