I have a Luxman L550AX that is a Japanese spec 100v version. I am using an external transformer but I want to move the internal jumpers to set it up for 120v 60hz.
I opened it up expecting to see something like the first picture (A Musical Fidelity piece that I am working on) where I can just move the jumper.
But then I opened the Chassis, it is much more crowded and the power inlet has no easily accessible jumpers. It looks like the power supply is under the grey shield marked in the picture.
Does anyone know how to change the input voltage on a Luxman L-550 AX? I am assuming that it is a simple jumper change and that the jumpers are located below the grey shield, but I do not have a schematic and I don't want to take this apart if I don't know what I have to change ahead of time.
I opened it up expecting to see something like the first picture (A Musical Fidelity piece that I am working on) where I can just move the jumper.
But then I opened the Chassis, it is much more crowded and the power inlet has no easily accessible jumpers. It looks like the power supply is under the grey shield marked in the picture.
Does anyone know how to change the input voltage on a Luxman L-550 AX? I am assuming that it is a simple jumper change and that the jumpers are located below the grey shield, but I do not have a schematic and I don't want to take this apart if I don't know what I have to change ahead of time.
Attachments
I've found a service manual, but not sure if it's for your amp--- and though is shows line adjustment taps, there are no details offered.
If you have an AC voltmeter and are comfortable with powered troubleshooting, you should be able to sort this out. I can offer advice, but don't want you to put yourself at any risk.
If you have an AC voltmeter and are comfortable with powered troubleshooting, you should be able to sort this out. I can offer advice, but don't want you to put yourself at any risk.
Followup thoughts: The enclosure in your picture looks very thin to accommodate a traditional power transformer. I'm wondering if it might house a switching power supply. If that's the case, there's some chance that it it can handle a wide range of supply voltages and that you don't have to change anything. Can you provide more detailed model and serial number info to explore this notion? Any info on rear panel about supply range?
In my experience JDM versions are just that JDM, no other voltage choices. I have a few JDM Luxman pieces and they are 100V only. I lived in Japan for 9 years and bought several other JDM pieces, all only 100V.
Craig
Craig
Thank you for looking into this.
The Unit is a Luxman L-550AX Integrated amplifier.
Marked as AC100V 50/60 HZ'
Serial Number is G5090XXXXD - I x'd out the last four. If you need the entire serial number I can send it to you.
Hi TWKhorn,
I'm afraid I'm not having any success in finding a schematic for your amp. The link below seems to be an owner's manual and its block diagram does not seem to suggest a switching supply, but that enclosure sure seems small. I find several L-550 variants, but none that I'm confident represents your amp. You could do some exploratory disassembly, but it looks arduous.
A thought is to try to fit a transformer into the corner compartment to perform the 115V to 100V voltage reduction. It appears power consumption is 230W, so 100VAC line current would about 2.3A. On that assumption, a possible candidate is: http://catalog.triadmagnetics.com/Asset/F7-20.pdf. Not sure there's room or if the idea has any appeal.
Craig in post above may be a good resource.
Good luck!
https://luxmanamerica.com/wp-content/uploads/2019/06/L-550AX_eng_AG00987C82A_110328.pdf
I'm afraid I'm not having any success in finding a schematic for your amp. The link below seems to be an owner's manual and its block diagram does not seem to suggest a switching supply, but that enclosure sure seems small. I find several L-550 variants, but none that I'm confident represents your amp. You could do some exploratory disassembly, but it looks arduous.
A thought is to try to fit a transformer into the corner compartment to perform the 115V to 100V voltage reduction. It appears power consumption is 230W, so 100VAC line current would about 2.3A. On that assumption, a possible candidate is: http://catalog.triadmagnetics.com/Asset/F7-20.pdf. Not sure there's room or if the idea has any appeal.
Craig in post above may be a good resource.
Good luck!
https://luxmanamerica.com/wp-content/uploads/2019/06/L-550AX_eng_AG00987C82A_110328.pdf
Thanks. Taking this apart does look very time consuming and I have an outboard transformer that I can use for now.
