135 History please.
Posted by: mark dunsford on 20 December 2001
please. Thanks.
123570 onwards NADI's dimmer
133065 onwards diodes on PA board changed
137288 onwards new PA board layout
137912 onwards R22 resistors changed
146082 onwards IEC mains socket now floating
quote:
Well worth the phone call though...I had the option of buying a pair of 1988 or 1989 and was advised to go for the 1989 pair as there was a reasonably significant electronics board upgrade that would be included in the latter but not the former.
In my six-pack, I have 2 circa 1997 135s and 4 circa 1984 135s;the latter were updated by NANA circa 1997. Although I am sure there are some differences internally, the reconditioned 1984 pair sounds very very similar to the new-style ones.
Oddly enough there appears to be a bigger difference between old-style and new-style 250s with the older ones sounding a tad warmer, sweeter and minimally slower than the new ones.
So regardless of the age of the 135s, once they have been serviced/recapped there will be only minimal differences between them. If the price is right, get them and don't develop an oenophile-like obsession with the vintage. I cannot of course address how the very latest breed perform as my 1997 (SN 124*** or so) pair probably do not have the latest changes.
Ron
Dum spiro audio
Dum audio vivo
I have found significant differences between my NAP135s.
My 1987 pair have had their transformers replaced with the current-spec ones.
The ones with the new transformers have a wider bandwidth, the old ones are more forward. Quite a different sound all round.
cheers, Martin
this is a difficult one for me to answer.
On a general level I find that comparing a current-spec item to a 10-15 year old (serviced) one I do prefer the new one, as they tend to be tighter & more dynamic. I would not be surprised if this made them more revealing of source deficiencies (but I haven't actually tried this).
Comparing my two types of 135s (not something I have done more than once or twice, briefly) has given inconsistent results. With Kans, the new transformers seemed to squeeze more from them.
With Isobariks (not my pair, some passive ones) the results were more mixed. I have since replaced my racks (with AF Base) and the frequency extremes are now much better controlled. I suspect that if I did it again, the newer amp would be much better than the old one, because it is not forcing the system into areas which were poorly controlled due to issues elsewhere in the system. Setup, setup, setup!
Basically, it seems to come down to personal taste, and the circumstances of your setup.
cheers, Martin