Naim Nac 12

[andyr]

The remote is quite clever, it is via the replacement 729 board and operates on a frequency, not infra red. It has a zapper, not unlike a car remote central locking device, it works from a long range, indeed from a different room.

It effectively cuts/boosts the gain, not rotate the vol pot.

Aah, OK, thanks G.

I looked inside my 12S today (it's not in my main system but is at my beach house) and it has the following boards (no phono):
* 321/5, and
* 729/1.

I'm not particularly in need of a remote volume/gain control - so I wonder which delivers the better sound ... boards from Ryan Sound Labs or the UK guy who markets drop-in Naim replacement boards (forget his name, sorry! )?


Regards,

Andy

 

[Svein]

Svein

Look after yer knobs

I've had a 12 for years, tried to sell it here but people wanted it cheap.. Glad I kept it

I had the loan of the solid state plugin exact but space age naim replacementfrom the USA so kindly lent out to PCM

Apologies I forget the name a total gentleman and his firm just now

and i haven't been able to justify the 500 notes

However IMO they were best in the 12 over the 32 and 42 I also own

At the end of course I could drop in the original cards

The remote volume control, total silence of the circuits made the 12 frightening thru my esls

Just sayin, if you like retro and remote control and way way ahead quality with an otherwise mod free 12... then track down the cards

Shocking I can't recall

I will edit when reminded of the product

Yes, the knobs are a problem,-
I have replaced them with a Kilo variety. I would be interested to buy some originals knobs if available somewhere.
I have owned all the other Naim shoebox preamps many times. I had a Nac42 and a 72 that hinted at what the 12 does. I bought my first because of the look and was totally surprised by how good it sounded.

Yes the difference in front between version 2 and 3 is 'Gram' and 'Phono'
A pic of the examples:

 

[Gaius]

Aah, OK, thanks G.

I looked inside my 12S today (it's not in my main system but is at my beach house) and it has the following boards (no phono):
* 321/5, and
* 729/1.

I'm not particularly in need of a remote volume/gain control - so I wonder which delivers the better sound ... boards from Ryan Sound Labs or the UK guy who markets drop-in Naim replacement boards (forget his name, sorry! )?


Regards,

Andy

There are the replacement 321 boards from Les at Avondale, these are 821 and 821A, many like them.

There are also the Neil Jadman boards, these replace the 321/324 or 729 boards.

They all sound slightly different and change the Naim sound a bit, as ever they have plus and minus attributes and it is horses for courses!

 

[andyr]

There are the replacement 321 boards from Les at Avondale, these are 821 and 821A, many like them.

There are also the Neil Jadman boards, these replace the 321/324 or 729 boards.

They all sound slightly different and change the Naim sound a bit, as ever they have plus and minus attributes and it is horses for courses!

Thanks, Gaius.

Andy

 

[LPSpinner]

If what you were trying to think of was the Ryan Soundlab cards which LPSpinner provided the link to ... I'm curious to know how the remote control operates. Shirley, you need a new (motorised) volume pot and (motorised) source selector switch?


Andy

The remote is quite clever, it is via the replacement 324/729 board and operates on a frequency, not infra red. It has a zapper, not unlike a car remote central locking device, it works from a long range, indeed from a different room.

It effectively cuts/boosts the gain, not rotate the vol pot.

Yup Gaius is onto it... Just looking at the Circuit boards it appears he uses a whole lot of surface mount relays and some fancy logic circuitry to behave like a stepped attenuator, quite clever indeed. It looks like you set the upper limit of your volume range with the 72/32’s volume knob then use the Ryan sound-lab’s attenuator board to change the volume via the remote. Pretty cool actually…

While I am not criticising his work (far from it in fact) for me part of the charm of the my 72 and also the 12 is the physical interaction and the tactile experience. I’m not likely to do the remote thing. The ALPS Big-Black pot just feels so smooth and silky it seems a shame to use a remote.

Nice work though…

LPSpinner

 

[andyr]

The ALPS Big-Black pot just feels so smooth and silky it seems a shame to use a remote.

LPSpinner

Sure there's "smooth & silky", LPS ... but if you like smooth & silky and you want great-sounding ... replace your ALPS pot with a TKD CP2500 plastic pot!

See p14 here: http://www.percyaudio.com/Catalog.pdf

Even better sounding - but stepped, rather than silky - is the TKD stepped attenuator. Unfortunately Michael only sells mono ones but you can buy stereo attenuators direct from TKD (for a helluva price! ).


Regards,

Andy

 

[misterc6]

I used to have a device whose s/n was 1383, its panels were painted like those of devices from the CB era.

I believe it was one of the last samples released in 1979 or 1980. So the total number of those preamps was about 1500 which gives us the average number of 250 devices per year.

From the start of production in 1973/4 until the end of 1980 Naim used a total of 2357 serial numbers for all units except the NAP110 and NAC42 which started again from 0001 on their introduction in 1979. The present system of including all units in a single numbering system was introduced in 1983.

Those 2357 units produced between 1973 and 1980 included (at a minimum):

NAPS
SNAPS
NAC12
NAC22
NAC32
NAP120
NAP160
NAP200 (the original not the later model with the same number)
NAP250

On that basis 1500 has to be a gross overestimate of the number of NAC12s that were produced.

Your unit with serial number 1383 was produced in the first half of 1978.

 

[yurivv]

From the start of production in 1973/4 until the end of 1980 Naim used a total of 2357 serial numbers for all units except the NAP110 and NAC42 which started again from 0001 on their introduction in 1979.

I thought that in the 70's each type of Naim devices had its own system of serial numbers, so serial number 1383 for NAC 12 means that at least 1383 NAC 12s have been manufactured. Am I wrong?