Thanks for the info. What is a JDM? Japan Designated Market or something similar?
Thanks for the info. What is a JDM? Japan Designated Market or something similar?
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Got it, thanks. So their doestic products have no way of changing voltage for USA or Europe. I have an external transformer but might add one of the transformers above if it will fit.
I like the idea of adding a good quality internal transformer. I measured the space and the one that you recommend looks like it will fit as I have 2.75" in one direction and 2.25" clear of the auxiliary outlets in the other direction and a good 4" to the opening for the wires to the next chamber.
I cannot find the winding ratios for the inlet and outlet and I assume I need a 1.2 : 1 ratio to get from 120v to 100v. Sorry for the novice question, but 120v power in looks like it goes to taps 2 and 4, but where do I wire the 100v power out? 6, 8 and 10 are the options. Is polarity an issue?
The inlet power also powers up a small circuit board to power the two auxiliary outlets. These do not show in the manual and the back states that they are unswitched. It does not look like either can be switched as there ar no wires going to them or relays. I will check with with a meter to verify. If one is switched I need to figure out if 120v to them is OK as this will be before a splice that I make.
OK, I checked and the auxilary outlets are unswitched so nice and simple. I guess the only other question besides what taps to use on the transformer is do I put the magnet on the wire before or after the transformer? I ussume before.
You cannot use the tiny little free space in the corner to insert a transformer for the voltage reduction, the space isn't big enough as said transformer needs to be AS BIG as the amp’s power transformer...
The spec sheet of your amp shows the draw at 230W at max, with an idle of 170W -
You need, at minimum, a 300VA transformer for your 120 to 100v transformer. You don't want to run a transformer at 100%, so a little bigger is required.
The linked transformer above is completely wrong for the job. It’s 115V to 20V, and a little less than 60VA. It will not work. (perhaps he sent the wrong link?)
The long story short is you have two options -
1) Use an external transformer like you have been, or
2) Get a replacement transformer from Luxman that has the proper voltages and swap it. If that is a part available separately, which it very likely isn‘t. :/
The spec sheet of your amp shows the draw at 230W at max, with an idle of 170W -
You need, at minimum, a 300VA transformer for your 120 to 100v transformer. You don't want to run a transformer at 100%, so a little bigger is required.
The linked transformer above is completely wrong for the job. It’s 115V to 20V, and a little less than 60VA. It will not work. (perhaps he sent the wrong link?)
The long story short is you have two options -
1) Use an external transformer like you have been, or
2) Get a replacement transformer from Luxman that has the proper voltages and swap it. If that is a part available separately, which it very likely isn‘t. :/
Triad specs the voltage ratio as 115VAC in and 20VAC out, so a voltage ratio of 0.174
We've been targeting line voltage of 120V, so when the Triad transformer is with driven with 120V, it will deliver 20.9V You arrange the phasing to subtract 20.9V from 120V to deliver 99.1VAC to the Lux input. As mentioned earlier, the current drawn by the amplifier at 100VAC is 2.3A. Thus power handled by the Triad is about 20.9V*2.3 A = 48Watts, well within the Triad specs.
I'll attach a sketch if this isn't clear.
We've been targeting line voltage of 120V, so when the Triad transformer is with driven with 120V, it will deliver 20.9V You arrange the phasing to subtract 20.9V from 120V to deliver 99.1VAC to the Lux input. As mentioned earlier, the current drawn by the amplifier at 100VAC is 2.3A. Thus power handled by the Triad is about 20.9V*2.3 A = 48Watts, well within the Triad specs.
I'll attach a sketch if this isn't clear.
…you want to buck with the triad instead of doing a straight transformation. Ok, that makes a bit more sense, but yes, please draw it out.
Wow, thanks everyone. This does make sense and great references. I did see the 20.v rating of the F7 but it did not occur to me that this would be subtracted from the input voltage.
The space where this can be installed is not very big and is not vented. If the transformer is handling 48 watts is it simply passing it along (and running cool) or dissipating it as heat?
Again, sorry for the novice questions.