In my quest for high sensitivity speakers to drive with tubes...

[Sir Thrift-a-Lot]

Today I got from the thrift a rather beat looking pair of Pioneer CS-77.   If I end up liking them, the tops will need new laminate, but the lattice grills are perfect.   A couple of web sources put them at 35-25k @ 102 db sensitivity (though I really doubt the 35 Hz spec, maybe at -10db or something).   A 12" alnico woofer, 3" cone midrange and a bullet horn tweeter.   At $5 for the pair I can put a few more bucks into laminate.   Anyone know a good source?

[Sir Thrift-a-Lot]

I mis-spoke.   I think the mid is a 5".

[Sir Thrift-a-Lot]

I stand corrected.   The 77A is spec'd @ 102db sensitivity.   The older, ported 77 is listed @ 108!

[Dicky]

Nice find man

[MacGeek]

Sounds like a deal, Mark.  How do they sound?

[Sir Thrift-a-Lot]

I haven't listened yet.  I had just enough time to drag them from the car to the basement before I had to go out again.   Hopefully I'll hear them this weekend.    I'll report back when I do.

[tinpan]

Hmmm... nice find and what a great idea.

Makes me want to drive over to pop's house and find his Sansui SP-100's.

I'll bet there are a lot alike.

[Kingman]

Super Snag!!!

[schwarcw]

Very nice!  102 dB sensitivity is very efficient.  I wonder why the specs recommend 100 watts amplification?  10 -25 wpc would be more than enough??

Good luck Mark!

[SunnyDaze]

You may want to read this thread on AK regarding the sensitivity rating of the 77's.

http://www.audiokarma.org/forums/archive/index.php/t-447024.html

There were a few different "standards" that may have been used to measure the sensitivity of the 77's. In any case, it seems likely that the modern standard of 1 watt RMS measured at 1 meter was not utilized in Japan at the time of their manufacture.

[Sir Thrift-a-Lot]

Well, I looked at that ad again this morning and realized that it was listing the "wattage" or recommended receivers by their current draw.   I'm sure those aren't Pioneer specs, but probably an ad in some Army PX catalog or something else of the sort.

That said, the woofer in those is very similar to the ones used in Heresys.   The box size is also similar and the port is close to what was found in a Heresy IP, so I don't buy 108, but I think the 102 I've seen listed other places is entirely possible.

Maybe I'll bring 'em to Pepe's and let him go over them with his new calibration mic.

[SunnyDaze]

I believe Heresy I's and II's are on the order of 95 dB. Heresy III's are on the order of 97 dB.

Mine are over at Dicky's. If you want to grab them and compare, be my guest.

[Sir Thrift-a-Lot]

I said Heresy IP.   Those and the KP-250s (also ported) are listed at 102.   But they give up bass to do it, only going down to about 70 Hz.

[SunnyDaze]

What is a Heresy IP?

[Sir Thrift-a-Lot]

Sorry, Heresy Industrial Ported.   It was a PA speaker.



KP-250



Both are essentially Heresys with ports.   Both are listed @102 db sensitivity.