advertisement


Revisiting Jim Rogers JR149s

KevinHiFi said:
Yes, I used those for my 149s earlier this year., they sound fine.

I'm not sure how many of each value you will need but I used the Jantzen caps you've linked for the 3x 3,3uf on mine. However, the 1,5uf (1x on each of my crossovers) weren't available in the same range so I used these https://www.hificollective.co.uk/components/jantzen-elecap-electrolytic-cap.html just for the convenience of making one order.

Mine also have 1x 2,2uf capacitors on each circuit but the originals are the green Erie (polypropylene?) so I left them.

Good luck,
Kevin
Click to expand...
Thanks for that Kevin. Much appreciated.

As mine are the early ones I am only looking to replace the 3.3uf ones. Falcon acoustics are also out of the 1.5uf too, hence they can't offer the kit, but as I don't need those for my crossover I'll order the Jantzen ones.
 
r-lecto said:
I've recently bought a pair of red logo JR149s, serial 2477, with the older style crossover 2 x 3.3mfd electrolytics, poly & tropical fish, the same as post 1194 on page 60, which are all original.

I've looked back on the previous advice and I want to replace the electrolytics but Falcon don't have the kit at the moment (spring 2024 was when they said they may have them) and I can't find the appropriate value alcaps on their site.

Can anyone advise if these would these be a suitable alternative?
https://www.hificollective.co.uk/components/jantzen-premium-elko-smooth-capacitors.html
Click to expand...

I have an unused Falcon kit for the JR149, that I never got to use. If you are interested PM me
 
lilolee said:
I have an unused Falcon kit for the JR149, that I never got to use. If you are interested PM me
Click to expand...
Thanks for your kind offer but I have already ordered the Jantzen 3.3uf ones as those are the only ones I need. If I have any issues with those I may be in touch!

As Falcon won’t have any in until spring 2024 someone else who needs to recap their crossover may be interested.
 
KevinHiFi said:
Yes, I used those for my 149s earlier this year., they sound fine.
Click to expand...

would you use the ones you linked to for the 2,2uf as well if need to change?

Also is it advisable to replace the resistors as well?

cant post link as new member

If anyone has a link to a European supplier and can tell me what Capacitors they used please either post or pm me
 
Last edited:
paulfg said:
would you use the ones you linked to for the 2,2uf as well if need to change?

Also is it advisable to replace the resistors as well?
Click to expand...

I'd use them for any of the values; as I wrote, I only used the 1,5uf from the other range as none where in stock from the same range as the 3,3uf. I only left the original 2,2uf in mine as, according to my research, that type of cap doesn't degrade.

The general consensus seems to be to leave the original resistors.
 
I did read somewhere that’s resistor values did vary between speakers due to measured discrepancies with the driver units and as such the XO was tweaked.
 
Rexton said:
I did read somewhere that’s resistor values did vary between speakers due to measured discrepancies with the driver units and as such the XO was tweaked.
Click to expand...

That is interesting and makes some sense, though I’m surprised things were mismatched more than could be brought back with the tweeter pot. I’d love to understand what values altered what outcome! Mine have been rebuilt with pair-matched Falcon units so it needed reversing-out anyway. The thing which has always confused me is the significance of the BBC LS3/5A selection criteria. As I understand it the BBC selected from one end of the B110 bell-curve, which is fine, but how this relates to a JR149 I have no idea. I assume Falcon are building to that spec, so the 110s in my 149s may not be typical of what originally ended up there.
 
KevinHiFi said:
Yes, I used those for my 149s earlier this year., they sound fine.

I'm not sure how many of each value you will need but I used the Jantzen caps you've linked for the 3x 3,3uf on mine. However, the 1,5uf (1x on each of my crossovers) weren't available in the same range so I used these https://www.hificollective.co.uk/components/jantzen-elecap-electrolytic-cap.html just for the convenience of making one order.

Mine also have 1x 2,2uf capacitors on each circuit but the originals are the green Erie (polypropylene?) so I left them.

Good luck,
Kevin
Click to expand...

Well the Jantzen capacitors arrived today so I have swapped them over and although I've only just had a quick listen, they have made a big difference over the originals.

I measured the 4 x 3.3uf ELCAP ones I removed and got 19, 25, 29 & 41uf so it's fair to say they were well off spec.
 
The black and red caps I took out of my set were all over the place too. They are notorious for going bad in any speaker you find them. Never on spec. IIRC there were a couple I couldn’t even get a reading from with whatever meter I had when the thread started (probably the Chinese-market Fluke 17, which was a nice meter).
 
Tony L said:
That is interesting and makes some sense, though I’m surprised things were mismatched more than could be brought back with the tweeter pot. I’d love to understand what values altered what outcome! Mine have been rebuilt with pair-matched Falcon units so it needed reversing-out anyway. The thing which has always confused me is the significance of the BBC LS3/5A selection criteria. As I understand it the BBC selected from one end of the B110 bell-curve, which is fine, but how this relates to a JR149 I have no idea. I assume Falcon are building to that spec, so the 110s in my 149s may not be typical of what originally ended up there.
Click to expand...

I have early pair of Mk 1 (No 2137) which I fully restored and I used the Falcon replacement cap pack. I must admit to never messing with the tweeter pot I presume it's still in the same position as when it left the factory altough I can't prove this. I'm not going to be too anal about things. All I know is that this little pair of speakers does sound exceptionally good.
 
Mine had the treble pots cranked, they sounded horrible. I’ve tuned them by ear/taste with reference to REW measurements, though I may do it again as I’m using lower stands now and could maybe get away with nudging the tweeter up a tiny bit, though likely not. When adjusting I went for the smoothest transition between drivers I could get rather than ‘bright’, ‘smooth’ or whatever. Just what looked the best on the REW plot and gave the most seamless transition across the vocal, violin and brass ranges. They really sound great, though it has to be said not quite as good as the LS3/5A in that specific area (they are much better in the bass and dynamics areas).
 
Well its an early pair. There is no fuse. I would say, how do we know if this needs a recap? Why don't you measure the caps and see if they are in spec and then you'll answer your own question.
 
Rexton said:
Well its an early pair. There is no fuse. I would say, how do we know if this needs a recap? Why don't you measure the caps and see if they are in spec and then you'll answer your own question.
Click to expand...


Well, according to the information I've got, it has been recaped already, using Falcon kit. But as I'm not an expert here, decide to double check with you guys - if this crossover looks like it's been recaped with the capacitors from Falcon kit?
 
andriirad said:
Well, according to the information I've got, it has been recaped already, using Falcon kit. But as I'm not an expert here, decide to double check with you guys - if this crossover looks like it's been recaped with the capacitors from Falcon kit?
Click to expand...

I'm gonna venture a tentative "yes". The black capacitors with white writing are not like the ones originally fitted in the 1970s, so it must be re-capped.
 
It is definitely not original JR, though I don’t recognise the black caps.

47570762991_e352e2a8f9_b.jpg


Here’s the cap kit I got from Falcon, though don’t obsess over it, if the values are correct (check they are!) it should be fine. The problems come when changing to modern film-caps IME, sounds clear and detailed initially; but after a while I found them sterile and uninvolving. See upthread for that journey. Mine are now exactly as pictured above.
 
You must log in or register to reply here.


advertisement


Back
Top