Snell JIII crossover capacitors

[kcbluesman]

Hello. I was hoping that someone could provide the crossover capacitor values for the Snell Jiii. Thank you for any help.

[Carlspeak]

I can help you with the JII, but not the III.

You will be wise to duplicate his bundling of caps if you want to maintain Peter Snell's original voicing. They were typically a combination of NPE's and at least one film cap on the tweeter and NPE's elsewhere.

Because of ESR differences, you will alter the voicing if you simply replace a cap bundle with an equivalent film cap the is = to the sum of the bundle uF.

[kcbluesman]

Thank you for the advice. It is consistent with input from others as regards capacitor replacement in the Snells.

And of course there are those that advise against updating them at all. But in my experience, the rise in capacitance and ESR as a result of capacitor aging is already altering the original performance of these speakers much more significantly than will replacing those caps with correct values.

I've been surprised by the difficulty I've had in getting the specific crossover information....I've done some pretty extensive searching, and have posted this same query in several forums, with no luck.

No big deal...I had just hoped to be able to keep listening to them while I waited for the caps to arrive. Once I take them down to the workshop and open them up, they'll stay that way until I've got the new caps in.

[Carlspeak]

You seem well read on capacitor issues.

Good luck with your upgrade.

[kcbluesman]

Not so much well-read as "experienced" (the kind that comes with age!). I'll post a crossover schematic once I get them opened up...maybe someone else can benefit from it.

I've ordered a set of surrounds from AudioFriends. Any experience with them?

[Carlspeak]

Not so much well-read as "experienced" (the kind that comes with age!). I'll post a crossover schematic once I get them opened up...maybe someone else can benefit from it.

I've ordered a set of surrounds from AudioFriends. Any experience with them?

No I haven't. I looked but could not find any mention of Snell foams.

Most of the US foam sellers now have the correct Snell foams. They all buy from MWA who only sells to re-sellers. I helped MWA identify a European foam supplier that most closely matched the Snell foams I was buying from AudioNote at rediculous prices.

[kcbluesman]

Here is a link to the Audiofriends site (the page for the Snell J-IV...which uses the same Vifa M21WN-07 woofer). It seems that a goodly number of the Snell devotees think highly of them. They apparently use 3D imaging to create a perfectly-shaped replacement for a variety of drivers, and then have them fabricated in foam that is as close to original compliance as possible. The price was not much more than a good set of domestic surrounds, which I was worried might be too rigid.

http://www.repairyourspeakers.com/index.php?action=article&aid=794〈=EN

[Carlspeak]

Thanks for the link. I couldn't find a way yesterday browsing the site to get to specific foams.

The pic sure looks like the real deal.

How do they measure compliance? if at all.

[kcbluesman]

I don't know how they determined the compliance of the original. There is some info on their website in the Q&A about the topic, and I think the "proprietor" might be able to provide more detail via email.

[DavidR]

Have you tried contacting the company.

Here's a link to Customer Support.

Its 2 miles down the road from me.

http://www.snellacoustics.com/CustomerSupport.html

[kcbluesman]

I chose to replace only the electrolytic caps (of which two were >20% out of spec...the others were within 10%).

In each crossover, there are three electrolytics, all 100V:

2.2uf (stacked with a couple of film caps, which I did not pull and therefore could not make out the capacitance values)

12uf

100uf

[kcbluesman]

I've since discovered that another JIII owner found only one film cap in parallel with the 2.2uf electrolytic in one of his cabinets, but two film caps plus the 2.2uf electrolytic in the other cabinet. Based on the way they were glued in, he was quite sure that both were original.

Also wanted to add that I did some experimentation while doing the crossover work. Specifically, after testing all of the electrolytics, I re-installed the originals in one cabinet (they were all at about 10% above capacitance spec, with ESR in "typical" (normal) range) and replaced the old electrolytics with new ones in the other cabinet.

I then connected both speakers and let them run at normal volume for a few hours, after which I sat down and carefully listened to them (with preamp set to mono). There were no differences that were audible to me. I don't have a scope, so no way to more objectively compare them. While some might conclude that replacing the old with new therefore was not justified, I like knowing that I'm at the beginning of their lifecycle rather than the end.

I also concluded that contrary to what is suggested in many Snell threads, recapping had no negative effects (at least with the JIII's, and when keeping the original configuration and mix of electrolytics and films).

I then went ahead and updated the electrolytics in the other cabinet, and again did a listening comparison. They still sounded identical to me.

Next, just for fun, I replaced the 12uf electrolytic in the woofer circuit with a film cap in one cabinet. After letting the speakers run a few hours again, I sat down for another listening session. Still sounded the same.

And that's where I stopped, at least for now (I was getting tired of opening them up over and over again). So, I now have a pair of Snell JIII's with new surrounds (perfect fit, by the way) and all new electrolytics, plus one of the cabinets has a new 12uf film instead of a new electrolytic. I'll see if any differences develop over the next few weeks, after which I'll make them "match" again by either a) putting an electrolytic back in instead of the film, or replacing the 12uf electrolytic in the other cabinet with a film.

[Carlspeak]

I've since discovered that another JIII owner found only one film cap in parallel with the 2.2uf electrolytic in one of his cabinets, but two film caps plus the 2.2uf electrolytic in the other cabinet. Based on the way they were glued in, he was quite sure that both were original.

Also wanted to add that I did some experimentation while doing the crossover work. Specifically, after testing all of the electrolytics, I re-installed the originals in one cabinet (they were all at about 10% above capacitance spec, with ESR in "typical" (normal) range) and replaced the old electrolytics with new ones in the other cabinet.

I then connected both speakers and let them run at normal volume for a few hours, after which I sat down and carefully listened to them (with preamp set to mono). There were no differences that were audible to me. I don't have a scope, so no way to more objectively compare them. While some might conclude that replacing the old with new therefore was not justified, I like knowing that I'm at the beginning of their lifecycle rather than the end.

I also concluded that contrary to what is suggested in many Snell threads, recapping had no negative effects (at least with the JIII's, and when keeping the original configuration and mix of electrolytics and films).

I then went ahead and updated the electrolytics in the other cabinet, and again did a listening comparison. They still sounded identical to me.

Next, just for fun, I replaced the 12uf electrolytic in the woofer circuit with a film cap in one cabinet. After letting the speakers run a few hours again, I sat down for another listening session. Still sounded the same.

And that's where I stopped, at least for now (I was getting tired of opening them up over and over again). So, I now have a pair of Snell JIII's with new surrounds (perfect fit, by the way) and all new electrolytics, plus one of the cabinets has a new 12uf film instead of a new electrolytic. I'll see if any differences develop over the next few weeks, after which I'll make them "match" again by either a) putting an electrolytic back in instead of the film, or replacing the 12uf electrolytic in the other cabinet with a film.

Thanks for experimenting and sharing your impressions KC.

Now, Enjoy the music!

[kcbluesman]

Oh yes...I've been enjoying them quite a bit for the past few days. They may not have the oomph of some of my other speakers, or the accuracy, but the detail, soundstage and imaging are exceptional...very, very enjoyable speakers, especially with a nice subwoofer.