Not owning a 52/135 I can’t answer your question as you ask but the nDAC/555 is a brilliant configuration and I’m not sure a NDS would add much? What I can say is I’ve heard the 552 on many occasions in numerous different systems and by common consent it’s a superb pre-amp, but never heard with 135s but can’t think of any reason why it wouldn’t be superb.
To my ears the NDAC/555 has slightly more of an old school Naim sound, great for rock music, plenty of bass with the right system, and very enjoyable.
The NDS is perhaps smoother and more refined. Maybe not as much of a party animal, but great for Classical and for more relaxed listening sessions.
On balance I tend to prefer the NDAC but both are very good, and others may well prefer the NDS. Only you can decide what you prefer.
I went from ndac/555 to NDS/555 and it is an overall improvement in detail, in my case the source was the same via UPNP ie a modified PC. Cost me about £2k second hand, can do this upgrade for even less these days.
On the preamp I went from a late model 252DR/Supercap to an older 552DR/552PS which cost me about £4k second hand. Again a lot more detail plus notable deepening of bass, clarity of vocals.
In terms of VFM I would say they were about right to each other regarding the scale of improvement versus the price difference
Another point to remember is that going back to a 1st gen streamer when you are used to the 2nd gen ND5XS2 will bring limitations in terms of connectivity and which services are supported. Think carefully about whether this will meet your needs.
Chrissu said that the Nds is more suited to classical music, less for rock.
If it’s connected straight to the router, I agree. I remind that I missed first my ex Cdx2 / Xps2 when I got the Nds.
Later I understood that a dedicated switch is necessary to uplift its sound. With a good quality lan cable, a Cisco switch, my Cdx2 was completely forgotten : the prat was restored, the urgency, and a much more organic and open and detailed sound vs the Cdx2 / Xps2.
Add an audiophile switch, and the sound will be still better.
I don’t listen to classical music, only jazz rock, fusion, funk, soul and blues. Can’t complain on the grip, prat, and urgency of the music with my Nds today. ( enhanced still with a Melco and PhoenixNet switch).
I found the NDS to be the main bottleneck, not the 52, so auditioned a number of premium streamers including the ND555.
We preferred our current streaming set up with the 52/135s over the ND555 + 1 power supply but others prefer the ND555. Both are absolutely excellent music makers.
You currently have a more capable streaming module than is in the NDS and an equivalent DAC, so the rationale for changing to NDS does not appear compelling. The 52/135s is a real music maker and is easily capable of letting the benefits of a better streamer shine through.
From what I have read, it seems that the advantage and uniqueness of the 555 are reflected with the 552,
If I don’t intend to go wild in terms of financial expenditure, it seems that the NDS is more suitable for 52?
nds at second hand price has tremendous value for money.
consider nd555 uses same dac chip Burr Brown PCM1704, one of the best dac chip ever, used also in esoteric d 01 dac, and same chipset sharc 40 bits.
I moved from nd5xs to nds (keeping a non naim PS) and the uplift in terms of detail, natural expression of the sound, analogical feeling were incredible. moving to nd555 will add a notch but that notch is very very expensive. to play with strange streaming services I connected to NDS a blusound node worth 500 eur. cannot help in pre amp upgrade.
This has really not been our experience at all. The 52 effortlessly revealed the extra musical goodness that an ND555, Chord M Scaler + DAVE, DCS Rossini + dac or MSB Premier + Powerbase brought to these cloth ears over the already very, very good Naim CDS3 + 555PSDR that we had at the time.
All of these brought us materially closer to the music than an NDS + 555PSDR could.
A 552 is a more capable pre-amp than a NAC52 but the 52 isn’t your system’s limiting factor. Your streamer is the limiting factor and it is already approximately equivalent to (but not the same as) a serviced NDS/555PSDR.
A decent dealer demo (as we did at the time) will lay this open for you. FYI in our demos, we used a 552, a 252/Supercap DR and our own serviced 52/olive Supercap, so we have tried the different pre-amps too.