MPS-1 power supply

[scenaria]

Hi,

I have an MPS-1 that recently went dead. I have narrowed it down to the toroid transformer. It must be shorted as it keeps blowing fuse 3. It provides a 12v and 36v secondary to the chassis. I searched everywhere for a similar transformer and am having problems locating one. Most secondary’s are simple centers taps. Like dual 18v etc.

Does Emotiva sell repair parts or could you point me in the right direction for a replacement transformer?

The numbers on it are
H0010-027 (EM07200-10W)

It’s hard to accept the amp being trashed because of a simple transformer

Thanks a bunch

Steve

[KeithL]

We no longer have replacement transformers in stock.

The transformer has dual secondaries - 12 VAC and 36 VAC.

Any transformer that provides at least 500 mA at both voltages should work.

You could even use two separate transformers - one for each voltage.

Just make sure that, if you use a single transformer, the two windings are separate (not connected together at all).

(The tricky part will be finding one that physically fits in the available space.)

Also remember that, if a transformer has a center tap, you are not required to connect it.

If you find a 36 VAC center tapped transformer, simply cut the center tap wire short, and insulate it.

The same goes for the 12 VAC transformer.

(If you don't use that wire, then you must insulate it, so it doesn't short to anything else.)

Jun 24, 2019 8:13:41 GMT -5 scenaria said:

Hi,

I have an MPS-1 that recently went dead. I have narrowed it down to the toroid transformer. It must be shorted as it keeps blowing fuse 3. It provides a 12v and 36v secondary to the chassis. I searched everywhere for a similar transformer and am having problems locating one. Most secondary’s are simple centers taps. Like dual 18v etc.

Does Emotiva sell repair parts or could you point me in the right direction for a replacement transformer?

The numbers on it are
H0010-027 (EM07200-10W)

It’s hard to accept the amp being trashed because of a simple transformer

Thanks a bunch

Steve

[scenaria]

That’s a bummer. So what your saying is once I fix it, sell it! Because what if the large amp toroids go bad? There’s no way those can be replaced

[KeithL]

Not really...

If the main big toroidal power transformer in any amplifier were to fail it would be bad.

They're big, heavy, expensive, and most of them are more or less of a custom part (if you want one that fits the mounts properly).

However, for whatever reason, while the little ones fail from time to time, big power-amplifer-sized toroids almost never fail.

Jun 25, 2019 10:01:35 GMT -5 scenaria said:

That’s a bummer. So what your saying is once I fix it, sell it! Because what if the large amp toroids go bad? There’s no way those can be replaced

[scenaria]

It’s back up and running again.

I’m stoked

[GreenKiwi]

Did you fix something? Or did it fix itself?

[scenaria]

Woke up one day and the amp wouldn’t turn on anymore. No led’s, no relays.

Messed with checking the main fuses and they were good, but when I checked them the plastic broke apart, very brittle.

So one problem led to another, had to replace the two fuse holders. And found fuse 3 which is on a small relay board was toast.

Got my hopes up and replaced it only to see it pop over and over.

Ended up isolating the small toroid from the rest of the circuit (only mains through fuse) and it still popped. which convinced me the toroid was shorted.

The toroid has a 12v and 36v secondary. Finding one with those values was impossible.

I ended up getting two sepperate toroids. One 12 and one 36z
The only issue is I had to install that first amp card with the lid off and some side panel screws loosened up. Because the metal plate on the amp card could not make it past the new transformers. So the modulari aspect for channel 1 is gone. But it works just fine . Oh and I had to increase fuse 3 to 2.5 amps because the new toroids were bigger. One was 25va and the other was 15va compared to the original being a 14va.

[Casey Leedom]

I've had an issue with my MPS-1 for the last few years ever since I briefly shorted across one of the pairs of speaker outputs — a cable with a metal jacket fell and landed in just the wrong manner ... (sigh)

Ever since then, any time I completely power down the amplifier, in order to power it up again, I need to hold down the front-panel power button for about 60s. Other than that, everything seems to be working ...

Casey

[scenaria]

Have you ever pulled the amp card that was shorted out of the chassis to see if you still have to hold the power down ?

[Casey Leedom]

Nope. I can't even remember which one it was now. Maybe the Center? But it might be good to pull them all out and inspect fuses, etc.

Casey