Mark Levinson 326S with Nelco board

The latest incarnation of the Levinson 326S now has a Nelco board rather than Arlon. Does anyone know why and when the change was implemented and what sonic improvement this material produces for the 326S?
Maybe it's simply that the Arlon material was no longer available, and the change doesn't produce a performance 'improvement'. You should contact them directly and ask. This is the first I've heard of it, so thanks. Where did you hear/read about this?
Nsgarch, there's a review of the 326s by Jason website. I found it by googling 326s reviews. He states that Nelco material has replaced Arlon due to better insulation properties. I plan to call Harmon and find out what sonic differences the unit has. I have a 380s, which I've used for about 12 years. I found it superior to a 32 in my system, which absolutely shocked me. I tried the 326s about 2 years ago and found it to better the 32 and to have greater clarity and transparency than my 380s. But....the 326s had a leaner bass, while the 380s had greater weight throughout the midbass into the lower midrange. As Atkinson pointed out in his 326s review in Stereophile, some people find the the 380s to have over ripe, plummy bass while others find it sounds just right in their system. I'm in the latter group, but I'd love to have what the 326s does in the upper mids through the treble. I'm hoping the change to Nelco gives the bass greater impact.
According to Harman there are no sonic differences between Arlon 25N and Nelco N4000-13 SI. However, at least one source shows Nelco as less expensive than Arlon (see 1st link below).

The data also reveals that while Nelco has slightly better dialectric properties than Arlon, Arlon has superior loss characteristics. I'm not an engineer so I won't even speculate as to how these differences potentially relate to performance in a high-end preamp.

You can also find full data sheets for each product here...

Not sure why the change (I didn't ask), but it would be interesting to know
if any folks out there (including Levinson dealers) have compared the two.

Happy Listening!
My skeptic self would say costs as with most anything else.
Just spoke to Richard at Harman....he says no sonic differences, with the Nelco actually being a little more durable. The change was made due to stricter regulations abroad....hmm, I also think costs come into play here.
RoHS compliance plays a large factor here (lead free), which is now mandatory everywhere I believe.  Besides, I believe that the Nelco 25N has been replaced by an RoHS complant product.
Is the Nelco board used in the No.585 integrated amp?