Revisiting Jim Rogers JR149s
Wasn't looking at the software, but I did pause to look at the black Nikon (Nikkormat EL?) on the shelf in the 2nd pic.....
davidsrsb
pfm Member
Seconded. I would love to know how real the aging problem with bipolar electrolytics really is.
The JR150 is interesting. Two Audax woofers in parallel, with the tweeter above the woofers. It seems that 2.5 way was not really considered in those days. It must have had some combing problems in the vertical plane
Tony L
Administrator
It's an FTn, a nice early one with Nippon Kogaku branded lenses (a 50mm and a 35mm). Purely ornamental now - I hate to admit it, but I don't use anything more than my iPhone 4S these days!
Sure ... Now where did I put them?. I never throw stuff like this away so I still have them somewhere
Mr Tibbs
And in black too, very nice!
Just don't go to the extremes of this chap.....
http://www.destoutz.ch/nikon-f.html
Tony L
Administrator
I've ordered some grill foam. I've gone with this as a spec:
I slightly changed the spec from the eBay chap's as I'm just unbelievably pedantic and wanted a 'bar' to align over the logo as on the original, plus 'cuts' on each end to slide slightly under the strip on the back, again matching the originals as I remember them / can tell from pictures. I also arrived at some slightly different measurements than those I was given. I'll publish those here as well so anyone interested has a choice!
JR149 foam specs from eBay seller gsh3824 (who no longer makes the foams): "It is acoustic foam 32mm bars 12mm spaces and 318mm high it works out 16 x32mm bars in length total 698mm in length."
....
"The bars are 12mm thick with with a 6mm step x12mm so 32 x 12 groove x 6mm depth 318mm x698mm overall size a sheet to cover 1 x149 speaker".
I'd advise no one orders any to my spec until I report back that they fit as they are very slightly shorter! I've measured everything about 87 times and assumed that when curved a piece of foam will contract on the inside and expand on the outside pretty much evenly, especially given the notches, i.e. I've gone for a length based mid-way between the inner (alloy can) and outer (wood end-cap) circumference, as based on a small piece of similar foam I have to hand that seems to be how it behaves. I've ordered the grills from www.foamspeakergrilles.com at $120 a pair. They are pretty backlogged at present so it will be a few weeks before they are done. Will be interesting to see if they fit...
PS mine aren't quite as much shorter as they first appear as 32mm x 16 +12mm x15 is actually 692mm, not 698! I'm coming in 19mm shorter for some reason, but I do trust my own measurements here, plus over that length there will be a pit of stretch as leeway anyway.
I slightly changed the spec from the eBay chap's as I'm just unbelievably pedantic and wanted a 'bar' to align over the logo as on the original, plus 'cuts' on each end to slide slightly under the strip on the back, again matching the originals as I remember them / can tell from pictures. I also arrived at some slightly different measurements than those I was given. I'll publish those here as well so anyone interested has a choice!
JR149 foam specs from eBay seller gsh3824 (who no longer makes the foams): "It is acoustic foam 32mm bars 12mm spaces and 318mm high it works out 16 x32mm bars in length total 698mm in length."
....
"The bars are 12mm thick with with a 6mm step x12mm so 32 x 12 groove x 6mm depth 318mm x698mm overall size a sheet to cover 1 x149 speaker".
I'd advise no one orders any to my spec until I report back that they fit as they are very slightly shorter! I've measured everything about 87 times and assumed that when curved a piece of foam will contract on the inside and expand on the outside pretty much evenly, especially given the notches, i.e. I've gone for a length based mid-way between the inner (alloy can) and outer (wood end-cap) circumference, as based on a small piece of similar foam I have to hand that seems to be how it behaves. I've ordered the grills from www.foamspeakergrilles.com at $120 a pair. They are pretty backlogged at present so it will be a few weeks before they are done. Will be interesting to see if they fit...
PS mine aren't quite as much shorter as they first appear as 32mm x 16 +12mm x15 is actually 692mm, not 698! I'm coming in 19mm shorter for some reason, but I do trust my own measurements here, plus over that length there will be a pit of stretch as leeway anyway.
Robert
Tapehead
I wee bit under or over in the dimensions is fine with this sort of open cell foam since you can pull or push it into shape to some degree.
That's a good price for something made entirely to order as one off.
If the quality comes up trumps it could be very useful for lots of other loudspeakers - Briks, Saras and HB2s spring to mind.
You should be able to measure the capacitance on your meter.
They'll likely be specified to 10% though might be then selected further.
If they are within 5% of value you'll be fine regardless.
