Stuck on nac preamp choices

I'd go for the Nac 72 or the Nac 102. If the 102 sounds harsh at the top end, there can be many reasons. I would check the cable dressing first and ensure the signal cables do not touch the power cables. Preferably, the signal cables stay far from the power cables.

It could be that either or both the Nac / Nap need a service.

It could also simply be that the 102 is showing a weakness of the source.

I have been told that the 102 shows more detail than the 72, but I only know the 72. Its a wonderful small pre which I really love.

First and most importantly, I would contact Cymbiosis and ask this very question to them too. They are helpful and absolute experts in my experience.

Sounds like the NAC112s encoder has failed.  This started to become problem after the supplier of the part moved their production to a new factory, and it necessitated Naim making an early revision to the units that used it and moving to a different make of encoder.

The NAC112 has a softer and slightly rolled off sounding top end compared either the NAC102 or the NAC152xs, both of which are more open and detailed at HF.  Any harshness in the source will be amplified by the NAC102, the NAC152xs is possibly a little more forgiving here.  If your source is up to snuff then the NAC102 is a natural partner for the NAP180, or as others have suggested, a NAC72, which is slightly sweeter than the 102, if softer up top and at bottom.  You do lose R/C though, but the NAC72 is a honey and potentially best of the lot. Of course, both the NAC102 and NAC72 are getting on in years so age and use/abuse will have taken their toll unless they have been recently serviced.  Which could mean that any sonic impressions back in the day are now for nothing...

As has been suggested, best chat with Peter at Cymbiosis.  He should be able to guide you best here.

Brilliant bit of advise there

The 102 on Loan has not been serviced but I’ve been offered another 102 with a napsc, it was serviced 2 years ago by witch hat, I’m tempted on that and to be honest I do prefer the olive sound, so much more detail but I can’t help wondering about what the 152x sounds like...

my source is a pi with an allo boss master dac (really does sound fantastic) and an audiolab 8000CDM/8000DAC combo.

Cheers!

I had the opportunity to compare the 152 XS with the previous x model, listened to in isolation it was rather good, however a back to back comparison with and without flatcap, in my opinion showed the 152 to lack dynamics. Rich 

Very pleased with my NAC152XS, all the more so when it has both outputs of my FCXS on it. I'm not quite sure how that helps you though within the context of your set. I'd like to think it would run the NAC102 close. Dem needed.