Naim Nac 12
- Thread starter Svein
- Start date
John_73
pfm Member
I believe these are the ones used:
http://rover.ebay.com/rover/1/710-5...0001&campid=5338728743&icep_item=121407780812
http://rover.ebay.com/rover/1/710-5...0001&campid=5338728743&icep_item=121407780812
This site contains affiliate links for which pink fish media may be compensated.
Yes
They Placed the 12 into the stratosphere re quality and clarity
Simple silent clarity
I tested it into esl57
As I said it was like adding a new soundfield
Frankly if I was spending money on any naim it would be Ryanslab cards
Instantly reversible
yurivv
pfm Member
Yes, exactly.
This site contains affiliate links for which pink fish media may be compensated.
Siemens and Roederstein were very similar, here a comparison old Siemens with new others copied from diyaudio.com (you could ruin a good preamp blindly replacing the old caps for new ones, thinking new ones must be better)
I just made actual ESR measurements on some samples, including a Siemens 220µF/16V GSF in an epoxy-sealed thermosetting orange case, just like the ones pictured. That capacitor is ~32 years old.
Modern types of same value are included for comparison (@1KHz):
Code:
Siemens GSF: 76mΩ
Multicomp LL: 152mΩ
Sanyo SE8D CG: 154mΩ
Nic NRSZ: 101mΩ
Sanyo OSCON: 66mΩ(All capacitors are unused and are relatively recent, except for the Siemens, of course)
I just made actual ESR measurements on some samples, including a Siemens 220µF/16V GSF in an epoxy-sealed thermosetting orange case, just like the ones pictured. That capacitor is ~32 years old.
Modern types of same value are included for comparison (@1KHz):
Code:
Siemens GSF: 76mΩ
Multicomp LL: 152mΩ
Sanyo SE8D CG: 154mΩ
Nic NRSZ: 101mΩ
Sanyo OSCON: 66mΩ(All capacitors are unused and are relatively recent, except for the Siemens, of course)
Hi yurivv and markdv,
Yes this is my experience as well, if the Orange caps are not showing any physical sign of aging, crazing or cracking on the phenolic casing then leave them in. They are a fully sealed construction with no vent or opening that can allow contamination or leaking of the electrolyte inside.
My 12 and my 72 both have the original Siemens (NAC12) and Roederstein (NAC72) phenolic resin electrolytic and they perform very nicely indeed.
If you look at the picture of my NAC 12 back on page 2 of this thread, you can see the crazing or breaking down of the phenolic casing that I am referring to on the maroon Roederstein caps on the two phono boards. In my case this damage was probably caused by excessive exposure to UV light and poor storage as the previous owner was a little careless in the storage of these boards. The boards came from a different source than the rest of the NAC12.
As stated in previous posts from several learned members the main reason for these caps failing is exposure to heat that causes the phenolic resin to break down. This wont happen in a pre-amp since there is nothing to generate any heat within the pre-amp.
LPSpinner.
yurivv
pfm Member
Unfortunately, as I mentioned above, all six decoupling capacitors (including four orange Siemens caps on the 112 and 114 boards and two maroon Roederstein caps on the 323 phono boards) need to be replaced. I saw signs of leakage between the cap and the board through a magnifying glass. The preamp sounds very good though...
yurivv
pfm Member
Yes, I have seen photos of orange capacitors the same as ours but with Roederstein logo instead of Siemens. I wonder if these the same caps inside?
One can't have too many NAC 12s as mentioned another place in this thread. A cleaning job is waiting with the example under and maybe some new din sockets. I have tried the unit for some hours and it sounds good. The gain is good deal higher on this item than I am used to from the other 12s.
Rosewind
Lost in Translation
Hi there.
Interesting read and nice to see internal photos of Nac 12s. I have one that has been modified to work with a home-built Snaps. Components from the main board has been removed and a few things changed on the daughter boards NA112 +NA114. Because of faulty transistors (ZTX 384) I sent it to Class A who courteously repaired the fault and cleaned up the PCBs of the NA112 + NA114 boards although it was made clear to me that it would not be possible to get the NAC12 back to standard due to lack of spare parts.
I have now asked what parts would be needed to restore my NAC 12 to what I assume would be dual railed standard. Let me say that it sounds very good now with the ALPS (Snaps clone) and Nap 160 / NCC200 monos. Before the repair I had put everything up for sale, but now I am not convinced that I should part with my last Naim kit.
Here are hi res photos of the Nac 12 + NA 112/NA114 boards: It can fit 6 daughter boards and it has had RCAs fitted for phono at the back (but the DIN has not been blocked out). It has screw on side panels and a serial number that says 0215
http://1drv.ms/1HsA7Li
Interesting read and nice to see internal photos of Nac 12s. I have one that has been modified to work with a home-built Snaps. Components from the main board has been removed and a few things changed on the daughter boards NA112 +NA114. Because of faulty transistors (ZTX 384) I sent it to Class A who courteously repaired the fault and cleaned up the PCBs of the NA112 + NA114 boards although it was made clear to me that it would not be possible to get the NAC12 back to standard due to lack of spare parts.
I have now asked what parts would be needed to restore my NAC 12 to what I assume would be dual railed standard. Let me say that it sounds very good now with the ALPS (Snaps clone) and Nap 160 / NCC200 monos. Before the repair I had put everything up for sale, but now I am not convinced that I should part with my last Naim kit.
Here are hi res photos of the Nac 12 + NA 112/NA114 boards: It can fit 6 daughter boards and it has had RCAs fitted for phono at the back (but the DIN has not been blocked out). It has screw on side panels and a serial number that says 0215
http://1drv.ms/1HsA7Li
Rosewind
Lost in Translation
I just read the part of this thread where single vs dual rail use of the Nac 12 is discussed. If I decide to try to get my Nac 12 back to some semblance of "standard" (meaning Naim single railed or dual railed), I will see what makes the most sense.
I can go both ways as of now: (1) Stay with a Snaps-powered Nac 12 (2x24v?) leaving me open to use it with the NCC200 monos or other amps without a psu for a pre, or (2) go with a Nap 160-powered Nac 12. I had my Nap 160 serviced at Witchhat and they put in a Hicap psu instead of the usual Snaps psu. Previously the Snaps psu had been removed for use with the Nac 12 + Snaps-clone. I was told that the hicap psu could easily be taken out and a Snaps psu fitted, if I ever wanted to so. So I decided to go over the top with the Hicap psu.
Kind regards,
Peter
I can go both ways as of now: (1) Stay with a Snaps-powered Nac 12 (2x24v?) leaving me open to use it with the NCC200 monos or other amps without a psu for a pre, or (2) go with a Nap 160-powered Nac 12. I had my Nap 160 serviced at Witchhat and they put in a Hicap psu instead of the usual Snaps psu. Previously the Snaps psu had been removed for use with the Nac 12 + Snaps-clone. I was told that the hicap psu could easily be taken out and a Snaps psu fitted, if I ever wanted to so. So I decided to go over the top with the Hicap psu.
Kind regards,
Peter
HiCap-powered sounds right - not 'OTT' at all!
I'm sure a SuperCap would make your 12s-5 sound even better! Andy