Shahinian Obs 2 & Naim NAP135’s
- Thread starter matfff
- Start date
rogerredhat
pfm Member
Hope it’s a good match
I been using a cb250 for about a year with mixed results with ob1’s
Definitely a lack of mid range and high frequency output on a lot of recordings ,not balanced at times
Trying to decide a way forward with other amps integrated into a naim system after reading other people’s experience
I been using a cb250 for about a year with mixed results with ob1’s
Definitely a lack of mid range and high frequency output on a lot of recordings ,not balanced at times
Trying to decide a way forward with other amps integrated into a naim system after reading other people’s experience
Yep, been there with Ob 1’s!
Please read my post #31.
The 250 regulator boards (CB as well as olive) can stifle upper mid and all treble output from ob 1s depending on sample variation it would seem.
Try a 180 (maybe even a 140) in place of the 250. Honestly!
I read a post some time ago from @MJS (and he should know!) that the older 250’s that have not been serviced, I.e tired caps can have a knock on issue with the power supply boards, think I’ve got that right. So maybe a service required?
My issues with ob1 s & olive 250 arose quite shortly after a service on the 250 which was fine into sbls.
The issue is with the regulator boards basic circuit design I believe.
The naim power amp design, based on RCA application notes nearly as old as me(!) and including the regulator circuit, pre dated speakers with umpteen parallel connected tweeters and hence low impedance at high frequencies and I think that's the cause of the problems that some of us have had with this amp/speaker combination.
The issue is with the regulator boards basic circuit design I believe.
The naim power amp design, based on RCA application notes nearly as old as me(!) and including the regulator circuit, pre dated speakers with umpteen parallel connected tweeters and hence low impedance at high frequencies and I think that's the cause of the problems that some of us have had with this amp/speaker combination.
rogerredhat
pfm Member
Amp was serviced about 5 years ago
Dynavector keeps coming up as being very good but a bit hard to find one
Maybe the 180 is worth considering as another option
I was considering a 250-2 as another option as the dynamic power at 2 ohm is a lot higher than the original 250
Dynavector keeps coming up as being very good but a bit hard to find one
Maybe the 180 is worth considering as another option
I was considering a 250-2 as another option as the dynamic power at 2 ohm is a lot higher than the original 250
Bartman
pfm Member
I have been driving my Obs2s with a 300 for the last 5 years and am very pleased with the results. Before the Obs2s I had Arcs. I believe the 300 is quite close to the 135. I borrowed a friend’s HX75 for a few weeks and I did not like it as much as the 300. I would have liked to try one of the bigger DV power amps but there were supply problems when I was buying the 252/SC/300 so I stuck with Naim (I didn’t like the look of the DV Pre in any case!). I have Powerlines on the SC and 300PS, Superlumina between SC and 300 but NACA5 speaker cable (running through underfloor conduits so not easily to replace; at the time SL was not affordable). I think it all sounds fabulous, both with a decent LP12 and with ND555/ 2x555PS, the Shahinians aren’t going anywhere and a 552/500 is still a few years away.
boneman
pfm Member
A Densen B330 will give you all the current you need for Obs and likely not nearly as difficult to find as a DV. Another possibility that has been highly recommended to me is the Karan Acoustincs KA l180. Certainly seems to have bags of power and current from the spec sheet.
Yes, they were. I’ve been discussing placement/orientation with him and got this from him as part of a wider discussion;
“Truth be told - before I got the Diapasons; I actually used two pairs of Obelisk-2s! (I still have another 'two pairs' of Ob-2s, and I might sell another pair!). Anyway, Pre – Diapasons; I used two pairs of Obelisk-2s side by side kinda like baby-size Diapasons. ‘’Sounded truly excellent ’’. Two pairs of Obelisks filling the whole room with omni-direction sound and music - has to be experienced.. It is indeed something else !! That said, the Diapasons are much better in many areas/many ways! And one becomes immersed in the music with both setups...”
