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Courtiestown - Naim Amplifier (Avondale) Upgrade Project

Good Morning All,

Component sourcing and pricing continue to drive me barmy.

I placed an order with Farnell the other day working around the first choices being on backorder. 5 resistors are being supplied from their Belgium warehouse!!!!!!! This is being delivered by UPS. I was a little surprised that it wasn't dropped off at the same time as the Digi-Key order above. Having clicked on the Farnell link which took me through to the UPS site I was advised the item was out for delivery on Tuesday from 0930 - 1230 which was, after 1230, updated to by the end of the day. Nothing was delivered.

Later on Tuesday evening the site was updated to indicate delivery between 0930 - 1230 (again) which didn't happen and the site was updated to indicate delivery by the end of the day which, again, didn't happen. These resistors aren't mission critical but UPS are taking the p**s so I sent an EM to Farnell last night.

I think I reported elsewhere that neither RS or Farnell can supply MJ15003 at this time. Whilst looking further afield, in this case Mouser, I noted that the polystyrene capacitor I bought from Farnell the other day for £2.53 could have been bought for £0.65. Mouser can supply 6off MJ15003 for very slightly more than Cricklewood can supply 3off.......

Priority today, after mucking out the horses as Kate is at work in Aberdeen today, is loading up the trailer with more rubbish ex the recent fencing work.

Regards

Richard
 
laverda said:
Richard,

RICHARD……

don’t forget to separate the PSUs on the board (cut the link) … or you let the smoke out.

Graham
Click to expand...

I run mine with the links in place.
Under normal conditions the input stage raw ps voltage is higher than the output stage ps and the series diode is reverse biased.

On power-off, if for some reason the i/p supply falls faster than the output supply then the diode conducts and the front end still gets some supply... this keeps some output stage quiescent running and helps to discharge the o/p stage ps caps. The series resistor (IIRC 220R) limits any current flow anyway, although it limits the ability of the front end to discharge the supply caps lower than a particular voltage.
 
Richard Lines said:
Good Morning All,

Component sourcing and pricing continue to drive me barmy.

I placed an order with Farnell the other day working around the first choices being on backorder. 5 resistors are being supplied from their Belgium warehouse!!!!!!! This is being delivered by UPS. I was a little surprised that it wasn't dropped off at the same time as the Digi-Key order above. Having clicked on the Farnell link which took me through to the UPS site I was advised the item was out for delivery on Tuesday from 0930 - 1230 which was, after 1230, updated to by the end of the day. Nothing was delivered.

Later on Tuesday evening the site was updated to indicate delivery between 0930 - 1230 (again) which didn't happen and the site was updated to indicate delivery by the end of the day which, again, didn't happen. These resistors aren't mission critical but UPS are taking the p**s so I sent an EM to Farnell last night.

I think I reported elsewhere that neither RS or Farnell can supply MJ15003 at this time. Whilst looking further afield, in this case Mouser, I noted that the polystyrene capacitor I bought from Farnell the other day for £2.53 could have been bought for £0.65. Mouser can supply 6off MJ15003 for very slightly more than Cricklewood can supply 3off.......

Priority today, after mucking out the horses as Kate is at work in Aberdeen today, is loading up the trailer with more rubbish ex the recent fencing work.

Regards

Richard
Click to expand...

As I just found out a couple of days ago. The whole component supply and price situation is a piss take right now!
 
Richard Lines said:
Good Evening All,

There's been a setback today in that I finally decided to get on with powering the amplifier up and almost immediately it was apparent that something was amiss. I was seeing circa 2.2 - 2.3V bias but was seeing very high voltages on the speaker terminals i.e. -38V one side and -49V the other.

I have been in contact with Graham and will be carrying out further investigations tomorrow.

I'm not too disheartened more mystified. I see the stereo 'Voyager' as a more 'complex' build than this amplifier.

Having gotten to the bottom of the power supply issues I was quite happy that they were performing correctly.

At no point was any power knowingly applied to the NCC300 boards before the links were cut. Everything was 'dead' as the loom was made up.

Graham assures me the boards worked when they left him.

In terms of power there are only 7 connections to the boards. A positive, negative and earth to the MiniCap6 from the regulator side of the board and a positive, negative and two earths from the top half of the board to the CAP6. TBH just how difficult can it be?????

The wiring has been checked repeatedly. The link cables I've made up as part of the loom have all been tested for continuity. That they go from and to the correct location has been checked repeatedly.

Having said this something has taken out both boards.

Suggestions welcome.
Click to expand...
Caveat: I've assembled only two NCC300 systems, both mono. One had separate supplies for input and output, and other had a single supply for both stages. There's a document from Avondale that describes the steps, although it assumes you're using a single supply for both stages. The core steps are:
  1. Connect power to the input stage first (A+ and A-), and set the TP voltages to be 5V below the rail voltages?
  2. Connect power to the output stage (B+ and B-, with ammeter inserted on the positive rail) and adjust the bias to 120mA.
  3. Remove the ammeter, and measure the DC offset at the speaker terminals, to ensure it's less than 50mV.
Of course, between each step you should drain the capacitors in the Mini-Cap and CAP6 modules.
 
