NAD C320BEE - JH Capacitors

[seanc]

As I may have mentioned elsewhere, I'm tasked with a NAD C320BEE.

All of the smaller caps in this are JH CD110 series rated at 85˚C

Bought new in 2002, it developed a start-up problem where it would need to be left on for an hour before it would come out of protect mode & power up.
This went on for some years until 2009 when it was replaced.

I'm finding loads of bad caps, I just can't believe it. Someone confirm I'm not going mad.

I noted that the two 15000µ 50v capacitors had bulged - I've replaced them.

Next I found a 100µ 6.3v cap measuring 70µ 1.49Ω ESR. Replaced with 100uf 25v Panasonic FM - still not working.

2 x 220uf 35v cap 89.02µ 3.4Ω & 67.26µ 3.6Ω - replaced with 220uf 50v Panasonic FC
2 x 220uf 50v cap 125.4µ 0.50Ω & 123.2µ 0.38Ω - the capacitance of these are close - replaced with 220uf 50v Panasonic FC
These last four caps mentioned, all have their blue sleeves turned slightly green, maybe from heat.

Last but not least 1 x 330µ 16v cap 96.40µ 5.1Ω - T style Panasonic vent - replaced with Panasonic FM.
This one is a green/grey.

So, these JH caps are just crap right?

I realise FC and FM may not produce good sound, but once I can get the amp powering up properly, I can look to using different caps if necessary.

[PCBONEZ]

Re: NAD C320BEE - JH Capacitors

Sound like crap to me...
And an 85˚C rating isn't helping them any..
.

[willawake]

Re: NAD C320BEE - JH Capacitors

i heard those units run real hot
they are supposed to have nice sound
i dunno about FM and FC having bad sound i would have thought they would have been very nice for that.

needing to be left on for a long time would be classic badcaps, ie the caps having disgusting esr when cold and it coming down to a usable level when warming up

[seanc]

Re: NAD C320BEE - JH Capacitors

They do have a nice sound.

I also had a 320 (not BEE) of my own. Same 15000µ 50v capacitors failed - but none of the others that I noticed.

I think I read a thread once that someone had replaced the caps in their amp (I can't remember what type) with FM and the sound was less than stellar, but perhaps I'm mistaken.
We'll see soon enough.

[weirdlookinguy]

Re: NAD C320BEE - JH Capacitors

I've heard a lot of good things about the C320BEE.

[PCBONEZ]

Re: NAD C320BEE - JH Capacitors

I've heard a lot of good things about the C320BEE.

If you are referring to my post I was talking about the JH capacitors.

[weirdlookinguy]

Re: NAD C320BEE - JH Capacitors

I meant that I heard it was a good amplifier. There's no dispute that the caps they put in there are shitty.

[seanc]

Re: NAD C320BEE - JH Capacitors

Having now changed all of the caps in this amp for Panasonic FC/FK/FM, bar two larger ones next to the 15000µ 50v caps, it now runs perfectly.

Almost all of those JH caps tested bad on the ESR meter, the really bad ones having discoloured sleeves, but not bulging.

Thank goodness NAD built a large 'service' panel into the bottom of the amp, meaning that the main board didn't have to be removed.

[linuxguru]

Re: NAD C320BEE - JH Capacitors

Panasonic FM should be fine, but FC and FK may sound too harsh if they're in or near the signal path. However, all three caps will probably outlast the other electronics in the amp, so it should be good for a decade or more.

I personally found the stock NAD320BEE to have an edgy solid-state sound, with significant amount of audible IMD (intermodulation distortion). The sound is nothing special, just typical low-end consumer-grade audio. Most gainclones sound better.

[seanc]

Re: NAD C320BEE - JH Capacitors

Yes I've read about that, however at least for now it's working properly, which is a step in the right direction.

I need to move it from the garage to inside - it certainly sounds better than the Sherwood home cinema receiver I was using in the garage.

[Scenic]

Re: NAD C320BEE - JH Capacitors

lol.. i found those JH craps mostly in noname chinese DVD players (Denver, Yamada, Red Star, Mustek, ...)



what scared me a bit was that all of the smaller ones (8mm dia) had a panasonic style T-vent

[seanc]

Re: NAD C320BEE - JH Capacitors

Yep, those are the ones!

[junkmansam]

Re: NAD C320BEE - JH Capacitors

What a timely thread and some great information.

A friend of mine gave me his C320BEE about 10 months ago because he said the amber led would just stay on and it wouldn't power on to green led. I'm tempted to dig in to it after reading the OP's good results. I'd like to use the best cap sonically if any of those JH caps are in the signal path but I doubt if any are.

Any other tips would be greatly appreciated.

[junkmansam]

Re: NAD C320BEE - JH Capacitors

Well I got around to this finally. Opened it up and found that nearly every cap in my NAD C320BEE had these JH caps. Some of them randomly were brownish color (burnt). I plan on ordering all replacements using high temp FM caps. Funny thing is the caps on the power board all look normal. Looks can be deceiving I guess.

Shame on NAD for not going with reliable caps for this one.


Is there any other specs(besides size and lead) I should be aware of before ordering? Thanks

[seanc]

Re: NAD C320BEE - JH Capacitors

Even the 15000µ - not wobbly or bulgy? Fair enough. You'll soon know they're bad if you crank up the volume and the unit starts dropping into protect mode.

Physical size is a must.
It was either the 2200uf or 220uf 63v capacitors that I ordered for mine which were too large in diameter. I ended up installing them crooked. Doesn't look pretty, but works fine.

[junkmansam]

Re: NAD C320BEE - JH Capacitors

In better lighting here are some pics of some of the noticable bad caps. The power board has a pool of dried brown gunk on it. One secondary cap has a bulging top. The main 15000 caps are also suspect. The main board has 3 or 4 caps with brown tint to them.

[seanc]

Re: NAD C320BEE - JH Capacitors

The 15000µ caps do have glue holding them down.
Push down on the black top and see if it's flat or not.

As for photo 2 - anything which is not a bright clear blue, like the capacitors on the power board, is suspect.

You're best off replacing them all, because even the ones that looked the correct colour in mine, tested bad. I changed all of them one or two at a time, taking them out & replacing to ensure that polarity was correct and I didn't get mixed up with what went where.

Powers up instantly every time and works as expected.

[junkmansam]

Re: NAD C320BEE - JH Capacitors

Guess I'll do a section at a time good to know seanc. Thanks, glad you got yours going right. Without your post, I still would have been scratching my head.

[junkmansam]

NAD C320BEE - Smoke Signals

I could always plot the smoke residue under this amps cover.

[seanc]

Re: NAD C320BEE - JH Capacitors

Ha - heat