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Naim Supernait 1 re-cap...what other components can be upgraded?

R

Robbie Inglis

Active Member
HI,
My SuperNait 1, is currently about to be re-capped, with Mundorf caps. Whilst it is on the workbench, can anyone here share their experiences / suggestions with upgrades of other components. I know there is some great advice for upgrading the earlier NAC preamps, is any of this that is applicable to the SuperNait 1.
I recall reading in the original press release that the pre was based on the 282 design, so hoping that there is scope for improvement.

I am based in New Zealand, so shipping cost prohibits sending it to a UK repairer, so needs to be a DIY option. The work will be carried out by a qualified service technician / amp builder.

Thanks in advance, Regards Robbie
 
Other than the reservoir capacitors, there is not much that can be done and the Mundorf are the best you can have.
I would also replace the tantalum caps to make it safe and same brand as the existing ones will be fine.
The rest of the components are either surface mount that cannot be replaced, polystyrene or polyester caps that lasts for ever and are already the best ones you can have for sound quality.
 
T
Gervais Cote said:
Other than the reservoir capacitors, there is not much that can be done and the Mundorf are the best you can have.
I would also replace the tantalum caps to make it safe and same brand as the existing ones will be fine.
The rest of the components are either surface mount that cannot be replaced, polystyrene or polyester caps that lasts for ever and are already the best ones you can have for sound quality.
Click to expand...
Thanks for you reply.
We are changing the main power caps, and the smaller smoothing caps with Mundorf
 
A standard Hicap with an Avondale regulator is probably the best value for money.
Took me 1/2 hour to install mine in my CB Hicap so rather easy to do.
 
One of the first things I had done in the extensive set of CDS3 mods was to bypass the 10uF/35V output coupling caps with some decent 0.22uF film caps.

Robbie Inglis said:
HI,
My SuperNait 1, is currently about to be re-capped, with Mundorf caps. Whilst it is on the workbench, can anyone here share their experiences / suggestions with upgrades of other components. I know there is some great advice for upgrading the earlier NAC preamps, is any of this that is applicable to the SuperNait 1.
I recall reading in the original press release that the pre was based on the 282 design, so hoping that there is scope for improvement.

I am based in New Zealand, so shipping cost prohibits sending it to a UK repairer, so needs to be a DIY option. The work will be carried out by a qualified service technician / amp builder.

Thanks in advance, Regards Robbie
Click to expand...
 
Thanks for this thread, I need to service mine also. As all wires are not plugged like in the older amps but soldered to the board, it's not so easy to take out the board: any advice?

Also I wonder: my Supernait1 has a PCM1791 as a DAC chip, but the reviews I saw mentioned the PCM1792...

OT: Ron, is it posssible to add an i2s input to the DAC of the CDS3 to use it as a stand alone DAC? If yes do you have some diagrams/advice?
 
The CDS3 can....with quite some effort be converted to a transport-only device; although this would not be a particularly wise choice.
I do not think it can be converted to have a digital input because of the firmware built into it.
Here is a Dropbox link to all the CDS3 schematics
https://www.dropbox.com/sh/l7aar4adpt76ga2/AADJbNlLsL7k8YJO7rM0xAkqa?dl=0

And if you need- them the XPS2 schematics are here....
https://www.dropbox.com/sh/uhkq4h4t58mwdhz/AAC8vWjrR8RCplAgBNDARcMwa?dl=0

jpk said:
Thanks for this thread, I need to service mine also. As all wires are not plugged like in the older amps but soldered to the board, it's not so easy to take out the board: any advice?

Also I wonder: my Supernait1 has a PCM1791 as a DAC chip, but the reviews I saw mentioned the PCM1792...

OT: Ron, is it posssible to add an i2s input to the DAC of the CDS3 to use it as a stand alone DAC? If yes do you have some diagrams/advice?
Click to expand...
 
I am about to recap my Supernait1: it has SMD electrolytic caps, and I think I can remove them, but what about replacement? Should I fit SMD-tants, or solder through-hole caps with bent legs to the pads?
 
Both options require skill............
Given the value of such amp, I would tend to keep it as original as possible unless you’re a 100% sure you will keep it forever.
 
OK, completed recap, replaced the main caps and all SMD electrolytic caps (but not the tants), this is the BOM of what I did:

cMZwjo3.jpeg


I found some schematics online that were useful:

ZTtlDap.png


fm4av28.jpeg


The amp sounds way better now! I fogot to check bias before recap, now it reads 5mV across both emitter resistors when idle: is that OK?
 
I'm intrigued by the schematics for the power amp sections. I was vaguely aware that the Supernait 3 had fully complementary output stages in Sziklai configuration but didn't realise that this started with Supernait 1 and that the Nait XS and NAP100 also followed suit.
Quite an evolution elsewhere in the circuit as well with active constant current sources for the differential and VAS stages and a Cascode pair for the VAS. They've also balanced the current in the differential stage (like the Avondale Qudos amp) unlike the original Naim circuits.
Only omission seems to be lack of emitter degeneration for the differential amp, I wonder why?

Also just noticed the optocoupler... that has me confused!
 
Pirx said:
Pics are before or after the re-cap?
Click to expand...

I take it as a huge compliment :)

The pics are after recap. The main caps are 4pin and don't fit the PCB holes, so I wired them in with thick copper wire and using hot glue as spacer. Hence their minus markings do not point exactly in line.

The only other deviation is the top most SMD cap in the first picture: there was a 10uF Panasonic, I fitted a yellow 10uF tant because I ran out of stock.

Taking the amp apart was easier than I thought: the cables are soldered to posts, so easy to remove. SMD caps go off easily by twisting them with pliers. The logo was looking strange: I took the foil that is glued behind the logo off, cleaned the black color totally off with alcohol, blackened it with permanent marker and fixed it back with 4 small blobs of superglue. Now it looks good.
 
My congrats on the soldering. Looks absolutely pro:)
I removed my post because I made beginner's mistake assuming power transistors are bad based on indicating dead short on both directions DNM buzz when measured in circuit.
Apparently some active elements are fried on the input stages .Q604 in current source for one. I lifted Sanken power transistor emiter leg and the transistor measures OK now. That's actually a good news. Original Sankens are not made anymore and there are lots of fakes around. That would also explain why the speakers survived.
Now the fun with tinny SMD transistors will begin :)
 
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