Olympus S-7 MOD

[SUPERBEE]

OK.....OK......

As most of you know I have a very early set of Olympus with the S-7 load that I absolutley love.

Recently after hearing my friend Bills new L-300's I know my S-7 load is lacking a little in the high end. I have a friend with a brand new in the box set of 075 bullet tweeters. How can I OR can I incorporate those into the Olympus with out cutting anything?

Is this a good route to go or does anyone have a better suggestion?

As always.....TYIA!!!!!!

[yggdrasil]

Some of the Olympus came with cutouts for the 075. If you don't find any extra plugged hole on the baffle, you'll have to make it. My Sovereign's have cutouts for 075 on both sides of the baffle (to make a mirrored pair). I can provide the measurements over the weekend.

Before doing any cutting you can add the 075 with an appropriate crossover. And do the cutting if the result is pleasing.

[Zilch]

My S7s have no cutouts. I measure only 3" to 3-1/4" behind the grille near the top (depending where,) so I don't think it's possible to squeeze an 075 in there without cutting mounting holes. Measure the overall depth of 075 to be sure.

Making the cutouts is an easy task with a hole saw, once you get past the "vintage correctness" thing.

Sovereign dimensions may be a little different from Olympus. To be certain of the location JBL used in the later "R" versions, perhaps another member can take some measurements on Olympus. No more "Rs" here, alas.

For what it's worth, here's my original drawing from 18 years ago upgrading S7 to biradial mid (2426J on 2370A) and UHF, with ported bass. They're still here today to play.

The cutout size shown is for 2404H tweeters; 075 or 077 would be smaller, of course.

You'll need to consider what you're going to do about installing the additional crossover (N7000 or 3105) required, as well....

[SUPERBEE]

Thanks all. What crossover should I use and how and where do I wire that in?

[Zilch]

N7000 or 3105 crossover input comes from LX5 HF output. LE85 and 075 then connect to new crossover LF and HF outputs, respectively.

N7000 is the correct "Vintage," but finding a decent pair will be difficult.

3105 is newer and more available, but also an easy DIY build....

[Steve Gonzales]

Those look sweet Zilch! They must sound pretty damn good if they've "made the cut" around your digs.

[SUPERBEE]

So I can just run this thing on top of my cabinets for awhile to see if I like the sound?

[Zilch]

So I can just run this thing on top of my cabinets for awhile to see if I like the sound?

Yup.

For "just to see," a lone 3 uF capacitor in series with each 075 can serve as a rudimentary crossover in the 7 kHz range. The full crossover will be even better, of course....

[Zilch]

Those look sweet Zilch! They must sound pretty damn good if they've "made the cut" around your digs.

Thanks, Steve.

2235H in 6 cuft was a good starting point, for sure. Not that I knew that then, tho.

Now that I have the measurement gear and know more about it, I'm gonna try to sweeten them a bit with proper driver balancing and tuning. As built, midrange is "Too Darn Hot." I used to like that voicing better than I do now.

I'll document that process here, when the time comes. Gonna be interesting to see what the fretwork grille actually does to the polar response of the tweeter.

Too many projects.

This is really about helpin' SuperBee, tho. I hope there's some ideas for him here, is all....

[Zilch]

Here's S7s with 075 installed:

http://cgi.ebay.com/JBL-Olympus-C50-...QQcmdZViewItem

You can see where JBL installed them and the crossover from this:

[toddalin]

So I can just run this thing on top of my cabinets for awhile to see if I like the sound?

I just cannablized a couple N7000 crossovers for the cases. The two capacitors are 1.5 mfd and I ended up using these on my garden railroad for filters on a 555 chip that would otherwise "false trigger."

But! if you want them, I still have the chokes. You would just need to get the caps. I've been happy with the Theta by-passed Solens I got from Parts Express and feel these are much better than the original 40+(?) year old caps. (I know some on the board will say there is no need to by-pass the Solens.) You need two for each channel.

http://www.jblproservice.com/pdf/Net...%20Network.pdf