Lol, he seems like a really nice chap and has been very attentive and fastidious in expediting the delivery, so fingers crossed!
boneman
pfm Member
Wow, I wish I had his problems!
Well, their here, set up and playing away. Good old DPD, all in one piece and no signs of droppage!
Beautifully made and far prettier in the flesh than any photo I’ve ever seen. Seem to be heavier than my old Ob 1’s, but that was many years ago and perhaps I’m now considerably more feeble.
Have been listening for about an hour and wow is all I can say. So far (my ears, my room and my preferred listening levels) no issues with amplification at all. The 252 volume pot is considerably reduced for the same perceived volume. Will need many hours of burn in as they have haven’t been used for a while. Will report back in a few months time.
Beautifully made and far prettier in the flesh than any photo I’ve ever seen. Seem to be heavier than my old Ob 1’s, but that was many years ago and perhaps I’m now considerably more feeble.
Have been listening for about an hour and wow is all I can say. So far (my ears, my room and my preferred listening levels) no issues with amplification at all. The 252 volume pot is considerably reduced for the same perceived volume. Will need many hours of burn in as they have haven’t been used for a while. Will report back in a few months time.
An update.
To answer my own original question, yes NAP 135’s can drive Obs 2 beautifully with no issues whatsoever. NOTE, the amps have been serviced and are running the WitchHat Phoenix boards.
Far more difficult to set up than my Arcs. Seemed to be a lot more fussy than my Obs 1 as well, but I was using an Olive 250 back then and considerable time has passed.
VERY fussy about placement and toe in. Also, EXTREMELY sensitive to the balance control of the pre amp. With the Arcs, you just plonked ‘em down, set the balance to approx midday and all was good. Have ended up with them much closer together than the Arcs and further out into the room, with significantly more toe in.
However, once you have it figured out, the effect is startling. It’s like the Arcs, but with more of everything that makes them a great speaker. Very happy!
To answer my own original question, yes NAP 135’s can drive Obs 2 beautifully with no issues whatsoever. NOTE, the amps have been serviced and are running the WitchHat Phoenix boards.
Far more difficult to set up than my Arcs. Seemed to be a lot more fussy than my Obs 1 as well, but I was using an Olive 250 back then and considerable time has passed.
VERY fussy about placement and toe in. Also, EXTREMELY sensitive to the balance control of the pre amp. With the Arcs, you just plonked ‘em down, set the balance to approx midday and all was good. Have ended up with them much closer together than the Arcs and further out into the room, with significantly more toe in.
However, once you have it figured out, the effect is startling. It’s like the Arcs, but with more of everything that makes them a great speaker. Very happy!
Darth Vader
From the Dark Side
Well I find the Obs the easiest speaker to set up once you have a suitable power amp. Totally unfussy with position. I keep mine against the wall when not in use and just pull them out for a listen. No need for any toe in as they are omni directional. They sound good anywhere you listen in the room and the presentation changes just like at a real live venue.
Cheers,
DV
Cheers,
DV
Mark Packer
All Rev'd up!
FWIW, I’m running Obs1s with a pair of 200w IcePower class D amps. They sound fantastic.
These took over from a Mr6C pair of mono-blocked 110s which had trounced a Chrome bumper 250.
These took over from a Mr6C pair of mono-blocked 110s which had trounced a Chrome bumper 250.
Well, apologies have to do to @Darth Vader! I stand by my assertion that the Obs 2 sound fine and sweet with the 135’s at low to moderate volumes, HOWEVER, now running with an amp that can do 330W into 8, 660 into 3 and 1320 into 2 with a peak current capability of 160A. Different speakers. The super tweeters are now super refined, no hint of harshness at higher volumes, the mids are great, not as sweet perhaps as the 135’s, but it’s early days yet for the amp. But the bass. Blimey, it’s like the woofer and rear passive were turned off before! So thanks to DV for giving me that nagging feeling that he might be right and trying this amp. I think a pair of mint 135’s with the Witchhat Phoenix upgrades might be on the bay soon!