[deanorth]

hello there

Stephane, from France:)
In my homecinema setup, gear wise, I own an Anthem AVM90 pre amp, and for powering my surround, surround back and atmos, a Nuforce MCH 300SEC7.
I was very, and I mean very happy with it, despite channel 4 was not working (I have bought it second hand 1 year ago), but the sound was really great. It was powering for Sr, waterfall Victoria EVo, Sr back Hurricane Evo, and 4 focal atmos. My central speaker is powered by a mono amp. My front are stuck with my hifh gear, based on Mola Mola products
So not very power hungry things.
Two months ago, I started hearing "poc" on my speakers when the amp was powering up. And since the XLR base were kinda lose, I decided to change them. A friend of mine know a guy that was an electronician tech guy, and was ok to solder the XLR embase. he also took a look at why the channel 4 was not working, and.... the conclusion he drew were kinda an horror to me:
- the PSU is at max 60% of it's original capacity
- all the the condo from the two control area are tired or close to not beeing good anymore, and need to be changed
- channel 4 is at 40% capacity, that's why it's on fault and no powering up
- all the other channels are between 50-55% capactiy

which means I need to rebuild everything inside, which will cost around 3K euro...
considering I have bought it 1.5k euros, that's a lot, but that amp was 6k euro new, so that still sound logical

yet, I was not aware that the power unit could kinda "crumble" like that, efficiency wise. Condo, I know they grow old, but I thought we were talking 20/30 years lifespan, not 10 or less. And the class D module, 55% overall capacity, how is that even possible?

Yeah, I know close to nothing about how electronical component work, I have no shame in that, it's not my area of expertise. But I have a hard time saying to myself I'm going to throw that amp away, so if anyone got any experience and can tell me if what i'm going through is normal in the life of a product....?

[FullRangeMan]

What is Condo?
How old are this equipment ?
Do you mean say output Watts capacity or power supply capacity ?

[deanorth]

Sorry, my french...
Capacitor I mean:)

It's about 10 years old.
That, I don't know, the guy that perform the check told me there is only xx% left. I don't think it's about watts, because both the power supply and the amp channel were involved.
So if I try to translate, for the power supply, he meant % capacity left, and for D amp, maybe output watts capacity?

[FullRangeMan]

Seems what this tech guy are saying are strange ?

[Speedskater]

Maybe you could find someone that specializes in audio equipment repair.

There was a long period of time, when electrolytic capacitors, unexpectedly failed.

[rotarius]

You are not going to get the reliability of vintage amps like Pioneer and yamaha from these small boutique outfits, sorry.  For example, Topping amps that measure great and get high praise from the ASR crowd but prone to failure due to heat issues.  Maybe, your situation is similar?

[richidoo]

Bad caps can cause the issues you describe. Like speedskater mentioned, there was a rash of junk electrolytic caps that came out of china about 10-20 years ago back when NuForce was in business. Counterfeit electronic parts are still prevalent.

IMO, it should not cost 3k euro to replace the caps. I would try to get another quote for the repair, from an audio equipment specialist if possible.  You might have to mail it away but that is common for audiophile grade repairs these days.

If you can't find another technician I would recommend buying a different amplifier rather than investing more in the old NuForce.

EDIT:  Emotiva makes good amps, like a 5 channel class AB for $1900 USD

https://emotiva.com/collections/amps

[mjosef]

Caps in a SMPS type 'power supply' takes a beating, when the esr 'drops' below certain level the power supply will not 'fire' (stabilize)...I had this happen with Hypex power supplies caps, after about 10 years of constant powered on, one of the power supply (in a NCore NC400 build) had to have the power caps replaced.

https://www.electronica-pt.com/images/fbfiles/files/JOURNAL_OF_CONVERGENCE_INF.pdf

[listenermark]

I agree with richidoo that Emotiva makes good-sounding gear. However, my Emotiva Bas-x integrated amp crashed just outside the three year warranty. Emotiva repaired it for a flat rate of 149 dollars and six months on it's working like a champ.

[deanorth]

Hi friends

thanks for all the reply. Sadly Emotiva is not distributed anymore in Europe.
I'll try to find another electronician specialist, to get a second opinion.

[deanorth]

Hi everyone. Got my amp back. I definitely need to find a new PSU for the MCH300 sec 7, that plus a amp module. But the PSU is key there. Anyone know a source to get one? Nuprime wouldn't respond sadly.

[novice]

IMO, it should not cost 3k euro to replace the caps. I would try to get another quote for the repair, from an audio equipment specialist if possible. 

100% agreement, that is an outrageous charge for a recap. Unless the switching PSU is custom with non-standard voltages would explore finding new ones. If not, a recap should not be that tough. Below is a pic of an open-frame, multi-voltage, switching PSU. There's not that much going on -