Revisiting Jim Rogers JR149s
Tony L
Administrator
Thanks for that - it makes the decision to recap even harder!
I also note from looking at images on teh internets that some seemed to have film caps factory fitted, e.g. these:
From a thread on AudioKarma.
So the choice is a) leave as-is, b) replace with the Falcon electrolytic kit, or c) try to figure out what film caps would fit and not alter the overall character too much.
I also note from looking at images on teh internets that some seemed to have film caps factory fitted, e.g. these:
From a thread on AudioKarma.
So the choice is a) leave as-is, b) replace with the Falcon electrolytic kit, or c) try to figure out what film caps would fit and not alter the overall character too much.
Yeah sorry about that - I figured it might
They are very probably OK and if the speakers sound decent (and importantly, equal) that's a further positive indication. This being the case a new set of bipolars from Falcon would make hardly any difference IMO. I'd still be inclined to use them for a while as is and see how they turn out - particularly if they've been sitting unused for some time.
A move to film cap's is a whole different ball game. You could expect to hear a marked increase in clarity, for example. With my own 401s I was (still am!) blown away by the gain in clarity since the rebuild and am pretty convinced it's mostly down to the change to good quality film cap's. That said, the tweeter in the Gales was originally served by a couple of big wax/paper oil/paper ITT capacitors (which measure fine) so they could be destined for a trial return at some stage. The Elcap's served the midrange and that's where the Solen film cap's appear to have worked their magic the most.
Mr Tibbs
Tony L
Administrator
There is a very slight discrepancy between them. Hard to put into words, but pink or white noise sounds slightly different, one speaker having a bit more 'body' / 'presence' than the other, though it's clear all drivers are functioning correctly (very clean with no scrapes, rattles or buzzes on sweeps etc). I think they are getting closer though. I'll do nothing for a few weeks (they'll be getting a lot of use as they are in the TV room / office) then I'll try swapping the crossovers across and see if the issue moves with them. If not then I'd be inclined to suspect a slight air-leak somewhere (either driver gasket or end-caps).
I've had mixed experiences with speaker caps etc. The Heresys really responded well to the cap kit Bob Crites sells (Sonicaps IIRC, I can't remember). That just opened them up and smoothed them out, so a real win-win. The various Tannoys I've owned have proved much more challenging: I've tried high-spec custom crossovers and also recapping the originals with nice film caps, and each time eventually found myself wanting to return to the tired old wooly originals with their naff control-knobs in circuit etc. There's just something incredibly 'right' about the Tannoy's voicing as stock that I've killed to some degree every time I've tried to improve things. I'm currently running my 15" Monitor Golds 100% stock / unmolested (i.e. there's a 45 year old electrolytic in there somewhere!), and I love them.
It perhaps needs to be pointed out that I'm a pretty crap audiophile - I just don't like a bright, "wide open" or spotlit sound at all, I'm far more into overall coherence and the extent to which the system just gets out of the way so you don't notice it. I hate attention-seeking hi-fi!
davidsrsb
pfm Member
Tony, the photo you put up with film caps, some of the parts just do not look big enough to be the values used with the bipolars. It is possible that the values were tweaked down a bit for commercial reasons when fitting films as new became fashionable.
The JR149's are well behaved at the top end, just rolling off before 20 kHz where I don't think many of us can hear anyway. Too many modern designs have serious boosting above 10 kHz
The JR149's are well behaved at the top end, just rolling off before 20 kHz where I don't think many of us can hear anyway. Too many modern designs have serious boosting above 10 kHz
jfs
pfm Member
Just to throw my twopenneth in to the rumination cauldron.
I recapped my jr's with Solen polypropylene, the resulting sound was quite lifeless, very little sparkle and much of the magic of the speakers had disappeared. To say I was disappointed would be an understatement. I then tried the type 24 x/over, again with polypropylene caps and found no improvement to speak of.
Falcons replacement electrolytics up next at 2% tolerance. Everything returned to how it should be, retaining the jr sound characteristics with sparkle, definition, sound stage and depth all in all very pleasing. On testing the original 'elcap' caps were within 10% tolerance, new caps took the speakers a step higher in their performance.
I certainly wouldn't replace the electrolytics with poly's, the whole character of the loudspeakers changed to a drab lifeless mess at two attempts with polypropylene.
As I say, just my twopenny worth of opinion.
I recapped my jr's with Solen polypropylene, the resulting sound was quite lifeless, very little sparkle and much of the magic of the speakers had disappeared. To say I was disappointed would be an understatement. I then tried the type 24 x/over, again with polypropylene caps and found no improvement to speak of.
Falcons replacement electrolytics up next at 2% tolerance. Everything returned to how it should be, retaining the jr sound characteristics with sparkle, definition, sound stage and depth all in all very pleasing. On testing the original 'elcap' caps were within 10% tolerance, new caps took the speakers a step higher in their performance.
I certainly wouldn't replace the electrolytics with poly's, the whole character of the loudspeakers changed to a drab lifeless mess at two attempts with polypropylene.
As I say, just my twopenny worth of opinion.
Tony L
Administrator
Interesting about the caps, I don't understand the circuit so have nothing intelligent to add here. I agree the top end is really nice, anything the T27 does badly it does higher than I can hear. If I was voicing them I think I'd have given them just a little more 'BBC dip' or saddle as they do seem just a little mid-forward to my ears. I'll need to play with the tweeter pot at some stage as I'm sure that was set wrongly on my pair (it was up full and they sounded way too bright). I've got them set in the middle of the range now and I think they sound fine, though I'll try doing it a little more subjectively at some point, but I'll run them for a month or so first just so they are warmed up / settled in and I've got more used to the sound.
