Rectilinear IIIs

drbiggles said:
Hey,

OoOoOOoO, III's !!! Oh, I don't have anything much to add. Kirk has got more on the ball here than I do. I'm just a huge enthusiast and love these particular rigs.

My earlier III's have the 100uF cap and the later versions have the 60uF. New caps are necessary with all those tweeters and that nice midrange, you want them at their best.

Congratulations !!!

Biggles

RectilinearII045.jpg
Click to expand...

Ahhh, another piece of the puzzle:)

100uf - older
60uf - newer

It's been indicated mine seem to be originals.

Perhaps positive ID can be made identifying the woofer:scratch2:
 
60uf? Any idea what version yours are?:) [/QUOTE said:
Mine have 2 controls In back (mid and tweeters). Perhaps mine are newer version. Hopefully yours will have some markings on them so you can know for sure.
Click to expand...
 
I dunno... it's also possible that the schematics showing the 60uF are (at least in some cases) wrong.

All three pairs I have are the later ones, with 2 pots on the back, with the larger caps.
 
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tubed said:
It's been indicated mine seem to be originals.

Perhaps positive ID can be made identifying the woofer:scratch2:
Click to expand...

Hey,

Your woofers, if I had to make an educated guess, were made by Jensen. However, I have some spare III woofers in my stash and a few of them look like Jensens from the cone and surround, but are made by CTS (Chicago Telephone Service). So, until we can see the baskets, it's just a good guess.


Biggles
 
Early version of the Rectilinear III's tone control on the back.

RectilinearII008.jpg


And, the later version of the Rectilinear III's tone controls on the back.

RectilinearIII022.jpg


Biggles
 
kirk57 said:
I dunno... it's also possible that the schematics showing the 60uF are (at least in some cases) wrong.

Mine are later ones, with 2 pots on the back, with the larger caps.
Click to expand...

I guess they'll need to be measured.

drbiggles said:
Hey,

Your woofers, if I had to make an educated guess, were made by Jensen. However, I have some spare III woofers in my stash and a few of them look like Jensens from the cone and surround, but are made by CTS (Chicago Telephone Service). So, until we can see the baskets, it's just a good guess.


Biggles
Click to expand...

I'm busy listening to them so I have no pic of the basket but I did copy down a frame number.

After a net search #2200933 indicates they are Jensens made in the 33th week of 1969
The same week of Woodstock:)
 
tubed said:
Ahhh, another piece of the puzzle:)

100uf - older
60uf - newer

It's been indicated mine seem to be originals.

Perhaps positive ID can be made identifying the woofer:scratch2:
Click to expand...


Which brand of caps did you use for your old rectiliners? I have a set that are in need of new caps and am looking for ideas and since you have done yours and are happy with the results I would like to hear your experience and advice. Sorry I meant to direct this ? to Dr Biggles
 
EarHole said:
Which brand of caps did you use for your old rectiliners? I have a set that are in need of new caps and am looking for ideas and since you have done yours and are happy with the results I would like to hear your experience and advice. Sorry I meant to direct this ? to Dr Biggles
Click to expand...

I don't stick to any one brand. The 60uF and 100uF (2x30's or 2x25's) can get a bit on the pricey side, at least for me. If you've got the cash, the easy route would be the Dayton Audio rigs. Another brand I've enjoyed are Solen. I've got a pair of Lowboy's and a pair of the Mini III's that still need caps and will go that route for sure.

If you're a little strapped, which I always am, you can run the old NP electrolytics for the 60's or 100's. It isn't as critical for the midrange as it is for the tweeters. I'm running Bennic NP electrolyitics on my later pair of III's and they sound just fine to me. They've been up and running for maybe 2 or 3 years now and always impress.

And remember, you can always go back and put in different brands later on if you want to. It's not as though you have just the one chance to get it right. Some day, when I'm flush I'll go back and put film/foil in to replace the Bennics.

Biggles
 
tubed said:
I guess they'll need to be measured.



I'm busy listening to them so I have no pic of the basket but I did copy down a frame number.

After a net search #2200933 indicates they are Jensens made in the 33th week of 1969
The same week of Woodstock:)
Click to expand...

Yes, they really should be measured. At least you'll have some kind of gauge to know what was in there.

