I didn’t know wether to post this in class D or power supply. It‘s a class D amp, but the question deals with the Power supply lol. I found an amplifier that I’ve been lusting at for a couple of years now. Don’t see them too often, I have one now that runs on US power and the one I found runs on 230v 50Hz. I’m curious if i could swap some components and convert it to 120v. It’s a Yamaha PC9501N.
Looking at the service manual it seems all of the versions of this amp (100V, 120v, 230v) have the same circuit board. it would seem that they actually made a list of the differences between the amplifiers if I’m reading it correctly. The components needing swapped should be available, the four transformers may be the only tricky part. I’m going to call Yamaha parts to see if they can be purchased. Luckily I have a US model to use as a blueprint.
Here is the schematic of the power supply.
Here is a small key in the corner, this is the list I was figuring that had the differences between the amplifiers.
I‘d love thoughts from others. I have no problem doing the work, soldering skills and tools are up to the job, but curious if my thinking will result in a successful amp that runs on 120v 60Hz power.
Thank you,
Dan
Looking at the service manual it seems all of the versions of this amp (100V, 120v, 230v) have the same circuit board. it would seem that they actually made a list of the differences between the amplifiers if I’m reading it correctly. The components needing swapped should be available, the four transformers may be the only tricky part. I’m going to call Yamaha parts to see if they can be purchased. Luckily I have a US model to use as a blueprint.
Here is the schematic of the power supply.
Here is a small key in the corner, this is the list I was figuring that had the differences between the amplifiers.
I‘d love thoughts from others. I have no problem doing the work, soldering skills and tools are up to the job, but curious if my thinking will result in a successful amp that runs on 120v 60Hz power.
Thank you,
Dan
Leave the amp as is and simply buy a step up transformer to convert your 120Vac to 240Vac that feeds the amp. Need to make sure the VA rating of your step-up matches the total demand of the amp. There is very little impact of using either 50 or 60Hz mains and most equipment is designed to handle either.
That is safest, or the other way is to build another supply with +5, +15 , and again +15 volts.
But unless you have a problem, don't do it.
There is a place called Jackson Heights in Queens borough of New York City, which is having a lot of Indians, and in those stores the converters are easily available, as in other cities with migrants from 220V countries...you can of course buy on line.
500 VA transformer with 110V and 220 V windings should be enough.
Mains frequency will not be an issue, there seems to be no frequency sensing, the supply looks simple: step down + bridge, and filter capacitors.
But unless you have a problem, don't do it.
There is a place called Jackson Heights in Queens borough of New York City, which is having a lot of Indians, and in those stores the converters are easily available, as in other cities with migrants from 220V countries...you can of course buy on line.
500 VA transformer with 110V and 220 V windings should be enough.
Mains frequency will not be an issue, there seems to be no frequency sensing, the supply looks simple: step down + bridge, and filter capacitors.
Thank you both, I hadn’t thought about a transformer. Went ahead and grabbed the amp. I’ll take a look inside once in receive it, but will likely use it on the transformer for quite awhile. It would be nice if it matched my current PC9501N though.
Dan
Dan
1. Keep them in separate rooms, very easy to mistake the supply and fry parts!
2. Compare, you just might luck out and find there is a 220V tap on the primary.
Check with a meter, then with the transformer connected with a series lamp, AND SECONDARY DISCONNECTED, and if that is the case, you are going to be a happy man. Check the outputs on the suitable unit (existing one) as a comparison.
2. Compare, you just might luck out and find there is a 220V tap on the primary.
Check with a meter, then with the transformer connected with a series lamp, AND SECONDARY DISCONNECTED, and if that is the case, you are going to be a happy man. Check the outputs on the suitable unit (existing one) as a comparison.
Hello
I have a couple of PC9501n 120V amps. Bought from the US. But I live in Norway were we use 230V. So I use a stepdown transformer. Works OK.
But since I need 230V amp & and you need 120V amp, we can just swap amps🙂
But I guess shipping will cost a lot.....
I have a couple of PC9501n 120V amps. Bought from the US. But I live in Norway were we use 230V. So I use a stepdown transformer. Works OK.
But since I need 230V amp & and you need 120V amp, we can just swap amps🙂
But I guess shipping will cost a lot.....
Do a little research on the amp and see if the switch mode power supply is a universal one. Lots of switch mode supplies take anything from 90 to 250 volts AC with no changes. Verify this is one of those supplies before trying it.