ESR will also potentially deteriorate over time but isn't too important in a loudsepeaker crossover since the impedance are relatively high compared to say a PSU where impedances are usually low and deteriorating ESR matters.
That's a good price for something made entirely to order as one off.
If the quality comes up trumps it could be very useful for lots of other loudspeakers - Briks, Saras and HB2s spring to mind.
You should be able to measure the capacitance on your meter.
They'll likely be specified to 10% though might be then selected further.
If they are within 5% of value you'll be fine regardless.
ESR will also potentially deteriorate over time but isn't too important in a loudsepeaker crossover since the impedance are relatively high compared to say a PSU where impedances are usually low and deteriorating ESR matters.
Tony L
Administrator
I'm reluctant to meddle with them unless I have to - don't want to risk lifting tracks etc. To be honest I can't even figure out how the white 'plug' thing that connects the four driver leads to the crossover works! I wanted to give the contacts a clean but couldn't work out how it unplugged. I think I'd need to undo that to get the board out.
I spent another good couple of hours with the 149s earlier, and dragged the Quad 303 through from system #2 for a listen, which is actually the first time I've compared it to the 306. They sound totally different! The 303 making the 149s sound much more as I recall from the past, a smoother, warmer, lazier sound - very stereotypically "tube amp" in character as is it's reputation. Makes for an interesting comparison; the 306 is very obviously the better amp, it's a lot more dynamic, way tighter and more controlled in the bass and just crisper and more detailed throughout. There's something really nice about the 303 though, it has a very non-explicit, non-hyped / non-spotlit way of just getting out of the way. If I had to choose I'd go with the 306 though.
I'm really enjoying the 149s, they are a cracking little speaker with remarkably few vices. The cabinet is pure genius, I've always been sold on infinite baffle speakers, and these do it so cleanly as they clearly have resonance and internal reflection etc well under control. Now if I could find some 75 litre ones for my 15" Tannoys... The 149s bass is tight, in tune, clean and surprisingly deep at times, but obviously lacking in any real weight and push - unlike many small speakers they don't bite off more than they can chew, nor do they play tricks - they do not attempt to rival big full-range speakers, and therefore they don't boom, blow, chuff or sound hollow as so many little 'uns do. The ideal compromise IMO. I think they may have just the slightest hint of what folk describe as a 'Bextrene quack', just a tiny little bit of edge / lift in the upper mid, but nothing severe, they do voices, sax, trumpet etc really rather nicely. It would be be interesting to see how they stack up against modern equivalents, e.g. Spendor S3/5R, Harbeth P3ESR, Stirling LS3/5A V2 etc.
I think I'll transfer them to TV room duties over the weekend and leave them there for a few weeks to give them a really good chance to warm up / reform their caps etc (that system is on for many hours a day either TV, radio or streaming), then give them another go in the main rig once the grills turn up.
I spent another good couple of hours with the 149s earlier, and dragged the Quad 303 through from system #2 for a listen, which is actually the first time I've compared it to the 306. They sound totally different! The 303 making the 149s sound much more as I recall from the past, a smoother, warmer, lazier sound - very stereotypically "tube amp" in character as is it's reputation. Makes for an interesting comparison; the 306 is very obviously the better amp, it's a lot more dynamic, way tighter and more controlled in the bass and just crisper and more detailed throughout. There's something really nice about the 303 though, it has a very non-explicit, non-hyped / non-spotlit way of just getting out of the way. If I had to choose I'd go with the 306 though.
I'm really enjoying the 149s, they are a cracking little speaker with remarkably few vices. The cabinet is pure genius, I've always been sold on infinite baffle speakers, and these do it so cleanly as they clearly have resonance and internal reflection etc well under control. Now if I could find some 75 litre ones for my 15" Tannoys... The 149s bass is tight, in tune, clean and surprisingly deep at times, but obviously lacking in any real weight and push - unlike many small speakers they don't bite off more than they can chew, nor do they play tricks - they do not attempt to rival big full-range speakers, and therefore they don't boom, blow, chuff or sound hollow as so many little 'uns do. The ideal compromise IMO. I think they may have just the slightest hint of what folk describe as a 'Bextrene quack', just a tiny little bit of edge / lift in the upper mid, but nothing severe, they do voices, sax, trumpet etc really rather nicely. It would be be interesting to see how they stack up against modern equivalents, e.g. Spendor S3/5R, Harbeth P3ESR, Stirling LS3/5A V2 etc.