69 Dude!

Biggles
 
Any suggestions for a nice but inexpensive capacitance meter?

Also Dr., stacked IIIs?
OMG, that must tax the amp(s).
 
kirk57 said:
Keep in mind when looking at the size of modern-day film caps that most are rated for much higher voltage than needed for a speaker, often 400v and up. (it looks like the Clarity caps in the pic above are 250V) The original spec caps would were often more along the lines of 50v (still way higher than needed) and hence much smaller than modern-day, high voltage replacements. I haven't had much luck finding modern film caps with lower voltage ratings, for whatever reason. My guess is it's because there is a perception that higher voltage is better (founded upon... well, I don't know what that's founded upon :) )
Click to expand...

Exactly. Can't find lower voltage these days. The Clarity Caps I used are indeed 250 vdc, and were not cheap, but I thought the IIIs were worth it. The IIIs really shine when it comes to separation and definition.
 
tubed said:
Any suggestions for a nice but inexpensive capacitance meter?

Also Dr., stacked IIIs?
OMG, that must tax the amp(s).
Click to expand...

It depends on the amp. I would think though that even less of an amp it the III's would do really well. While they can soak up a lot of juice, they don't need a lot to let loose. I was running 4 of them on an old Toshiba SA-7150 receiver. It's rated at 140 or 150, I don't exactly remember. It's a dual mono design and it'll push 100 very clean watts to all 4 of them without breathing hard.

When I stacked them, they were unlistenable. And what I mean by that is, listening to anything for more than 20 seconds was hard on the ears and skull. The bass was flubby, in really nasty shape. Horrible sounds coming from them. But side by side, they were magic. I had my oldest boy there for the audition and we were both absolutely floored with what 4 of them were delivering. If I had the available space, it'd be 4 at a time all the time.

As far as a capacitance meter, I dunno. A friend gave me a really nice Fluke meter and it just happened to have a capacitance meter built in. However, that's just a portion of the equation. I would suggest also looking into an ESR meter. I don't have one yet, but am going to get an Anatek Blue ESR meter when money permits. Now that right there is affordable.

Biggles
 
^^^^^^^^
I wonder which meter Kirk uses?

I have my pair being powered at 200 watts per channel and they soak it up maintaining realistic listening levels, quite eager for more(like drunken sailors) if room allowed:)

A Note:
As per the Stereo Review Hirsch Houck 1967 test report where they compared to the Quad 57, the '67 originals were SANS exterior level controls.
 
tubed said:
^^^^^^^^
I wonder which meter Kirk uses?

I have my pair being powered at 200 watts per channel and they soak it up maintaining realistic listening levels, quite eager for more(like drunken sailors) if room allowed:)

A Note:
As per the Stereo Review Hirsch Houck 1967 test report where they compared to the Quad 57, the '67 originals were SANS exterior level controls.
Click to expand...

I wish I could say it's a nice Fluke, but my capacitance/inductance meter comes from the #3 Electronic Meter factory in China somewhere. I got it for $25. it's Yellow. It works fine.

I'm also using 165 wpc (or whatever the McCormack DNA 1.0 Deluxe puts out into 8 ohms). Sounds great. When I sold my Pioneer SA-8100 (40 wpc) I used the Highboys to demo and that sounded really good too. I've also heard them at AK member Robie's house connected to an old Mac tubed receiver. Sounded wonderful.

They just sound good.

Edit: OK, the actual meter is a Vichy VC6243+

http://www.amazon.com/VICHY-VC6243-Inductance-Digital-Capacitance/dp/B00CJ2S5FO
 
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I believe there were two types of the older one and two types of the newer ones, and even in this Rectilinear switched certain components likely because of availabilities from their suppliers. Supposedly their engineers qualified these replacements, since owners of more than one variant have reported no significant differences in sound.

I've posted my beliefs on this before only gleaned from posted comments by owners. The earliest older variant had no mid-tweeter adjustments (as reported I believe by Hirsch), the next had one control for both mid and tweets, then they switched woofers and added separate controls, and finally they switched from a parallel xover configuration to a series config. I had though that the change from Jensen to the CTS woofer was accompanied by the change from 60 to 100MFD because of differences in speaker impedance (inductance really). But now I am not at all sure about that.
 
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