Snell E type ll crossover rebuild thoughts

Snell E type ll crossover schematics

https://www.audiocircle.com/image.php?id=148157

https://www.audiocircle.com/image.php?id=148158

I highly recommend going with good film in place of the Electrolytic period.  As Erik said,  there are several Electrolytic in the tweeter circuit alone. If I recall correctly,  Peter used series crossovers in these speakers and I could be wrong, but if they are indeed series.  ESR can easily be compensated.  There are a couple resistors in there,  changing all the Electrolytic to film won't change total resistance by more than maybe .25 ohm per leg.  You can easily add that to the resistors that run next to the Electrolytic.  So measure ESR on the caps and add that total resistance to the resistors that follow and rock on.  Also,  Erik recommended the DATS 2,  the DATS 3 is out and the same price,  you might as well get the new version.  I hope this helps,  Tim 

Hey @crom - How did that end up sounding for you?

It sounds like some good advice. Not to invasive. I get them back in my hands June 1st so will diving into them then.

Thanks 

Hi pkvintage,
I have Snell E II’s and sent you a PM. Erik gave me guidance when I tackled the crossover. I would follow his advice and replace the capacitor bundle (should be 5.6uf) in series with the tweeter with a good quality film cap (Clarity CSA or CMR and Erik would probably recommend adding a .01uf Audyn True Copper bypass).  Without test equipment I would just replace the old NPE’s with new NPE’s and swap out the sandcast resistors with Mills. 

The x-overs were built with premium parts. 

And a lot of electrolytics which are now aging.

If it were me, I'd absolutely replace them with modern film or new bi-polars, but as I mentioned above, doing so can be tricky.

Good to know. Thanks. Nice find to. I picked up mine last year for $500cdn. Delivered. I was happy when they arrived in mint condition. I hooked them up and went Wow!  They sent the An K spe's to the second line. Not by much though. That rear tweeter made the difference. 

For your knowledge the E's and other Snells used SEAS woofers and other drivers. So replacements are still available today!

If the E's are working and sounding fine, leave them alone! The x-overs were built with premium parts. I have a pair of the first generation E's that I rescued from a GoodWill. They had rotted surrounds. Paid $18 + sales tax for the pair. Took out the woofers to replace with new SEAS woofers with rubber surrounds. Had a look at the x-overs. Beautiful work! So leave them alone! 

op:  If you want to be safe, just replace the caps in series with the tweeter. 

They are worth restoration for sure !!!! Coils should be good, don’t mess with those IMO

Thanks Erik. This is beyond my current skill level. It not beyond my learning capabilities though. I think the speakers deserve the effort that Snell/Voecks put in to the design. 

I have had them in storage for 5 months now awaiting their 1st hook up to my  newly acquired level 3/4 Audio Note system. This will happen mid June. 

Regards all. 
Enjoy the music. 

Found this from the type III, use the impedance curve here as a rough guide.  Measure both speakers before beginning, to ensure you are picking the better curve. One could be bad already.

https://www.stereophile.com/content/snell-type-eiii-loudspeaker-measurements

Hey there,

I think I can help.  I remember seeing some of those crossovers in real life. Lots of parallel electrolytics with film. 

The biggest issue with rebuilding old crossovers like that is that the ESR of the 1980's era caps are much worse than modern, so you can in fact alter the sound, and in some cases drop the impedance so low the amp no longer drives them properly, or the crossover no longer does what you think it's doing.  The former is a more subtle problem that newbies often get trapped by.

So I strongly suggest you purchase a DATS V2 and measure the ESR of every cap system before replacing it, ESPECIALLY in shunt (going to ground) configurations.  You'll need to add small amounts of R to compenstate for lost ESR.


https://www.daytonaudio.com/product/1051/dats-v2-dayton-audio-test-system


I also strongly encourage you to do a complete electronic analysis prior to replacement.  You don't have to do the acoustical measurements, just the electrical.  Measure the impedance curve of the entire speaker, and each driver, and simulate the whole thing.  This will be a useful guide as  you contemplate replacement parts.

You can do this for free with XSim. 

http://techtalk.parts-express.com/forum/tech-talk-forum/62978-xsim-free-schematic-based-crossover-de...

You want to pay attention to the simulated impedance curve and the voltage transfer functions. These will allow you to compare any changes you are contemplating.

And, of course, the same goes for any coils.  Ensure you do NOT reduce the DCR of the originals unless you are sure the transfer functions are equivalent.

Otherwise, I encourage you to visit over in the DIY audio forum.

Best,

E

Great advice. Thankyou. The reasons you mention are exactly why I posted the thread. 

would be careful on recapping snells. Peter Snell hand matched all the components for each speaker.

years ago I had a pair of Snell type 1s. decided to "improve" the sound by upgrading all the caps. Speakers sounded like S _ __ _ afterward. Thankfully I had marked all the components before removing them so could fit back in their same location.

its been a long time since i looked at a Snell xover, but my guess is on the E2 you have lytics bypassed with film caps. you may want to test the lytics and make sure tehy are still good. if not would only replace with same value and voltage rating of the originals.