I need to build a power supply for a Musical Fidelity M3 Nu Vista Integrated Amplifier.
Is it feasible to undertake this as a newbie?
What would the potential cost be for the entire project.
Where does one start?
The backstory
I won the M3 in a Thiel Audio liquidation auction. It didn’t come with the power supply so I’m investigating building my own.
Is it feasible to undertake this as a newbie?
What would the potential cost be for the entire project.
Where does one start?
The backstory
I won the M3 in a Thiel Audio liquidation auction. It didn’t come with the power supply so I’m investigating building my own.
it seems its just transformers. Its not that hard, but you need transformers and, and to know the voltage/VA rating, and of course the pinout. If you get this wrong you may damage the amplifier. Look around the web for a service manual. One other thing, are the power plugs speakon? If so it shouldn't be hard to buy these, if they are propriety, you may need to replace them.
http://www.hifishock.org/galleries/...-amplifier/nu-vista-m3-1-musical-fidelity.jpg
http://www.hifishock.org/galleries/...-amplifier/nu-vista-m3-1-musical-fidelity.jpg
I have the schematics from Musical Fidelity. They sent them to me this morning. Problem is, I've never designed a power supply or any electrical components for that matter. Translation: I haven't the foggiest idea of how to read the diagram. I'd like to learn for this project, but would need some help.
They look like speakon's. See the attached diagrams.
Copyrighted material removed by moderation. Just read some reviews about this and it seems like a nice amp. If you are not able to read schematics this is probably not a good place to start. Why not get someone to build it for you? I think you are also missing the power amp psu diagram.
So You have four white Powercons...
Standard is Blue for 115/230 V inputs (Think as a plug) and white for outputs (Think as a Harness).
There are two standard colors in order not to short connections. One for In and another for out.
I believe Your outputs are secondary rectified transformer outputs.
I wouldn't use Powercons here...I would use some other type of connectors.
What happens if You actually connect You amp or pre-amp to a standard powered speaker 115 /230 V white output ?
Accidents happen You know.
I can't believe manufacturers doing such strange things... well The Chinese use 3 pin XLR for 5 pin XLR DMX standard, but those adhere to their standards..
Standard is Blue for 115/230 V inputs (Think as a plug) and white for outputs (Think as a Harness).
There are two standard colors in order not to short connections. One for In and another for out.
I believe Your outputs are secondary rectified transformer outputs.
I wouldn't use Powercons here...I would use some other type of connectors.
What happens if You actually connect You amp or pre-amp to a standard powered speaker 115 /230 V white output ?
Accidents happen You know.
I can't believe manufacturers doing such strange things... well The Chinese use 3 pin XLR for 5 pin XLR DMX standard, but those adhere to their standards..
For a newbie it is not complicated to build, but for a newbie who doesn't understand schematic symbols...
According to the schematics the PSU SK3 connector delivers 90V for the amp rails, but the amp schematics talk about 80V.
Ask them for the power transformer ratings, since the rest is not difficult to understand.
Three transformers 3 bridges and caps.
For muting a couple of transistors and resistors.
The PTC's are here and You need them or You'll blow fuses on power-up.
B59955C0120A070 EPCOS (TDK) | Circuit Protection | DigiKey
Start learning electronics here first to get You going
DIY Audio Articles
Check the PSU section. The whole site has valuable information.
According to the schematics the PSU SK3 connector delivers 90V for the amp rails, but the amp schematics talk about 80V.
Ask them for the power transformer ratings, since the rest is not difficult to understand.
Three transformers 3 bridges and caps.
For muting a couple of transistors and resistors.
The PTC's are here and You need them or You'll blow fuses on power-up.
B59955C0120A070 EPCOS (TDK) | Circuit Protection | DigiKey
Start learning electronics here first to get You going
DIY Audio Articles
Check the PSU section. The whole site has valuable information.
Do not plug anything into the M3 until the replacement power supply has been well tested,
with dummy loads on its outputs. You don't want to cause expensive damage to the M3.
I received the M3 yesterday. Now I've gotta get serious about designing a power supply for it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Might be worth contacting John Sampson here in the uk, he offers a range of mods and upgrades for MF kit. Hes a commercial operation but he might be willing to help out with the basics.
JS Audio Repairs >> Upgrades
JS Audio Repairs >> Upgrades
This PSU is a bit out of my league so I'd rather not get deep into it. I would like to hire someone else to build it for me.
I'm not sure what you mean by "build a PSU for the amp".
What is it you want to improve: the preamp, the power amp, the capacitors, add regulators?
Be aware that you will be messing with an integrated amp made by a reputable manufacturer, so I wonder what you don't like in it or what you are looking for.
The fact that you have no experience in DIY is a major concern. Even those that do know mess up things, so if you have none, I wonder what you have been reading that made you think of changing this design.
Can you be more specific on what you are looking for?
There's that saying if it isn't broken, leave it alone, or something like that, that does apply here.
What is it you want to improve: the preamp, the power amp, the capacitors, add regulators?
Be aware that you will be messing with an integrated amp made by a reputable manufacturer, so I wonder what you don't like in it or what you are looking for.
The fact that you have no experience in DIY is a major concern. Even those that do know mess up things, so if you have none, I wonder what you have been reading that made you think of changing this design.
Can you be more specific on what you are looking for?
There's that saying if it isn't broken, leave it alone, or something like that, that does apply here.
Little late to the party, but as a nu-Vista m3 owner myself, I can tell you that it would be fairly trivial to build a PSU for the amp. There's nothing complicated about the "outboard power supply box." Actually, considering all the rectifiers are in the main integrated unit, maybe it should be better termed, the "power switch and transformer box." 3 toroidal transformers, 1 for each channel of the amp, and 1 for the pre-amp board. 2 Large relays and a small circuit board also live in the box (likely just to power on that power LED). If need be, I can take a few pictures/draw a few circuit diagrams.
Thanks!
verkion
Thanks!
verkion
The M3 has an outboard power supply. I believe it is not really a true power supply but more of an external housing of the transformers and a few other items (maybe a soft start.) I believe the rectification and filtering occur in the integrated amp unit. So I think mostly he needs to get the proper AC voltage going to his amp from the transformer, of which there are three. I just noticed this is an old post, so I wonder how things worked out for him.
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Wow, separating trafo and rectifier means a cable carrying all those high current charging pulses, wait.... I think my radio can pick them up from here....
Yep...that's exactly what is in there. Transfos, light, switches, a relay or two.
I have to verify that the board in there is for soft start (gotta crack it open to check).
I'm in the process of re-capping my unit and maybe making a few minor tweaks here and there which is why I have been searching online to see what people have been doing with their nu-Vista M3's, stumbling across this page in the process.
@Intelonetwo How did it work out? Considering only 500 units were ever built, it'd be a shame to see one of them "non-functional" (and odd that it was missing an outboard power unit).