 

[yurivv]

I think it may come in handy so the marking of these KILO knobs is JD-90-2-5.

DSC_6706 by yurivv69, on Flickr

 

[yurivv]

I might have a go at cloning one at some point and do my own artwork using Yurivv's great photos as a basis, and a little Photoshop magic to create a clean artwork woth which to create new PCBs. I have one of the spare Nap 140/Hicap style cases from Tukans on Ebay, which would make an appropriate home for a clone!

Here are the links to hi-res images of NAC 12 v2 boards in case you need them.

https://farm1.staticflickr.com/400/19611271568_ed76569d60_o.jpg

https://farm4.staticflickr.com/3786/19773103106_57c0c8d5ec_o.jpg

https://farm1.staticflickr.com/267/19773100186_88fe09558c_o.jpg


DP2M0007 by yurivv69, on Flickr

DP2M0005 by yurivv69, on Flickr

DP3M0012 by yurivv69, on Flickr

 

[misterc6]

Yes, I believe you are wrong.

I worked for a company that supplied test equipment and I visited the very small Naim production and sales facility at 11 Salt Lane many times during the 1970s for meetings with Julian Vereker. As late as 1977 all pcb and final assembly was being done by just a few operatives with no mechanisation. When they moved to the Southampton Road factory in 1980 they had just 9 employees. Here's a link to some interesting history:

https://www.naimaudio.com/our-story/18043/heritage

I was also fortunate to get a large file from a former Naim employee containing much useful technical, service and production information. I was given the file on the strict understanding that I would never put it in the public domain but I could use the information to help others on this forum.

I believe that the following document about serial numbers from the Naim web site is a little misleading:

https://www.naimaudio.com/serial-numbers

in that the serial number of 006933 given for 1982 represents the total production of the company from 1973/4 to the end of 1982 and is not the figure for 1982. Looking at the serial numbers for 1983 you will see that just over 5,000 units were made that year and this was a time of major growth for Naim.

In the very early days (1971 - 1973) very few units were made and many of these went to friends and relations, probably without serial numbers. The serial number information that I have shows sales of:

1974 - 54
1975 - 166
1976 - 426
1977 - 582

these figures are in line with the size of the operation I visited and indicate strong growth becoming limited by the size of the facility.

In recent years I've owned a NAP120 and three NAP160s and each one had date codes on the electrolytic capacitors that agree with the dates from the serial number information that I have. It's harder to date a NAC12 from its components but I've had three v3 12s with serial numbers between 08xx and 12xx. I know that one was manufactured in 1977 because I bought it from the original owner and the other two were very similar in terms of issue numbers on the daughter boards and the components used.

 

[Svein]

Interesting post misterc6, many thanks.

 

[Robert]

Theres a Polish company on eBay that sells NOS ROE Maroon caps... Possibly useless now having sat dormant for years but interesting if you were to reform them.

http://rover.ebay.com/rover/1/710-5...0001&campid=5338728743&icep_item=261966375801

It's probably worth pulling just one or two and testing them.
Those maroons usually test just fine IME when run in low heat conditions such as a NAC.

Everyone assumes old caps must be off - they usually aren't to any degree which would impact the audio.

 

[yurivv]

Thanks Malcolm, very interesting!

 

[istari_knight]

It's probably worth pulling just one or two and testing them.
Those maroons usually test just fine IME when run in low heat conditions such as a NAC.

Everyone assumes old caps must be off - they usually aren't to any degree which would impact the audio.

They are decent (by standards of the time) and do last quite well in Naim equipment agreed but are usually on their last legs in B&O gear... Depends how they are used within a circuit I suppose.

 

[Robert]

They are decent (by standards of the time) and do last quite well in Naim equipment agreed but are usually on their last legs in B&O gear... Depends how they are used within a circuit I suppose.

Absolutely. Run well within voltage and kept cool they seem to last forever.
However in a high ripple situation and running warm/hot it's a different story.

 

[LPSpinner]

It's probably worth pulling just one or two and testing them.
Those maroons usually test just fine IME when run in low heat conditions such as a NAC.

Everyone assumes old caps must be off - they usually aren't to any degree which would impact the audio.

They are decent (by standards of the time) and do last quite well in Naim equipment agreed but are usually on their last legs in B&O gear... Depends how they are used within a circuit I suppose.

I agree, in my experience, if the phenolic resin casing is in good visual condition with no sign of crazing or cracking (as Rob said, usually a sign of exposure to heat) then there is very little to go wrong. The Phenolic resin (Bakelite) casing and the epoxy-sealed base it pretty much sealed. The electrolyte cannot leak or dry out and nothing gets in, it’s a sealed environment inside the can.

Its only if the casing is cracked or has gone brittle and flakey, then they should be replaced. In preamps this generally doesn’t happen. My NAC12 and NAC72 still have their original RDE electrolytics and they look and work just fine.

LPSpinner.

 

[yurivv]

The boards of my "new" NAC 12 (see above) are in good condition, but decoupling caps on all six boards (four "earliest type" orange caps on the 112 and 114 boards and two maroon caps on the 323 phono boards) need to be replaced because of leaking.
Weird, but this is a best sounding NAC 12 I've ever owned, so I don't want to loose this sound signature.

 

[misterc6]

Coupling capacitors may affect the sound signature but capacitors decoupling the supply rail are unlikely to do so. You should try the Samwha capacitors that Naim use these days.

 

[yurivv]

Thanks Malcolm. I used to have NAC 12 serviced by Naim (all Samwha caps), but it sounded not quite as good as my unserviced ones, maybe because of coupling caps and yellow tants. I have some Nichicon Muse and NOS maroons, so maybe I will try one of these.