Newbie with a Nad 214

Hi everyone, I've just got myself a Nad 214 which I'd like to replace the main caps and the speaker relay. As this is the first time I've done something like this I'd like a bit of advice please, can anyone suggest suitable caps I could use, I'm not sure which manufactures to look out for or even the best place to buy them? these have been suggested on another thread UVY1J472MRD Nichicon | Mouser as I've never brought caps before I'm unsure if they're any good.
Also this relay has been suggested as a suitable replacement G2R-2 48DC | DPDT PCB Mount Non-Latching Relay Through Hole, 48V dc | Omron again does anyone know if this is ok?
Thanks in advance for any help
 
Measure the physical size and look up a suitable replacement for the main smoothing capacitors. Aluminium Capacitors | RS Components
I think you will find the capacitors are Snap In type. Check before you buy!
On this site you can find relays as well, at a proper price!
Question, is the amplifier faulty? If not, why replace things? I have never has a faulty relay that NAD have used and the main smoothing capacitors are very reliable. I have been repairing NAD from pre 1984 and under NAD warranty.
 

Ian Finch

Member
Paid Member
2010-04-11 4:22 am
Coffs Harbour, NSW
Brands aren't the issue - the main improvement in recapping is simply fitting fresh caps of good industry standard quality. It's an expensive operation, so being able to afford any exotics you may have a leaning toward, could be a bigger issue.
For the large reservoir caps, go for highest ripple current rating at a reasonable price from Panasonic, Nichicon, Elna, Rubycon, Nippon Chemicon or any competitive grade cap with a good rap and brand profile. For the smaller electrolytics, you are looking at Low ESR types but not the lowest ESR. Panasonic FC is a popular, long standing favorite for general purpose use in decoupling and small power supplies where the values are covered by the available range. Naturally, all those manufacturers will have suitable equivalent grades and there are plenty of strong opinions as to which is best. But often, they are really just chosen by the sentimental ring of the brand name - like cars.

Whatever, never Buy caps on Ebay unless the seller is known to you. Even if the product is genuine, old stock is deteriorated stock and that's what you could be wasting money and time over, when you find your replacements just don't seem worthwhile.

This only applies to electrolytic caps, the other film and ceramic types will not deteriorate in normal use and you can leave them alone unless you decide at some to experiment for the hell of it. Just make sure you have read about the issues surrounding the particular caps you want to change - some are critical types and the amp. won't take kindly to messing with frequency compensation caps for example.

Do you really need to replace the relay? (Free manual download here: NAD 214 Manual - Stereo Power Amplifier - HiFi Engine)

You appear to have found an equivalent to the unusual 48V DEC relay, but the issue can only be dirty contacts and this is easily dealt with as long as the cover can be prised off with a suitable small hooked tool like a tiny screwdriver bent at 90 degrees for 5-8 mm at the blade or a short length of stiff steel wire similarly treated.

Then, a few simple wipes with small strips of stiff card squeezed lightly between the contacts, will do the trick. Wet the card with contact cleaner, rubbing alcohol or IPA to lubricate the process and leave clean, untouched surfaces. Just spraying contacts though, is a waste of time.

You will have to see this guy to get the gist of relay cleaning and the results if you aren't used to tinkering with stuff - at least you get a laugh. ;) https://www.youtube.com/watch?v=naEajoxaUu0
 
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Thank you both for your very helpful replies.
To be honest the amp isn't faulty however to my ears it does seem a little weak in the bass department when pushing on a bit! I've been reading up on this amp and going by this article https://fittingmedia.wordpress.com/2013/01/16/nad-214-poweramp-refurbishment/ I wondered due to the age of the amp if the main psu caps had dried up and gone weak? The article also mentions utilising the 2 spare connections on the board to fit 2 more caps making a total of 6.
As for the relay again going from that article I was just going to replace it while I was in there as they are not a lot of money!
Obviously I'm new to amplifier repairs so I do appreciate the help given!
 
Thinking of going for the 105degree Panasonic caps from the RS link given above, how would I tell if the capacitors are the snap in type?
Thanks for your help

Look at the first photo on this site and you'll see both types:
Capacitors | Tubelab

The snap-in type have the heavier, bent leads that look like they are retained by some type of rivet on the bottom of the cap.
 

Ian Finch

Member
Paid Member
2010-04-11 4:22 am
Coffs Harbour, NSW
Look at the bottom of the board where the pins protrude under the solder.
2 features: Snap-ins are always 10mm between hole centres and the legs are of thick, rectangular cross-section because they are punched from sheet metal. Wire legs are well...round wire and probably different centre spacing - just as you see in Ammel68's post.

A check from the service manual I posted earlier shows there are 4700 uF caps with space for 4. Obviously, you could fit 2 or 4 x 10,000uF which is something I would certainly do for an 80W amp also rated higher for 4R loads because only 10,000uF/rail is penny-pinching and if there are only 2 caps fitted, this will show up in performance in later years, as you may be experiencing. Check the height will fit with larger values as advised earlier but I don't think there will be issues as modern caps are generally much smaller.

Few manufacturers anywhere are as tight-a**ed as NAD and many issues with their amplifiers are about just-bearable quality parts or simply not enough of them. Note on values of capacitance - these are very nominal because of wide tolerance on the value, so saying 2 x 4700uF = 9400uF is unrealistic with tolerances as high as electrolytic values have. 2x 4700 = 10,000 uF is conventional.
 
