Re-capping Snells.....yay or nay

[Jonesy09]

I understand there are aurguments on both sides of re-capping. But I also hear that one of the design philosphies of Peter Snell was to keep tolerences of capacitors, and I suppose the rest of the rig, within a certian spec. Would re-capping a pair of JII's be doing more harm than good? Can new caps be found that are close to enough to each other to not have a negative effect?

[spkrdtr]

I understand there are aurguments on both sides of re-capping. But I also hear that one of the design philosphies of Peter Snell was to keep tolerences of capacitors, and I suppose the rest of the rig, within a certian spec. Would re-capping a pair of JII's be doing more harm than good? Can new caps be found that are close to enough to each other to not have a negative effect?

You have one YAY from me. I don't know about PS's methods for meeting specs (other than his adjustable series resistors) but do know after having worked on a few of his speakers that he used bundles of low, like-value NPE caps in parallel & series to get the total value he was seeking. If you read up on recapping you'll see that NPE's inherently drift over time with their uF values going out of spec and ESR's generally rising due to deterioration of the eletrolytic paste with age.
Consequently, recapping your Snells will probably do more good than harm. Oh, and don't recap with NPE's. Use MPP or FF types. If you look for a brand recommendation in posts here, you'll find as many different brands as recommendations. PE's Daytons seem to be recommended most often here as the most cost effective.

[Urizen]

PE's Daytons seem to be recommended most often here as the most cost effective.

Yep. Cap tolerances are much better than in Peter's day. Dayton has 1% available.

[gearhound]

+1 on the Dayton caps.

Steve

[Jonesy09]

Thanks. I'm no EE so I was curious if there was some 'magic' there that I'd be messing with, or that oculdn't be replicated (or at least closely approximated). I'd like to utilize our local resource (Madisound). Any rec's on brands they carry?

[spkrdtr]

Thanks. I'm no EE so I was curious if there was some 'magic' there that I'd be messing with, or that oculdn't be replicated (or at least closely approximated). I'd like to utilize our local resource (Madisound). Any rec's on brands they carry?

Wow, you're lucky to be so close to Madisound. I buy from them quite often and of course, pay shipping charges. I have had good luck with their Clarity caps.

[lukiedog]

Try not to destroy the old caps when you pull them off and keep track of which ones came from where in case there really is some "magic" in them...

[Bluzmaster]

The J's were, I believe, created after Peter Snell's death. If I'm right, from what I hear, the Kevin Voeck designed (pseudo?) "Snells" are not created w/ near the same "magic" as PS's creations -A and C-series, I think. So, you may not have as much to worry about as you thought.

I don't know what your crossovers look like, but my Type A's have those crazy bundles of multi-caps that Carl is so familiar with.

Good luck!

[spkrdtr]

Below is a photo of an EII (mid to late 80's vintage) crossover. This model came out shortly after Peter Snell's passing but seem to bear his 'stamp'.

At the bottom are 3 black NPE's. They comprise the woofer's parallel circuit. There are two 4 uF's in series bypassed by a 12 uF... Go figure

In the upper right is the tweeter and super tweeter circuits. The tweeter circuit has an 8 uF and 4 uf NPE in series bypassed by a 3 uf polypro (the yellow one). The super tweeter circuit also has an 8 and 4 uF in series.
Again, go figure why they did this.

At the top is the tweeter's adjustable series resistor. A typical part of many of Peter's designs. This had to be the key component in Peter's claimed .5 dB system tuning mentioned in the history referenced below. He could have developed a way to get test data on drivers going into each box and was somehow able to set the tweeter's output accordingly. Or, there could have been a test bench set up during assembly where tweeter output was modulated by sliding the adjustment along the coil while playing a signal. Once balanced, the screw was tightened and hot melt glue applied on top as shown in the pic.

And, as usual, to keep everything from vibrating from the woofer's back wave energy, everything is gooped down with lots of hot melt.

A link to a brief history of Snell Acoustics follows: http://www.snellacoustics.com/History.asp

[botrytis]

I am hoping to buy some JIII's in the near future - besides refoam would recapping help?

[spkrdtr]

I am hoping to buy some JIII's in the near future - besides refoam would recapping help?

Below is a pic of a JII crossover. The JIII can't be much different. Look at all the NPE's. :thumbsdn:
If you haven't perused the pinned thread on recapping, do so; it might help with your decision - knowing what you are going to have for a crossover.

[Bluzmaster]

Carl -

That pic of the E crossover looks so gloriously simple compared to the A crossovers!

[gearhound]

I have purchased Bennic Poly caps from Madisound in the past - nice caps!
BTW: Bennic makes the Dayton Poly caps.
Also, check out Madisounds deals on "surplus" caps.
I have purchased GE and Panasonic poly caps for WELL under a $1.00 a piece.

Steve

[Jonesy09]

Below is a pic of a JII crossover. The JIII can't be much different. Look at all the NPE's. :thumbsdn:
If you haven't perused the pinned thread on recapping, do so; it might help with your decision - knowing what you are going to have for a crossover.

Thanks for the pic. That looks like a total cluster compared to the simple xover in my EPI 150's. Maybe I'll start with those to get some practice in before tackling the surgical procedure on the JII's.