Good Morning All,

Currently at work offshore but addressing some parts recently supplied by RS which weren't what I expected.

I was looking to get some more of the M4 plastic shoulder sleeves/ nylon screw insulator thingies. Once upon a time the desired M4 x 5mm bits were RS 178-743 but if you enter that in to the RS web site you land at this page - https://uk.rs-online.com/web/p/screw-insulators/0178743 advising the part is no longer available and are directed to 178-838 as an alternative - https://uk.rs-online.com/web/p/screw-insulators/0178838

I didn't pay the suggested alternative much heed and just ordered a bag of 50 and then, when they arrived, noted they were for 6mm diameter screws and not 4mm ones......

I have now ordered the required part off eBay as neither RS/ Farnell/ Mouser or Digi-Key supply an identical part.

Regards

Richard
 
Good Afternoon All,

That's me back onshore again.

Opened what looks like the right sized case from ModuShop and this one does come with a diagram:-

tVYVKEy.jpg


It does clearly show the perforated base 'upside down'.

It's arrived in what looks like a suitable box to ship a NAP250 in......

Making the most of the sunny weather 'sieving' soil and will progress this latest amplifier this evening.

Graham has kindly said he'll look at the NCC300 boards for me but he is away this week.

Regards

Richard
 
Good Morning All,

Boring mundane tasks this morning like packing sold amplifiers:-

P9nBXqW.jpg


It's all boxed up now and when I've drunk my mug of tea I'll be off to the Post Office.

When I get back I can start up where I left off yesterday:-

SVSsgej.jpg


There's 20mtrs of verge to go as well as the pile..........

Currently generating 6.9kWh of Solar PV, some charging the PW2, some charging the heat store via the eddi and some doing the laundry (it's already cooked the fresh loaf).

Back on amplifier stuff this evening..........

Regards

Richard
 
Good Evening All,

That's me started assembling the next amplifier. Found one toroidal 8mm threaded insert was 1cm off centre, glad I determined that before I drilled the hole.....

76ASZ2j.jpg


Am going with no inductors on the CAP6's and, following comments by Alan regarding the LED's, I've used a 4k7 resistor and both LED's are green ones.

More tomorrow.

Regards

Richard
 
Last edited:
Good Morning All,

Done a bit more work this morning before I have to go out and enjoy the lovely weather we're getting.

Looking out of the kitchen window and after spreading pig slurry and our two year old pile of horse pooh/ straw on the field yesterday the farmer is busying ploughing.

I've started on connecting the mains/ transformers:-

1XSb0rN.jpg


An overview:

OJYrdVN.jpg


Crimped connectors have been soldered as well, need more practice with the crimping machine although an extra hand/ arm would be required to hold everything in place:-

VaJDd7h.jpg


How far do you take your recycling? All cut off component leads, bits of copper wire etc. find their way in to the scrap metal bin here:-

8J7BO7n.jpg


First off this morning is leading three horses out, followed by manual pooh picking (the PTO driven device has a flat tyre), topping up the water buckets (as two of the horses are fenced off from the actual water butt until that bit of the field dries out) before I go back to soil sieving.

Regards

Richard
 
Last edited:
Richard, is there any logic to the different cap brands/positioning on those cap6 boards? I see you have what look like a mixture of Nichicon and Samwha caps there, and in different positions on each board? (that would freak my ocd out ;-) )
 
James,

Absolutely no logic at all. I pulled these off the HackerCap board I blew the diodes on and they just ended up wherever. They're all 10,000uF/ 80V..........

Regards

Richard
 
Good Morning All,

Mid-morning cup of tea time..... had to come in around now to remove the loaf from the bread making machine.

Putting off pooh picking I'm on with metalwork for the new amplifier:-

Gq6RJoE.jpg


Busily making a series of small holes bigger to fit the mains switch and the plate now looks like this:-

SVyFRh5.jpg


Just taken off the draining board after being de-greased.

That's the bread out of the machine so it looks like I'll be out pooh picking shortly....... :(

Regards

Richard
 
Good Morning All,

Kate sent me this picture of RGU's Dept. of Computing Sciences latest acquisition:-

utXVWXE.jpg


Currently still being programmed before being let loose about the university.......... (although a bit Dalek like stairs will obviously defeat it)

This is the foal (I say foal but it is already at 14hands) using the barrow for a scratch, she wasn't helping me pooh picking between nudging me to pay her attention whilst standing in the pooh I'm trying to scrape up:-

HIpp8sQ.jpg


Finally an amplifier shot:-

Y9OcCRS.jpg


I'll be making a start on the mains wiring shortly but I need to wait until the foal has woken up before assisting Kate in sticking the three of them out in the top field, still waiting on the expectant mare dropping the foal.

A variac should be arriving today so power can be introduced in a more controlled way.......

Regards

Richard
 
Good Evening All,

Well that's the latest amplifier 'completed'.

Making up speaker leads earlier this evening:-

lQH5BXA.jpg


Finished articles:-

CRtkJLz.jpg


Amplifier on test driving Linn Sara9's from Tidal on my MacBook:-

ocbJ52C.jpg


First time I've listened to anything non-active in a very long time.........

Regards

Richard
 
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