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Thanks again for a very informative reply, I'll flip the board over later and check which type are fitted.
Looking at the board there are 4caps fitted with space for 2 more, do you think I should therefore fit 6 x 10,000 caps in place of the 4x4700?
Thanks again
image.jpg
 

Ian Finch

Member
Paid Member
2010-04-11 4:22 am
Coffs Harbour, NSW
You are quite right and I should have looked more carefully at the parts lists and your pics.
6 caps and I expect that the extra pair suits NAD 216. Note that you already have the empty
holes for the extra caps to check for pin spacing, no? If the holes are the right spacing you
dont need to faff about with disassembly just yet. Just order snap-ins and wait.

Looking at the slim diameter of those caps and the tight packing though, I would consider the
diameter of your replacements a first priority. Buying stuff that won't fit isn't a lot of fun.
Anyway, 6 x 4700 or 4 x 10,000 is plenty already, IMHO. Enough is as good as a feast... ;)
 
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Ian Finch

Member
Paid Member
2010-04-11 4:22 am
Coffs Harbour, NSW
In principle, yes and all of them because examining the issues of each application will exhaust anyone and be a right PITA. It will obviously be expensive and time consuming, needing a shopping list cobbled from from the parts list in the service manual with checks on sizes and lead spacings as necessary since the original part numbers won't be of any use. I find vernier calipers good for this and even cheap plastic ones can be fine for the number of uses and accuracy you may need.

On the other hand, many small caps are not required to perform at their limits in normal use and best quality caps will last a very long time. How long is anyone's guess so this is largely precautionary. 20 years is an arbitrary but reasonable time to begin routine replacement of all caps but many think "If it ain't broke...." etc. The amps were made from 1995-2000 apparently so taking a median of 1997-8, you could be a tad keen to get your hands dirty.

DIYs may have their doubts and misunderstandings about what they are doing but still expect 110% return for their effort. Some folk leave no stone unturned, real or imaginary and spend up on useless gilt-edged parts. Others just buy what fits the ratings at the lowest price. Often it doesn't really matter but as a blanket measure, the quality needs to be as good as the highest needed and that means reputable brands and best suited overall grades.

A common problem with amplifiers that have relay protection circuits, is that the timing and filter caps around the protection control chip (IC202 here) seem to cause erratic or complete shutdown. I suspect it is heat related as the chip is often sited near the heatsink and I don't say they are a problem here but be sure to replace C223,224,237,238. If 105° rated parts are available (and these don't need to be low ESR types at all) use them there.
 
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Thanks again Ian, I see what your saying with if it ain't broke don't fix it! I think as the sound seems a little bass light to me although I am no expert and the caps are only a matter of a couple of quid each I'll change the main caps as mentioned earlier and also the few you have mentioned above and give the relay a clean and see how I get on!
The amp doesn't owe me a lot of money so I think I'd like to see if I can improve it rather than not use it!
Thanks for your help, I'll keep the thread updated with how I get on!
 

Lstlaure

Member
2015-02-16 8:24 am
Hi! I happen to own a pair of NAD 214s that I use in bridge mode. I replaced the caps and the speaker relay on both amps last year. For the caps, I used six (6) EPCOS B41231A8478M. These are rated 85°C, but have low ESR. For the speaker relay I used an Omron G2R-2-DC48. The results are excellent. The bass is never too light, just where it should be. I use the 214s to drive a pair of brand new Paradigms Monitor 11. This is a very good match.
 

Lstlaure

Member
2015-02-16 8:24 am
More details: at first I also looked at using 105°C rated caps. But I couldn't find any that would match the performance of the original Nichicons LQ in terms of low ESR and high ripple current. The Nichicon LQ used by NAD in the 214 are 4700 μF, 63 Vdc, +85°C, max ripple current = 3.69 ARMS, and ESR max = 0.071. The EPCOS B41231A8478M caps have the exact same spec as the Nichicon LQ, except that they have a higher ripple current rating at 4.19 ARMS which can only help. Also using 6 instead of 4 caps provides more reserve, and can only improve the performance of the amplifier. As mentioned earlier, I'm quite pleased with the results.
 
Thanks Lstlaure for the very helpful reply and sorry for the late reply!
Its good to know you've done what I'm thinking of doing and have got excellent results!
I'll look into the caps you suggested and see if I can get hold of any as they sound ideal, I was originally thinking of these but they appear to have a lower ripple current. ECEC1JA472CJ | Panasonic 4700μF 63 V Aluminium Electrolytic Capacitor, HA SNAP IN Series 2000h 25 Dia. x 50mm | Panasonic although they are rated at 105 degrees.
 
I've been looking into the other caps that Ian Finch suggested replacing in his above post however I cannot find c237 & c238 in the service manual or in the amp?
Also c224 according to the service manual is 10v 22uf whereas on the cap itself it says 16v 22uf so I'm confused as to which I need?
Thanks for everyone's help
 
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Ian Finch

Member
Paid Member
2010-04-11 4:22 am
Coffs Harbour, NSW
The voltage rating given for electrolytics is a minimum spec. for cost control in commercial quantities. When buying only a few parts, the unit cost will be relatively high so voltage ratings are less important, so long as high enough. Here, almost any voltage rating part that still fits comfortably on the board, from 10V to even 100V will be fine, and could well perform better in an audio circuit.

I did slip up and read off a couple of nearby resistor part numbers instead (even after double checking ) Apologies if I wasted your time looking. The list is C223, 224, 227,228 and they are simply all those associated with IC202, the protection control chip.