I think I'll transfer them to TV room duties over the weekend and leave them there for a few weeks to give them a really good chance to warm up / reform their caps etc (that system is on for many hours a day either TV, radio or streaming), then give them another go in the main rig once the grills turn up.
Robert
Tapehead
I heard that on my pair as a slightly nasal vocal quality.
You can hear it on Radio 4 male presenters and newsreaders.
Very slight though and I think a characteristic of the B110.
Seems to be a bextrene thing as my Rogers exports have it and a little pair of B&W DM23 three-ways which landed this week have it too, and they use a little bextrene mid.
Its a very easy colouration to live with though if well tamed. I don't much like the polyprop alternatives which always seem to sound a bit congested and 'dulled down' by comparison to a good bextrene driver.
I've just bought a pair in piano black, fantastic speakers, can't believe how good they are.
I paid £275 for them posted and they have new foam, original instruction manual and wall brackets but no speaker wire.
Bought them about three weeks ago, to my ears they are amazing with CD, good with FM and decent with a TT.
Tony
I paid £275 for them posted and they have new foam, original instruction manual and wall brackets but no speaker wire.
Bought them about three weeks ago, to my ears they are amazing with CD, good with FM and decent with a TT.
Tony
Robert
Tapehead
These are DM23 dating from 79 I think.
Imagine a Harb C7 about 1 inch smaller in all dimensions.
They were boxed in really nice condition for £120 so I took punt.
Never had B&Ws before and these are really very nice.
Don't go very low and sound quite warm and smooth. Lovely silky top end and the drivers are nicely integrated. The antithesis of modern Missions, MAs and Focals etc as so many decent late 70s loudspeakers are. I've got them plonked on HB2 stands in the middle of the room either side of the Okki Nokki as I'm spending all my time cleaning and re-bagging all my vinyl at the moment.
So I'm sitting on the floor flanked by these B&Ws acting as huge headphones, washing vinyl I haven't played in years and flinging it onto the TT for a spin.
Bliss
149 wall brackets - now that's a rare find!
TheDecameron
Unicorns fart glitter.
I acquired JRs late on in my career, after two pairs of Rogers LS 3/5a's and was strangely disappointed. Couldn't get them to come alive- maybe the amps, maybe expectations. I was convinced they would be 3/5a's with enhancements owing to that clever enclosure. Anyone else heard them alongside 3/5a's? Design/aesthetics-wise they are right up there with the Mini, Quad and the steering wheel from the Allegro.
Those bipolar Elcaps are foul sounding. I hoiked them out of my Castle Tynes and put in Wilmslow /Ansar polypropylenes to great effect.
Those bipolar Elcaps are foul sounding. I hoiked them out of my Castle Tynes and put in Wilmslow /Ansar polypropylenes to great effect.
Yank
Bulbous Also Tapered
Tony L
Administrator
That's a great price! Are they the black perspex tops? I wasn't aware they made them in piano black, though might be a refinish I guess. The wall brackets look really cool, though I don't feel it's the best place for them - they seem to come to life well out into the room a bit even if they lack weight.
There's a lot of comment on the Yahoo LS3/5A group, most preferring the LS3/5A, though some preferring the 149. The general consensus is that the 149 doesn't match the LS3/5A's mid-band openness and projection, though beats it above and below and is more dynamic. I've never had a pair of LS3/5As at home, so have no opinion myself - my 149 (re)purchase is purely to revisit an old speaker I discovered a lot of good music through in the late 70s - early 80s, it's not an attempt to buy the best mini-monitor or anything.
Tony L
Administrator
Just tried the Leak Stereo 20 with the 149s. Not a good match to my ears; soft, dull, slow, compressed even a little saturated, all the things the Leak isn't into my usual much higher-efficiency Tannoys or Klipsch. That surprised me as a lot of LS3/5A folk seem to love Leaks etc, and I'm not playing loud at all (around 75db at the listening seat). Looks like the 149s like some power / current (the 306 is certainly the most powerful amp of the three, and by some margin if impedance drops below 8 Ohms).
Robert
Tapehead
I think they sound quite different.
I'm sure there is some assumption that they should sound similar because of the BBC heritage, same drivers and Jim Rogers connection. But they are very different things IME. I've not had them side by side, but whenever I've heard LS3/5s I've hated them and whenever I've heard the 149 I've liked them. For starters the 149 lacks the BBC dip and is much flatter, which makes them tonally quite different. Secondly I'm convinced the very complex crossover in the 3/5 squashes dynamics since it does a considerable amount of response shaping well beyond simple crossover slopes. The 149 crossover is more traditional and doesn't knock the life out of the sound.