Thanks, that's very useful info indeed. I'm now at the stage I'll leave well alone unless I can detect a fault condition in the crossover. If so I'll recap with the tighter tolerance of the two Falcon kits. I lean towards sympathetic restoration / conservation rather than modification with vintage kit anyway.
The Type 24 crossovers confuse me as they arrived very late indeed (1991 IIRC), which was long after JR and the 149 was gone from the market. I don't understand it's context at all. Is it the crossover from a MkII JR149? If so it will be way different as the drivers, slopes and overall efficiency are entirely altered in that model as I understand it.
Yank
Bulbous Also Tapered
None of the caps in the original JR149 crossover design were particularly large.
There was a 1.5uF, 2.2uF and 3.3uF in the woofer circuit, and two 3.3uF on the tweeter. All well within the range for compact film caps. I wonder how it would do with all WIMA MKP10s?
jfs
pfm Member
They were developed by Jim Rogers, perhaps bringing the x/over of the 149's into vogue, I really don't know the answer to their late arrival.
Introduced as an improvement ?, they certainly didn't rock my boat, but I believe were intended to smooth out the somewhat bumpy frequency response of the 149's, and tame what some deemed an unruly top end.
The type 24 just seemed to make the speaker a docile and drab version of its former self, they didn't stay in-situ very long.
That's about all I know, sorry I can't help further.
chfs911
pfm Member
I have seen a few pairs of original crossovers for sale in the last few months. Owners have maybe made the move to the T24 and are selling the original pair.
Ideally I would buy a second set of crossovers to play with new capacitors.
If it is not broken then why meddle. So I am just enjoying my 149s as they are.
I love them with Classical and Jazz but not as good with some rock music.
Ideally I would buy a second set of crossovers to play with new capacitors.
If it is not broken then why meddle. So I am just enjoying my 149s as they are.
I love them with Classical and Jazz but not as good with some rock music.
Those reversible capacitors are generally sniffed at by the connoisseurs of speaker crossovers but they do seem to work. Unlike Mr Tibbs, I was less than impressed by the sound of a set of Gale 401s when recapped. I will have to break into them to find the make I used and in fairness I did not change the resistors so perhaps I should have done more.
Bearing in mind that the 149s would have been voiced with the crossovers made up from the same components, I can only assume that they would have been right at the time. The decision to check the values and replace if not off spec is a good one in my view and reversible electrolitics are very available from the usual sources still. Cleaning the contacts is mandatory, I would solder the cables to the circuit board myself and a modest speaker cable to replace the bell wire seems right too.
I have had a pair or two in recent years and one pair is on loan making good sounds while a red label pair is awaiting the treatment soon. They are different to the LS3/5a pair I have around the computer screen and I agree with the other comments on this thread about the differences. The main thing that is in their favour though after agreeing that they make a good sound is that they have the highest WAF of any speaker I know! Having them around the TV in the lounge and "upgrading" to JR150s did not provoke any comment! Now there is a pair of 150s for surround duties, again, no problem. Using the now redundant 149s as a centre pair might be a bit much for my style consultant though!
Bearing in mind that the 149s would have been voiced with the crossovers made up from the same components, I can only assume that they would have been right at the time. The decision to check the values and replace if not off spec is a good one in my view and reversible electrolitics are very available from the usual sources still. Cleaning the contacts is mandatory, I would solder the cables to the circuit board myself and a modest speaker cable to replace the bell wire seems right too.
I have had a pair or two in recent years and one pair is on loan making good sounds while a red label pair is awaiting the treatment soon. They are different to the LS3/5a pair I have around the computer screen and I agree with the other comments on this thread about the differences. The main thing that is in their favour though after agreeing that they make a good sound is that they have the highest WAF of any speaker I know! Having them around the TV in the lounge and "upgrading" to JR150s did not provoke any comment! Now there is a pair of 150s for surround duties, again, no problem. Using the now redundant 149s as a centre pair might be a bit much for my style consultant though!
Nothing wrong with having a preference for ely cap's over film types (and vice-versa). Some time ago I tried replacing the tantalum coupling cap's in my preamp with some Wima films and (contrary to popular opinion) decided they robbed some of the immediacy and ultimately, involvement in the music. But here's the rub; The tradeoff (and there always is a tradeoff IMO) is that the tantalum cap's are very probably adding a flavour of their own compared to the Wima's. I accept it's not the whole truth I'm getting IOW. On the subject of crossover resistors; do not underestimate the difference they can make - especially regarding 401s where they are taking quite a lot of power and can deteriorate badly over the years. A fresh set of good quality resistors is IMO an essential part of restoring them.
Though "right at the time" would include other factors such as available choice of capacitor and prohibitive cost of the alternatives.
Mr Tibbs
Thanks for that;probably wouldn't be happy with a big Sony av amp then
I've read that the JRs need a lot of current/power to make them 'sing' but I have them on the end of an A&R A60 and they sound superb to my ears.
Tony L
Administrator
I can only comment on the three amps I've tried: 306, 303, Stereo 20, and I'd rate them in that order with the 306, by far the most powerful and grippy of the three and a good way ahead. I considered the Stereo 20 to be struggling to such an extent I didn't actually see a whole track out with it - it was very obviously compressing. I'd expect your A60 to lie somewhere between the 303 and 306, probably closer to the latter as it's a very capable and surprisingly powerful little amp IME.
My Dad has been using a pair of JR149s on the end of a Naim 250 for the last decade and they sound bl**dy good. Come to think of it, both amp and speakers are probably due a service now....
Cheers
Adrian
You beat me to it - was just about to joke with Tony that he'll be needing a nice 42/110 to make those 149s really sing
Mr Tibbs
TheDecameron
Unicorns fart glitter.
Wonder how they would sound with a set of Derek Hughes' cicable external crossovers.....
Martyn Miles
pfm Member
EXPENSIVE...