Info Jeff Rowland & Rowland Research model 7

Good morning, I would like information about jeff rowland.
I would have the opportunity 'to buy 2 mono jeff rowland golden / black
but 'I want to know what difference exists between the Jeff Rowland and Rowland research model 7. what are the concerns of those objects JR / RR
I've always liked but I'm afraid being a bit 'old age'
I currently am satisfied with my setup and my sound I have a pair of natural well-sounding speakers and very linear and consistent Triangle Magellan SW2 with preamplifier Spectral DMC 30 ss and mono amplifiers in class A Pass Labs xa 160.5.
and just the model 7 take the place of XA 160.5 Pass.
thank you very much for your advice about.
Gustavo Naples Italy
 
MY QUESTION AND 'THE FOLLOWING;
I WOULD LIKE TO BUY THE MODEL 7 JEFF ROWLAND AND PRE CHOERENCE THEN THESE SHOULD BE TO REPLACE MY CURRENT PASS XA 160.5, AND I WOULD LIKE TO KNOW 1, WHAT CHANGES BY JEFF ROWLAND A RESEARCH ALWAYS ROWLAND MODEL 7, E 2, THEN WHAT I HAVE SEEN worry L 'ETA' WHO.

THANK YOU FOR YOUR VALUABLE ADVICE
 
Ah, then you could tell Gustavo that Mr. Rowland changed the name of the company from Rowland Research to JRDG in the early 90s.

The Model 7 was manufactured both as a RR and a JR(dg) product.
Officially there are 3 versions of the Model 7 : Series I, II and III.
(there apparently was also a Series-O, or a pre-production model, there's a thread on those at this forum)
1990 manufacture was still Series II, the Model 9 of 1992 was only manufactured as a JRDG power amp.

There's not been a Series IV.
Circuitry of a JRDG Model 7 is basically the same as a Series III Rowland Research.
Cosmetics of both differ, rear panel + inside, but Mr. Rowland has made a habit of making small changes without upping the Mark/Series a point.

(I'd keep the 160.5 if I were him. Sorry for the Gustava typo)